Pub Date : 2022-11-16DOI: 10.1017/s0014479722000400
T. Erkossa, F. Laekemariam, W. Abera, L. Tamene
{"title":"Evolution of soil fertility research and development in Ethiopia: From reconnaissance to data-mining approaches – CORRIGENDUM","authors":"T. Erkossa, F. Laekemariam, W. Abera, L. Tamene","doi":"10.1017/s0014479722000400","DOIUrl":"https://doi.org/10.1017/s0014479722000400","url":null,"abstract":"","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57071858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-16DOI: 10.1017/s0014479722000382
G. Sileshi
{"title":"Dose-response models to guide site-specific nutrient management and lessons for fertiliser trial design in sub-Saharan Africa – CORRIGENDUM","authors":"G. Sileshi","doi":"10.1017/s0014479722000382","DOIUrl":"https://doi.org/10.1017/s0014479722000382","url":null,"abstract":"","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45010352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-16DOI: 10.1017/S0014479722000436
J. Kihara, B. Gurmessa, L. Tamene, T. Amede, R. Sommer
{"title":"Understanding factors influencing wheat productivity in Ethiopian highlands – CORRIGENDUM","authors":"J. Kihara, B. Gurmessa, L. Tamene, T. Amede, R. Sommer","doi":"10.1017/S0014479722000436","DOIUrl":"https://doi.org/10.1017/S0014479722000436","url":null,"abstract":"","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43855163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-04DOI: 10.1017/S0014479722000308
N. Bagheri, Maryam Rahimi Jahangirlou, Mehryar Jaberi Aghdam
Abstract Timely estimation of silage maize protein provides an effective decision to adapt optimized strategies for nitrogen fertilizer management and also harvesting time for farmers. So, this research aimed to investigate whether using vegetative indices (VIs) derived from UAV remotely sensed multispectral (with 520–900 nm wavelengths) imagery and also Soil Plant Analysis Development (SPAD) greenness index can be used to detect the leaf protein concentration (LPC) of silage maize, as a function of various nitrogen rates (0, 50, 100, and 150% of recommended dosage). Results of principal component analysis (PCA) suggested that LPC was highly correlated with leaf greenness index in all developmental stages. In addition, LPC was highly correlated with most of the VIs investigated. A PCA clustering showed the meaningful pattern of N rates. Higher LPC values, VIs, and greenness index were more concentrated in the higher nitrogen (N100% and N150%) sectors. Nitrogen Reflectance Index (NRI) was identified as the most important VIs to monitor and predict LPC in the silage maize field, showing a strong polynomial relationship with LPC in both eight-leaf collar (V8) (R 2 = 0.81, p ≤ 0.01) and tasseling (VT) (R 2 = 0.98, p ≤ 0.001) stages. In addition, among VIs, the Normalized Difference Vegetation Index (NDVI) demonstrated a significant linear regression relationship with LPC (R 2 = 0.80, p ≤ 0.01) in the VT. Findings suggested the high potential of VIs extracted by UAV-taken multispectral imagery and also SPAD proximal sensing to help farmers rapidly diagnose LPC in silage maize, in line with the objectives of precision farming.
