Mechanical pot-seedling transplanting is an innovatively developed transplanting method that has the potential to replace mechanical carpet-seedling transplanting. However, the initial pot-seedling transplanting machi...Mechanical pot-seedling transplanting is an innovatively developed transplanting method that has the potential to replace mechanical carpet-seedling transplanting. However, the initial pot-seedling transplanting machine lacked optimized density spacing and limited yield potential for japonica rice. Therefore, ascertaining the optimized density by wide-narrow rows and the appropriate transplanting method for yield formation and grain quality of japonica rice is of great importance for high-quality rice production. Field experiments were conducted using two japonica rice cultivars Nanjing 9108 and Nanjing 5055 under three transplanting methods in 2016 and 2017: mechanical pot-seedling transplanting with wide-narrow row(K, average row spacing of 30 cm);equidistant row(D, 33 cm×12 cm);and mechanical carpet-seedling transplanting(T, 30 cm×12.4 cm). In addition, five different density treatments were set in K(K1–K5, from 18.62×10~4 to 28.49×10~4 hills ha^(–1)). The results showed that the highest yield was produced by a planting density of 26.88×104 hills ha^(–1) in mechanical pot-seedling transplanting with wide-narrow row with a greater number of total spikelets that resulted from significantly more panicles per area and slightly more grain number per panicle, as compared with equidistant row, and yield among density in wide-narrow row showed a parabolic trend. Compared with mechanical carpet-seedling transplanting, the treatment of the highest yield increased yield significantly, which was mainly attributed to the larger sink size with improved filled-grain percentage and grain weight, higher harvest index, and increased total dry matter accumulation, especially the larger amount accumulated from heading stage to maturity stage. With the density in wide-narrow row decreasing, processing quality, appearance quality, and nutrition quality were all improved, whereas amylose content and the taste value were decreased. Compared with mechanical carpet-seedling transplanting, mechanical pot-seedling transplanting improved processing quality and nutrition quality, but decreased amylose content and deteriorated appearance quality. These results suggested that mechanical pot-seedling transplanting with wide-narrow row coupling produced a suitable planting density of 26.88×10~4 hills ha^(–1) and may be an alternative approach to improving grain yield and quality for japonica rice.展开更多
Epoxiconazole is a triazole compound.However,the effects of epoxiconazole on crop productivity and quality were rarely reported.In this study,we investigated the effects of epoxiconazole application on yield formation...Epoxiconazole is a triazole compound.However,the effects of epoxiconazole on crop productivity and quality were rarely reported.In this study,we investigated the effects of epoxiconazole application on yield formation,grain quality attributes,and 2-acetyl-1-pyrroline(2-AP)content in fragrant rice.A three-year field experiment was carried out with a fragrant rice variety,Meixiangzhan 2.At the heading stage,0,0.02,0.04,0.08,0.16 and 0.32 g/L epoxiconazole solutions were foliar applied to fragrant rice plants,respectively.The results showed that epoxiconazole application significantly increased grain yield,seed-setting rate and 1000-grain weight.Chlorophyll content and net photosynthetic rate of fragrant rice during the grain-filling stage significantly increased due to epoxiconazole application.Foliar application of epoxiconazole at 0.08 g/L increased grain protein content and decreased both chalky rice rate and chalkiness area ratio of fragrant rice.Epoxiconazole also substantially increased grain 2-AP content by inducing the regulation in contents of related synthetic precursors,including proline,pyrroline-5-carboxylic acid,Δ1-pyrroline and methylglyoxal.Overall,foliar application of epoxiconazole could be used for the improvement in grain yield,grain quality and 2-AP content in fragrant rice production when applied concentration at 0.08-0.32 g/L.Our findings provided the new roles of epoxiconazole in crop production.展开更多
The high labor demand during rice seedling cultivation and transplantation poses a significant challenge in advancing machine-transplanted rice cultivation.This problem may be solved by increasing the seeding rate dur...The high labor demand during rice seedling cultivation and transplantation poses a significant challenge in advancing machine-transplanted rice cultivation.This problem may be solved by increasing the seeding rate during seedling production while reducing the number of seedling trays.This study conducted field experiments from 2021 to 2022,using transplanting seedling ages of 10 and 15 days to explore the effects of 250,300,and 350 g/tray on the seedling quality,mechanical transplantation quality,yields,and economic benefits of rice.The commonly