In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisit...In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisite for successful highdensity cultivation.However,the photosynthetic mechanisms underlying improved density tolerance in maize hybrids released across different eras in China remain unclear.This study investigates 40 years of breeding progress toward enhanced photosynthetic traits under varying planting densities and elucidates the physiological and ecological bases of improved density tolerance in maize hybrids.A three-year field experiment was conducted from 2019 to 2021 to compare eight major Chinese hybrids from four decadal cohorts under three planting densities:45,000(D1),67,500(D2),and 90,000(D3)plants ha^(-1).At high density(D3),modern hybrids exhibited a more optimal canopy architecture and superior leaf photosynthetic performance compared to older hybrids,despite a slight reduction in specific leaf nitrogen.Notably,modern hybrids(2000s)were able to maintain higher net photosynthetic rates and photosynthetic nitrogen use efficiency(PNUE)at D3,resulting in the highest grain yield(GY),which was 118.47%greater than that of older hybrids(1970s).Leaf area duration after anthesis,total chlorophyll content,key photosynthetic enzyme activities,and maximum quantum efficiency of PSII photochemistry were all positively correlated with GY.Among these,PNUE showed the strongest correlation with grain yield and thus represents a key indicator for optimizing maize hybrids.Based on these findings,breeders should continue selecting hybrids under high-density and suboptimal conditions,focusing on optimizing population architecture and enhancing photosynthetic capacity while fine-tuning leaf nitrogen status to develop high-yielding,density-tolerant hybrids capable of sustaining long-term increases in maize grain yield.展开更多
Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to t...Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to these threats on a regional scale have been challenging to ascertain due to scarce continuous observation data.This study compiled county-level data on maize yield and yield loss across China's six primary cropping regions over twenty years from 1999 to 2018.These include the Spring-sown area of Northern China(1-NC),the Summer-sown Huang-Huai-Hai Plain(2-HHP),the Southwest Mountain(3-SM),the Southern Hilly(4-SH),the Northwest Irrigated(5-NI),and the Qinghai-Tibet Plateau Maize Regions(6-QTP).We identified 15 major diseases affecting these regions.The annual average yield loss due to maize diseases in the regions 1-NC,2-HHP,3-SM,4-SH,5-NI,and 6-QTP were 0.40,0.58,0.12,0.05,0.04 and<0.01 million tons,respectively,and the corresponding average yield loss rate(the ratio of yield loss to total yield)in these regions was 0.63,0.90,0.65,0.63,0.44,and 0.05.The yield loss due to all diseases increased for three regions in 3-SM,4-SH and 5-NI.The yield loss rate due to diseases significantly increased in region 4-SH and 5-NI.Predominantly,maize leaf blight has become the most significant threats.In region 1-NC,maize head smut(D1)and maize leaf blight(D2)were the primary diseases.In region 2-HHP,maize leaf blight(D2),maize rust(D3),maize brown spot(D5),Curvularia leaf spot(D7),and maize virus disease(D14)were the key pathogens.Bivariate trend analysis(joint analysis of yield loss and loss rate trends)indicated that maize head smut(D1)decreased significantly in 1-NC,while in 2-HHP,six diseases showed a significant decrease in both yield loss and loss rate,namely sheath blight(D4),brown spot(D5),root rot(D11),downy mildew(D12)and virus disease(D14).By providing a long-term,national-scale perspective,this study not only supports the development of broad management strategies but also guides the creation of precise,region-specific control protocols to safeguard maize production.展开更多
Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combi...Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combined effects of waterlogging and shading on maize yield losses remain understudied,particularly across different growth stages.Denghai 605(DH605)was selected to be subjected shading,waterlogging,and their combined stress at the 3rd leaf stage(V3),the 6th leaf stage(V6),and tasseling stage(VT).Results showed that shading,waterlogging and their combination significantly restricted leaf area expansion,reduced leaf net photosynthetic rate(P_(n))and net assimilation rate(NAR),thereby decreasing the crop growth rate(CGR)and biomass accumulation.Additionally,compared to control,the process of lignin synthesis was inhibited under stressed treatment,resulting in diminished stem mechanical strength and impaired vascular system development,which substantially reduced assimilate remobilization efficiency to the ear and ultimate grain yield.Waterlogging and combined stresses exhibited maximum impact at the V3 stage,followed by V6 and VT stages,while shading effects were most pronounced at the VT stage,followed by V6 and V3 stages.Moreover,the compound stress exacerbated the damage brought about by a single stress.As climate change is projected to increase the frequency of multiple abiotic stress occurrences,these findings provide valuable insights for future summer maize breeding research under persistent rainfall conditions.展开更多
[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different f...[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.展开更多
High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V1...High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V14 stage with three densities(60,000,75,000,and 90,000 plants ha-1,indicated by D1,D2,and D3,respectively)for two seasons.The results showed that the IC-treated wavy canopy featuring both natural height(IC-H)and dwarfed(IC-L)plants,improved light transmission by 8.54%,8.49%,and 16.49%on average than the corresponding controls(CK)at D1,D2,and D3,respectively.The alleviation of canopy crowding stimulated leaf photosynthesis,sugar availability,basal-internode strength,and decreased plant lodging ratios in both IC-H and IC-L,particularly under higher densities.Meanwhile,the IC populations produced significantly higher yield than CK,with an average increase of 3.38%,16.70%,and 15.28%at D1,D2,and D3,respectively.Collectively,this study proposed a new wavy canopy strategy using plant growth retardant to simultaneously increase yield performance and lodging resistance,thus offering a sustainable solution for further development of high-density maize production.展开更多
Maize is an important source of calories and protein in human lives in many countries of the world and is the main staple food in Africa, particularly in eastern Africa. In the Sudan, the low yield of maize was mainly...Maize is an important source of calories and protein in human lives in many countries of the world and is the main staple food in Africa, particularly in eastern Africa. In the Sudan, the low yield of maize was mainly due to the use of low yielding landraces. It is necessary to carry out breeding programs that deal with the production of high yielding, adaptable new varieties. Therefore, this study aimed to estimate genetic variability, heritability, genotypic performance and interrelationships among the traits. Ten maize genotypes evaluated at White Nile Research Station Farm, Kosti, of the Agricultural Research Corporation (ARC), Wad Medani Sudan were planted in a randomized complete block design with three replications during the two seasons of 2021 and 2022. Most evaluated genotypes exhibited a wide and significant variation in the 11 measured traits. Genotypic coefficient of variation and genetic advance were recorded for days to 50% tasseling, ear diameter (cm), number of grains per row and grain yield (t/ha) in both seasons. High heritability and genetic advance were recorded for grain yield, ear length, ear height, plant height, number of rows per ear, ear weight, days to 50% tasseling, 100-grain weight and days to 50% silking. Moreover, there was a highly significant and positive correlation of grain yield with number of rows per ear (r = 0.479), ear length (r = 0.381), 100-grain weight (r = 0.344) and days to 50% tasseling (r = 0.214). The highest yielding five genotypes across the seasons were TZCOM1/ZDPSYN (4.2 t/ha), EEPVAH-3 (4.2 t/ha), F2TWLY131228 (4.1 t/ha), PVA SYN6F2 (3.9 t/ha) and EEPVAH-9 (3.8 t/ha) these were needed to check the adaptability, stability and to test major maize growing areas to make sound recommendations for release.展开更多
