A mixture of controlled-release urea and normal urea(CRUNU)is an efficient nitrogen(N)fertilizer type,but little is known about its effects on stem lodging resistance,grain yield,and yield stability of wheat.In this s...A mixture of controlled-release urea and normal urea(CRUNU)is an efficient nitrogen(N)fertilizer type,but little is known about its effects on stem lodging resistance,grain yield,and yield stability of wheat.In this study,a 4-year field experiment(from 2017 to 2021)was conducted to analyze the effects of N fertilizer types(CRUNU and normal urea(NU))and application rates(low level(L),135 kg ha^(–1);medium level(M),180 kg ha^(–1);high level(H),225 kg ha^(–1))on population lodging resistance,basal internode strength,lignin content and synthetase activity,stem lodging resistance,grain yield,and yield stability of wheat.Our results showed that the two N fertilizer types had the highest lodging rate under high N application rates,and the M-CRUNU treatment showed the lowest lodging rate.Compared with NU,CRUNU improved the wheat population lodging resistance under the three N application rates,mainly related to improving wheat population characteristics and breaking the strength of the second basal internode.Correlation analysis showed that the breaking strength of the second basal internode was related to the physical characteristics,chemical components,and micro-structure of the internode.Compared with NU,CRUNU significantly increased wheat grain yield by 4.47,14.62,and 3.12%under low,medium,and high N application rates,respectively.In addition,CRUNU showed no significant difference in grain yield under medium and high N application rates,but it presented the highest yield stability under the medium N application rate.In summary,CRUNU,combined with the medium N application rate,is an efficient agronomic management strategy for wheat production.展开更多
Rice yield stability is a breeding goal,particularly for short-growth duration rice,but its underlying mechanisms remain unclear.In an attempt to identify the relationship between yield stability and source–sink char...Rice yield stability is a breeding goal,particularly for short-growth duration rice,but its underlying mechanisms remain unclear.In an attempt to identify the relationship between yield stability and source–sink characteristics in short-growth duration rice,a field experiment was conducted at three sites(Yueyang,Liuyang,and Hengyang)in 2021 and 2022.This study compared yield,yield components,source–sink characteristics,and their stability between two stable-yielding short-growth duration rice cultivars,Zhongzao 39(Z-39)and Lingliangyou 268(L-268),and two unstable-yielding short-growth duration rice cultivars,Zhongjiazao 17(Z-17)and Zhuliangyou 819(Z-819).The stability of agronomic parameters was represented by the coefficient of variation(CV).The respective CVs of yield in Z-17,Z-819,Z-39,and L-268 were 10.2%,10.1%,4.5%,and 5.7%in 2021 and 19.7%,15.0%,5.4%,and 6.5%in 2022.The respective CVs of grain weight were 6.3%,5.7%,3.4%,and 4.5%in Z-17,Z-819,Z-39,and L-268 in 2021,and 8.1%,6.3%,1.5%,and 0.8%in 2022.The mean source capacity per spikelet and pre-heading non-structural carbohydrate reserves per spikelet(NSC_(pre))were 7%–43%and7%–72%lower in Z-819 and Z-17than in L-268 and Z-39 in 2021 and 2022.The mean quantum yield of photosystem II photochemistry of leaf,leaf area index,and specific leaf weight of L-268 and Z-39 were higher than those of Z-819 and Z-17 at the heading stage.This study suggests that high NSC_(pre),caused by great leaf traits before heading,increases source capacity per spikelet and its stability,thereby increasing the stability of grain weight and yield.Increasing NSC_(pre)is critical for achieving grain weight and yield stability in short-growth duration rice.展开更多
[Objective] The aim was to analyze yield stability of attar No.8, which is direct sowing and early-maturing. [Method] Analysis was made on yielding ability, stability and adaptability of attar No.8 in Yunnan Province ...[Objective] The aim was to analyze yield stability of attar No.8, which is direct sowing and early-maturing. [Method] Analysis was made on yielding ability, stability and adaptability of attar No.8 in Yunnan Province during 2006-2009 with DPS software and stability assessment was conducted on yield and major economic characters of the variety in different periods and experimental plots. [Result] Average yield of attar No.8 during three years in 24 plots achieved 3 379.17 kg/hm2; it grew tightly and is featured with early matureness. In addition, grain density, pod number and annul production differed little in different years and the variety in eight ecological conditions all showed high production potential, yielding ability and stability, which proved that attar No.8 is suitable to be grown in Yunnan and southern early-maturing areas in China. [Conclusion] The research provided references for selection and breeding of rapeseeds＇ variety which enjoys high and stable yield.展开更多
To provide a scientific basis for sustainable land management, a 20-year fertility experiment was conducted in Changwu County, Shaanxi Province, China to investigate the effects of long-term application of chemical fe...To provide a scientific basis for sustainable land management, a 20-year fertility experiment was conducted in Changwu County, Shaanxi Province, China to investigate the effects of long-term application of chemical fertilizers on wheat grain yield and yield stability on the Loess Plateau using regression and stability analysis. The experiment consisted of 17 fertilizer treatments, containing the combinations of different N and P levels, with three replications arranged in a randomized complete block design. Nitrogen fertilizer was applied as urea, and P was applied as calcium superphosphate. Fertilizer rates had a large effect on the response of wheat yield to fertilization. Phosphorus, combined with N, increased yield significantly （P 〈 0.01）. In the unfertilized control and the N or P sole application treatments, wheat yield had a declining trend although it was not statistically significant. Stability analysis combined with the trend analysis indicated that integrated use of fertilizer N and P was better than their sole application in increasing and sustaining the productivity of rainfed winter wheat.展开更多
The experiments were conducted for three consecutive years across 14 locations using 9 non-waxy proso millet genotypes and 16 locations using 7 waxy proso millet genotypes in China. The objectives of this study were t...The experiments were conducted for three consecutive years across 14 locations using 9 non-waxy proso millet genotypes and 16 locations using 7 waxy proso millet genotypes in China. The objectives of this study were to analyze yield stability and adaptability of proso millets and to evaluate the discrimination and representativeness of locations by analysis of vari- ance （ANOVA） and genotype and genotype by environment interaction （GGE） biplot methods. Grain yields of proso millet genotypes were significantly influenced by environment （E）, genotype （G） and their interaction （GxE） （P〈0.1%）. GxE inter- action effect was six times higher than G effect in non-waxy group and seven times in waxy group. N04-339 in non-waxy and Neimi 6 （NM6） in waxy showed higher grain yields and stability compared with other genotypes. Also, Neimi 9 （NM9, a non-waxy cultivar） and 90322-2-33 （a waxy cultivar） showed higher adaptability in 7 and in 11 locations, respectively. For non-waxy, Dalat, Inner Mongolia （E2） and Wuzhai, Shanxi （E5） were the best sites among all the locations for maximizing the variance among candidate cultivars, and Yanchi, Ningxia （El0） had the best representativeness. Wuzhai, Shanxi （e9） and Yanchi, Ningxia （e14） were the best representative locations, and Baicheng, Jilin （e2） was better discriminating location than others for waxy genotypes. Based on our results, El0 and e14 have enhanced efficiency and accuracy for non-waxy genotypes and waxy genotypes selection, respectively in national regional test of proso millet varieties.展开更多