used combination of 150 g/tray with a 20-day seedling age in rice production was used as CK.The cultivation of seedlings under a high seeding rate and short seedling age significantly affected seedling characteristics,but there was no significant difference in seedling vitality compared to CK.The minimum number of rice trays used in the experiment was observed in the treatment of 350-10(300 g/tray and 10-day seedling age),only 152-155 trays ha^(-1),resulting in a 62%reduction in the number of trays needed.By increasing the seeding rate of rice,missed holes during mechanical transplantation decreased by 2.8 to 4%.The treatment of 300-15(300 g/tray and 15-day seedling age)achieved the highest yields and economic gains.These results indicated that using crop straw boards can reduce the application of seedling trays.On that basis,rice yields can be increased by raising the seeding rate and shortening the seedling age of rice without compromising seedling quality.展开更多
Fragrant rice is popular for the good grain quality and special aroma.The present study conducted a field experiment to investigate the effects of ultrasonic seed treatment on grain yield,quality characters,physiologi...Fragrant rice is popular for the good grain quality and special aroma.The present study conducted a field experiment to investigate the effects of ultrasonic seed treatment on grain yield,quality characters,physiological properties and aroma biosynthesis of different fragrant rice genotypes.The seeds of three fragrant rice genotypes were exposed to 1 min of ultrasonic vibration and then cultivated in paddy field.The results of present study showed that ultrasonic seed treatment increased grain yield of all fragrant rice genotypes but the responses of yield formation to ultrasonic were varied with different genotypes.Compared with control,ultrasonic seed treatment increased grain 2-acetyl-1-pyrroline(2-AP,the key component of fragrant rice aroma)content by 13.40%–44.88%.Ultrasonic seed treatment also reduced the crude protein contents in grains.The head rice rate,rice length,chalky rice rate,and chalkiness degree were influenced by ultrasonic for one or two fragrant rice genotypes.The activities of peroxidase and superoxide dismutase were also enhanced due to ultrasonic seed treatment.In conclusion,ultrasonic seed treatment increased grain,regulated grain aroma and quality,and improved stress resistance of fragrant rice varieties.展开更多
This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings （HLMS） on seedling quality and field growth characteristics of transplanted super japonica rice. ...This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings （HLMS） on seedling quality and field growth characteristics of transplanted super japonica rice. A widely grown conventional super japonica rice cultivar （Wuyunjing 23） was selected as the test material. The effect of HLMS on seedling quality, mechanical transplantation quality, field growth characteristics, yield, and benefit-cost ratio were compared with seedlings grown in organic substrates and traditional nutritive soil, whJch was selected as the control. Root number, root twJstJng power and root activity of seedlings cultivated by HLMS were decreased compared to that of the organic substrates andcontrol. However, seedling root length as well as aboveground growth were increased compared to the organic substrates and control seed- lings. In the HLMS, the content of gibberellin acid （GA3） decreased while abscisic acid （ABA） content increased compared to that of the organic substrates and control seedlings. During the early stages after transplanting, the re-greening of HLMS was delayed compared to that of the organic substrates and control seedlings. Nevertheless, there were no significant differences in tiller dynamics and crop yield among the HLMS, organic substrates and control treatments. The effects of HLMS on seedling production were similar to those of the organic substrates and traditional nutritive soil in the present study, suggesting that HLMS have the potential to replace traditional nutritive soil in seedling production without decreasing crop yield. Finally, it is important to reduce organic substrates and topsoil dependence during rice seedling production and worthwhile to consider HLMS popularization and its application on a larger scale.展开更多