{"title":"Predicting protein content of silage maize using remotely sensed multispectral imagery and proximal leaf sensing","authors":"N. Bagheri, Maryam Rahimi Jahangirlou, Mehryar Jaberi Aghdam","doi":"10.1017/S0014479722000308","DOIUrl":"https://doi.org/10.1017/S0014479722000308","url":null,"abstract":"Abstract Timely estimation of silage maize protein provides an effective decision to adapt optimized strategies for nitrogen fertilizer management and also harvesting time for farmers. So, this research aimed to investigate whether using vegetative indices (VIs) derived from UAV remotely sensed multispectral (with 520–900 nm wavelengths) imagery and also Soil Plant Analysis Development (SPAD) greenness index can be used to detect the leaf protein concentration (LPC) of silage maize, as a function of various nitrogen rates (0, 50, 100, and 150% of recommended dosage). Results of principal component analysis (PCA) suggested that LPC was highly correlated with leaf greenness index in all developmental stages. In addition, LPC was highly correlated with most of the VIs investigated. A PCA clustering showed the meaningful pattern of N rates. Higher LPC values, VIs, and greenness index were more concentrated in the higher nitrogen (N100% and N150%) sectors. Nitrogen Reflectance Index (NRI) was identified as the most important VIs to monitor and predict LPC in the silage maize field, showing a strong polynomial relationship with LPC in both eight-leaf collar (V8) (R 2 = 0.81, p ≤ 0.01) and tasseling (VT) (R 2 = 0.98, p ≤ 0.001) stages. In addition, among VIs, the Normalized Difference Vegetation Index (NDVI) demonstrated a significant linear regression relationship with LPC (R 2 = 0.80, p ≤ 0.01) in the VT. Findings suggested the high potential of VIs extracted by UAV-taken multispectral imagery and also SPAD proximal sensing to help farmers rapidly diagnose LPC in silage maize, in line with the objectives of precision farming.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43238271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-10DOI: 10.1017/S0014479722000369
M. Ruiz-Torres, A. García-Martínez, C. Arriaga-Jordán, P. Dorward, A. Rayas-Amor, C. G. Martínez-García
Abstract The aim of the study was to analyze the role of small-scale dairy farms in central Mexico in combating rural poverty from a gender perspective. Specifically, it was determined whether these production systems generated sufficient income for alleviating poverty and purchasing the basic food basket. Two hundred and twelve farmers were selected through snowball sampling. To maintain a gender perspective, female-headed farms were considered as an independent group, and male-headed farms were grouped according to multivariate statistics. Two official indicators of poverty were considered in the economic analysis: income and the extreme poverty line. Factor analysis identified four factors that explained 66.10% of accumulated variance. The cluster analysis identified five groups of farms headed by males. Then, a comparative analysis was carried out for the six groups, including the female-headed group (FG). The economic analysis revealed that, if 52% of income are production costs, groups 1, 2, 3, and 4 generated sufficient gross income to purchase the basic food basket to the household of the area. However, the FG and group 5 did not generate sufficient gross income to purchase the food basket. In contrast, if 70% of income are productions costs, only groups 1 and 4 generated sufficient gross income. It can be concluded that small-scale dairy farms generate sufficient daily income under certain conditions for the purchase of the basic food basket and, therefore, help to fight poverty in rural families, especially in groups 1 and 4. In the case of the FG and groups 2, 3, and 5, dairy production along with the diversification of productive activities and backyard activities supports the livelihoods of rural families. It is recommended that existing gender norms be further explored because these could directly influence the motivation of farmers, particularly female producers, to adopt or reject agricultural and livestock technologies.
{"title":"Role of small-scale dairy production systems in central Mexico in reducing rural poverty","authors":"M. Ruiz-Torres, A. García-Martínez, C. Arriaga-Jordán, P. Dorward, A. Rayas-Amor, C. G. Martínez-García","doi":"10.1017/S0014479722000369","DOIUrl":"https://doi.org/10.1017/S0014479722000369","url":null,"abstract":"Abstract The aim of the study was to analyze the role of small-scale dairy farms in central Mexico in combating rural poverty from a gender perspective. Specifically, it was determined whether these production systems generated sufficient income for alleviating poverty and purchasing the basic food basket. Two hundred and twelve farmers were selected through snowball sampling. To maintain a gender perspective, female-headed farms were considered as an independent group, and male-headed farms were grouped according to multivariate statistics. Two official indicators of poverty were considered in the economic analysis: income and the extreme poverty line. Factor analysis identified four factors that explained 