Identification and deployment of high-yielding and stress-tolerant maize hybrids adapted to stress-prone agro-ecologies is important for improving the food security and livelihoods of smallholder farmers in eastern Af...Identification and deployment of high-yielding and stress-tolerant maize hybrids adapted to stress-prone agro-ecologies is important for improving the food security and livelihoods of smallholder farmers in eastern Africa.The objectives of this study were to(i)assess the performance of maize hybrids under well-watered and drought stress conditions;(ii)evaluate grain yield stability of 65 intermediate-maturing and 55 early-maturing hybrids in 24 well-watered locations and seven drought stress locations;and(iii)identify representative and/or discriminative testing locations for increasing genetic gains for the target traits.There were significant differences for grain yield among early-and intermediatematuring hybrids tested under well-watered and drought stress environments.Among the early-maturing hybrids,the top 10 hybrids produced 46.8%–73.9%and 31.2%–42.1%higher mean grain yields than the best commercial check under drought and well-watered conditions,respectively.Among the intermediate-maturing hybrids,the top 10 hybrids produced 25.2%–47.7%and 8.5%–13.5%higher grain yield than commercial checks under drought stress and well-watered conditions,respectively,suggesting improvement in the levels of drought tolerance in both early-and intermediate-maturing hybrids.GGE biplot analysis and a bi-segmented regression linear method identified specific early-maturing and intermediate-maturing hybrids that performed well under both well-watered and drought stress conditions.These hybrids could be recommended for commercial production in eastern Africa.Kakamega in Kenya was found to be the most representative and highly discriminating site among well-watered testing locations,while Kabuku in Tanzania was the least representative of test locations.For testing under drought stress conditions,Kiboko in Kenya was identified as the most representative location.This information could be useful for allocating resources and streamlining CIMMYT maize hybrid testing in eastern Africa.展开更多
[Objective] This study was conducted to select new hybrids with good ex- tension prospect, and to comprehensive assess various varieties and combinations from yielding ability, yield stability and adaptability. [Metho...[Objective] This study was conducted to select new hybrids with good ex- tension prospect, and to comprehensive assess various varieties and combinations from yielding ability, yield stability and adaptability. [Method] The yielding ability and yield stability of 5 varieties and 2 pioneer combinations in 5 test locations in Jiang- su Province in 2013-2015 were analyzed comprehensively. [Result] The environment effects and genotype x environment interaction effects of various tested varieties differed very significantly. It could be seen from various test locations that Mingyu 1301 and Sushi 51417 had very good yielding ability and yield stability, and were comprehensively assessed to be very good, Suyu 41 had very good yield stability and better yielding ability, and was comprehensively assessed to be good, while Suyu 29 and Suyu 39 showed instable yields in various locations and were greatly affected by environment, and thus should be planted in carefully-selected areas in extension. [Conclusion] This study provides theoretical foundation for breeding and extension of new varieties.展开更多
Thirteen promising clones from population B3C2 potato genotypes （bred for quantitative resistance to late blight） obtained from the International Potato Center and three control cultivars were evaluated for four pla...Thirteen promising clones from population B3C2 potato genotypes （bred for quantitative resistance to late blight） obtained from the International Potato Center and three control cultivars were evaluated for four planting dates within two cropping seasons at Kalengyere Research Station in Southwestern Uganda in order to determine performance and yield stability. The analysis of variance of the relative area under disease progress curve （rAUDPC） revealed significant difference （P 〈 0.001） among genotype x planting date interaction, and significant difference （P 〈 0.001） among genotypes x fungicide treatments x planting date interaction. The analysis of variance （ANOVA） of yield revealed also significant difference among genotypes x planting date interaction and significant difference （P 〈 0.05） among genotypes x fungicide treatments x planting date interaction, showing the variable response of genotypes and the need for stability analysis. The additive main effects and multiplicative interactive （AMMI） statistical model showed that the most stable and high yielding genotypes were 396038.107, 396026.103 and 393280.82. The cultivars Victoria, Nakpot 5 and Cruza recorded low yields （below the average）, but Nakpot 5 was generally more variable, and is therefore highly adaptable to some environments.展开更多
Background:The performance of oat genotypes differs across environments due to variations in biotic and abiotic factors.Thus,evaluation of oat genotypes across diverse environments is very important to identify superi...Background:The performance of oat genotypes differs across environments due to variations in biotic and abiotic factors.Thus,evaluation of oat genotypes across diverse environments is very important to identify superior and stable genotypes for yield improvement.Methods:The study aimed to assess the interaction(genotype-by-environment interaction;GEI)effect and determine the stability of grain yield in oat(Avena sativa L.)genotypes in Ethiopia using parametric and nonparametric stability statistics.Twenty-four oat genotypes were evaluated in nine environments using a randomized complete block design replicated three times.Results:The pooled analysis of the variance of grain yield showed significant variations among genotypes,environments,and their interaction effects.Significant GEI revealed the rank order change of genotypes across environments.The environment main effect captured 44.62%of the total grain yield variance,while genotype and GEI effects explained 28.84%and 26.54%of the total grain yield variance,respectively.The grain yield stability was assessed based on 12 parametric and two nonparametric stability statistics.The results indicated that genotypes with superior grain yield-showed stable performance on the basis of the stability parameters of the genotypic superiority index(P_(i)),the Perkins and Jinks adjusted linear regression coefficient(B_(i)),and the yield stability index(YSI),indicating that selection using these stability parameters would be efficient for grain yield enhancement in oat genotypes.Spearman's rank correlation coefficients also showed that the stability parameters of P_(i),B_(i),and YSI had a significant positive association with grain yield.However,grain yield had an inverse correlation with the stability parameters of standard deviation,deviation from regression (S_(di)^(2)),the Hernandez desirability index(D_(ji)),Wricke ecovalence(W_(i)),the Shukla stability variance(σ_(i)^(2)),the AMMI stability value(ASV),and environmental variance (S_(i)^((2))),indicating that oat genotype selection using these stability parameters would not be efficient for yield enhancement because these stability parameters favor low-yielding genotypes more,compared to high-yielding ones.Conclusions:Therefore,G5,G8,G11,G12,G14,G16,G17,G19,and G22 genotypes were adaptable in all nine environments based on stability parameters of Pi,Bi,and YSI,and selection of these superior genotypes would improve grain yield in oat genotypes.However,the validity of this result should be confirmed by repeating the experiment in the same environments over two or more years.展开更多