The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive,time consuming and laborious.The improvement and optimization of nutrient management in soil-less nursery...The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive,time consuming and laborious.The improvement and optimization of nutrient management in soil-less nursery raising methods like tandem long-mat seedlings(TLMS)are necessary for the resource-efficient cultivation of rice.In the present study,a controlled-release fertilizer(CRF)-polymer-coated compound fertilizer with 3 months release period(PCCF-3M)was applied as seedling fertilizer(SF),and five different dosages of SF(SF-0,SF-10,SF-20,SF-30,and SF-40)were compared with an organic substrate as the control(CK).Among all SF treatments,the best results were obtained with the application of 20 g/tray of SF(SF-20),as the seedling quality and machine transplanting quality were comparable to those of CK.In contrast,the lower dosages(SF-0 and SF-10)resulted in low nitrogen content and reduced shoot growth,while the higher dosages(SF-30 and SF-40)resulted in toxicity(increased malondialdehyde accumulation)and inhibited the root growth.Similarly,SF-20 increased panicle number(5.6-7.0%)and yield(4.3-5.3%)compared with CK,which might be related to the remaining SF entangled in the roots supporting the tiller growth of rice seedlings in the field.Moreover,SF-20 reduced the seedling block weight(53.1%)and cost of seedling production(23.5%)but increased the gross margin,indicating that it was easy to handle and economical.Taken together,our results indicate that SF-20 is a cost-effective way to promote the growth and transplanting efficiency of rice seedlings.To our knowledge,this study is the first to determine the optimum dosage of CRF for the soil-less production of rice seedlings.展开更多
To address problems caused by rice machine transplanting such as injury to the seedlings and recovery period that extend growth period,this study explored the effects of different machine transplanting methods on the ...To address problems caused by rice machine transplanting such as injury to the seedlings and recovery period that extend growth period,this study explored the effects of different machine transplanting methods on the physiological and yield characteristics of late rice in China,and determine the appropriate machine transplanting method for late rice,which was expected to provide a basis for high-yield and high-efficient cultivation of machine-transplanted late rice.Hybrid indica rice Taiyou 398 and conventional indica rice Jing Gangruanzhan were selected as the research objects,and large-pot carpet seedling machine transplanting(M1),conventional pot carpet seedling machine transplanting(M2)and ordinary carpet seedling machine transplanting(M3)were adopted respectively to analyze their effects on seedling quality,population physiological characteristics,yield and its components and economic benefits of late rice.The results showed that compared with M2 and M3,M1 achieved higher seedling quality,showing significant advantages in the early stage despite average root entwining force that met the requirement of machine transplanting.The seedlings transplanted using M1 had shorter recovery period after mechanical transplanting,with earlier tillering,earlier peak seedling,and slower declining of stems and tillers in the late stage;the peak seedling number was not high,but the effective tiller number and earbearing tiller percentage were significantly higher than those achieved by the other two machine transplanting methods.Also,M1 achieved stronger photosynthetic capacity of flag leaves before HS,with more photosynthetic products in stems and leaves transported to panicles and more efficiently after HS.Compared with seedlings transplanted using M2 and M3,the recovery period of those transplanted using M1 was shortened by 3 and 5 d,the heading stage(HS),and maturity stage(MS)were advanced,which effectively reduced the risk and impact of“cold dew wind”on machine-transplanted late rice.M1 had significant yield increase advantage and economic benefit,with better grain maturity,and“larger panicles,more panicles,more and fuller grains”.M1 achieved an average yield increase of 10.31%-11.10%,20.67%-25.10%in 2 years,and an average income increase of 18.65%-131.06%and 62.85%-323.78%,respectively.Therefore,vigorously developing M1 is the key to the high-yield and high-efficient cultivation of machine-transplanted late rice in China.展开更多
The growth period, population tiller dynamics, plant characters, paniclegrain structure, yielding ability and stress resistance of a wheat variety Heibaoshi 1 were studied using a two-factor split plot design to inves...The growth period, population tiller dynamics, plant characters, paniclegrain structure, yielding ability and stress resistance of a wheat variety Heibaoshi 1 were studied using a two-factor split plot design to investigate the effects of different density and fertilizer levels on individual development and yield of Heibaoshi 1 in riparian region of Jiangsu Province. In addition, high-yielding agronomic measures were explored through multiple non-linear regression analysis. The results showed that low density was not conducive to the formation of panicles, while high density affected grain number per panicle; low fertilizer level restricted individual development, while high fertilizer level affected grain number per panicle and grain weight and was prone to leading to lodging. Reasonable combination of density and fertilizer could coordinate individual development and balance panicle, grain and weight, thus achieving a high yield. The yield potential was highest （7 384.3 kg/hm2） under density of 239.6×104 basic seedlings/hm2 and N level of 237.7 kg/hm2. When the planting density ranged from 200×104 to 270×104 basic seedlings/hm2 and the N level ranged from 220 to 260 kg/hm2 or the density basic seedling number ranged from 210×104/hm2 to 260×104/hm2 and the N level ranged from 210 to 270 kg/hm2, the yield could exceed 7 200 kg/hm2.展开更多