Unbalanced fertilizer application with high intensity nitrogen(N)and insufficient potassium(K)results in declining soil fertility.Balanced fertilization represents an effective approach to reduce fertilizer usage whil...Unbalanced fertilizer application with high intensity nitrogen(N)and insufficient potassium(K)results in declining soil fertility.Balanced fertilization represents an effective approach to reduce fertilizer usage while enhancing maize yield and efficiency.This study examined two N levels(180 and 225 kg N ha^(-1),abbreviated N12 and N15)and four K treatments(0,75,150,and 75+75 kg K_(2)O ha^(-1),abbreviated K0,K5,K10,and K5+5)to investigate the effects of combined N and K application on biomass,nutrient accumulation,and remobilization characteristics in waxy maize.Results indicated that grain yield increased with higher K application at constant N levels,demonstrating an average increase of 1,254.8 kg ha^(-1)(2020)and 727.3 kg ha^(-1)(2021)compared with K0.Under identical N and K applications,K5+5 enhanced grain yield through increased kernel weight.The K5+5 treatment showed no significant difference in biomass and nutrient accumulation between N12 and N15.Compared to K10,K5+5 enhanced both the average remobilization amount(RBA)of biomass and increased RBA of N,phosphorus(P)and K.Additionally,the average remobilization efficiency(RBE)of biomass,N,P,and K in K5+5 increased by 3.3,4.6,10.6,and 4.2%,respectively.Moreover,topdressing K improved the apparent contribution to grain(AC)of biomass,N,P and K,facilitating greater nutrient transfer to grains and significantly increasing nutrient harvest index.Based on yield and fertilizer use efficiency,this study recommends optimized K application(basal and topdressing 75 kg ha^(-1))and moderate reduction in N application(from 225 to 180 kg ha^(-1))for spring-sown waxy maize production in southern China.展开更多
Using maize varieties including Zhengdan 958,Xianyu 335,Yudan 132,Xundan 20,Lianchuang 808,and Dingyou 163 as experimental materials,this study investigated the effects of two ethephon compound agents on the lodging r...Using maize varieties including Zhengdan 958,Xianyu 335,Yudan 132,Xundan 20,Lianchuang 808,and Dingyou 163 as experimental materials,this study investigated the effects of two ethephon compound agents on the lodging resistance and yield of different maize varieties across various ecological regions.The results demonstrated that the lodging resistance of maize was significantly enhanced after the application of the two chemical control agents.Specifically,the lodging rate of Xundan 20 was reduced by 6.1 percentage points following treatment with benzylaminopurine(6-BA)·ethephon(ETH),while the lodging rate of Zhengdan 958 was decreased by 6.2 percentage points after treatment with diethyl aminoethyl hexanoate(DTA-6)·ETH.In the Shangqiu area,treatment of Lianchuang 808 with DTA-6·ETH reduced its ear height coefficient by 9.8 percentage points,whereas in the Zhumadian area,treatment of Dingyou 163 with 6-BA·ETH lowered its ear height coefficient by 11.3 percentage points.Additionally,both ethephon compound agents improved the stalk puncture strength of maize.For the same maize variety,phenotypic traits such as ear length,ear diameter,and number of kernel rows showed no significant differences under different chemical control treatments.However,traits including kernel number per row,1000-kernel weight,and yield exhibited significant variations across treatments and years.Moreover,the yield performance of maize varieties after chemical control treatment varied by region.In Hebi,Zhoukou,and Zhumadian areas,the yield under the DTA-6·ETH treatment surpassed that under the 6-BA·ETH treatment,with average yield increases of 4.22%,8.41%,and 5.67%compared to the clear water control(CK),respectively.Conversely,in Shangqiu,Nanyang,and Changge areas,the 6-BA·ETH treatment outperformed DTA-6·ETH,resulting in average yield increases of 6.96%,7.54%,and 5.56%relative to CK.展开更多
Efficient nitrogen management is crucial for developing sustainable strategies aimed at enhancing yield while mitigating negative environmental impacts.However,research focusing on this aspect in the production of fre...Efficient nitrogen management is crucial for developing sustainable strategies aimed at enhancing yield while mitigating negative environmental impacts.However,research focusing on this aspect in the production of fresh maize is limited.Therefore,this study analyzed the effects of nitrogen application rates on the yields of 40 sweet and 44 waxy maize varieties at five sites in Zhejiang Province,China,from 2015 to 2019.The nitrogen application rates were categorized as either relatively high(RHN,>300 kg ha^(-1) for sweet maize and>320 kg ha^(-1) for waxy maize)or relatively low(RLN).An increase in nitrogen application rates significantly reduced nitrogen fertilizer partial productivity in both sweet and waxy maize(R^(2)=0.616,P<0.01;R^(2)=0.643,P<0.01),indicating that the optimum nitrogen application rates in this study might be the lowest values(160 kg ha^(-1) for sweet maize and 180 kg ha^(-1) for waxy maize).The kernel number per ear of sweet maize had a potentially more significant impact on fresh grain yield than the 1,000-fresh kernel weight under both RLN and RHN.In waxy maize,1,000-kernel weight contributed more to fresh grain yield under RLN,while kernel number per ear and 1,000-kernel weight cooperatively affected the yield under RHN.This study found that sweet maize required taller plant and ear heights,along with an optimal ear-plant height ratio,to enhance dry matter accumulation and increase source size,particularly under RLN,and to ultimately achieve a higher fresh grain yield.In contrast,a lower ear height and ear-plant height ratio in waxy maize probably contributed more to the greater kernel number and weight under RLN,likely due to a lower ear height which can reduce the distance between sink and source,enabling more efficient photoassimilate allocation to the ear.展开更多
Households in western Ethiopia are experiencing food insecurity driven by the effects of climate change.Hence,there is an opportunity to lessen the consequences of climate change by adopting climate-smart agriculture(...Households in western Ethiopia are experiencing food insecurity driven by the effects of climate change.Hence,there is an opportunity to lessen the consequences of climate change by adopting climate-smart agriculture(CSA).The study involved 385 households from western Ethiopia during the 2023–2024 production period.Specifically,we examined the variables that affect adoption decisions and investigated how the combined adoption of CSA practices affects maize yield.The multinomial endogenous switching regression(MESR)model was used to analyze these factors.The results showed that the adoption of CSA practices is positively impacted by age,gender,farm size,and education,but the distances from the household residence to market and plot have a negative impact.Adopters of CSA practices achieved a greater average yield per hectare than the non-adopters.Specifically,agroforestry,crop diversification,and adjusted planting dates all considerably increased maize yield,with gains of 0.21,0.70,and 0.52 t/hm^(2),respectively,compared to non-adoption.The implementation of combined CSA practices,rather than a single CSA practice,is a great way to mitigate the negative impacts of climate change.Therefore,we recommend ensuring adequate funding,providing incentives,facilitating technical assistance,and fostering community involvement when implementing combined CSA practices.This information is essential for reducing the negative consequences of climate change and developing successful adaptation strategies.展开更多
