Lessons learned from past experiences push for an alternate way of crop production.In India,adopting high density planting system(HDPS)to boost cotton yield is becoming a growing trend.HDPS has recently been considere...Lessons learned from past experiences push for an alternate way of crop production.In India,adopting high density planting system(HDPS)to boost cotton yield is becoming a growing trend.HDPS has recently been considered a replacement for the current Indian production system.It is also suitable for mechanical harvesting,which reducing labour costs,increasing input use efficiency,timely harvesting timely,maintaining cotton quality,and offering the potential to increase productivity and profitability.This technology has become widespread in globally cotton growing regions.Water management is critical for the success of high density cotton planting.Due to the problem of freshwater availability,more crops should be produced per drop of water.In the high-density planting system,optimum water application is essential to control excessive vegetative growth and improve the translocation of photoassimilates to reproductive organs.Deficit irrigation is a tool to save water without compromising yield.At the same time,it consumes less water than the normal evapotranspiration of crops.This review comprehensively documents the importance of growing cotton under a high-density planting system with deficit irrigation.Based on the current research and combined with cotton production reality,this review discusses the application and future development of deficit irrigation,which may provide theoretical guidance for the sustainable advancement of cotton planting systems.展开更多
Machine picking in cotton is an emerging practice in India,to solve the problems of labour shortages and production costs increasing.Cotton production has been declining in recent years;however,the high density planti...Machine picking in cotton is an emerging practice in India,to solve the problems of labour shortages and production costs increasing.Cotton production has been declining in recent years;however,the high density planting system(HDPS)offers a viable method to enhance productivity by increasing plant populations per unit area,optimizing resource utilization,and facilitating machine picking.Cotton is an indeterminate plant that produce excessive vegeta-tive growth in favorable soil fertility and moisture conditions,which posing challenges for efficient machine picking.To address this issue,the application of plant growth retardants(PGRs)is essential for controlling canopy architecture.PGRs reduce internode elongation,promote regulated branching,and increase plant compactness,making cotton plants better suited for machine picking.PGRs application also optimizes photosynthates distribution between veg-etative and reproductive growth,resulting in higher yields and improved fibre quality.The integration of HDPS and PGRs applications results in an optimal plant architecture for improving machine picking efficiency.However,the success of this integration is determined by some factors,including cotton variety,environmental conditions,and geographical variations.These approaches not only address yield stagnation and labour shortages but also help to establish more effective and sustainable cotton farming practices,resulting in higher cotton productivity.展开更多
Forage soybean is an important source of high protein forage.Variety screening and breeding not only can solve the adjustment of agricultural planting structure,but also can provide a large amount of high-protein fora...Forage soybean is an important source of high protein forage.Variety screening and breeding not only can solve the adjustment of agricultural planting structure,but also can provide a large amount of high-protein forage material,and effectively solve the problem of a serious shortage of high-protein forage in herbivorous animal husbandry in China.In this study,the feeding-type soybean strain HN389 was selected as experimental material,with three planting densities of 270000,405000 and 540000 plants•hm^(-2) and three cutting periods of the initial pod stage(R1),the initial grain stage(R2)and the early mature stage(R3)were set to determine the yield and feeding quality,in order to obtain the best planting density and harvest time of the variety.The results showed that in forage soybean strain HN389 at the R1 and R2 stages,plant height increased with increasing planting densities,while fresh and dry weight per plant decreased with increasing planting densities,and there was no significant difference at the R3 stage.The yield of hay at the R1,R2 and R3 stages increased firstly and then decreased with the increase of planting densities,and the yield per hectare was R3>R2>R1.The order of contents of crude protein(CP),neutral detergent fibers(NDF)and acid detergent fiber(ADF)in feeding quality of HN389 were R2>R1>R3,and ether extract(EE)content order was R3>R1>R2,and there was no significant difference among different groups.Two principal components were extracted from five forage indexes including CP,NDF,ADF,EE and fresh grass yield by principal component analysis.The cumulative contribution rate of principal components 1 and 2 was 90.053%,and their characteristic values were 3.617 and 0.885,respectively.After a comprehensive evaluation,harvested at the R3 stage and the density was 405000 plants•hm^(-2),HN389 had the highest comprehensive score of 0.344,yield of 38035.53 kg•hm^(-2),CP,NDF,ADF and EE contents of 17.61%,17.61%,21.54%and 3.81%,respectively.展开更多
Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain...Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain obscure.This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics,and thus final cotton yield.PPD of three levels(D1:2.25 plants·m^(-2),D2:4.5 plants·m^(-2),and D3:6.75 plants·m^(-2))and MC dosage of two levels(MC0:0 g·ha^(-2),MC1:82.5 g·ha^(-2))were combined to create six treatments.The dynamics of nonstructual carbohydrate concentration,carbon metabolism-related enzyme activity,and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.Results Among six treatments,the high PPD of 6.75 plants·m^(-2)combined with MC application(MC1D3)exhibited the greatest seed cotton yield and biological yield.The sucrose,hexose,starch,and total nonstructural carbohydrate(TNC)concentrations peaked at the first flowering(FF)stage and then declined to a minimum at the first boll opening(FBO)stage.Compared with other treatments,MC1D3 improved starch and TNC concentration by 5.4%~88.4%,7.8%~52.0% in 2019,and by 14.6%~55.9%,13.5%~39.7% in 2020 at the FF stage,respectively.Additionally,MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages,indicating greater carbon production and utilization efficiency.MC1D3 displayed the maximal specific leaf weight(SLW)at the FBO stage,and the highest chlorophyll a(Chl a),Chl b,and Chl a+b concentration at the mid-late growth phase in both years.The Rubisco activity with MC1D3 was 2.6%~53.2% higher at the flowering and boll setting stages in both years,and 2.4%~52.7% higher at the FBO stage in 2020 than those in other treatments.These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.Conclusion Increasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.展开更多
Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at diff...Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at different yield levels(medium yielding site(MYS)Luzhou City and high yielding site(HYS)Deyang City had not been described.Field experiments with hybrid rice Rongyou1015 were conducted to study the effects of two plant densities.High plant density(HD),low plant density(LD)and four N rates(without N,N_(0);a recommended N rate of 195 kg•hm^(-2),N_(CK);a 23%reduction in N rate,N_(-23%);a 46%reduction in N rate,N_(-46%)on yield attributes,grain yield,TNU and NUE of hybrid rice were studied under different yield levels in 2016-2017.The results showed that the grain yield and NUE of hybrid rice in response to plant density and N rate varied with yield levels.For MYS,reducing N rate by 46%result in significantly lower grain yield at LD treatment;whereas at HD treatment the grain yield of hybrid rice under N_(-46%) and N_(CK) were equal.For HYS,reducing N rate by 46% result in significantly lower grain yield regardless of low plant density and high plant density;however,a reduction in N rate by 23%increased grain yield,AE_(N) by 36%,PFP_(N) by 31% and RE_(N) by 11% over N_(CK) at HD treatment.Higher grain yield of hybrid rice under the combination of HD with low N rate was attributable to improvement in spikelets per panicle and harvest index.The results suggested that high plant density with low N rate might be an effective approach to improve grain yield and NUE in rice production,but reduction in N application rate was determined,according to yield levels.展开更多
Seeding rate is an important management practice for soybean production.Chinese and U.S.soybean growers use different seeding rates,and breeders in the two countries have developed cultivars adapted to respective plan...Seeding rate is an important management practice for soybean production.Chinese and U.S.soybean growers use different seeding rates,and breeders in the two countries have developed cultivars adapted to respective plant densities.The objective of this study was to compare the effect of plant density on cultivars recently released in different breeding programs,using four cultivars developed in Liaoning,China and four in Ohio,USA.We used 3 plant density treatments(7.5,15.0,22.5 x 104 plants/hm2) and assessed yield and agronomic traits from 2004 to 2006 in Liaoning.There was no significant effect of plant density on yield for either group of the cultivars.The average yield of Ohio cultivars was higher than that of Liaoning cultivars,and there was no significant interaction between plant density and cultivar for all the assessed traits.The plant height of Liaoning cultivars was significantly higher than that of Ohio cultivars,and there was a significant effect of plant density on plant height.The average branch number of Ohio cultivars was larger than that of Liaoning cultivars;higher plant density reduced the branch number per plant greatly.Plant density had a signifi-cant effect on the node number and internode length,Liaoning cultivars generally had longer internode length.Plant density had a significant effect on seed yield:stem ratio,as the plant density increased the seed yield:stem ratio decreased for both groups of cultivars.However,100-seed weight was not affected by plant density.展开更多
文摘Lessons learned from past experiences push for an alternate way of crop production.In India,adopting high density planting system(HDPS)to boost cotton yield is becoming a growing trend.HDPS has recently been considered a replacement for the current Indian production system.It is also suitable for mechanical harvesting,which reducing labour costs,increasing input use efficiency,timely harvesting timely,maintaining cotton quality,and offering the potential to increase productivity and profitability.This technology has become widespread in globally cotton growing regions.Water management is critical for the success of high density cotton planting.Due to the problem of freshwater availability,more crops should be produced per drop of water.In the high-density planting system,optimum water application is essential to control excessive vegetative growth and improve the translocation of photoassimilates to reproductive organs.Deficit irrigation is a tool to save water without compromising yield.At the same time,it consumes less water than the normal evapotranspiration of crops.This review comprehensively documents the importance of growing cotton under a high-density planting system with deficit irrigation.Based on the current research and combined with cotton production reality,this review discusses the application and future development of deficit irrigation,which may provide theoretical guidance for the sustainable advancement of cotton planting systems.