China＇s Super Hybrid Rice Breeding Program has made significant progress over the past two decades. In this paper, we reviewed our studies on the yield potential and stability in super hybrid rice and discussed the s...China＇s Super Hybrid Rice Breeding Program has made significant progress over the past two decades. In this paper, we reviewed our studies on the yield potential and stability in super hybrid rice and discussed the strategies for super hybrid rice production. The results of our studies show that rice yield potential has been increased by 12% in super hybrid cultivars as compared with ordinary hybrid and inbred cultivars. The higher grain yields in super hybrid rice cultivars are attributed to larger panicle size coupled with higher biomass production or higher harvest index. However, grain yields in super hybrid rice cultivars vary widely among locations depending on soil and climatic factors. Therefore, it is important to tailor target yield to local conditions in super hybrid rice production. The target yield for super hybrid rice production can be determined by the average yield method or the regression model method. Improving soil quality is critical to achieving the target yield in super hybrid rice production. Favorable crop rotations such as rice-oilseed rape and novel soil management practices, such as biochar addition, are effective approaches to improve soil quality. It is needed to develop simplified cultivation tech- nologies for super hybrid rice to meet the changes in socioeconomic environments during the period of transition. There are such technologies as no-tillage direct seeding and mechanized transplanting at high hill density with single seedling per hill.展开更多
The planting of upland rice is one cropping option in area with limited water availability and low soil fertility in North and Northeast Thailand. The varietal selection was determined by grain yield potential, wide a...The planting of upland rice is one cropping option in area with limited water availability and low soil fertility in North and Northeast Thailand. The varietal selection was determined by grain yield potential, wide adaptation, and good stability. This study was aimed at evaluation of indigenous upland rice germplasm for yield and yield stability in multi-locations. Thirty-six upland rice genotypes collected from six provinces of the North and Northeast Thailand and one check variety （Sewmaejan） were assessed under five locations in the rainy seasons of 2009 and 2010. The experiment was laid out in a randomized complete block design with three replications. The genotype grain yield was highly affected by location （59.90%）, followed by genotypes （G）xlocation （L） interaction （12.80%） and genotype （6.79%）. The most suitable location for the genotype eval- uation was L3 （Khon Kaen-KKU 10） which associated with stability of grain yield for all genotypes. Furthermore, biplot and regression analysis indicated that genotype numbers 6 （Jaowmong 1）, 10 （Neawmong 1）, 18 （Neawdum 1）, 19 （Leamna）, 20 （Prayaleamkang）, 32 （Kunwang 2）, and 33 （Kunwang 3） showed great yield stability over five locations. The genotypes will be applicant for upland rice production area and parental base in breeding program.展开更多
Rapeseed variety needs to be tested by regional trial in multiple sites for many years before being applied in market in China.Performants of rapeseed were affected by the interaction of sites and varieties.Evaluation...Rapeseed variety needs to be tested by regional trial in multiple sites for many years before being applied in market in China.Performants of rapeseed were affected by the interaction of sites and varieties.Evaluation of regional trials is very important for guiding rapeseed breeding.GGE(genotype main effects and genotypeenvironment interaction)biplot was used to evaluate yield,stability,adaptability,representativeness and discrimination of national winter rapeseed trials in the upper reaches of Yangtze River in 2017-2018.Results showed that the main effects of genotype(G),environment(E)and genotypeenvironment interaction(GE)were significant(P<0.01)for yield.Among them,E accounted for 46.95%total variation on average,G and GE accounted for 19.34%and 33.71%respectively.Eight varieties were found with high-yield,excellent stability and adaptability,including‘Yiyou 29’,‘Xiwang 920’,‘Liyouza 108’,‘Nanyou 546’,‘Dadi 195’,‘Jiayou 1’,‘Huayouza 28’and‘Yuhua 2’.Test sites included Nanchong,Mianyang,Wanzhou,Shuangliu and Chengdu in Sichuan Province and Zunyi together with Guiyang in Guizhou Province were selected for their excellent representativeness and discrimination.These results would provide theoretical basis for rapeseed breeding.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
Abiotic stresses, such as drought, salt, extreme temperatures, and heavy metal pollution, are the main environmental factors that limit crop growth and yield. Sorghum, a C4 grass plant with high photosynthetic efficie...Abiotic stresses, such as drought, salt, extreme temperatures, and heavy metal pollution, are the main environmental factors that limit crop growth and yield. Sorghum, a C4 grass plant with high photosynthetic efficiency, can grow in adverse environmental conditions due to its excellent stress resistance characteristics. Therefore, unraveling the stress-resistance mechanism of sorghum could provide a theoretical basis for developing and cultivating various stress-resistant crops. This understanding could also help to create a conducive environment for using marginal soil in agriculture and ensuring food security. In this review, we discuss the adaptation mechanisms of sorghum under drought, salinity, temperature, and soil heavy metal stresses, the specific response to stress, the screening of sorghum-resistant germplasm, and the identification and functional analysis of the relevant genes and quantitative trait loci(QTL). In addition, we discuss the application potential of different stress-tolerant sorghum germplasms reported to date and emphasize the feasibility and potential use in developing and promoting highly stress-tolerant sorghum in marginal soil.展开更多
