Pub Date : 2021-09-11DOI: 10.1016/s0262-4079(09)60110-x
Ken Babstock
{"title":"At Eye Level","authors":"Ken Babstock","doi":"10.1016/s0262-4079(09)60110-x","DOIUrl":"https://doi.org/10.1016/s0262-4079(09)60110-x","url":null,"abstract":"","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"8 1","pages":"225 - 225"},"PeriodicalIF":0.0,"publicationDate":"2021-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80162935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Little Lord Fauntleroy","authors":"Maxim D. Osipov, N. P. Slater","doi":"10.1093/nq/178.6.101e","DOIUrl":"https://doi.org/10.1093/nq/178.6.101e","url":null,"abstract":"","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"8 4 1","pages":"57 - 67"},"PeriodicalIF":0.0,"publicationDate":"2021-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90681185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-03DOI: 10.17170/KOBRA-202107134318
So Durosaro, O. S. Jeje, B. Ilori, O. S. Iyasere, M. Ozoje
Growth is explained mathematically by models that have parameters with biological interpretations. This study was conducted to compare five non-linear growth models (Gompertz, Brody, Logistics, Von Bertalanffy and Negative exponential) in order to describe growth in the three genotypes (normal feather, naked neck and frizzle feather) of the dual purpose FUNAAB Alpha chickens (n=332). Doesn’t Use Derivative iterative method of nonlinear procedure in SAS was used to estimate the model parameters. Computational difficultly, goodness of fit and residuals of the five models were also evaluated. Negative exponential model predicted the highest mature weight for the three genotypes while Logistics model predicted the highest coefficient of intensity of growth. The fitting of the five models presented no computational difficulty for normal feather chickens while Logistics failed to converge for male, naked neck and frizzle feather chickens. Based on goodness of fit (coefficient of determination, Bayesian information criterion, mean square error and residuals), Gompertz model was observed to have the best fit for normal feather and naked neck chickens while Brody model have the best fit for frizzle feather chickens and Von Bertalanffy for male chickens. From subjective approach (comparison of observed and predicted body weights), Logistics and Negative exponential models fitted well for normal feather than other models while Negative exponential model was the fittest among the models for naked neck and frizzle feather chickens and Gompertz for female chickens. It can be concluded that choice of appropriate model in description of growth depends on genotype and sex of dual purpose FUNAAB Alpha chickens.
{"title":"Application of non-linear models in description of growth of dual purpose FUNAAB Alpha chickens","authors":"So Durosaro, O. S. Jeje, B. Ilori, O. S. Iyasere, M. Ozoje","doi":"10.17170/KOBRA-202107134318","DOIUrl":"https://doi.org/10.17170/KOBRA-202107134318","url":null,"abstract":"Growth is explained mathematically by models that have parameters with biological interpretations. This study was conducted to compare five non-linear growth models (Gompertz, Brody, Logistics, Von Bertalanffy and Negative exponential) in order to describe growth in the three genotypes (normal feather, naked neck and frizzle feather) of the dual purpose FUNAAB Alpha chickens (n=332). Doesn’t Use Derivative iterative method of nonlinear procedure in SAS was used to estimate the model parameters. Computational difficultly, goodness of fit and residuals of the five models were also evaluated. Negative exponential model predicted the highest mature weight for the three genotypes while Logistics model predicted the highest coefficient of intensity of growth. The fitting of the five models presented no computational difficulty for normal feather chickens while Logistics failed to converge for male, naked neck and frizzle feather chickens. Based on goodness of fit (coefficient of determination, Bayesian information criterion, mean square error and residuals), Gompertz model was observed to have the best fit for normal feather and naked neck chickens while Brody model have the best fit for frizzle feather chickens and Von Bertalanffy for male chickens. From subjective approach (comparison of observed and predicted body weights), Logistics and Negative exponential models fitted well for normal feather than other models while Negative exponential model was the fittest among the models for naked neck and frizzle feather chickens and Gompertz for female chickens. It can be concluded that choice of appropriate model in description of growth depends on genotype and sex of dual purpose FUNAAB Alpha chickens.","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"122 1","pages":"147-158"},"PeriodicalIF":0.0,"publicationDate":"2021-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44909551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-08DOI: 10.17170/KOBRA-202105253967
.. O.M.Popoola, Samuel Temitayo Oguntade, O. T. Adebayo