基金funded by the National Key Research Program of China(2016YFD0300503)the Key Research Program of Jiangsu Province,China(BE2016344 and BE2018355)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China。
文摘Mechanical pot-seedling transplanting is an innovatively developed transplanting method that has the potential to replace mechanical carpet-seedling transplanting. However, the initial pot-seedling transplanting machine lacked optimized density spacing and limited yield potential for japonica rice. Therefore, ascertaining the optimized density by wide-narrow rows and the appropriate transplanting method for yield formation and grain quality of japonica rice is of great importance for high-quality rice production. Field experiments were conducted using two japonica rice cultivars Nanjing 9108 and Nanjing 5055 under three transplanting methods in 2016 and 2017: mechanical pot-seedling transplanting with wide-narrow row(K, average row spacing of 30 cm);equidistant row(D, 33 cm×12 cm);and mechanical carpet-seedling transplanting(T, 30 cm×12.4 cm). In addition, five different density treatments were set in K(K1–K5, from 18.62×10~4 to 28.49×10~4 hills ha^(–1)). The results showed that the highest yield was produced by a planting density of 26.88×104 hills ha^(–1) in mechanical pot-seedling transplanting with wide-narrow row with a greater number of total spikelets that resulted from significantly more panicles per area and slightly more grain number per panicle, as compared with equidistant row, and yield among density in wide-narrow row showed a parabolic trend. Compared with mechanical carpet-seedling transplanting, the treatment of the highest yield increased yield significantly, which was mainly attributed to the larger sink size with improved filled-grain percentage and grain weight, higher harvest index, and increased total dry matter accumulation, especially the larger amount accumulated from heading stage to maturity stage. With the density in wide-narrow row decreasing, processing quality, appearance quality, and nutrition quality were all improved, whereas amylose content and the taste value were decreased. Compared with mechanical carpet-seedling transplanting, mechanical pot-seedling transplanting improved processing quality and nutrition quality, but decreased amylose content and deteriorated appearance quality. These results suggested that mechanical pot-seedling transplanting with wide-narrow row coupling produced a suitable planting density of 26.88×10~4 hills ha^(–1) and may be an alternative approach to improving grain yield and quality for japonica rice.
基金This study was supported by the National Natural Science Foundation of China(Grant No.31971843)the Technology System of Modern Agricultural Industry in Guangdong(Grant No.2020KJ105)Guangzhou Science and Technology Project in China(Grant No.202103000075).
文摘Epoxiconazole is a triazole compound.However,the effects of epoxiconazole on crop productivity and quality were rarely reported.In this study,we investigated the effects of epoxiconazole application on yield formation,grain quality attributes,and 2-acetyl-1-pyrroline(2-AP)content in fragrant rice.A three-year field experiment was carried out with a fragrant rice variety,Meixiangzhan 2.At the heading stage,0,0.02,0.04,0.08,0.16 and 0.32 g/L epoxiconazole solutions were foliar applied to fragrant rice plants,respectively.The results showed that epoxiconazole application significantly increased grain yield,seed-setting rate and 1000-grain weight.Chlorophyll content and net photosynthetic rate of fragrant rice during the grain-filling stage significantly increased due to epoxiconazole application.Foliar application of epoxiconazole at 0.08 g/L increased grain protein content and decreased both chalky rice rate and chalkiness area ratio of fragrant rice.Epoxiconazole also substantially increased grain 2-AP content by inducing the regulation in contents of related synthetic precursors,including proline,pyrroline-5-carboxylic acid,Δ1-pyrroline and methylglyoxal.Overall,foliar application of epoxiconazole could be used for the improvement in grain yield,grain quality and 2-AP content in fragrant rice production when applied concentration at 0.08-0.32 g/L.Our findings provided the new roles of epoxiconazole in crop production.
基金funded by the Jiangsu Key Research Program,China(BE2022338)the Jiangsu Agricultural Science and Technology Innovation Fund,China(CX(23)3107)+3 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions,China(22KJB210004)the Jiangsu Province Agricultural Major Technology Collaborative Promotion Project,China(2022-ZYXT-04-1)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX23_3569)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.