We investigated the soil microbiologic characteristics, and the yield and sustainable production of winter wheat, by conducting a long-term fertilization experiment. A single application of N, P and K （NPK） fertiliz...We investigated the soil microbiologic characteristics, and the yield and sustainable production of winter wheat, by conducting a long-term fertilization experiment. A single application of N, P and K （NPK） fertilizer was taken as the control （CK） and three organic fertilization treatments were used： NPK fertilizer＋pig manure （T1）, NPK fertilizer＋straw return （T2）, NPK fertilizer＋pig manure＋straw return （T3）. The results showed that all three organic fertilization treatments （T1, T2 and T3） significantly increased both soil total N （STN） and soil organic carbon （SOC） from 2008 onwards. In 2016, the SOC content and soil C/N ratios for T1, T2 and T3 were significantly higher than those for CK. The three organic fertilization treatments increased soil microbial activity. In 2016, the activity of urease （sucrase） and the soil respiration rate （SRS） for T1, T2 and T3 were significantly higher than those under CK. The organic fertilization treatments also increased the content of soil microbial biomass carbon （SMBC） and microbial biomass nitrogen （SMBN）, the SMBC/SMBN ratio and the microbial quotient （qMB）. The yield for T1, T2 and T3 was significantly higher than that of CK, respectively. Over the nine years of the investigation, the average yield increased by 9.9, 13.2 and 17.4% for T1, T2 and T3, respectively, compared to the initial yield for each treatment, whereas the average yield of CK over the same period was reduced by 6.5%. T1, T2, and T3 lowered the coefficient of variation （CV） of wheat yield and increased the sustainable yield index （SYI）. Wheat grain yield was significantly positively correlated with each of the soil microbial properties （P〈0.01）. These results showed that the long-term application of combined organic and chemical fertilizers can stabilize crop yield and make it more sustainable by improving the properties of the soil.展开更多
AMMI analysis was performed to assess yield stability of twenty-five bread wheat （Triticum aestivum L.） genotypes grown in a 5 ×5 Lattice Square Design at seven sites under irrigation during 2009 season. AMMI A...AMMI analysis was performed to assess yield stability of twenty-five bread wheat （Triticum aestivum L.） genotypes grown in a 5 ×5 Lattice Square Design at seven sites under irrigation during 2009 season. AMMI ANOVA for grain yield indicated that genotypes, environments and G×E interaction were significantly different （P 〈 0.001）. Environments, genotypes and GxE accounted for 78.9, 4.6 and 16.4% of the treatment sum of squares, respectively. The proportion of environmental and G×E interaction variation for grain yield was larger than genotypes main effects. Genotype dendogram showed nine clusters with a yield range of 6,373.546 kg·ha-1 to 7,687.243 kg.hal. W1494/6/1, SC Sky and W2045/6/13 had high yields and exhibited negligible interactions with the environment. These were widely adapted and stable across high yielding sites. RARS （Normal）, ART （Normal） and ART （Deficit） were best yielding sites among eight environmental groups. ART （Deficit） had the best mean （9,764.479 kg·ha-1） followed by RARS （Normal） at 9,522.119 kg·ha-1 Chiredzi （Group 6） had the lowest mean yield （4,393.400 kg.hal）. Results show that high yields （〉 9,000 kg·ha-1） are achievable in high altitude areas of Zimbabwe （≥1,200 masl）. Dendograms were used to characterize both genotypes and environments and the AMMI model was used to select genotypes with specific or broad adaptation.展开更多
In this paper the stability problem of Bingham flowing down an inclinedplane is studied with respect to two dimensional disturbances, The critical Reynolodsnumber is given in the. case. of long wayes and the effect o...In this paper the stability problem of Bingham flowing down an inclinedplane is studied with respect to two dimensional disturbances, The critical Reynolodsnumber is given in the. case. of long wayes and the effect of yield stress on stability isanalysed.展开更多
Growing concerns for food security and the alleviation of hunger necessitate knowledge-based crop management technologies for sustainable crop production.In this study,13 winter bread wheat genotypes(old,relatively ol...Growing concerns for food security and the alleviation of hunger necessitate knowledge-based crop management technologies for sustainable crop production.In this study,13 winter bread wheat genotypes(old,relatively old,modern,and breeding lines)were evaluated under three different tillage systems,i.e.,conventional tillage(CT,full tillage with residue removed),reduced tillage(RT,chisel tillage with residue retained)and no-tillage(NT,no-tillage with residue retained on the soil surface)in farmer’s fields under rainfed conditions using strip-plot arrangements in a randomized complete block design with three replications in the west of Iran(Kamyaran and Hosseinabad locations)over two cropping seasons(2018–2019 and 2019–2020).The main objectives were to investigate the effects of tillage systems and growing conditions on the agronomic characteristics,grain yield and stability performance of rainfed winter bread wheat genotypes.Significant(P<0.01)genotype×tillage system interaction effects on grain yield and agronomic traits suggested that the genotypes responded differently to the different tillage systems.The number of grains per spike and plant height were positively(P<0.0)associated with grain yield under the NT system,so they may be considered as targeted traits for future wheat breeding.Using statistical models,the modern cultivars(“Sadra”and“Baran”)were identified as high yielding and showed yield stability across the different tillage systems.As per each tillage system,genotype“Sadra”followed by“Zargana-6//Dari 1-7 Sabalan”exhibited higher adaption to CT;while cultivars“Jam”and“Azar2”showed better performance under the RT system;and cultivars“Varan”and“Baran”tended to have better performance expression in the NT condition.The increased grain yields achieved in combination with lower costs and greater profits from conservation agriculture suggest that adapted cultivar and NT systems should be evaluated and promoted more widely to farmers in the west of Iran as an attractive package of crop management technologies.In conclusion,variations in the performance of genotypes and the significant genotype×tillage system interaction effects on grain yield and some agronomic traits assessed in this study suggest that the development and selection of cultivars adapted to the NT system should be considered and included in the strategies and objectives of winter wheat breeding programs for the temperate and cold dryland conditions of Iran.展开更多
基金the Key R&D Plan of Shaanxi Province Project,China(2023-YBNY-041)the Doctoral Graduates and Postdoctoral Researchers from Shanxi Province Come to Work to Reward Scientific Research Projects,China(SXBYKY2022119)the Key Laboratory Project of Shanxi Province,China(202001-4)。
文摘A mixture of controlled-release urea and normal urea(CRUNU)is an efficient nitrogen(N)fertilizer type,but little is known about its effects on stem lodging resistance,grain yield,and yield stability of wheat.In this study,a 4-year field experiment(from 2017 to 2021)was conducted to analyze the effects of N fertilizer types(CRUNU and normal urea(NU))and application rates(low level(L),135 kg ha^(–1);medium level(M),180 kg ha^(–1);high level(H),225 kg ha^(–1))on population lodging resistance,basal internode strength,lignin content and synthetase activity,stem lodging resistance,grain yield,and yield stability of wheat.Our results showed that the two N fertilizer types had the highest lodging rate under high N application rates,and the M-CRUNU treatment showed the lowest lodging rate.Compared with NU,CRUNU improved the wheat population lodging resistance under the three N application rates,mainly related to improving wheat population characteristics and breaking the strength of the second basal internode.Correlation analysis showed that the breaking strength of the second basal internode was related to the physical characteristics,chemical components,and micro-structure of the internode.Compared with NU,CRUNU significantly increased wheat grain yield by 4.47,14.62,and 3.12%under low,medium,and high N application rates,respectively.In addition,CRUNU showed no significant difference in grain yield under medium and high N application rates,but it presented the highest yield stability under the medium N application rate.In summary,CRUNU,combined with the medium N application rate,is an efficient agronomic management strategy for wheat production.