This study was conducted to examine the growth and immune performance of catfish ( Clarias gariepinus ) juveniles cultured in a biofloc fish farming system. To achieve this, 900 C. gariepinus juveniles (9.0 ± 0.23 g) were cultured in an intensive zero water exchange biofloc system for 72 days in 9 separate tanks (2 m 3 each) aerated by an air blower, after which growth assessment of fish was conducted. The trial consisted of three treatments in triplicates, a control without carbon source addition, and two biofloc treatments with carbon source addition of rice bran or cassava flour. The two carbon sources added had a C/N rate of 15:1 to form the floc. The results showed no significant difference between dissolved oxygen (DO), pH, and temperature in all the treatments, however, conductivity, total dissolved solids, and salinity showed significant differences between the bioflocs and control treatments and the treatment group. Nevertheless, the obtained values for the water parameters were within the range required for culturing C. gariepinus. Survival rate of catfish was significantly higher in the biofloc culture with a cassava carbon source (98.3%) compared with the control experiment (64.3 %). Weight gain of the fish was highest in rice bran based biofloc (44.9 ± 3.00 g) and lowest (37.0 ± 4.15 g) in the control treatment. The non-specific immune assay revealed that monocytes, serum lysozyme, and myeloperoxidase were higher in the biofloc treated groups compared to the control group. In contrast, neutrophils' percentage was lower in the treated groups than in the control group. Therefore, this study demonstrated the suitability of biofloc as an aquaculture wastewater purifier, growth-promoting, and immune-enhancing technology for the small-scale culture of C . gariepinus .
{"title":"Growth performance and immunological response of African Catfish (Clarias gariepinus) juveniles reared in biofloc system","authors":".. O.M.Popoola, Samuel Temitayo Oguntade, O. T. Adebayo","doi":"10.17170/KOBRA-202105253967","DOIUrl":"https://doi.org/10.17170/KOBRA-202105253967","url":null,"abstract":"This study was conducted to examine the growth and immune performance of catfish ( Clarias gariepinus ) juveniles cultured in a biofloc fish farming system. To achieve this, 900 C. gariepinus juveniles (9.0 ± 0.23 g) were cultured in an intensive zero water exchange biofloc system for 72 days in 9 separate tanks (2 m 3 each) aerated by an air blower, after which growth assessment of fish was conducted. The trial consisted of three treatments in triplicates, a control without carbon source addition, and two biofloc treatments with carbon source addition of rice bran or cassava flour. The two carbon sources added had a C/N rate of 15:1 to form the floc. The results showed no significant difference between dissolved oxygen (DO), pH, and temperature in all the treatments, however, conductivity, total dissolved solids, and salinity showed significant differences between the bioflocs and control treatments and the treatment group. Nevertheless, the obtained values for the water parameters were within the range required for culturing C. gariepinus. Survival rate of catfish was significantly higher in the biofloc culture with a cassava carbon source (98.3%) compared with the control experiment (64.3 %). Weight gain of the fish was highest in rice bran based biofloc (44.9 ± 3.00 g) and lowest (37.0 ± 4.15 g) in the control treatment. The non-specific immune assay revealed that monocytes, serum lysozyme, and myeloperoxidase were higher in the biofloc treated groups compared to the control group. In contrast, neutrophils' percentage was lower in the treated groups than in the control group. Therefore, this study demonstrated the suitability of biofloc as an aquaculture wastewater purifier, growth-promoting, and immune-enhancing technology for the small-scale culture of C . gariepinus .","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"122 1","pages":"137-145"},"PeriodicalIF":0.0,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46656050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-07DOI: 10.17170/KOBRA-202105253966
R. Mwesigwa, P. K. Migwi, A. King’ori, P. Onjoro, M. Mwesigwa, R. Lumu
The use of dried goat rumen content (DGRC) as a partial replacement for fish meal in layer diets was investigated. A total of 90 H&N Brown Nick layer chickens were offered diets in which DGRC were incorporated at 0, 5 and 10% levels. Iso-caloric and nitrogenous diets were formulated to meet the recommended nutritional requirements for laying hens. Experimental birds were assigned to 9 cages (10 birds/cage) and experimental diets offered in a completely randomized design (CRD) with three replications. Data was collected on egg production and sensory characteristics of the eggs, and a partial budget analysis was undertaken. Diet significantly (P 0.05). Eggs from layers offered 10% DGRC were more acceptable than those of layers fed on 0 and 5% diets. A significant effect (P<0.05) of treatments on yolk colour was observed. Eggs from 10% DGRC diets had more deep yellow yolks than eggs from 0 and 5% diets. It was concluded that use of DGRC in layer diets improved yolk colour, acceptability of the eggs and marginal rate of return (MRR).