66.10% of accumulated variance. The cluster analysis identified five groups of farms headed by males. Then, a comparative analysis was carried out for the six groups, including the female-headed group (FG). The economic analysis revealed that, if 52% of income are production costs, groups 1, 2, 3, and 4 generated sufficient gross income to purchase the basic food basket to the household of the area. However, the FG and group 5 did not generate sufficient gross income to purchase the food basket. In contrast, if 70% of income are productions costs, only groups 1 and 4 generated sufficient gross income. It can be concluded that small-scale dairy farms generate sufficient daily income under certain conditions for the purchase of the basic food basket and, therefore, help to fight poverty in rural families, especially in groups 1 and 4. In the case of the FG and groups 2, 3, and 5, dairy production along with the diversification of productive activities and backyard activities supports the livelihoods of rural families. It is recommended that existing gender norms be further explored because these could directly influence the motivation of farmers, particularly female producers, to adopt or reject agricultural and livestock technologies.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42682030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-10DOI: 10.1017/S0014479722000357
M. Caulfield, S. Vanek, Katherin Meza, Jhon Huaraca, Jose Luis Loayza, Samuel Palomino, Edgar Olivera, Raul Ccanto, M. Scurrah, Lionel Vigil, S. Fonte
Abstract This study analyses the experience and response of farmers within a multi-year collaborative research trial focused on the development of forage-based fallows in eight communities in the central Peruvian Andes. Quantitative data from a rural household survey were used to characterize farming household socioeconomic factors, livelihood strategies and soil and crop management practices of community members belonging to four participation groups with respect to the trials: 1) current participants near the end of the trial; 2.) those who participated early on, but dropped the trials after the first year; 3) those who participated in meetings but not directly in experiments; and 4) those who never participated meaningfully in the process. Furthermore, qualitative interviews of farmers in the four groups were used to examine trends and questions arising from the quantitative survey findings. Analysis of this mixed-methods dataset showed that better resource-endowed households (in terms of human and social capital, more livestock assets, higher levels of farm value production and income, and farm inputs) tended to be more likely to participate compared to households with lower levels of these variables. Our findings suggest that the differences in resource endowment among participation group households may be related to household life cycles, where access to resources change over time, reflecting the changing demography of a household. It was established that farm households with intermediate-age children, that is near the middle of a farm life cycle trajectory, are those with the most wherewithal to participate in trials and likely serve as examples and test cases for other farms with younger parents or older farmers with children moved away. Follow-up interviews indicated that farming households at either end of the farm life cycle trajectory may be using a ‘wait-and-see’ approach to the trials carried out by their neighbours who have more labour and other resources to deploy. In light of these findings, we suggest that participatory research should aim to ensure that the voices, challenges and opportunities of Non-participants are represented in the research process and experimental design. Additionally, greater consideration should be placed on understanding management by context issues in order to better target potential farming innovations such as improved fallows, at multiple levels, from the field to the household and to the community and beyond.
{"title":"Drivers of farmer involvement in experimental forage trials in the Peruvian Andes and implications for participatory research design","authors":"M. Caulfield, S. Vanek, Katherin Meza, Jhon Huaraca, Jose Luis Loayza, Samuel Palomino, Edgar Olivera, Raul Ccanto, M. Scurrah, Lionel Vigil, S. Fonte","doi":"10.1017/S0014479722000357","DOIUrl":"https://doi.org/10.1017/S0014479722000357","url":null,"abstract":"Abstract This study analyses the experience and response of farmers within a multi-year collaborative research trial focused on the development of forage-based fallows in eight communities in the central Peruvian Andes. Quantitative data from a rural household survey were used to characterize farming household socioeconomic factors, livelihood strategies and soil and crop management practices of community members belonging to four participation groups with respect to the trials: 1) current participants near the end of the trial; 2.) those who participated early on, but dropped the trials after the first year; 3) those who participated in meetings but not directly in experiments; and 4) those who never participated meaningfully in the