基金the National Natural Science Foundation of China(32001470)the Scientific Research Fund of Hunan Provincial Education Department(21B0184)The Science and Technology Innovation Program of Hunan province(2021RC3088).
文摘Rice yield stability is a breeding goal,particularly for short-growth duration rice,but its underlying mechanisms remain unclear.In an attempt to identify the relationship between yield stability and source–sink characteristics in short-growth duration rice,a field experiment was conducted at three sites(Yueyang,Liuyang,and Hengyang)in 2021 and 2022.This study compared yield,yield components,source–sink characteristics,and their stability between two stable-yielding short-growth duration rice cultivars,Zhongzao 39(Z-39)and Lingliangyou 268(L-268),and two unstable-yielding short-growth duration rice cultivars,Zhongjiazao 17(Z-17)and Zhuliangyou 819(Z-819).The stability of agronomic parameters was represented by the coefficient of variation(CV).The respective CVs of yield in Z-17,Z-819,Z-39,and L-268 were 10.2%,10.1%,4.5%,and 5.7%in 2021 and 19.7%,15.0%,5.4%,and 6.5%in 2022.The respective CVs of grain weight were 6.3%,5.7%,3.4%,and 4.5%in Z-17,Z-819,Z-39,and L-268 in 2021,and 8.1%,6.3%,1.5%,and 0.8%in 2022.The mean source capacity per spikelet and pre-heading non-structural carbohydrate reserves per spikelet(NSC_(pre))were 7%–43%and7%–72%lower in Z-819 and Z-17than in L-268 and Z-39 in 2021 and 2022.The mean quantum yield of photosystem II photochemistry of leaf,leaf area index,and specific leaf weight of L-268 and Z-39 were higher than those of Z-819 and Z-17 at the heading stage.This study suggests that high NSC_(pre),caused by great leaf traits before heading,increases source capacity per spikelet and its stability,thereby increasing the stability of grain weight and yield.Increasing NSC_(pre)is critical for achieving grain weight and yield stability in short-growth duration rice.
基金Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2010BAD01B08)Yunnan Programs for Science and Technology Development(2011BB010)+2 种基金Fund for Fostering Talents in Yunnan Province(2011CI062)National Program of Modern Industrial Technology System of Rapeseed(NYCYTX-00564)Program of Modern Industrial Technology System of Rapeseed in Yunnan Province~~
文摘[Objective] The aim was to analyze yield stability of attar No.8, which is direct sowing and early-maturing. [Method] Analysis was made on yielding ability, stability and adaptability of attar No.8 in Yunnan Province during 2006-2009 with DPS software and stability assessment was conducted on yield and major economic characters of the variety in different periods and experimental plots. [Result] Average yield of attar No.8 during three years in 24 plots achieved 3 379.17 kg/hm2; it grew tightly and is featured with early matureness. In addition, grain density, pod number and annul production differed little in different years and the variety in eight ecological conditions all showed high production potential, yielding ability and stability, which proved that attar No.8 is suitable to be grown in Yunnan and southern early-maturing areas in China. [Conclusion] The research provided references for selection and breeding of rapeseeds＇ variety which enjoys high and stable yield.
基金Project supported by the Agricultural Development Program of the Chinese Academy of Sciences (No. KSCX1-YWN1504)the West Light Foundation of the Chinese Academy of Sciences (No. 2005404)the National Natural Science Foundation of China (Nos. 50479065 and 40601041).
文摘To provide a scientific basis for sustainable land management, a 20-year fertility experiment was conducted in Changwu County, Shaanxi Province, China to investigate the effects of long-term application of chemical fertilizers on wheat grain yield and yield stability on the Loess Plateau using regression and stability analysis. The experiment consisted of 17 fertilizer treatments, containing the combinations of different N and P levels, with three replications arranged in a randomized complete block design. Nitrogen fertilizer was applied as urea, and P was applied as calcium superphosphate. Fertilizer rates had a large effect on the response of wheat yield to fertilization. Phosphorus, combined with N, increased yield significantly （P 〈 0.01）. In the unfertilized control and the N or P sole application treatments, wheat yield had a declining trend although it was not statistically significant. Stability analysis combined with the trend analysis indicated that integrated use of fertilizer N and P was better than their sole application in increasing and sustaining the productivity of rainfed winter wheat.