研究了在蛋鸡日粮中使用干山羊瘤胃内容物（DGRC）作为鱼粉的部分替代品。向总共90只H&N Brown Nick蛋鸡提供了DGRC含量分别为0%、5%和10%的日粮。制定了等热量和含氮日粮，以满足蛋鸡的推荐营养需求。实验鸟被分配到9个笼子（10只/笼子），实验饮食以完全随机设计（CRD）提供，共有三次重复。收集了鸡蛋产量和鸡蛋感官特征的数据，并进行了部分预算分析。日粮中添加10%DGRC的蛋鸡产蛋率高于0和5%日粮的蛋鸡（P＜0.05）。不同处理对蛋黄色泽有显著影响（P＜0.05）。10%DGRC日粮的鸡蛋比0%和5%日粮的蛋有更多的深黄色蛋黄。结果表明，在蛋鸡日粮中使用DGRC可以改善蛋黄颜色、鸡蛋的可接受性和边际收益率（MRR）。
{"title":"Incorporation of dried goat rumen contents in layer diets improves egg yolk colour and acceptability of eggs","authors":"R. Mwesigwa, P. K. Migwi, A. King’ori, P. Onjoro, M. Mwesigwa, R. Lumu","doi":"10.17170/KOBRA-202105253966","DOIUrl":"https://doi.org/10.17170/KOBRA-202105253966","url":null,"abstract":"The use of dried goat rumen content (DGRC) as a partial replacement for fish meal in layer diets was investigated. A total of 90 H&N Brown Nick layer chickens were offered diets in which DGRC were incorporated at 0, 5 and 10% levels. Iso-caloric and nitrogenous diets were formulated to meet the recommended nutritional requirements for laying hens. Experimental birds were assigned to 9 cages (10 birds/cage) and experimental diets offered in a completely randomized design (CRD) with three replications. Data was collected on egg production and sensory characteristics of the eggs, and a partial budget analysis was undertaken. Diet significantly (P 0.05). Eggs from layers offered 10% DGRC were more acceptable than those of layers fed on 0 and 5% diets. A significant effect (P<0.05) of treatments on yolk colour was observed. Eggs from 10% DGRC diets had more deep yellow yolks than eggs from 0 and 5% diets. It was concluded that use of DGRC in layer diets improved yolk colour, acceptability of the eggs and marginal rate of return (MRR).","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"122 1","pages":"127-135"},"PeriodicalIF":0.0,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49079062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-25DOI: 10.17170/KOBRA-202104133656
Harriet Mawia, F. Simtowe, D. Rahut
Households in developing countries employ a wide range of mechanisms for making cash and in-kind (goods and services) savings which are either formal or informal. Yet, literature on how choices about appropriate savings instruments are made remains scanty. We examine the patterns and choice of these saving instruments using household data from women farmers in eastern Uganda. In particular, the paper focuses on the choice between formal cash saving instruments like commercial banks, village savings and loans associations (VSLAs) and savings at home. A multinomial logit model was applied to identify and quantify the effects of socio-economic factors on farmers’ choice of different savings instruments. The results reveal that financial capital and socio-economic factors such as age, education, farm size, and level of maize commercialisation were the critical drivers of women maize farmers’ choices of saving in informal and formal instruments.