文摘The high labor demand during rice seedling cultivation and transplantation poses a significant challenge in advancing machine-transplanted rice cultivation.This problem may be solved by increasing the seeding rate during seedling production while reducing the number of seedling trays.This study conducted field experiments from 2021 to 2022,using transplanting seedling ages of 10 and 15 days to explore the effects of 250,300,and 350 g/tray on the seedling quality,mechanical transplantation quality,yields,and economic benefits of rice.The commonly used combination of 150 g/tray with a 20-day seedling age in rice production was used as CK.The cultivation of seedlings under a high seeding rate and short seedling age significantly affected seedling characteristics,but there was no significant difference in seedling vitality compared to CK.The minimum number of rice trays used in the experiment was observed in the treatment of 350-10(300 g/tray and 10-day seedling age),only 152-155 trays ha^(-1),resulting in a 62%reduction in the number of trays needed.By increasing the seeding rate of rice,missed holes during mechanical transplantation decreased by 2.8 to 4%.The treatment of 300-15(300 g/tray and 15-day seedling age)achieved the highest yields and economic gains.These results indicated that using crop straw boards can reduce the application of seedling trays.On that basis,rice yields can be increased by raising the seeding rate and shortening the seedling age of rice without compromising seedling quality.
基金supported by National Natural Science Foundation of China(31971843)The Technology System of Modern Agricultural Industry in Guangdong(2020KJ105)Guangzhou Science and Technology Project(202103000075).Xiangru Tang received the grants.
文摘Fragrant rice is popular for the good grain quality and special aroma.The present study conducted a field experiment to investigate the effects of ultrasonic seed treatment on grain yield,quality characters,physiological properties and aroma biosynthesis of different fragrant rice genotypes.The seeds of three fragrant rice genotypes were exposed to 1 min of ultrasonic vibration and then cultivated in paddy field.The results of present study showed that ultrasonic seed treatment increased grain yield of all fragrant rice genotypes but the responses of yield formation to ultrasonic were varied with different genotypes.Compared with control,ultrasonic seed treatment increased grain 2-acetyl-1-pyrroline(2-AP,the key component of fragrant rice aroma)content by 13.40%–44.88%.Ultrasonic seed treatment also reduced the crude protein contents in grains.The head rice rate,rice length,chalky rice rate,and chalkiness degree were influenced by ultrasonic for one or two fragrant rice genotypes.The activities of peroxidase and superoxide dismutase were also enhanced due to ultrasonic seed treatment.In conclusion,ultrasonic seed treatment increased grain,regulated grain aroma and quality,and improved stress resistance of fragrant rice varieties.
基金provided by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2016YFD0300505 and 2015BAD01B03)the Public Welfare and Industry,Ministry of Agriculture,China(201403039 and 201303102)the Fundamental Research Funds for the Central Universities,China(KYTZ201402)
文摘This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings （HLMS） on seedling quality and field growth characteristics of transplanted super japonica rice. A widely grown conventional super japonica rice cultivar （Wuyunjing 23） was selected as the test material. The effect of HLMS on seedling quality, mechanical transplantation quality, field growth characteristics, yield, and benefit-cost ratio were compared with seedlings grown in organic substrates and traditional nutritive soil, whJch was selected as the control. Root number, root twJstJng power and root activity of seedlings cultivated by HLMS were decreased compared to that of the organic substrates andcontrol. However, seedling root length as well as aboveground growth were increased compared to the organic substrates and control seed- lings. In the HLMS, the content of gibberellin acid （GA3） decreased while abscisic acid （ABA） content increased compared to that of the organic substrates and control seedlings. During the early stages after transplanting, the re-greening of HLMS was delayed compared to that of the organic substrates and control seedlings. Nevertheless, there were no significant differences in tiller dynamics and crop yield among the HLMS, organic substrates and control treatments. The effects of HLMS on seedling production were similar to those of the organic substrates and traditional nutritive soil in the present study, suggesting that HLMS have the potential to replace traditional nutritive soil in seedling production without decreasing crop yield. Finally, it is important to reduce organic substrates and topsoil dependence during rice seedling production and worthwhile to consider HLMS popularization and its application on a larger scale.
基金This work was funded by the National Natural Science Foundation of China(31871573)the Key Research and Development Program of Jiangsu Province,China(BE2017369)the Jiangsu Agriculture Science and Technology Innovation Fund,China(JASTIF)(CX(18)1002).
