[Objectives]This study was conducted to investigate the effects of different planting densities on rice tillering dynamics and yield. [Methods]The effects of different planting densities on rice yield were studied bas...[Objectives]This study was conducted to investigate the effects of different planting densities on rice tillering dynamics and yield. [Methods]The effects of different planting densities on rice yield were studied based on seedlings dry raised in plug trays. [Results]Planting density had obvious effects on tillering dynamics,number of panicles per unit area,number of grains per panicle and rice yield under the condition of seedlings dry raised in plug trays. Comprehensive analysis showed that the row spacing × hill spacing = 25 cm × 14 cm,that is,the planting density of 2. 85 × 10~5 hills/hm^2,achieved the highest yield,at 9 960 kg/hm^2. [Conclusions]This study provides a scientific basis for optimizing rice cultivation techniques and achieving high yield and high efficiency in rice production.展开更多
A machine vision based system to estimate the nursery plug tray sowing quantity is necessary in the rice seedling nursery.Because the super hybrid rice is of small diameter,in order to obtain better estimation results...A machine vision based system to estimate the nursery plug tray sowing quantity is necessary in the rice seedling nursery.Because the super hybrid rice is of small diameter,in order to obtain better estimation results of sowing quantity,only part of the tray scene is captured by machine vision system.Therefore,nursery tray image sequence mosaic algorithm is required so as to obtain the whole nursery tray sowing performance.In this paper,a fast nursery plug tray image mosaic technique based on Phase Correlation and Speeded up Robust Features(the PC-SURF)algorithm was introduced.To reduce huge computational complexity in feature extraction and avoid wrong match points from non-overlapping regions between two adjacent images,firstly the proposed method used Phase Correlation to approximately locate the overlapping regions between two sequential images so as to narrow down the processing area for further feature extraction.Then,the SURF algorithm was implemented in the overlapping region of the images to perform image registration and image blending.Image registration and blending were then performed using the RANSAC algorithm and transition smoothing method.Finally,sequential images were warped into a single frame to produce a panoramic tray image with high resolution and better quality.The test results showed that the PC-SURF algorithm greatly outperforms the SURF algorithm in point matching accuracy,time consumption,and image mosaic accuracy.The average feature point matching accuracy of the PC-SURF algorithm was improved by approximately 7.14%.The implementation time was almost three times faster.The Root Mean Squared Error(RMSE)of image blending in the R,G,B channels(RMSEr,RMSEg,and RMSEb)decreased by approximately 8.4%,6.9%,6.9%respectively.The RMSE of image registration RMSEreg decreased by 33.8%.In addition,the speed of the nursery tray image mosaic technology could meet the requirements for real-time implementation in super hybrid rice automated sowing machines.展开更多
Atractylodes Chinensis(DC)Koidz is a perennial herb often used as a prescription medicine for influenza,to invigorate the spleen and remove dampness.The quality of the herb is determined by the quality of the seedling...Atractylodes Chinensis(DC)Koidz is a perennial herb often used as a prescription medicine for influenza,to invigorate the spleen and remove dampness.The quality of the herb is determined by the quality of the seedlings.The traditional A.chinensis seedling production technique has nonuniform seedlings and low mechanisation.The plug seedling technique was used to produce A.Chinensis seedlings.This study was conducted to determine the growth characteristics of A.Chinensis seedlings according to the cell size of plug trays and number of days after sowing.Plant height,stem diameter,rhizome diameter,number of leaves,leaf area,and shoot dry and fresh weight of A.Chinensis seedlings were significantly higher in the P32-D treatment than in the P72,P50,and P32 treatments,but not significantly different from the P28-D treatment 60 d after sowing.The P28-D treatment resulted in a considerable drop in rhizome fresh weight and healthy seedling index,both of which are key indicators for assessing seedling quality.Although the differences in Pn among treatments were not significantly different,Tr was considerably greater in A.Chinensis seedlings treated with P32-D and P28-D than in the other three treatments.The P32-D and P28-D treatments had considerably greater potential maximum photochemical efficiency of PSII,quantum yield of photosystem II,photochemical quenching and electron transport rate than the other three treatments.Root vitality of A.Chinensis seedlings was significantly stronger in the P32-D treatment than in the other four treatments,and it was 1.9 times higher than in the P28-D treatment.The soluble protein,soluble sugar,and starch contents of A.Chinensis seedlings were highest in the P32-D treatment,but the differences among treatments were not significant.LUE,EUE,PY and EY were significantly higher in the P32-D treatment than in the other four treatments,being 1.3,1.3,1.4 and 1.4 times higher than in P28-D,respectively.On the other hand,as for the change in the growth of A.Chinensis seedlings according to the number of days after sowing,the growth of shoots and rhizome was most vigorous at the 60 d after sowing,while the fresh weight of the rhizome,which can be considered as an indicator of root growth,increased steadily during the experiment but slowed down after 60 d.As a result,32-cell deepened plug trays and a seedling nursery for a period of 60-75 d are recommended for commercial cultivation of A.Chinensis seedlings.This will provide technical support for production in A.Chinensis seedling.展开更多
基金Supported by Major Applied Agricultural Technology Innovation Project of Shandong Province (SD2019ZZ020)Key R&D Program of Shandong Province(2019GSF109078)+2 种基金Rice Innovation Team Construction Project of Shandong Modern Agricultural Industry Technology System (SDAIT-17-09)Innovation Project of Shandong Academy of Agricultural Sciences (CXGC2018E03)Youth Fund Project of Shandong Academy of Agricultural Sciences (2015YQN25)。
文摘[Objectives]This study was conducted to investigate the effects of different planting densities on rice tillering dynamics and yield. [Methods]The effects of different planting densities on rice yield were studied based on seedlings dry raised in plug trays. [Results]Planting density had obvious effects on tillering dynamics,number of panicles per unit area,number of grains per panicle and rice yield under the condition of seedlings dry raised in plug trays. Comprehensive analysis showed that the row spacing × hill spacing = 25 cm × 14 cm,that is,the planting density of 2. 85 × 10~5 hills/hm^2,achieved the highest yield,at 9 960 kg/hm^2. [Conclusions]This study provides a scientific basis for optimizing rice cultivation techniques and achieving high yield and high efficiency in rice production.