基金funded by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period (2014BAD07B03)the National Natural Science Foundation of China (31371529)+2 种基金the Postdoctoral Science Foundation of Heilongjiang Province, China (LBH-Z14177)the project of Education Department in Heilongjiang Province, China (12541599)the China Agricultural Research System (CARS07-13.5-A9)
文摘The experiments were conducted for three consecutive years across 14 locations using 9 non-waxy proso millet genotypes and 16 locations using 7 waxy proso millet genotypes in China. The objectives of this study were to analyze yield stability and adaptability of proso millets and to evaluate the discrimination and representativeness of locations by analysis of vari- ance （ANOVA） and genotype and genotype by environment interaction （GGE） biplot methods. Grain yields of proso millet genotypes were significantly influenced by environment （E）, genotype （G） and their interaction （GxE） （P〈0.1%）. GxE inter- action effect was six times higher than G effect in non-waxy group and seven times in waxy group. N04-339 in non-waxy and Neimi 6 （NM6） in waxy showed higher grain yields and stability compared with other genotypes. Also, Neimi 9 （NM9, a non-waxy cultivar） and 90322-2-33 （a waxy cultivar） showed higher adaptability in 7 and in 11 locations, respectively. For non-waxy, Dalat, Inner Mongolia （E2） and Wuzhai, Shanxi （E5） were the best sites among all the locations for maximizing the variance among candidate cultivars, and Yanchi, Ningxia （El0） had the best representativeness. Wuzhai, Shanxi （e9） and Yanchi, Ningxia （e14） were the best representative locations, and Baicheng, Jilin （e2） was better discriminating location than others for waxy genotypes. Based on our results, El0 and e14 have enhanced efficiency and accuracy for non-waxy genotypes and waxy genotypes selection, respectively in national regional test of proso millet varieties.
基金supported by the Bill and Melinda Gates Foundationthe Howard G.Buffett Foundation+4 种基金the United States Agency for International Development(USAID)through the Water Efficient Maize for Africa(WEMA)projectthe Stress Tolerant Maize for Africa(STMA)projectthe CGIAR Research Program MAIZEThe CGIAR Research Program MAIZE receives W1&W2 support from the Governments of Australia,Belgium,Canada,China,France,India,Japan,the Republic of Korea,Mexico,the Netherlands,New Zealand,Norway,Sweden,Switzerland,United Kingdom,the United States,and the World BankBrazilian Coordination for the Improvement of Higher Education Personnel(CAPES)for a scholarship supporting Wender Rezende
文摘Identification and deployment of high-yielding and stress-tolerant maize hybrids adapted to stress-prone agro-ecologies is important for improving the food security and livelihoods of smallholder farmers in eastern Africa.The objectives of this study were to(i)assess the performance of maize hybrids under well-watered and drought stress conditions;(ii)evaluate grain yield stability of 65 intermediate-maturing and 55 early-maturing hybrids in 24 well-watered locations and seven drought stress locations;and(iii)identify representative and/or discriminative testing locations for increasing genetic gains for the target traits.There were significant differences for grain yield among early-and intermediatematuring hybrids tested under well-watered and drought stress environments.Among the early-maturing hybrids,the top 10 hybrids produced 46.8%–73.9%and 31.2%–42.1%higher mean grain yields than the best commercial check under drought and well-watered conditions,respectively.Among the intermediate-maturing hybrids,the top 10 hybrids produced 25.2%–47.7%and 8.5%–13.5%higher grain yield than commercial checks under drought stress and well-watered conditions,respectively,suggesting improvement in the levels of drought tolerance in both early-and intermediate-maturing hybrids.GGE biplot analysis and a bi-segmented regression linear method identified specific early-maturing and intermediate-maturing hybrids that performed well under both well-watered and drought stress conditions.These hybrids could be recommended for commercial production in eastern Africa.Kakamega in Kenya was found to be the most representative and highly discriminating site among well-watered testing locations,while Kabuku in Tanzania was the least representative of test locations.For testing under drought stress conditions,Kiboko in Kenya was identified as the most representative location.This information could be useful for allocating resources and streamlining CIMMYT maize hybrid testing in eastern Africa.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-02-50)Jiangsu Agricultural Science and Technology Independent Innovation Fund(CX(14)2006)Jiangsu Science and Technology Support Program(BE2013434)~~
文摘[Objective] This study was conducted to select new hybrids with good ex- tension prospect, and to comprehensive assess various varieties and combinations from yielding ability, yield stability and adaptability. [Method] The yielding ability and yield stability of 5 varieties and 2 pioneer combinations in 5 test locations in Jiang- su Province in 2013-2015 were analyzed comprehensively. [Result] The environment effects and genotype x environment interaction effects of various tested varieties differed very significantly. It could be seen from various test locations that Mingyu 1301 and Sushi 51417 had very good yielding ability and yield stability, and were comprehensively assessed to be very good, Suyu 41 had very good yield stability and better yielding ability, and was comprehensively assessed to be good, while Suyu 29 and Suyu 39 showed instable yields in various locations and were greatly affected by environment, and thus should be planted in carefully-selected areas in extension. [Conclusion] This study provides theoretical foundation for breeding and extension of new varieties.
文摘Thirteen promising clones from population B3C2 potato genotypes （bred for quantitative resistance to late blight） obtained from the International Potato Center and three control cultivars were evaluated for four planting dates within two cropping seasons at Kalengyere Research Station in Southwestern Uganda in order to determine performance and yield stability. The analysis of variance of the relative area under disease progress curve （rAUDPC） revealed significant difference （P 〈 0.001） among genotype x planting date interaction, and significant difference （P 〈 0.001） among genotypes x fungicide treatments x planting date interaction. The analysis of variance （ANOVA） of yield revealed also significant difference among genotypes x planting date interaction and significant difference （P 〈 0.05） among genotypes x fungicide treatments x planting date interaction, showing the variable response of genotypes and the need for stability analysis. The additive main effects and multiplicative interactive （AMMI） statistical model showed that the most stable and high yielding genotypes were 396038.107, 396026.103 and 393280.82. The cultivars Victoria, Nakpot 5 and Cruza recorded low yields （below the average）, but Nakpot 5 was generally more variable, and is therefore highly adaptable to some environments.