A population of 180 recombinant inbred lines （RILs） was developed by single seed descended from the cross of high yield Upland cotton （Gossypium hirsutum L.） varieties Zhongmiansuo12 （ZMSI2） and 8891, the two pa...A population of 180 recombinant inbred lines （RILs） was developed by single seed descended from the cross of high yield Upland cotton （Gossypium hirsutum L.） varieties Zhongmiansuo12 （ZMSI2） and 8891, the two parents of Xiangzamian2 （XZM2）. A genetic linkage map consisting of 132 loci and covering 865.20 cM was constructed using the RIL population chiefly with SSR markers. Yield and yield components were investigated for RILs in three environments in China. The purpose of the present research was to analyze the relationship between yield and its components and to map QTL for yield and yield components in cotton. QTL were tagged with data sets from single environment （separate analysis） and a set of data from means of the three environments （joint analysis）. A total of 34 QTL for yield and yield components were independently detected in three environments, whereas fifteen QTL were found in joint analysis. Notably, a stable lint percentage QTL qLP-A10-1 was detected both in joint analysis and in two environments of separate analysis, which might be of special value for marker-assisted selection. The QTL detected in the present study provide new information on improving yield and yield components. Results of path analysis showed that bolls/plant had the largest contribution to lint yield, which is consistent with the mid-parent heterosis value in F1. Accordingly, in cotton breeding, bolls/plant can be considered first and other yield components measured as a whole to implement variety enhancement and hybrid selection of cotton.展开更多
The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new con...The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.展开更多
Rational close planting is an economical and effective measure to increase crop yield.In order to explore the suitable planting density of major maize cultivars in northern Anhui,we studied the grain number per spike ...Rational close planting is an economical and effective measure to increase crop yield.In order to explore the suitable planting density of major maize cultivars in northern Anhui,we studied the grain number per spike and 1 000-grain weight of three major maize cultivars,including ‘Zhengdan958＇,‘Ludan981＇ and ‘Longping206＇.The effects of planting density on yield and correlated characters were further analyzed.The study was performed at agricultural experiment farms of Suzhou Academy of Agricultural Sciences.The planting density was set from 7 500 to 30 000 plants/hm^2 with an interval of 7 500 plants/hm^2.Water and fertilizer were supplied sufficiently.High yield cultivation method was also used.Based on the high yield achieved,we analyzed the relationship between crop yield and correlated characters.The results showed that,the planting density had the parabolic relation with the yield of ‘Zhengdan958＇ and ‘Longping206＇.The most suitable density of compact type cultivar ‘Zhengdan 958＇ was 73 300 plants/hm^2.The most suitable density of semi-compact type cultivar ‘Longping 206＇ was 68 600 plants/hm^2.The most suitable density of flat type cultivar ‘Ludan981＇ was 45 000-52 500 plants/hm^2.The planting density of compact type cultivar could be increased appropriately.However,it was negatively related to the grain number per spike and 1 000-grain weight if the planting density is out of range.So,Ludan981 should be planted in low density to avoid risk.展开更多
[Objective] The aim was to study on effects of N fertilizer on yield, N absorption and utilization of different cultivars of super high-yielding summer maize, in order to provide reference for reasonable N fertilizati...[Objective] The aim was to study on effects of N fertilizer on yield, N absorption and utilization of different cultivars of super high-yielding summer maize, in order to provide reference for reasonable N fertilization in accordance with different cultivars. [Method] Field experiment was conducted to study on effects of different N fertilizers on yield, N absorption and use efficiency of Zhengdan 958 and Xundan 20, in order to learn the effect differences at different N fertilizer levels. [Result] After N was applied, yields of the two summer maize increased significantly. Zhengdan 958 achieved the highest in yield and proceeds at 12 051.18 kg/hm2 and 1 722.40 yuan/hm2, respectively in low N level. In contrast, Xundan 20 achieved the highest at 13 166.00 kg/hm2 and 1 343.92 yuan/hm2 in the above two aspects in high N level. Compared with Zhengdan 958, Xundan 20 increased by 9.90%, 5.20% and 12.00% in N levels of 0, 240, and 450 kg/hm2, respectively. When N fertilizers were applied, protein yield of Xundan 20 was significantly higher than that of Zhengdan 958, so that higher N fertilizers contributed higher protein yield for Xundan 20. In high N level, N efficiency, N-fertilizer utilization and partial productivity of Xundan 20 were significantly higher than that of Zhengdan 958. [Conclusion] Lower N-fertilizer was suitable for Zhengdan 958 and Xundan 20 would get a good harvest if more N-fertilizers were applied. The results provided references for reasonable N fertilization.展开更多
[Objective] To study the effects of Zinc on the yield,nitrogen/phosphorus/potassium/Zinc uptake and distribution of different genotypes of maize.[Method] Using two different genotypes of maize as materials,the effects...[Objective] To study the effects of Zinc on the yield,nitrogen/phosphorus/potassium/Zinc uptake and distribution of different genotypes of maize.[Method] Using two different genotypes of maize as materials,the effects of Zn on the yield,N/P/K /Zn uptake and distribution of different genotypes of maize were studied by pot cultivation.[Result] Appropriate Zn supply could improve the grain number per kernel.The Zn content in different organs of maize showed little difference under low Zn treatment （Zn0,Zn1）.With the increase of Zn supply,Zn content in leaf,stem and sheath rapidly increased,but the increasing amplitude of Zn content in the kernel and bract were less.The excessive Zn in maize was mainly translocated in lower organs to reduce the damage of them to plants.Different Zn supply levels had less effects on the absorption and translocation of N,P and K in low-Zn insensitive variety Mudan 9.While the absorption and translation of N,P,K in low Zn sensitive variety （Sidan 19） was more easily influenced by the amount of Zn supplied.[Conclusion] Appropriate Zn supply could enhance the maize yield and utilization rate of N and K,and reduce the absorption and utilization of P.展开更多
[Objective] The experiment was conducted to explore the suitable planting density and nitrogen amount for summer maize in Sichuan Basin with the objective to provide technical reservation and scientific basis for high...[Objective] The experiment was conducted to explore the suitable planting density and nitrogen amount for summer maize in Sichuan Basin with the objective to provide technical reservation and scientific basis for high-yielding cultivation technique.[Method] A widely planted maize cultivar ＇Chengdan 30＇ was used as experimental material to study the effects of planting density and nitrogen amount on the stalk agronomic traits,stalk lodging-resistance mechanical characters,stalk breaking percentage and yield of maize.Experiment was arranged in a two-factor split plot design with three replicates.The planting density was the main factor with three density gradients（4.5×10^4,6.0×10^4 and 7.5×10^4 plants/hm^2） and the nitrogen amount was the second factor with two different levels of nitrogen content（300 and 375 kg/hm^2）.[Result] The stalk lodging-resistance and yield were affected by planting density significantly.The increase of planting density would result in an increase of internode length and decrease of internode diameter,dry matter weight of per unit stalk length,rind penetration strength and breaking resistance of 3rd and 4th basal internodes.When planting density increased from 6.0×10^4 plants/hm2 to 7.5×10^4 plants/hm^2,the stalk breaking percentage in the whole growing season increased by 17.17%,and the yield reduced by 17.58%.The interaction between planting density and nitrogen amount affected the stalk breaking percentage in the whole growing season and yield significantly.The treatment with planting density of 6.0×104 plants/hm^2 and nitrogen amount of 375 kg/hm^2 of pure N was an optimal combination,which may not only control the stalk breaking percentage of whole growing stage effectively,but also could obtain an optimum grain yield.[Conclusion] In Sichuan Basin,the appropriate planting density and nitrogen amount for summer maize were 6.0×10^4 plants/hm^2 and 375 kg/hm^2.展开更多