基金The authors gratefully acknowledge the financial support from the National Key Research and Development Program of China(Grant No.2017YFD0700802)the National Natural Science Foundation of China(Grant No.51505156)the Earmarked Fund for Modern Agro-industry Technology Research System(Grant No.CARS-01-43).
文摘A machine vision based system to estimate the nursery plug tray sowing quantity is necessary in the rice seedling nursery.Because the super hybrid rice is of small diameter,in order to obtain better estimation results of sowing quantity,only part of the tray scene is captured by machine vision system.Therefore,nursery tray image sequence mosaic algorithm is required so as to obtain the whole nursery tray sowing performance.In this paper,a fast nursery plug tray image mosaic technique based on Phase Correlation and Speeded up Robust Features(the PC-SURF)algorithm was introduced.To reduce huge computational complexity in feature extraction and avoid wrong match points from non-overlapping regions between two adjacent images,firstly the proposed method used Phase Correlation to approximately locate the overlapping regions between two sequential images so as to narrow down the processing area for further feature extraction.Then,the SURF algorithm was implemented in the overlapping region of the images to perform image registration and image blending.Image registration and blending were then performed using the RANSAC algorithm and transition smoothing method.Finally,sequential images were warped into a single frame to produce a panoramic tray image with high resolution and better quality.The test results showed that the PC-SURF algorithm greatly outperforms the SURF algorithm in point matching accuracy,time consumption,and image mosaic accuracy.The average feature point matching accuracy of the PC-SURF algorithm was improved by approximately 7.14%.The implementation time was almost three times faster.The Root Mean Squared Error(RMSE)of image blending in the R,G,B channels(RMSEr,RMSEg,and RMSEb)decreased by approximately 8.4%,6.9%,6.9%respectively.The RMSE of image registration RMSEreg decreased by 33.8%.In addition,the speed of the nursery tray image mosaic technology could meet the requirements for real-time implementation in super hybrid rice automated sowing machines.
基金supported by the earmarked fund for CARS(Grant No.CARS-21).
文摘Atractylodes Chinensis(DC)Koidz is a perennial herb often used as a prescription medicine for influenza,to invigorate the spleen and remove dampness.The quality of the herb is determined by the quality of the seedlings.The traditional A.chinensis seedling production technique has nonuniform seedlings and low mechanisation.The plug seedling technique was used to produce A.Chinensis seedlings.This study was conducted to determine the growth characteristics of A.Chinensis seedlings according to the cell size of plug trays and number of days after sowing.Plant height,stem diameter,rhizome diameter,number of leaves,leaf area,and shoot dry and fresh weight of A.Chinensis seedlings were significantly higher in the P32-D treatment than in the P72,P50,and P32 treatments,but not significantly different from the P28-D treatment 60 d after sowing.The P28-D treatment resulted in a considerable drop in rhizome fresh weight and healthy seedling index,both of which are key indicators for assessing seedling quality.Although the differences in Pn among treatments were not significantly different,Tr was considerably greater in A.Chinensis seedlings treated with P32-D and P28-D than in the other three treatments.The P32-D and P28-D treatments had considerably greater potential maximum photochemical efficiency of PSII,quantum yield of photosystem II,photochemical quenching and electron transport rate than the other three treatments.Root vitality of A.Chinensis seedlings was significantly stronger in the P32-D treatment than in the other four treatments,and it was 1.9 times higher than in the P28-D treatment.The soluble protein,soluble sugar,and starch contents of A.Chinensis seedlings were highest in the P32-D treatment,but the differences among treatments were not significant.LUE,EUE,PY and EY were significantly higher in the P32-D treatment than in the other four treatments,being 1.3,1.3,1.4 and 1.4 times higher than in P28-D,respectively.On the other hand,as for the change in the growth of A.Chinensis seedlings according to the number of days after sowing,the growth of shoots and rhizome was most vigorous at the 60 d after sowing,while the fresh weight of the rhizome,which can be considered as an indicator of root growth,increased steadily during the experiment but slowed down after 60 d.As a result,32-cell deepened plug trays and a seedling nursery for a period of 60-75 d are recommended for commercial cultivation of A.Chinensis seedlings.This will provide technical support for production in A.Chinensis seedling.