process. Furthermore, qualitative interviews of farmers in the four groups were used to examine trends and questions arising from the quantitative survey findings. Analysis of this mixed-methods dataset showed that better resource-endowed households (in terms of human and social capital, more livestock assets, higher levels of farm value production and income, and farm inputs) tended to be more likely to participate compared to households with lower levels of these variables. Our findings suggest that the differences in resource endowment among participation group households may be related to household life cycles, where access to resources change over time, reflecting the changing demography of a household. It was established that farm households with intermediate-age children, that is near the middle of a farm life cycle trajectory, are those with the most wherewithal to participate in trials and likely serve as examples and test cases for other farms with younger parents or older farmers with children moved away. Follow-up interviews indicated that farming households at either end of the farm life cycle trajectory may be using a ‘wait-and-see’ approach to the trials carried out by their neighbours who have more labour and other resources to deploy. In light of these findings, we suggest that participatory research should aim to ensure that the voices, challenges and opportunities of Non-participants are represented in the research process and experimental design. Additionally, greater consideration should be placed on understanding management by context issues in order to better target potential farming innovations such as improved fallows, at multiple levels, from the field to the household and to the community and beyond.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43403228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-07DOI: 10.1017/S0014479722000333
Thomas Abrell, K. Naudin, F. Bianchi, de Aragao, P. Tittonell, M. Corbeels
Summary Cassava flour is the main source of carbohydrates for family farmers in the Amazon region of Brazil. Cassava is mainly grown under shifting cultivation, in recurrent cultivation periods initiated through slash-and-burn. Its sustainability is, however, questioned due to the associated deforestation and often rapidly decreasing crop productivity. There is an urgent need to make these cassava systems more sustainable and more profitable, but we currently lack a deep understanding of the key factors governing their productivity. We conducted an on-farm study on 37 cassava fields of smallholder farmers at three locations that spanned a range of crop-fallow frequencies, some of which were initiated through slash-and-burn while others through fire-free land clearance. First, we analysed how cassava plant density at harvest was related with pedoclimatic and management factors in slash-and-burn systems. Second, we assessed the relationship between plant density and cassava root yield at harvest and conducted a yield gap analysis to better understand which factors govern cassava productivity beyond plant density in slash-and-burn systems. Finally, we compared cassava productivity between slash-and-burn and the fire-free land clearing techniques that some farmers started to adopt in the study region. Cassava yields averaged 7.2 ± 5.4 Mg ha–1 (50% of the average yield of 14.2 Mg ha–1 in the Pará State), and ranged from 0 (in case of root rot diseases) to 24 Mg ha–1. Cassava yield was associated with plant density at harvest (ranging from 0 to 10 000 plants ha–1), suggesting that managing plant density is a key determinant of the attainable yield levels. In addition, differences in cassava root yields could be largely explained by differences in labour inputs for weeding and fallow clearing, the effect of the latter depending on soil texture. Therefore, our results suggest that labour is a key production factor for cassava in the shifting cultivation systems of the Eastern Amazon in which the use of external inputs, such as chemical fertilizers and herbicides, is limited. Further, root yields were influenced by the method of field preparation, whereby yields were about 50% lower (and more variable) when fields were prepared by slash-and-burn than by mechanical ploughing or herbicide application. Despite the significantly higher yields, these alternatives to burning the vegetation are, however, still hardly adopted in Paragominas. Hence, there is a need for supporting more sustainable production systems through local and national public policies. These new systems should not only focus on soil fertility management but also on weed control and, more generally, on labour productivity.