[Objective] The relationship between grain yield and yield components was investigated in .different rice cultivars at the target yield of 10.5-11.25 t/hm2, to provide theoretical basis for cultivation of high-yield r...[Objective] The relationship between grain yield and yield components was investigated in .different rice cultivars at the target yield of 10.5-11.25 t/hm2, to provide theoretical basis for cultivation of high-yield rice. [Method] The yield performance of various super rice and non-super rice cultivars that were cultivated in large area in Sichuan Chengdu was studied under high-yielding cultivation conditions from 2006 to 2008. [Result] The rice yield was closely correlated with the productive panicle number, grain number per panicle, seed setting rate and 1 000-grain weight. The four yield components showed different influences on the yield of different rice culti- vars. By adopting the high yielding cultivation technology （that the seedlings were planted in a triangle shape） at the target yield of 10.5-11.25 t/hm~, we found that the rice yield of super rice cultivars was closely correlated with productive panicle number and 1 000-grain weight, negatively correlated with grain number per panicle, and significantly negatively correlated with seed setting rate; the grain yield of non- super rice cultivars was negatively correlated with grain number per panicle and seed setting rate, and significantly negatively correlated with the productive panicle number and 1 000-grain weight. [Conclusion] The results revealed the relationship between grain yield and yield components in different rice cultivars, which provided references for developing reasonable cultivation measures and thus to improve the yield of super rice in large acreage.展开更多
[Objective] The aim was to select the optimal amount of controlled-release fertilizer and provide theoretical references for controlled-release fertilizers use in summer maize. [Method] Long-term controlled-release fe...[Objective] The aim was to select the optimal amount of controlled-release fertilizer and provide theoretical references for controlled-release fertilizers use in summer maize. [Method] Long-term controlled-release fertilizers were applied once at sowing summer maize to explore effects on maize growth, yield, economic profits and environment. [Result] Maize yield reduced a little in the treatment group with 60% CRF, and increased in varying degrees in the rest groups in the range of 1.1%-7.4%, and some showed significant differences. [Conclusion] Controlled-release fertilizers can be applied once at the amount of 80% common fertilizer＇s, with con- sideration of maize yield, nitrogen use rate and economic profits, which is beneficial for summer maize application and promotion in North China.展开更多
[Objective] The aim was to explore effects of application postponing of N fertilizer and the mechanism of yield increase in order to provide references for N fertilizer application in a rational way. [Method] In a sup...[Objective] The aim was to explore effects of application postponing of N fertilizer and the mechanism of yield increase in order to provide references for N fertilizer application in a rational way. [Method] In a super-high yielded region of summer maize, field experiment was conducted to research effects of N fertilizer postponing on key enzymes of N metabolism, yield of maize and N fertilizer use. [Result] After application of N fertilizer was postponed, NR, SPS and GS activities of ear-leaf of summer maize increased by 11.99%-34.87%, 8.25%-10.64% and 10.00%- 16.81% on the 28^th d of silking; content of soluble sugar in leaves enhanced signifi- cantly and accumulated nitrogen increased by 5.00%-9.74% in mature stage. The postponing fertilization of ＂30% of fertilizer in seedling stage＋30% of fertilizer in flare- opening stage＋40% of fertilizer in silking stage meets N demands of summer maize in late growth period. Compared with conventional fertilization, the maize yield, agro- nomic efficiency and use of N fertilizer all improved by 5.05%, 1.75 kg/kg and 6.87%, respectively, after application postponed. [Conclusion] Application postponing of N fertilizer maintains activity of NR, GS and SPS higher and coordinates metabolism of C and N in late growth period, to further improve yield of maize.展开更多
ObjectiveThis study aimed to investigate the effect of fulvic acid on the growth and yield components of direct seeding rice （Nanjing 44）. MethodThe rice seeds were soaked in 0 （water as a control）, 1, 2, 4 and 6 ...ObjectiveThis study aimed to investigate the effect of fulvic acid on the growth and yield components of direct seeding rice （Nanjing 44）. MethodThe rice seeds were soaked in 0 （water as a control）, 1, 2, 4 and 6 g/L fulvic acid （FA） before sowed. Then, the rice morphological indices, leaf chlorophyll content, photosynthesis parameters, root activity and chlorophyll fluorescence parameters were measured in the following field studies. ResultCompared with the control, the leaf area index, chlorophyll content, net photosynthetic rate, stomatal conductance and dry matter weight and some fluorescence parameters such as the maximum photochemical efficiency of photosystem II （PSII） （Fv/Fm）, excitation energy capture efficiency of opened PSII reaction center （Fv’/Fm’） and efficiency of the open reaction centre （ΦPS II） increased by different levels at both jointing stage and heading stage of direct seeding rice, whose seeds were soaked by FA with different concentrations. High FA concentration （4-6 g/L） significantly increased the cultivated rice leaf area index, chlorophyll content, net photosynthetic rate, stomatal conductance, transpiration rate and dry matter weight by 10.32% -22.88% , 5.88% -13.11% , 12.16% -26.84% , 11.43% -88.46% , 10.63% -21.63% , 18.49% -19.68% , respectively, thereby improving the physiological function and light energy transform efficiency of rice at the growth stage. With FA concentration increasing, the yield, effective panicles, grain number per panicle and seed setting rate were increased significantly compared with the control by 17.52%-18.71%, 3.46%-3.85%, 6.30%- 6.51% and 7.82%-8.69% respectively. ConclusionSoaking rice seed with FA could be considered as an effective way to improve the rice competitiveness at early growth stage.展开更多
基金supported by the National Natural Science Foundation of China(32071960)the National Key Research and Development Program of China(2018YFD0300603)。
文摘In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisite for successful highdensity cultivation.However,the photosynthetic mechanisms underlying improved density tolerance in maize hybrids released across different eras in China remain unclear.This study investigates 40 years of breeding progress toward enhanced photosynthetic traits under varying planting densities and elucidates the physiological and ecological bases of improved density tolerance in maize hybrids.A three-year field experiment was conducted from 2019 to 2021 to compare eight major Chinese hybrids from four decadal cohorts under three planting densities:45,000(D1),67,500(D2),and 90,000(D3)plants ha^(-1).At high density(D3),modern hybrids exhibited a more optimal canopy architecture and superior leaf photosynthetic performance compared to older hybrids,despite a slight reduction in specific leaf nitrogen.Notably,modern hybrids(2000s)were able to maintain higher net photosynthetic rates and photosynthetic nitrogen use efficiency(PNUE)at D3,resulting in the highest grain yield(GY),which was 118.47%greater than that of older hybrids(1970s).Leaf area duration after anthesis,total chlorophyll content,key photosynthetic enzyme activities,and maximum quantum efficiency of PSII photochemistry were all positively correlated with GY.Among these,PNUE showed the strongest correlation with grain yield and thus represents a key indicator for optimizing maize hybrids.Based on these findings,breeders should continue selecting hybrids under high-density and suboptimal conditions,focusing on optimizing population architecture and enhancing photosynthetic capacity while fine-tuning leaf nitrogen status to develop high-yielding,density-tolerant hybrids capable of sustaining long-term increases in maize grain yield.