{"title":"Choice of savings instruments among rural women maize farmers: evidence from Uganda","authors":"Harriet Mawia, F. Simtowe, D. Rahut","doi":"10.17170/KOBRA-202104133656","DOIUrl":"https://doi.org/10.17170/KOBRA-202104133656","url":null,"abstract":"Households in developing countries employ a wide range of mechanisms for making cash and in-kind (goods and services) savings which are either formal or informal. Yet, literature on how choices about appropriate savings instruments are made remains scanty. We examine the patterns and choice of these saving instruments using household data from women farmers in eastern Uganda. In particular, the paper focuses on the choice between formal cash saving instruments like commercial banks, village savings and loans associations (VSLAs) and savings at home. A multinomial logit model was applied to identify and quantify the effects of socio-economic factors on farmers’ choice of different savings instruments. The results reveal that financial capital and socio-economic factors such as age, education, farm size, and level of maize commercialisation were the critical drivers of women maize farmers’ choices of saving in informal and formal instruments.","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"122 1","pages":"103-114"},"PeriodicalIF":0.0,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43446599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-25DOI: 10.17170/KOBRA-202104133654
E. K. Eifediyi, Samson Adeunie Idowu, F. Ogedegbe, T. Agbede, I. Kareem
Low iodine content in soils is a common feature in lowland and in mountainous regions far from oceans. The diets of the people living in these regions are often deficient in dietary iodine, resulting in chronic iodine deficiency syndrome, goiter, hearing loss and other debilitating diseases. A field experiment was conducted at the Teaching and Research Farm, University of Ilorin, Nigeria during the 2017 and 2018 cropping seasons, to evaluate the response of amaranths to iodine enrichment using an agronomic approach. The trial consisted of potassium iodide (KI) applied as foliar spray at 0, 3.5, 7, 10.5, 14 kg ha -1 and soil applied at the rates of 4, 8, 12 and 16 kg ha -1 . These treatments were in four replicates laid out in a randomized complete block design. Data were collected on plant height, number of leaves, leaf area, crop growth rate, yield and iodine-leaf concentration. The data were subjected to analysis of variance (ANOVA) followed by mean separation using Duncan`s Multiple range test p < 0.05. The results indicated that the use of KI improved the growth of amaranthus at the low level of application, but foliar application at 10.5 and 14 kg ha -1 yielded the highest iodine leaf concentration. Although application of iodine in amaranthus improved iodine leaf concentration, there was a colour change at higher rates of application which may affect the acceptability of the vegetable by consumers.
{"title":"Potassium iodide influence on iodine-leaf concentration and growth of amaranth (Amaranthus cruentus L.)","authors":"E. K. Eifediyi, Samson Adeunie Idowu, F. Ogedegbe, T. Agbede, I. Kareem","doi":"10.17170/KOBRA-202104133654","DOIUrl":"https://doi.org/10.17170/KOBRA-202104133654","url":null,"abstract":"Low iodine content in soils is a common feature in lowland and in mountainous regions far from oceans. The diets of the people living in these regions are often deficient in dietary iodine, resulting in chronic iodine deficiency syndrome, goiter, hearing loss and other debilitating diseases. A field experiment was conducted at the Teaching and Research Farm, University of Ilorin, Nigeria during the 2017 and 2018 cropping seasons, to evaluate the response of amaranths to iodine enrichment using an agronomic approach. The trial consisted of potassium iodide (KI) applied as foliar spray at 0, 3.5, 7, 10.5, 14 kg ha -1 and soil applied at the rates of 4, 8, 12 and 16 kg ha -1 . These treatments were in four replicates laid out in a randomized complete block design. Data were collected on plant height, number of leaves, leaf area, crop growth rate, yield and iodine-leaf concentration. The data were subjected to analysis of variance (ANOVA) followed by mean separation using Duncan`s Multiple range test p < 0.05. The results indicated that the use of KI improved the growth of amaranthus at the low level of application, but foliar application at 10.5 and 14 kg ha -1 yielded the highest iodine leaf concentration. Although application of iodine in amaranthus improved iodine leaf concentration, there was a colour change at higher rates of application which may affect the acceptability of the vegetable by consumers.","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"122 1","pages":"83-89"},"PeriodicalIF":0.0,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45020768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.17170/KOBRA-202104133653
Risikat Mojisola Akinbode, K. O. Adebayo, R. Aderinboye, Hannah Damilola Adefalujo, Hakeem Oluwatobi Akiode
A large portion of agricultural crop residues are potential feed resources for ruminants in the tropics. This study therefore, investigated the intake, nutrient digestibility, nitrogen utilisation and rumen fermentation parameters of West African dwarf goats (WAD) fed treated and untreated maize stover supplemented with Gmelina arborea . Twenty male WAD goats (11.50 ± 0.45 kg body weight) were randomly allotted into four treatments with five animals each. Untreated maize stover (MS), urea treated maize stover (UT), molasses treated maize stover (MT) and urea-molasses treated maize stover (UMT) were supplemented with 300 g Gmelina arborea (G) and were offered to each group for three weeks. MS had highest dry matter (DM; 87.1%), neutral detergent fibre (76%), acid detergent fibre (45%) and acid detergent lignin (6%) contents (P<0.05). Crude protein content was high in UT (12.5%) and UMT (13%). Animals fed UMT+G recorded higher DM intake and digestibility, whereas crude protein digestibility was higher in animals on UT+G (72.8%) and UMT+G (76.2%). Nitrogen intake was more in goats fed UMT+G (P<0.05) and least in MS+G fed group. Higher nitrogen was absorbed and retained by goats on UMT+G. The pH of the ruminal fluid was not affected by the dietary treatments. Concentrations of ammonia‑nitrogen and total volatile fatty acids were higher in UMT+G fed animals. Thus, UMT+G is a good option for proper nutritional utilisation of maize stover which can easily be adopted by farmers given the availability of materials ( Gmelina arborea , maize stover, urea and molasses) and simplicity of the technology involved in the treatment of the stover.