文摘The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive,time consuming and laborious.The improvement and optimization of nutrient management in soil-less nursery raising methods like tandem long-mat seedlings(TLMS)are necessary for the resource-efficient cultivation of rice.In the present study,a controlled-release fertilizer(CRF)-polymer-coated compound fertilizer with 3 months release period(PCCF-3M)was applied as seedling fertilizer(SF),and five different dosages of SF(SF-0,SF-10,SF-20,SF-30,and SF-40)were compared with an organic substrate as the control(CK).Among all SF treatments,the best results were obtained with the application of 20 g/tray of SF(SF-20),as the seedling quality and machine transplanting quality were comparable to those of CK.In contrast,the lower dosages(SF-0 and SF-10)resulted in low nitrogen content and reduced shoot growth,while the higher dosages(SF-30 and SF-40)resulted in toxicity(increased malondialdehyde accumulation)and inhibited the root growth.Similarly,SF-20 increased panicle number(5.6-7.0%)and yield(4.3-5.3%)compared with CK,which might be related to the remaining SF entangled in the roots supporting the tiller growth of rice seedlings in the field.Moreover,SF-20 reduced the seedling block weight(53.1%)and cost of seedling production(23.5%)but increased the gross margin,indicating that it was easy to handle and economical.Taken together,our results indicate that SF-20 is a cost-effective way to promote the growth and transplanting efficiency of rice seedlings.To our knowledge,this study is the first to determine the optimum dosage of CRF for the soil-less production of rice seedlings.
基金sponsored by Science and Technology Power Economy 2020 (2020YFF0426562-2).
文摘To address problems caused by rice machine transplanting such as injury to the seedlings and recovery period that extend growth period,this study explored the effects of different machine transplanting methods on the physiological and yield characteristics of late rice in China,and determine the appropriate machine transplanting method for late rice,which was expected to provide a basis for high-yield and high-efficient cultivation of machine-transplanted late rice.Hybrid indica rice Taiyou 398 and conventional indica rice Jing Gangruanzhan were selected as the research objects,and large-pot carpet seedling machine transplanting(M1),conventional pot carpet seedling machine transplanting(M2)and ordinary carpet seedling machine transplanting(M3)were adopted respectively to analyze their effects on seedling quality,population physiological characteristics,yield and its components and economic benefits of late rice.The results showed that compared with M2 and M3,M1 achieved higher seedling quality,showing significant advantages in the early stage despite average root entwining force that met the requirement of machine transplanting.The seedlings transplanted using M1 had shorter recovery period after mechanical transplanting,with earlier tillering,earlier peak seedling,and slower declining of stems and tillers in the late stage;the peak seedling number was not high,but the effective tiller number and earbearing tiller percentage were significantly higher than those achieved by the other two machine transplanting methods.Also,M1 achieved stronger photosynthetic capacity of flag leaves before HS,with more photosynthetic products in stems and leaves transported to panicles and more efficiently after HS.Compared with seedlings transplanted using M2 and M3,the recovery period of those transplanted using M1 was shortened by 3 and 5 d,the heading stage(HS),and maturity stage(MS)were advanced,which effectively reduced the risk and impact of“cold dew wind”on machine-transplanted late rice.M1 had significant yield increase advantage and economic benefit,with better grain maturity,and“larger panicles,more panicles,more and fuller grains”.M1 achieved an average yield increase of 10.31%-11.10%,20.67%-25.10%in 2 years,and an average income increase of 18.65%-131.06%and 62.85%-323.78%,respectively.Therefore,vigorously developing M1 is the key to the high-yield and high-efficient cultivation of machine-transplanted late rice in China.
文摘The growth period, population tiller dynamics, plant characters, paniclegrain structure, yielding ability and stress resistance of a wheat variety Heibaoshi 1 were studied using a two-factor split plot design to investigate the effects of different density and fertilizer levels on individual development and yield of Heibaoshi 1 in riparian region of Jiangsu Province. In addition, high-yielding agronomic measures were explored through multiple non-linear regression analysis. The results showed that low density was not conducive to the formation of panicles, while high density affected grain number per panicle; low fertilizer level restricted individual development, while high fertilizer level affected grain number per panicle and grain weight and was prone to leading to lodging. Reasonable combination of density and fertilizer could coordinate individual development and balance panicle, grain and weight, thus achieving a high yield. The yield potential was highest （7 384.3 kg/hm2） under density of 239.6×104 basic seedlings/hm2 and N level of 237.7 kg/hm2. When the planting density ranged from 200×104 to 270×104 basic seedlings/hm2 and the N level ranged from 220 to 260 kg/hm2 or the density basic seedling number ranged from 210×104/hm2 to 260×104/hm2 and the N level ranged from 210 to 270 kg/hm2, the yield could exceed 7 200 kg/hm2.