基金supported by the National Key Research and Development Program of China,China(2022YFF1301801)Agricultural scientific and technological innovation project of Shandong Academy of Agricultural Sciences,China(333 Project)(06202214442066)+1 种基金Beijing Natural Science Foundation,China(5232018)Technology Innovation Project of Shandong Academy of Agricultural Sciences,China(06202214442062).
文摘Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to these threats on a regional scale have been challenging to ascertain due to scarce continuous observation data.This study compiled county-level data on maize yield and yield loss across China's six primary cropping regions over twenty years from 1999 to 2018.These include the Spring-sown area of Northern China(1-NC),the Summer-sown Huang-Huai-Hai Plain(2-HHP),the Southwest Mountain(3-SM),the Southern Hilly(4-SH),the Northwest Irrigated(5-NI),and the Qinghai-Tibet Plateau Maize Regions(6-QTP).We identified 15 major diseases affecting these regions.The annual average yield loss due to maize diseases in the regions 1-NC,2-HHP,3-SM,4-SH,5-NI,and 6-QTP were 0.40,0.58,0.12,0.05,0.04 and<0.01 million tons,respectively,and the corresponding average yield loss rate(the ratio of yield loss to total yield)in these regions was 0.63,0.90,0.65,0.63,0.44,and 0.05.The yield loss due to all diseases increased for three regions in 3-SM,4-SH and 5-NI.The yield loss rate due to diseases significantly increased in region 4-SH and 5-NI.Predominantly,maize leaf blight has become the most significant threats.In region 1-NC,maize head smut(D1)and maize leaf blight(D2)were the primary diseases.In region 2-HHP,maize leaf blight(D2),maize rust(D3),maize brown spot(D5),Curvularia leaf spot(D7),and maize virus disease(D14)were the key pathogens.Bivariate trend analysis(joint analysis of yield loss and loss rate trends)indicated that maize head smut(D1)decreased significantly in 1-NC,while in 2-HHP,six diseases showed a significant decrease in both yield loss and loss rate,namely sheath blight(D4),brown spot(D5),root rot(D11),downy mildew(D12)and virus disease(D14).By providing a long-term,national-scale perspective,this study not only supports the development of broad management strategies but also guides the creation of precise,region-specific control protocols to safeguard maize production.
基金supported by the University Youth Innovation Science and Technology Support Program of Shandong Province,China(2021KJ073)the Postdoctoral Innovation Program of Shandong Province,China(202003039)+2 种基金the China Agriculture Research System(CARS-02-21)the State Key Laboratory of North China Crop Improvement and Regulation(NCCIR2023KF-8)the Key R&D Program of Shandong Province,China(2023TZXD08603)。
文摘Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combined effects of waterlogging and shading on maize yield losses remain understudied,particularly across different growth stages.Denghai 605(DH605)was selected to be subjected shading,waterlogging,and their combined stress at the 3rd leaf stage(V3),the 6th leaf stage(V6),and tasseling stage(VT).Results showed that shading,waterlogging and their combination significantly restricted leaf area expansion,reduced leaf net photosynthetic rate(P_(n))and net assimilation rate(NAR),thereby decreasing the crop growth rate(CGR)and biomass accumulation.Additionally,compared to control,the process of lignin synthesis was inhibited under stressed treatment,resulting in diminished stem mechanical strength and impaired vascular system development,which substantially reduced assimilate remobilization efficiency to the ear and ultimate grain yield.Waterlogging and combined stresses exhibited maximum impact at the V3 stage,followed by V6 and VT stages,while shading effects were most pronounced at the VT stage,followed by V6 and V3 stages.Moreover,the compound stress exacerbated the damage brought about by a single stress.As climate change is projected to increase the frequency of multiple abiotic stress occurrences,these findings provide valuable insights for future summer maize breeding research under persistent rainfall conditions.
基金Supported by Construction Project of Maize Industry Technology System of Modern Agriculture in Yunnan Province(Yunnong(ke)2009-53Yunnongcai(2009-171))~~
文摘[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.
基金supported by the National Key Research and Development Program of China(2023YFD2303302,2022YFD2300803)the National Natural Science Foundation of China(32160445)the China Agriculture Research System of MOF and MARA(CARS-02-16).
文摘High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V14 stage with three densities(60,000,75,000,and 90,000 plants ha-1,indicated by D1,D2,and D3,respectively)for two seasons.The results showed that the IC-treated wavy canopy featuring both natural height(IC-H)and dwarfed(IC-L)plants,improved light transmission by 8.54%,8.49%,and 16.49%on average than the corresponding controls(CK)at D1,D2,and D3,respectively.The alleviation of canopy crowding stimulated leaf photosynthesis,sugar availability,basal-internode strength,and decreased plant lodging ratios in both IC-H and IC-L,particularly under higher densities.Meanwhile,the IC populations produced significantly higher yield than CK,with an average increase of 3.38%,16.70%,and 15.28%at D1,D2,and D3,respectively.Collectively,this study proposed a new wavy canopy strategy using plant growth retardant to simultaneously increase yield performance and lodging resistance,thus offering a sustainable solution for further development of high-density maize production.
文摘Maize is an important source of calories and protein in human lives in many countries of the world and is the main staple food in Africa, particularly in eastern Africa. In the Sudan, the low yield of maize was mainly due to the use of low yielding landraces. It is necessary to carry out breeding programs that deal with the production of high yielding, adaptable new varieties. Therefore, this study aimed to estimate genetic variability, heritability, genotypic performance and interrelationships among the traits. Ten maize genotypes evaluated at White Nile Research Station Farm, Kosti, of the Agricultural Research Corporation (ARC), Wad Medani Sudan were planted in a randomized complete block design with three replications during the two seasons of 2021 and 2022. Most evaluated genotypes exhibited a wide and significant variation in the 11 measured traits. Genotypic coefficient of variation and genetic advance were recorded for days to 50% tasseling, ear diameter (cm), number of grains per row and grain yield (t/ha) in both seasons. High heritability and genetic advance were recorded for grain yield, ear length, ear height, plant height, number of rows per ear, ear weight, days to 50% tasseling, 100-grain weight and days to 50% silking. Moreover, there was a highly significant and positive correlation of grain yield with number of rows per ear (r = 0.479), ear length (r = 0.381), 100-grain weight (r = 0.344) and days to 50% tasseling (r = 0.214). The highest yielding five genotypes across the seasons were TZCOM1/ZDPSYN (4.2 t/ha), EEPVAH-3 (4.2 t/ha), F2TWLY131228 (4.1 t/ha), PVA SYN6F2 (3.9 t/ha) and EEPVAH-9 (3.8 t/ha) these were needed to check the adaptability, stability and to test major maize growing areas to make sound recommendations for release.