基金financed by the Ethiopian Institute of Agricultural Research(EIAR)and the Bill and Melinda Gates Foundation through the Equip-Strengthening Smallholder Livestock Systems for the Future Project(sub-award agreement no.UFDSP00012156 between the University of Florida(UF)and EIAR)。
文摘Background:The performance of oat genotypes differs across environments due to variations in biotic and abiotic factors.Thus,evaluation of oat genotypes across diverse environments is very important to identify superior and stable genotypes for yield improvement.Methods:The study aimed to assess the interaction(genotype-by-environment interaction;GEI)effect and determine the stability of grain yield in oat(Avena sativa L.)genotypes in Ethiopia using parametric and nonparametric stability statistics.Twenty-four oat genotypes were evaluated in nine environments using a randomized complete block design replicated three times.Results:The pooled analysis of the variance of grain yield showed significant variations among genotypes,environments,and their interaction effects.Significant GEI revealed the rank order change of genotypes across environments.The environment main effect captured 44.62%of the total grain yield variance,while genotype and GEI effects explained 28.84%and 26.54%of the total grain yield variance,respectively.The grain yield stability was assessed based on 12 parametric and two nonparametric stability statistics.The results indicated that genotypes with superior grain yield-showed stable performance on the basis of the stability parameters of the genotypic superiority index(P_(i)),the Perkins and Jinks adjusted linear regression coefficient(B_(i)),and the yield stability index(YSI),indicating that selection using these stability parameters would be efficient for grain yield enhancement in oat genotypes.Spearman's rank correlation coefficients also showed that the stability parameters of P_(i),B_(i),and YSI had a significant positive association with grain yield.However,grain yield had an inverse correlation with the stability parameters of standard deviation,deviation from regression (S_(di)^(2)),the Hernandez desirability index(D_(ji)),Wricke ecovalence(W_(i)),the Shukla stability variance(σ_(i)^(2)),the AMMI stability value(ASV),and environmental variance (S_(i)^((2))),indicating that oat genotype selection using these stability parameters would not be efficient for yield enhancement because these stability parameters favor low-yielding genotypes more,compared to high-yielding ones.Conclusions:Therefore,G5,G8,G11,G12,G14,G16,G17,G19,and G22 genotypes were adaptable in all nine environments based on stability parameters of Pi,Bi,and YSI,and selection of these superior genotypes would improve grain yield in oat genotypes.However,the validity of this result should be confirmed by repeating the experiment in the same environments over two or more years.
基金supported by the Earmarked Fund for China Agriculture Research System(CARS-01)
文摘China＇s Super Hybrid Rice Breeding Program has made significant progress over the past two decades. In this paper, we reviewed our studies on the yield potential and stability in super hybrid rice and discussed the strategies for super hybrid rice production. The results of our studies show that rice yield potential has been increased by 12% in super hybrid cultivars as compared with ordinary hybrid and inbred cultivars. The higher grain yields in super hybrid rice cultivars are attributed to larger panicle size coupled with higher biomass production or higher harvest index. However, grain yields in super hybrid rice cultivars vary widely among locations depending on soil and climatic factors. Therefore, it is important to tailor target yield to local conditions in super hybrid rice production. The target yield for super hybrid rice production can be determined by the average yield method or the regression model method. Improving soil quality is critical to achieving the target yield in super hybrid rice production. Favorable crop rotations such as rice-oilseed rape and novel soil management practices, such as biochar addition, are effective approaches to improve soil quality. It is needed to develop simplified cultivation tech- nologies for super hybrid rice to meet the changes in socioeconomic environments during the period of transition. There are such technologies as no-tillage direct seeding and mechanized transplanting at high hill density with single seedling per hill.
基金supported by the Plant Breeding Research Centre for Sustainable Agriculture and Research Center of Agricultural Biotechnology for Sustainable Economy,Khon Kaen University,Thailandthe Faculty of Agriculture at Khon Kaen University for providing financial support for manuscript preparation activities
文摘The planting of upland rice is one cropping option in area with limited water availability and low soil fertility in North and Northeast Thailand. The varietal selection was determined by grain yield potential, wide adaptation, and good stability. This study was aimed at evaluation of indigenous upland rice germplasm for yield and yield stability in multi-locations. Thirty-six upland rice genotypes collected from six provinces of the North and Northeast Thailand and one check variety （Sewmaejan） were assessed under five locations in the rainy seasons of 2009 and 2010. The experiment was laid out in a randomized complete block design with three replications. The genotype grain yield was highly affected by location （59.90%）, followed by genotypes （G）xlocation （L） interaction （12.80%） and genotype （6.79%）. The most suitable location for the genotype eval- uation was L3 （Khon Kaen-KKU 10） which associated with stability of grain yield for all genotypes. Furthermore, biplot and regression analysis indicated that genotype numbers 6 （Jaowmong 1）, 10 （Neawmong 1）, 18 （Neawdum 1）, 19 （Leamna）, 20 （Prayaleamkang）, 32 （Kunwang 2）, and 33 （Kunwang 3） showed great yield stability over five locations. The genotypes will be applicant for upland rice production area and parental base in breeding program.
基金supported by the National Regional Trial of Crop Varieties,Scientific and Technical Innovation Project of Chinese Academy of Agricultural Sciences.
文摘Rapeseed variety needs to be tested by regional trial in multiple sites for many years before being applied in market in China.Performants of rapeseed were affected by the interaction of sites and varieties.Evaluation of regional trials is very important for guiding rapeseed breeding.GGE(genotype main effects and genotypeenvironment interaction)biplot was used to evaluate yield,stability,adaptability,representativeness and discrimination of national winter rapeseed trials in the upper reaches of Yangtze River in 2017-2018.Results showed that the main effects of genotype(G),environment(E)and genotypeenvironment interaction(GE)were significant(P<0.01)for yield.Among them,E accounted for 46.95%total variation on average,G and GE accounted for 19.34%and 33.71%respectively.Eight varieties were found with high-yield,excellent stability and adaptability,including‘Yiyou 29’,‘Xiwang 920’,‘Liyouza 108’,‘Nanyou 546’,‘Dadi 195’,‘Jiayou 1’,‘Huayouza 28’and‘Yuhua 2’.Test sites included Nanchong,Mianyang,Wanzhou,Shuangliu and Chengdu in Sichuan Province and Zunyi together with Guiyang in Guizhou Province were selected for their excellent representativeness and discrimination.These results would provide theoretical basis for rapeseed breeding.