{"title":"Cassava root yield variability in shifting cultivation systems in the eastern Amazon region of Brazil","authors":"Thomas Abrell, K. Naudin, F. Bianchi, de Aragao, P. Tittonell, M. Corbeels","doi":"10.1017/S0014479722000333","DOIUrl":"https://doi.org/10.1017/S0014479722000333","url":null,"abstract":"Summary Cassava flour is the main source of carbohydrates for family farmers in the Amazon region of Brazil. Cassava is mainly grown under shifting cultivation, in recurrent cultivation periods initiated through slash-and-burn. Its sustainability is, however, questioned due to the associated deforestation and often rapidly decreasing crop productivity. There is an urgent need to make these cassava systems more sustainable and more profitable, but we currently lack a deep understanding of the key factors governing their productivity. We conducted an on-farm study on 37 cassava fields of smallholder farmers at three locations that spanned a range of crop-fallow frequencies, some of which were initiated through slash-and-burn while others through fire-free land clearance. First, we analysed how cassava plant density at harvest was related with pedoclimatic and management factors in slash-and-burn systems. Second, we assessed the relationship between plant density and cassava root yield at harvest and conducted a yield gap analysis to better understand which factors govern cassava productivity beyond plant density in slash-and-burn systems. Finally, we compared cassava productivity between slash-and-burn and the fire-free land clearing techniques that some farmers started to adopt in the study region. Cassava yields averaged 7.2 ± 5.4 Mg ha–1 (50% of the average yield of 14.2 Mg ha–1 in the Pará State), and ranged from 0 (in case of root rot diseases) to 24 Mg ha–1. Cassava yield was associated with plant density at harvest (ranging from 0 to 10 000 plants ha–1), suggesting that managing plant density is a key determinant of the attainable yield levels. In addition, differences in cassava root yields could be largely explained by differences in labour inputs for weeding and fallow clearing, the effect of the latter depending on soil texture. Therefore, our results suggest that labour is a key production factor for cassava in the shifting cultivation systems of the Eastern Amazon in which the use of external inputs, such as chemical fertilizers and herbicides, is limited. Further, root yields were influenced by the method of field preparation, whereby yields were about 50% lower (and more variable) when fields were prepared by slash-and-burn than by mechanical ploughing or herbicide application. Despite the significantly higher yields, these alternatives to burning the vegetation are, however, still hardly adopted in Paragominas. Hence, there is a need for supporting more sustainable production systems through local and national public policies. These new systems should not only focus on soil fertility management but also on weed control and, more generally, on labour productivity.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42929885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-06DOI: 10.1017/S0014479722000345
M. Roostaei, J. Jafarzadeh, E. Roohi, Hossein Nazary, R. Rajabi, R. Mohammadi, G. Khalilzadeh, F. Seif, Seyyed Mohammad Mehdi Mirfatah, S. S. Amiri, Hoosein Hatamzadeh, M. Ahmadi
Abstract The genotype × environment (GE) interaction analysis is fundamental in crop breeding programs to guide selection and for recommendation of high performing and stable genotypes for breeding objectives. This study aimed at quantifying the GE interaction effects and determines grain yield stability among winter bread wheat genotypes under rainfed conditions of Iran. Twenty-four winter wheat genotypes were evaluated under nine test locations using a randomized complete blocks design with four replications during three cropping seasons (2019–21). The additive main effects and multiplicative interaction (AMMI) model and several parametric and nonparametric stability statistics were applied for analysis of grain yield data collected from the experiments. AMMI analysis of variance for grain yield revealed significant effects (p < 0.01) for genotype, environment, and GE interaction. The environment was the main source of variation and accounted for 83.5% of the total yield variation, followed by GE (6.5%) and genotype (1.0%) effects. The AMMI biplot analysis indicated the genotypes G3, G23, G22, G10, and G19 as high yielding with stability performance across environments. Genotypes G14, G13, G20, and G9 showed large positive interaction with the environments featuring the highest rainfall during growing season, while genotypes G7, G6, and G21 had a large positive interaction with environments with low rainfall. Spearman’s rank correlation analysis revealed that the AMMI stability value, Shukla’s stability variance (σ2 i), Wricke’s ecovalence (W2 i), coefficient of determination (R2 i), variance in regression deviations (S2 di), and nonparametric statistic of S2 (i) were not correlated with mean yield in tested genotypes, showing they are related to static/biological concept of stability. In contrast, the genotypic superiority index (Pi) and regression coefficient (bi) were significantly correlated (p < 0.01) with mean yield and corresponded to dynamic/agronomic concept of stability. These findings suggest that selection of genotypes should be considered based on selection objectives of using the various stability parameters described here. In conclusion, the selected genotypes in this study should be recommended as new cultivars or parental lines for grain yield and stability improvement under rainfed conditions of Iran or similar agro-ecologies.