{"title":"Nutrient digestibility, nitrogen balance and rumen fermentation parameters of West African dwarf goats offered treated maize stover supplemented with Gmelina arborea","authors":"Risikat Mojisola Akinbode, K. O. Adebayo, R. Aderinboye, Hannah Damilola Adefalujo, Hakeem Oluwatobi Akiode","doi":"10.17170/KOBRA-202104133653","DOIUrl":"https://doi.org/10.17170/KOBRA-202104133653","url":null,"abstract":"A large portion of agricultural crop residues are potential feed resources for ruminants in the tropics. This study therefore, investigated the intake, nutrient digestibility, nitrogen utilisation and rumen fermentation parameters of West African dwarf goats (WAD) fed treated and untreated maize stover supplemented with Gmelina arborea . Twenty male WAD goats (11.50 ± 0.45 kg body weight) were randomly allotted into four treatments with five animals each. Untreated maize stover (MS), urea treated maize stover (UT), molasses treated maize stover (MT) and urea-molasses treated maize stover (UMT) were supplemented with 300 g Gmelina arborea (G) and were offered to each group for three weeks. MS had highest dry matter (DM; 87.1%), neutral detergent fibre (76%), acid detergent fibre (45%) and acid detergent lignin (6%) contents (P<0.05). Crude protein content was high in UT (12.5%) and UMT (13%). Animals fed UMT+G recorded higher DM intake and digestibility, whereas crude protein digestibility was higher in animals on UT+G (72.8%) and UMT+G (76.2%). Nitrogen intake was more in goats fed UMT+G (P<0.05) and least in MS+G fed group. Higher nitrogen was absorbed and retained by goats on UMT+G. The pH of the ruminal fluid was not affected by the dietary treatments. Concentrations of ammonia‑nitrogen and total volatile fatty acids were higher in UMT+G fed animals. Thus, UMT+G is a good option for proper nutritional utilisation of maize stover which can easily be adopted by farmers given the availability of materials ( Gmelina arborea , maize stover, urea and molasses) and simplicity of the technology involved in the treatment of the stover.","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"122 1","pages":"73-81"},"PeriodicalIF":0.0,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49445328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-05DOI: 10.17170/KOBRA-202104133652
Nuttapon Khongdee, T. Hilger, W. Pansak, G. Cadisch
Maize ( Zea mays ) is an important food and cash crop of uplands in Southeast Asia, where it is often prone to drought and heat stress associated with climate change. This study aimed at assessing the effect of heat and drought on maize performance, testing coping strategies under such weather extremes, and understanding associated mechanisms. The experiment was carried out during 2018 in Thailand, using a split-plot design with three replications. Treatments were: July-planted maize sole cropping (control), July-planted maize-mungbean ( Vigna radiata ) relay cropping, and June-planted maize sole cropping. High temperatures and dry spells during July-August 2018 decreased maize growth strongest in the control and less so in maize relay cropping during generative growth stages, but not in June-planted maize sole cropping. Stress reduced maize nitrogen nutrition index by 40%. Relay-cropped maize had a significantly higher potential to keep stomata open (320 mmol m -2 s -1 ) than sole-cropped maize (100 mmol m -2 s -1 ). Δ 13 C of maize grains confirmed that June-planted maize (‑9.43‰) was less affected by dry spells and heat stress than July-planted sole cropped maize (‑10.23‰). Under relay cropping, the latter showed less water stress (δ 13 C: ‑10.12‰) compared to sole cropping and a higher soil water use. Maize was better able to cope with heat and drought stress when relayed-cropped, although less compared to early-planting of maize. Hence, the tested coping strategies are able to mitigate heat and drought effects on maize growth, while improving food security and crop diversification when relay-cropped with mungbeans.