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financial support from the National Key R&D Program of China(2022YFD1201702)the National Natural Science Foundation of China(32272040)the Agricultural Fine Seed Project of Shandong Province,China(2021LZGC006)。
文摘Abiotic stresses, such as drought, salt, extreme temperatures, and heavy metal pollution, are the main environmental factors that limit crop growth and yield. Sorghum, a C4 grass plant with high photosynthetic efficiency, can grow in adverse environmental conditions due to its excellent stress resistance characteristics. Therefore, unraveling the stress-resistance mechanism of sorghum could provide a theoretical basis for developing and cultivating various stress-resistant crops. This understanding could also help to create a conducive environment for using marginal soil in agriculture and ensuring food security. In this review, we discuss the adaptation mechanisms of sorghum under drought, salinity, temperature, and soil heavy metal stresses, the specific response to stress, the screening of sorghum-resistant germplasm, and the identification and functional analysis of the relevant genes and quantitative trait loci(QTL). In addition, we discuss the application potential of different stress-tolerant sorghum germplasms reported to date and emphasize the feasibility and potential use in developing and promoting highly stress-tolerant sorghum in marginal soil.
基金financial support from the National Key Research and Development Program of China (2017YFD0301106,2016YFD0300203-3)the Science and Technology Innovation Team Support Plan of Universities in Hennan Province,China (18IRTSTHN008)
文摘We investigated the soil microbiologic characteristics, and the yield and sustainable production of winter wheat, by conducting a long-term fertilization experiment. A single application of N, P and K （NPK） fertilizer was taken as the control （CK） and three organic fertilization treatments were used： NPK fertilizer＋pig manure （T1）, NPK fertilizer＋straw return （T2）, NPK fertilizer＋pig manure＋straw return （T3）. The results showed that all three organic fertilization treatments （T1, T2 and T3） significantly increased both soil total N （STN） and soil organic carbon （SOC） from 2008 onwards. In 2016, the SOC content and soil C/N ratios for T1, T2 and T3 were significantly higher than those for CK. The three organic fertilization treatments increased soil microbial activity. In 2016, the activity of urease （sucrase） and the soil respiration rate （SRS） for T1, T2 and T3 were significantly higher than those under CK. The organic fertilization treatments also increased the content of soil microbial biomass carbon （SMBC） and microbial biomass nitrogen （SMBN）, the SMBC/SMBN ratio and the microbial quotient （qMB）. The yield for T1, T2 and T3 was significantly higher than that of CK, respectively. Over the nine years of the investigation, the average yield increased by 9.9, 13.2 and 17.4% for T1, T2 and T3, respectively, compared to the initial yield for each treatment, whereas the average yield of CK over the same period was reduced by 6.5%. T1, T2, and T3 lowered the coefficient of variation （CV） of wheat yield and increased the sustainable yield index （SYI）. Wheat grain yield was significantly positively correlated with each of the soil microbial properties （P〈0.01）. These results showed that the long-term application of combined organic and chemical fertilizers can stabilize crop yield and make it more sustainable by improving the properties of the soil.
文摘AMMI analysis was performed to assess yield stability of twenty-five bread wheat （Triticum aestivum L.） genotypes grown in a 5 ×5 Lattice Square Design at seven sites under irrigation during 2009 season. AMMI ANOVA for grain yield indicated that genotypes, environments and G×E interaction were significantly different （P 〈 0.001）. Environments, genotypes and GxE accounted for 78.9, 4.6 and 16.4% of the treatment sum of squares, respectively. The proportion of environmental and G×E interaction variation for grain yield was larger than genotypes main effects. Genotype dendogram showed nine clusters with a yield range of 6,373.546 kg·ha-1 to 7,687.243 kg.hal. W1494/6/1, SC Sky and W2045/6/13 had high yields and exhibited negligible interactions with the environment. These were widely adapted and stable across high yielding sites. RARS （Normal）, ART （Normal） and ART （Deficit） were best yielding sites among eight environmental groups. ART （Deficit） had the best mean （9,764.479 kg·ha-1） followed by RARS （Normal） at 9,522.119 kg·ha-1 Chiredzi （Group 6） had the lowest mean yield （4,393.400 kg.hal）. Results show that high yields （〉 9,000 kg·ha-1） are achievable in high altitude areas of Zimbabwe （≥1,200 masl）. Dendograms were used to characterize both genotypes and environments and the AMMI model was used to select genotypes with specific or broad adaptation.
文摘In this paper the stability problem of Bingham flowing down an inclinedplane is studied with respect to two dimensional disturbances, The critical Reynolodsnumber is given in the. case. of long wayes and the effect of yield stress on stability isanalysed.
基金supported by the IRAN-ICARDA Enhanced Food Security Project,Iran(24-53-15-064-971144)。
文摘Growing concerns for food security and the alleviation of hunger necessitate knowledge-based crop management technologies for sustainable crop production.In this study,13 winter bread wheat genotypes(old,relatively old,modern,and breeding lines)were evaluated under three different tillage systems,i.e.,conventional tillage(CT,full tillage with residue removed),reduced tillage(RT,chisel tillage with residue retained)and no-tillage(NT,no-tillage with residue retained on the soil surface)in farmer’s fields under rainfed conditions using strip-plot arrangements in a randomized complete block design with three replications in the west of Iran(Kamyaran and Hosseinabad locations)over two cropping seasons(2018–2019 and 2019–2020).The main objectives were to investigate the effects of tillage systems and growing conditions on the agronomic characteristics,grain yield and stability performance of rainfed winter bread wheat genotypes.Significant(P<0.01)genotype×tillage system interaction effects on grain yield and agronomic traits suggested that the genotypes responded differently to the different tillage systems.The number of grains per spike and plant height were positively(P<0.0)associated with grain yield under the NT system,so they may be considered as targeted traits for future wheat breeding.Using statistical models,the modern cultivars(“Sadra”and“Baran”)were identified as high yielding and showed yield stability across the different tillage systems.As per each tillage system,genotype“Sadra”followed by“Zargana-6//Dari 1-7 Sabalan”exhibited higher adaption to CT;while cultivars“Jam”and“Azar2”showed better performance under the RT system;and cultivars“Varan”and“Baran”tended to have better performance expression in the NT condition.The increased grain yields achieved in combination with lower costs and greater profits from conservation agriculture suggest that adapted cultivar and NT systems should be evaluated and promoted more widely to farmers in the west of Iran as an attractive package of crop management technologies.In conclusion,variations in the performance of genotypes and the significant genotype×tillage system interaction effects on grain yield and some agronomic traits assessed in this study suggest that the development and selection of cultivars adapted to the NT system should be considered and included in the strategies and objectives of winter wheat breeding programs for the temperate and cold dryland conditions of Iran.