{"title":"Genotype × environment interaction and stability analyses of grain yield in rainfed winter bread wheat","authors":"M. Roostaei, J. Jafarzadeh, E. Roohi, Hossein Nazary, R. Rajabi, R. Mohammadi, G. Khalilzadeh, F. Seif, Seyyed Mohammad Mehdi Mirfatah, S. S. Amiri, Hoosein Hatamzadeh, M. Ahmadi","doi":"10.1017/S0014479722000345","DOIUrl":"https://doi.org/10.1017/S0014479722000345","url":null,"abstract":"Abstract The genotype × environment (GE) interaction analysis is fundamental in crop breeding programs to guide selection and for recommendation of high performing and stable genotypes for breeding objectives. This study aimed at quantifying the GE interaction effects and determines grain yield stability among winter bread wheat genotypes under rainfed conditions of Iran. Twenty-four winter wheat genotypes were evaluated under nine test locations using a randomized complete blocks design with four replications during three cropping seasons (2019–21). The additive main effects and multiplicative interaction (AMMI) model and several parametric and nonparametric stability statistics were applied for analysis of grain yield data collected from the experiments. AMMI analysis of variance for grain yield revealed significant effects (p < 0.01) for genotype, environment, and GE interaction. The environment was the main source of variation and accounted for 83.5% of the total yield variation, followed by GE (6.5%) and genotype (1.0%) effects. The AMMI biplot analysis indicated the genotypes G3, G23, G22, G10, and G19 as high yielding with stability performance across environments. Genotypes G14, G13, G20, and G9 showed large positive interaction with the environments featuring the highest rainfall during growing season, while genotypes G7, G6, and G21 had a large positive interaction with environments with low rainfall. Spearman’s rank correlation analysis revealed that the AMMI stability value, Shukla’s stability variance (σ2 i), Wricke’s ecovalence (W2 i), coefficient of determination (R2 i), variance in regression deviations (S2 di), and nonparametric statistic of S2 (i) were not correlated with mean yield in tested genotypes, showing they are related to static/biological concept of stability. In contrast, the genotypic superiority index (Pi) and regression coefficient (bi) were significantly correlated (p < 0.01) with mean yield and corresponded to dynamic/agronomic concept of stability. These findings suggest that selection of genotypes should be considered based on selection objectives of using the various stability parameters described here. In conclusion, the selected genotypes in this study should be recommended as new cultivars or parental lines for grain yield and stability improvement under rainfed conditions of Iran or similar agro-ecologies.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45868135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-26DOI: 10.1017/S001447972200031X
Daniel Gerardo Cayón Salinas, Gustavo Adolfo Ligarreto Moreno, Stanislav Magnitskiy, Gustavo Rosero, Omaira Leguizamón
Summary The OxG hybrid bunches contain more parthenocarpic fruits (PF) than normal fruits (NF) and present problems of development and ripening due to either an asynchronous opening of flowers or insufficient pollination. The objective of this study was to compare the effect of α-naphthaleneacetic acid (NAA) and gibberellic acid (GA3) in the induction and development of PF and NF, the fatty acid profile (FAP), and the oil potential in the ‘Coari x La Mé’ oil palm hybrid. NAA and GA3 induced parthenocarpy in the fruits and did not alter the FAP of the mesocarp oil. The commercial dose of pollen (0.9 g talc + 0.1 g pollen) resulted in increased bunch weight (BW) (20.8 kg) and lower percentage of PF in the bunch (65.4%). The most effective hormonal doses to induce the formation of PF in the bunch were NAA 300 and 600 mg L-1. GA3 alone or in mixture with NAA increased the percentage of PF but did not increase the BW, indicating that GA3 had no synergistic effect on BW. The NAA applications represent alternatives to complement assisted pollination of OxG hybrids to increase bunch production and oil yield.
OxG杂交束含有比正常果实（NF）更多的单性结实果实（PF），并且由于开花不同步或授粉不足而存在发育和成熟问题。本研究的目的是比较α-萘乙酸（NAA）和赤霉酸（GA3）在“Coari x La Mé”油棕榈杂交种中PF和NF的诱导和发育、脂肪酸谱（FAP）和油势的影响。NAA和GA3诱导果实单性结实，但不改变中果皮油的FAP。商业剂量的花粉（0.9克滑石粉+0.1克花粉）可增加束重（20.8公斤），降低束中PF的百分比（65.4%）。诱导束中PF形成的最有效激素剂量是NAA 300和600 mg L-1。GA3单独使用或与NAA混合使用增加了PF的百分比，但没有增加BW，表明GA3对BW没有协同作用。NAA的应用代表了补充OxG杂交种辅助授粉以提高丛产量和油产量的替代方案。
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Pub Date : 2022-09-26DOI: 10.1017/S0014479722000321
J. L. C. Baptistella, Ana Paula Bettoni Teles, J. L. Favarin, P. Pavinato, P. Mazzafera