基金the financial support of the Jiangsu Agricultural Industry Technology System of China(JATS[2022]497)the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX[23]3117)+2 种基金the Key Research&Development Program of Jiangsu Province,China(BE2021317)the National Natural Science Foundation of China(32101828)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)。
文摘Unbalanced fertilizer application with high intensity nitrogen(N)and insufficient potassium(K)results in declining soil fertility.Balanced fertilization represents an effective approach to reduce fertilizer usage while enhancing maize yield and efficiency.This study examined two N levels(180 and 225 kg N ha^(-1),abbreviated N12 and N15)and four K treatments(0,75,150,and 75+75 kg K_(2)O ha^(-1),abbreviated K0,K5,K10,and K5+5)to investigate the effects of combined N and K application on biomass,nutrient accumulation,and remobilization characteristics in waxy maize.Results indicated that grain yield increased with higher K application at constant N levels,demonstrating an average increase of 1,254.8 kg ha^(-1)(2020)and 727.3 kg ha^(-1)(2021)compared with K0.Under identical N and K applications,K5+5 enhanced grain yield through increased kernel weight.The K5+5 treatment showed no significant difference in biomass and nutrient accumulation between N12 and N15.Compared to K10,K5+5 enhanced both the average remobilization amount(RBA)of biomass and increased RBA of N,phosphorus(P)and K.Additionally,the average remobilization efficiency(RBE)of biomass,N,P,and K in K5+5 increased by 3.3,4.6,10.6,and 4.2%,respectively.Moreover,topdressing K improved the apparent contribution to grain(AC)of biomass,N,P and K,facilitating greater nutrient transfer to grains and significantly increasing nutrient harvest index.Based on yield and fertilizer use efficiency,this study recommends optimized K application(basal and topdressing 75 kg ha^(-1))and moderate reduction in N application(from 225 to 180 kg ha^(-1))for spring-sown waxy maize production in southern China.
基金Supported by Hebi Comprehensive Experimental Station Project of Henan Maize Industry Technology System(Z2010-02-07)Henan Science and Technology Research Project-Creating Maize Germplasm and New Varieties Resistant to Southern Rust Suitable for the Huang-Huai-Hai Ecological Region Based on RppC Gene(242102110236)+1 种基金Henan Science and Technology Research Project-Targeted Improvement Breeding Application of ZmREX4 in Regulating Kernel Length(232102110172)Henan Key Research and Development Special Project-Breeding and Industrialization Demonstration of New Varieties of Advantageous Characteristic Crops and Aquatic Products in Henan Province(241111114300).
文摘Using maize varieties including Zhengdan 958,Xianyu 335,Yudan 132,Xundan 20,Lianchuang 808,and Dingyou 163 as experimental materials,this study investigated the effects of two ethephon compound agents on the lodging resistance and yield of different maize varieties across various ecological regions.The results demonstrated that the lodging resistance of maize was significantly enhanced after the application of the two chemical control agents.Specifically,the lodging rate of Xundan 20 was reduced by 6.1 percentage points following treatment with benzylaminopurine(6-BA)·ethephon(ETH),while the lodging rate of Zhengdan 958 was decreased by 6.2 percentage points after treatment with diethyl aminoethyl hexanoate(DTA-6)·ETH.In the Shangqiu area,treatment of Lianchuang 808 with DTA-6·ETH reduced its ear height coefficient by 9.8 percentage points,whereas in the Zhumadian area,treatment of Dingyou 163 with 6-BA·ETH lowered its ear height coefficient by 11.3 percentage points.Additionally,both ethephon compound agents improved the stalk puncture strength of maize.For the same maize variety,phenotypic traits such as ear length,ear diameter,and number of kernel rows showed no significant differences under different chemical control treatments.However,traits including kernel number per row,1000-kernel weight,and yield exhibited significant variations across treatments and years.Moreover,the yield performance of maize varieties after chemical control treatment varied by region.In Hebi,Zhoukou,and Zhumadian areas,the yield under the DTA-6·ETH treatment surpassed that under the 6-BA·ETH treatment,with average yield increases of 4.22%,8.41%,and 5.67%compared to the clear water control(CK),respectively.Conversely,in Shangqiu,Nanyang,and Changge areas,the 6-BA·ETH treatment outperformed DTA-6·ETH,resulting in average yield increases of 6.96%,7.54%,and 5.56%relative to CK.
基金funded by the Zhejiang Science and Technology Major Program on Agricultural New Variety Breeding,China(2021C02064-4)the Zhejiang Province“Three Rural and Nine Party”Science and Technology Cooperation Plan Project,China(2023SNJF002).
文摘Efficient nitrogen management is crucial for developing sustainable strategies aimed at enhancing yield while mitigating negative environmental impacts.However,research focusing on this aspect in the production of fresh maize is limited.Therefore,this study analyzed the effects of nitrogen application rates on the yields of 40 sweet and 44 waxy maize varieties at five sites in Zhejiang Province,China,from 2015 to 2019.The nitrogen application rates were categorized as either relatively high(RHN,>300 kg ha^(-1) for sweet maize and>320 kg ha^(-1) for waxy maize)or relatively low(RLN).An increase in nitrogen application rates significantly reduced nitrogen fertilizer partial productivity in both sweet and waxy maize(R^(2)=0.616,P<0.01;R^(2)=0.643,P<0.01),indicating that the optimum nitrogen application rates in this study might be the lowest values(160 kg ha^(-1) for sweet maize and 180 kg ha^(-1) for waxy maize).The kernel number per ear of sweet maize had a potentially more significant impact on fresh grain yield than the 1,000-fresh kernel weight under both RLN and RHN.In waxy maize,1,000-kernel weight contributed more to fresh grain yield under RLN,while kernel number per ear and 1,000-kernel weight cooperatively affected the yield under RHN.This study found that sweet maize required taller plant and ear heights,along with an optimal ear-plant height ratio,to enhance dry matter accumulation and increase source size,particularly under RLN,and to ultimately achieve a higher fresh grain yield.In contrast,a lower ear height and ear-plant height ratio in waxy maize probably contributed more to the greater kernel number and weight under RLN,likely due to a lower ear height which can reduce the distance between sink and source,enabling more efficient photoassimilate allocation to the ear.
基金Jimma University and Wollega University in Ethiopia for their formal support and help。
文摘Households in western Ethiopia are experiencing food insecurity driven by the effects of climate change.Hence,there is an opportunity to lessen the consequences of climate change by adopting climate-smart agriculture(CSA).The study involved 385 households from western Ethiopia during the 2023–2024 production period.Specifically,we examined the variables that affect adoption decisions and investigated how the combined adoption of CSA practices affects maize yield.The multinomial endogenous switching regression(MESR)model was used to analyze these factors.The results showed that the adoption of CSA practices is positively impacted by age,gender,farm size,and education,but the distances from the household residence to market and plot have a negative impact.Adopters of CSA practices achieved a greater average yield per hectare than the non-adopters.Specifically,agroforestry,crop diversification,and adjusted planting dates all considerably increased maize yield,with gains of 0.21,0.70,and 0.52 t/hm^(2),respectively,compared to non-adoption.The implementation of combined CSA practices,rather than a single CSA practice,is a great way to mitigate the negative impacts of climate change.Therefore,we recommend ensuring adequate funding,providing incentives,facilitating technical assistance,and fostering community involvement when implementing combined CSA practices.This information is essential for reducing the negative consequences of climate change and developing successful adaptation strategies.