文摘Machine picking in cotton is an emerging practice in India,to solve the problems of labour shortages and production costs increasing.Cotton production has been declining in recent years;however,the high density planting system(HDPS)offers a viable method to enhance productivity by increasing plant populations per unit area,optimizing resource utilization,and facilitating machine picking.Cotton is an indeterminate plant that produce excessive vegeta-tive growth in favorable soil fertility and moisture conditions,which posing challenges for efficient machine picking.To address this issue,the application of plant growth retardants(PGRs)is essential for controlling canopy architecture.PGRs reduce internode elongation,promote regulated branching,and increase plant compactness,making cotton plants better suited for machine picking.PGRs application also optimizes photosynthates distribution between veg-etative and reproductive growth,resulting in higher yields and improved fibre quality.The integration of HDPS and PGRs applications results in an optimal plant architecture for improving machine picking efficiency.However,the success of this integration is determined by some factors,including cotton variety,environmental conditions,and geographical variations.These approaches not only address yield stagnation and labour shortages but also help to establish more effective and sustainable cotton farming practices,resulting in higher cotton productivity.
基金Supported by Fund of Popularization and Demonstration of Mixed Sowing of Forage Beans and Silage Corn to Improve Green Feeding Quality of Dairy Cows(2015RQXXJ013)。
文摘Forage soybean is an important source of high protein forage.Variety screening and breeding not only can solve the adjustment of agricultural planting structure,but also can provide a large amount of high-protein forage material,and effectively solve the problem of a serious shortage of high-protein forage in herbivorous animal husbandry in China.In this study,the feeding-type soybean strain HN389 was selected as experimental material,with three planting densities of 270000,405000 and 540000 plants•hm^(-2) and three cutting periods of the initial pod stage(R1),the initial grain stage(R2)and the early mature stage(R3)were set to determine the yield and feeding quality,in order to obtain the best planting density and harvest time of the variety.The results showed that in forage soybean strain HN389 at the R1 and R2 stages,plant height increased with increasing planting densities,while fresh and dry weight per plant decreased with increasing planting densities,and there was no significant difference at the R3 stage.The yield of hay at the R1,R2 and R3 stages increased firstly and then decreased with the increase of planting densities,and the yield per hectare was R3>R2>R1.The order of contents of crude protein(CP),neutral detergent fibers(NDF)and acid detergent fiber(ADF)in feeding quality of HN389 were R2>R1>R3,and ether extract(EE)content order was R3>R1>R2,and there was no significant difference among different groups.Two principal components were extracted from five forage indexes including CP,NDF,ADF,EE and fresh grass yield by principal component analysis.The cumulative contribution rate of principal components 1 and 2 was 90.053%,and their characteristic values were 3.617 and 0.885,respectively.After a comprehensive evaluation,harvested at the R3 stage and the density was 405000 plants•hm^(-2),HN389 had the highest comprehensive score of 0.344,yield of 38035.53 kg•hm^(-2),CP,NDF,ADF and EE contents of 17.61%,17.61%,21.54%and 3.81%,respectively.