Summary Phosphorus (P) is a limiting resource for agricultural production in the tropics. Urochloa spp. is commonly used as a cover crop and has mechanisms to mobilize partially the nonavailable P forms from the soil. The use of Urochloa intercropped with Arabica coffee (Coffea arabica L.) is increasing in Brazil, but P cycling has been overlooked in this system. Here, we proposed two experiments to test the hypothesis that Urochloa decumbens could mobilize and absorb P from deep soil layers and increase overall P cycling of the intercrop system. We measured U. decumbens root and shoot dry mass (SDM), root morphology and activity, nutrient uptake, soil nutrient availability, and soil P fractionation in both experiments. To better understand P cycling by Urochloa alone, in the first experiment, U. decumbens was cultivated in rhizotrons where adequate P was supplied in distinct soil layers – 0.0 to 0.3 m, 0.3 to 0.8 m, 0.8 to 1.3 m, and 1.3 to 2 m. Root dry mass (RDM) and morphology were not affected by P availability. Moreover, total biomass production (root plus shoot) and P uptake were higher when P was available in the superficial top soil layer compared to P availability in more than one layer or only in the bottom layer. Nevertheless, U. decumbens was able to reach and acquire P from depth. Correlation analysis showed that P cycling was strongly dependent on SDM, labile, and moderately labile fractions of soil P and was not significantly correlated with RDM. The second experiment aimed at verifying P uptake and mobilization from different soil depths in field conditions. P was supplied in different depths of the soil profile – 0.3 m, 0.6 m, and 0.9 m – in the field with preestablished U. decumbens intercropped with Arabica coffee plants. Shoot P content was higher at the first sample date when P was supplied at 0.3 m, compared to 0.6 m, 0.9 m, and control with no P. Soil P fractionation showed that there was no P mobilization of less labile forms by U. decumbens during the evaluated time. Our results showed that P fertilization in the top layer rather than suppling P trough the soil profile can maximize U. decumbens growth. Also, Urochloa P accumulation was enough to support coffee demand even in high yields and can be an alternative to increase P use efficiency in coffee production systems, being an effective recycler of P.
{"title":"Phosphorus cycling by Urochloa decumbens intercropped with coffee","authors":"J. L. C. Baptistella, Ana Paula Bettoni Teles, J. L. Favarin, P. Pavinato, P. Mazzafera","doi":"10.1017/S0014479722000321","DOIUrl":"https://doi.org/10.1017/S0014479722000321","url":null,"abstract":"Summary Phosphorus (P) is a limiting resource for agricultural production in the tropics. Urochloa spp. is commonly used as a cover crop and has mechanisms to mobilize partially the nonavailable P forms from the soil. The use of Urochloa intercropped with Arabica coffee (Coffea arabica L.) is increasing in Brazil, but P cycling has been overlooked in this system. Here, we proposed two experiments to test the hypothesis that Urochloa decumbens could mobilize and absorb P from deep soil layers and increase overall P cycling of the intercrop system. We measured U. decumbens root and shoot dry mass (SDM), root morphology and activity, nutrient uptake, soil nutrient availability, and soil P fractionation in both experiments. To better understand P cycling by Urochloa alone, in the first experiment, U. decumbens was cultivated in rhizotrons where adequate P was supplied in distinct soil layers – 0.0 to 0.3 m, 0.3 to 0.8 m, 0.8 to 1.3 m, and 1.3 to 2 m. Root dry mass (RDM) and morphology were not affected by P availability. Moreover, total biomass production (root plus shoot) and P uptake were higher when P was available in the superficial top soil layer compared to P availability in more than one layer or only in the bottom layer. Nevertheless, U. decumbens was able to reach and acquire P from depth. Correlation analysis showed that P cycling was strongly dependent on SDM, labile, and moderately labile fractions of soil P and was not significantly correlated with RDM. The second experiment aimed at verifying P uptake and mobilization from different soil depths in field conditions. P was supplied in different depths of the soil profile – 0.3 m, 0.6 m, and 0.9 m – in the field with preestablished U. decumbens intercropped with Arabica coffee plants. Shoot P content was higher at the first sample date when P was supplied at 0.3 m, compared to 0.6 m, 0.9 m, and control with no P. Soil P fractionation showed that there was no P mobilization of less labile forms by U. decumbens during the evaluated time. Our results showed that P fertilization in the top layer rather than suppling P trough the soil profile can maximize U. decumbens growth. Also, Urochloa P accumulation was enough to support coffee demand even in high yields and can be an alternative to increase P use efficiency in coffee production systems, being an effective recycler of P.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49099186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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