基金This work was supported by the National Science Foundation for Outstanding Youth Scholars (No. 30025029), Chinese National Programs for High Technology Research and Development (No. 2002AA207006), the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions, and Program for Changjiang Scholars and Innovative Research Team in University of MOE, China.
文摘A population of 180 recombinant inbred lines （RILs） was developed by single seed descended from the cross of high yield Upland cotton （Gossypium hirsutum L.） varieties Zhongmiansuo12 （ZMSI2） and 8891, the two parents of Xiangzamian2 （XZM2）. A genetic linkage map consisting of 132 loci and covering 865.20 cM was constructed using the RIL population chiefly with SSR markers. Yield and yield components were investigated for RILs in three environments in China. The purpose of the present research was to analyze the relationship between yield and its components and to map QTL for yield and yield components in cotton. QTL were tagged with data sets from single environment （separate analysis） and a set of data from means of the three environments （joint analysis）. A total of 34 QTL for yield and yield components were independently detected in three environments, whereas fifteen QTL were found in joint analysis. Notably, a stable lint percentage QTL qLP-A10-1 was detected both in joint analysis and in two environments of separate analysis, which might be of special value for marker-assisted selection. The QTL detected in the present study provide new information on improving yield and yield components. Results of path analysis showed that bolls/plant had the largest contribution to lint yield, which is consistent with the mid-parent heterosis value in F1. Accordingly, in cotton breeding, bolls/plant can be considered first and other yield components measured as a whole to implement variety enhancement and hybrid selection of cotton.
基金supported by the National Natural Science Foundation of China(U2243235)the Shaanxi Provincial Department of Water Resources,China(2022slkj-6)。
文摘The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.
基金Supported by Suzhou Experiment Station of National Maize Industry TechnologySystem(CARS-02-51)Anhui Key Scientific and Technological Project(12010302062)+1 种基金Anhui Strategic Emerging Industry Project(11010301026)Transformation Fund forAnhui Agricultural Science and Technology Achievements(2013-07)~~
文摘Rational close planting is an economical and effective measure to increase crop yield.In order to explore the suitable planting density of major maize cultivars in northern Anhui,we studied the grain number per spike and 1 000-grain weight of three major maize cultivars,including ‘Zhengdan958＇,‘Ludan981＇ and ‘Longping206＇.The effects of planting density on yield and correlated characters were further analyzed.The study was performed at agricultural experiment farms of Suzhou Academy of Agricultural Sciences.The planting density was set from 7 500 to 30 000 plants/hm^2 with an interval of 7 500 plants/hm^2.Water and fertilizer were supplied sufficiently.High yield cultivation method was also used.Based on the high yield achieved,we analyzed the relationship between crop yield and correlated characters.The results showed that,the planting density had the parabolic relation with the yield of ‘Zhengdan958＇ and ‘Longping206＇.The most suitable density of compact type cultivar ‘Zhengdan 958＇ was 73 300 plants/hm^2.The most suitable density of semi-compact type cultivar ‘Longping 206＇ was 68 600 plants/hm^2.The most suitable density of flat type cultivar ‘Ludan981＇ was 45 000-52 500 plants/hm^2.The planting density of compact type cultivar could be increased appropriately.However,it was negatively related to the grain number per spike and 1 000-grain weight if the planting density is out of range.So,Ludan981 should be planted in low density to avoid risk.
基金Supported by Cooperation project of International Plant Nutrition Institution(IPNI)(NMBF-HenanAU-2007)Special Fund for Construction of National Modern Maize Industrial Technology System(nycytx-02-17)~~
文摘[Objective] The aim was to study on effects of N fertilizer on yield, N absorption and utilization of different cultivars of super high-yielding summer maize, in order to provide reference for reasonable N fertilization in accordance with different cultivars. [Method] Field experiment was conducted to study on effects of different N fertilizers on yield, N absorption and use efficiency of Zhengdan 958 and Xundan 20, in order to learn the effect differences at different N fertilizer levels. [Result] After N was applied, yields of the two summer maize increased significantly. Zhengdan 958 achieved the highest in yield and proceeds at 12 051.18 kg/hm2 and 1 722.40 yuan/hm2, respectively in low N level. In contrast, Xundan 20 achieved the highest at 13 166.00 kg/hm2 and 1 343.92 yuan/hm2 in the above two aspects in high N level. Compared with Zhengdan 958, Xundan 20 increased by 9.90%, 5.20% and 12.00% in N levels of 0, 240, and 450 kg/hm2, respectively. When N fertilizers were applied, protein yield of Xundan 20 was significantly higher than that of Zhengdan 958, so that higher N fertilizers contributed higher protein yield for Xundan 20. In high N level, N efficiency, N-fertilizer utilization and partial productivity of Xundan 20 were significantly higher than that of Zhengdan 958. [Conclusion] Lower N-fertilizer was suitable for Zhengdan 958 and Xundan 20 would get a good harvest if more N-fertilizers were applied. The results provided references for reasonable N fertilization.
基金Supported by National "11th five-year" Plan Science and Technolo-gy Support Project (2006BAD02A11)"11th five-year plan" of Tackling Key Problems Projects of Heilongjiang Province(GA07B101)~~
文摘[Objective] To study the effects of Zinc on the yield,nitrogen/phosphorus/potassium/Zinc uptake and distribution of different genotypes of maize.[Method] Using two different genotypes of maize as materials,the effects of Zn on the yield,N/P/K /Zn uptake and distribution of different genotypes of maize were studied by pot cultivation.[Result] Appropriate Zn supply could improve the grain number per kernel.The Zn content in different organs of maize showed little difference under low Zn treatment （Zn0,Zn1）.With the increase of Zn supply,Zn content in leaf,stem and sheath rapidly increased,but the increasing amplitude of Zn content in the kernel and bract were less.The excessive Zn in maize was mainly translocated in lower organs to reduce the damage of them to plants.Different Zn supply levels had less effects on the absorption and translocation of N,P and K in low-Zn insensitive variety Mudan 9.While the absorption and translation of N,P,K in low Zn sensitive variety （Sidan 19） was more easily influenced by the amount of Zn supplied.[Conclusion] Appropriate Zn supply could enhance the maize yield and utilization rate of N and K,and reduce the absorption and utilization of P.