基金supported by the National Natural Science Foundation of China(grant no.31960385)the Natural Science Foundation of Jiangxi,China(grant no.20212BAB215009)。
文摘Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain obscure.This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics,and thus final cotton yield.PPD of three levels(D1:2.25 plants·m^(-2),D2:4.5 plants·m^(-2),and D3:6.75 plants·m^(-2))and MC dosage of two levels(MC0:0 g·ha^(-2),MC1:82.5 g·ha^(-2))were combined to create six treatments.The dynamics of nonstructual carbohydrate concentration,carbon metabolism-related enzyme activity,and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.Results Among six treatments,the high PPD of 6.75 plants·m^(-2)combined with MC application(MC1D3)exhibited the greatest seed cotton yield and biological yield.The sucrose,hexose,starch,and total nonstructural carbohydrate(TNC)concentrations peaked at the first flowering(FF)stage and then declined to a minimum at the first boll opening(FBO)stage.Compared with other treatments,MC1D3 improved starch and TNC concentration by 5.4%~88.4%,7.8%~52.0% in 2019,and by 14.6%~55.9%,13.5%~39.7% in 2020 at the FF stage,respectively.Additionally,MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages,indicating greater carbon production and utilization efficiency.MC1D3 displayed the maximal specific leaf weight(SLW)at the FBO stage,and the highest chlorophyll a(Chl a),Chl b,and Chl a+b concentration at the mid-late growth phase in both years.The Rubisco activity with MC1D3 was 2.6%~53.2% higher at the flowering and boll setting stages in both years,and 2.4%~52.7% higher at the FBO stage in 2020 than those in other treatments.These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.Conclusion Increasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.
基金Supported by Earmarked Fund for Modern Agro-industry Technology of China(CARS-01-25)National Key Research and Development Program of China(2017YFD0301705)Foundation of Youth Science Program of Sichuan Agricultural Sciences Academy(2019QNJJ-020)。
文摘Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at different yield levels(medium yielding site(MYS)Luzhou City and high yielding site(HYS)Deyang City had not been described.Field experiments with hybrid rice Rongyou1015 were conducted to study the effects of two plant densities.High plant density(HD),low plant density(LD)and four N rates(without N,N_(0);a recommended N rate of 195 kg•hm^(-2),N_(CK);a 23%reduction in N rate,N_(-23%);a 46%reduction in N rate,N_(-46%)on yield attributes,grain yield,TNU and NUE of hybrid rice were studied under different yield levels in 2016-2017.The results showed that the grain yield and NUE of hybrid rice in response to plant density and N rate varied with yield levels.For MYS,reducing N rate by 46%result in significantly lower grain yield at LD treatment;whereas at HD treatment the grain yield of hybrid rice under N_(-46%) and N_(CK) were equal.For HYS,reducing N rate by 46% result in significantly lower grain yield regardless of low plant density and high plant density;however,a reduction in N rate by 23%increased grain yield,AE_(N) by 36%,PFP_(N) by 31% and RE_(N) by 11% over N_(CK) at HD treatment.Higher grain yield of hybrid rice under the combination of HD with low N rate was attributable to improvement in spikelets per panicle and harvest index.The results suggested that high plant density with low N rate might be an effective approach to improve grain yield and NUE in rice production,but reduction in N application rate was determined,according to yield levels.
文摘Seeding rate is an important management practice for soybean production.Chinese and U.S.soybean growers use different seeding rates,and breeders in the two countries have developed cultivars adapted to respective plant densities.The objective of this study was to compare the effect of plant density on cultivars recently released in different breeding programs,using four cultivars developed in Liaoning,China and four in Ohio,USA.We used 3 plant density treatments(7.5,15.0,22.5 x 104 plants/hm2) and assessed yield and agronomic traits from 2004 to 2006 in Liaoning.There was no significant effect of plant density on yield for either group of the cultivars.The average yield of Ohio cultivars was higher than that of Liaoning cultivars,and there was no significant interaction between plant density and cultivar for all the assessed traits.The plant height of Liaoning cultivars was significantly higher than that of Ohio cultivars,and there was a significant effect of plant density on plant height.The average branch number of Ohio cultivars was larger than that of Liaoning cultivars;higher plant density reduced the branch number per plant greatly.Plant density had a signifi-cant effect on the node number and internode length,Liaoning cultivars generally had longer internode length.Plant density had a significant effect on seed yield:stem ratio,as the plant density increased the seed yield:stem ratio decreased for both groups of cultivars.However,100-seed weight was not affected by plant density.