基金Supported by the Special Fund for Agricultural and Rural Research in the Public Interest of Sichuan Province(12ZC1930)~~
文摘[Objective] The experiment was conducted to explore the suitable planting density and nitrogen amount for summer maize in Sichuan Basin with the objective to provide technical reservation and scientific basis for high-yielding cultivation technique.[Method] A widely planted maize cultivar ＇Chengdan 30＇ was used as experimental material to study the effects of planting density and nitrogen amount on the stalk agronomic traits,stalk lodging-resistance mechanical characters,stalk breaking percentage and yield of maize.Experiment was arranged in a two-factor split plot design with three replicates.The planting density was the main factor with three density gradients（4.5×10^4,6.0×10^4 and 7.5×10^4 plants/hm^2） and the nitrogen amount was the second factor with two different levels of nitrogen content（300 and 375 kg/hm^2）.[Result] The stalk lodging-resistance and yield were affected by planting density significantly.The increase of planting density would result in an increase of internode length and decrease of internode diameter,dry matter weight of per unit stalk length,rind penetration strength and breaking resistance of 3rd and 4th basal internodes.When planting density increased from 6.0×10^4 plants/hm2 to 7.5×10^4 plants/hm^2,the stalk breaking percentage in the whole growing season increased by 17.17%,and the yield reduced by 17.58%.The interaction between planting density and nitrogen amount affected the stalk breaking percentage in the whole growing season and yield significantly.The treatment with planting density of 6.0×104 plants/hm^2 and nitrogen amount of 375 kg/hm^2 of pure N was an optimal combination,which may not only control the stalk breaking percentage of whole growing stage effectively,but also could obtain an optimum grain yield.[Conclusion] In Sichuan Basin,the appropriate planting density and nitrogen amount for summer maize were 6.0×10^4 plants/hm^2 and 375 kg/hm^2.
基金Supported by the National Key Technology Research and Development Program of China during the 11thFive-Year Plan Period (2004BA520A05)Technology Research and Development Program of Sichuan Province (2008FZ0036)Key Technology Research and Development Program of Deyang City (2007ND028)~~
文摘[Objective] The relationship between grain yield and yield components was investigated in .different rice cultivars at the target yield of 10.5-11.25 t/hm2, to provide theoretical basis for cultivation of high-yield rice. [Method] The yield performance of various super rice and non-super rice cultivars that were cultivated in large area in Sichuan Chengdu was studied under high-yielding cultivation conditions from 2006 to 2008. [Result] The rice yield was closely correlated with the productive panicle number, grain number per panicle, seed setting rate and 1 000-grain weight. The four yield components showed different influences on the yield of different rice culti- vars. By adopting the high yielding cultivation technology （that the seedlings were planted in a triangle shape） at the target yield of 10.5-11.25 t/hm~, we found that the rice yield of super rice cultivars was closely correlated with productive panicle number and 1 000-grain weight, negatively correlated with grain number per panicle, and significantly negatively correlated with seed setting rate; the grain yield of non- super rice cultivars was negatively correlated with grain number per panicle and seed setting rate, and significantly negatively correlated with the productive panicle number and 1 000-grain weight. [Conclusion] The results revealed the relationship between grain yield and yield components in different rice cultivars, which provided references for developing reasonable cultivation measures and thus to improve the yield of super rice in large acreage.
基金Supported by S&T Development Plan Program of Shandong Province(2014GNC113001)State Key Laboratory for Biology of Crops(2014KF11)S&T Development Plan Program of Tai'an City~~
文摘[Objective] The aim was to select the optimal amount of controlled-release fertilizer and provide theoretical references for controlled-release fertilizers use in summer maize. [Method] Long-term controlled-release fertilizers were applied once at sowing summer maize to explore effects on maize growth, yield, economic profits and environment. [Result] Maize yield reduced a little in the treatment group with 60% CRF, and increased in varying degrees in the rest groups in the range of 1.1%-7.4%, and some showed significant differences. [Conclusion] Controlled-release fertilizers can be applied once at the amount of 80% common fertilizer＇s, with con- sideration of maize yield, nitrogen use rate and economic profits, which is beneficial for summer maize application and promotion in North China.
基金Crop Harvest Technology and Engineering in the Twelfth Five-year Plan (2011BAD16B15-2)Special Foundation of National Modern Maize Industrial Technology System(nycytx-02-17)Cooperation Project of China-International Plant Nutrition Research Institute (NMBF-HenanAU-2009)~~
文摘[Objective] The aim was to explore effects of application postponing of N fertilizer and the mechanism of yield increase in order to provide references for N fertilizer application in a rational way. [Method] In a super-high yielded region of summer maize, field experiment was conducted to research effects of N fertilizer postponing on key enzymes of N metabolism, yield of maize and N fertilizer use. [Result] After application of N fertilizer was postponed, NR, SPS and GS activities of ear-leaf of summer maize increased by 11.99%-34.87%, 8.25%-10.64% and 10.00%- 16.81% on the 28^th d of silking; content of soluble sugar in leaves enhanced signifi- cantly and accumulated nitrogen increased by 5.00%-9.74% in mature stage. The postponing fertilization of ＂30% of fertilizer in seedling stage＋30% of fertilizer in flare- opening stage＋40% of fertilizer in silking stage meets N demands of summer maize in late growth period. Compared with conventional fertilization, the maize yield, agro- nomic efficiency and use of N fertilizer all improved by 5.05%, 1.75 kg/kg and 6.87%, respectively, after application postponed. [Conclusion] Application postponing of N fertilizer maintains activity of NR, GS and SPS higher and coordinates metabolism of C and N in late growth period, to further improve yield of maize.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201303022)National Key Technology Research and Development Program during the 12th Five-Year Plan Period(2012BAD19B02)~~
文摘ObjectiveThis study aimed to investigate the effect of fulvic acid on the growth and yield components of direct seeding rice （Nanjing 44）. MethodThe rice seeds were soaked in 0 （water as a control）, 1, 2, 4 and 6 g/L fulvic acid （FA） before sowed. Then, the rice morphological indices, leaf chlorophyll content, photosynthesis parameters, root activity and chlorophyll fluorescence parameters were measured in the following field studies. ResultCompared with the control, the leaf area index, chlorophyll content, net photosynthetic rate, stomatal conductance and dry matter weight and some fluorescence parameters such as the maximum photochemical efficiency of photosystem II （PSII） （Fv/Fm）, excitation energy capture efficiency of opened PSII reaction center （Fv’/Fm’） and efficiency of the open reaction centre （ΦPS II） increased by different levels at both jointing stage and heading stage of direct seeding rice, whose seeds were soaked by FA with different concentrations. High FA concentration （4-6 g/L） significantly increased the cultivated rice leaf area index, chlorophyll content, net photosynthetic rate, stomatal conductance, transpiration rate and dry matter weight by 10.32% -22.88% , 5.88% -13.11% , 12.16% -26.84% , 11.43% -88.46% , 10.63% -21.63% , 18.49% -19.68% , respectively, thereby improving the physiological function and light energy transform efficiency of rice at the growth stage. With FA concentration increasing, the yield, effective panicles, grain number per panicle and seed setting rate were increased significantly compared with the control by 17.52%-18.71%, 3.46%-3.85%, 6.30%- 6.51% and 7.82%-8.69% respectively. ConclusionSoaking rice seed with FA could be considered as an effective way to improve the rice competitiveness at early growth stage.