玉米(Zea mays)是东南亚高地重要的粮食和经济作物，在那里，它经常容易受到与气候变化相关的干旱和热应激的影响。本研究旨在评估高温和干旱对玉米生产性能的影响，测试在这种极端天气下的应对策略，并了解相关机制。该实验于2018年在泰国进行，采用了三次重复的分块设计。处理为:7月种植玉米底(对照)、7月种植玉米绿豆(Vigna radiata)接力种植和6月种植玉米底。2018年7 - 8月的高温和干旱对玉米生长的影响在对照期最为明显，在生育生长期的玉米接力种植中影响较小，但在6月种植的玉米单作中影响较小。胁迫使玉米氮素营养指数降低40%。转播玉米保持气孔开放的潜力(320 mmol m -2 s -1)显著高于单播玉米(100 mmol m -2 s -1)。玉米籽粒Δ 13 C值证实，6月种植的玉米(- 9.43‰)受干旱和热胁迫的影响小于7月种植的单作玉米(- 10.23‰)。与单作相比，转作的水分胁迫较小(δ 13 C: - 10.12‰)，土壤水分利用率较高。延期种植的玉米能够更好地应对高温和干旱胁迫，尽管与早期种植的玉米相比效果较差。因此，经过试验的应对策略能够减轻高温和干旱对玉米生长的影响，同时在绿豆转种时改善粮食安全和作物多样化。
{"title":"Early planting and relay cropping: pathways to cope with heat and drought?","authors":"Nuttapon Khongdee, T. Hilger, W. Pansak, G. Cadisch","doi":"10.17170/KOBRA-202104133652","DOIUrl":"https://doi.org/10.17170/KOBRA-202104133652","url":null,"abstract":"Maize ( Zea mays ) is an important food and cash crop of uplands in Southeast Asia, where it is often prone to drought and heat stress associated with climate change. This study aimed at assessing the effect of heat and drought on maize performance, testing coping strategies under such weather extremes, and understanding associated mechanisms. The experiment was carried out during 2018 in Thailand, using a split-plot design with three replications. Treatments were: July-planted maize sole cropping (control), July-planted maize-mungbean ( Vigna radiata ) relay cropping, and June-planted maize sole cropping. High temperatures and dry spells during July-August 2018 decreased maize growth strongest in the control and less so in maize relay cropping during generative growth stages, but not in June-planted maize sole cropping. Stress reduced maize nitrogen nutrition index by 40%. Relay-cropped maize had a significantly higher potential to keep stomata open (320 mmol m -2 s -1 ) than sole-cropped maize (100 mmol m -2 s -1 ). Δ 13 C of maize grains confirmed that June-planted maize (‑9.43‰) was less affected by dry spells and heat stress than July-planted sole cropped maize (‑10.23‰). Under relay cropping, the latter showed less water stress (δ 13 C: ‑10.12‰) compared to sole cropping and a higher soil water use. Maize was better able to cope with heat and drought stress when relayed-cropped, although less compared to early-planting of maize. Hence, the tested coping strategies are able to mitigate heat and drought effects on maize growth, while improving food security and crop diversification when relay-cropped with mungbeans.","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"122 1","pages":"61-71"},"PeriodicalIF":0.0,"publicationDate":"2021-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45740470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-13DOI: 10.17170/KOBRA-202102113204
C. Nwankwo, L. Herrmann
The seedball technology is a simple and affordable seed-pelleting technique that uses locally available materials such as sand, loam, wood ash and seeds to enhance early crop establishment. It has been shown to be effective for pearl millet ( Pennisetum glaucum (L.) R.Br. ) subsistence production in Sahelian environments. The objective of this study was to optimise the seedball technology for sorghum ( Sorghum bicolor (L.) Moench) under greenhouse conditions. Series of pot experiments were conducted in order to identify optimal size, seed number as well as nutrient content under low- and normal-soil phosphorus availability. The identified optimal seedball formula for sorghum is: 80 g sand + 50 g loam + 25 ml water + about 20 seeds. As maximum 1.5 g NPK mineral fertiliser can be added as nutrient compound. Compared to the control treatment, seedballs significantly improved root and shoot biomass variables as well as nutrient uptake of sorghum seedlings grown for 19 days. The lower the substrate P level, the better the biomass enhancement effect of seedballs, i.e. likely caused by nutrient availability. The next step is on-farm field testing under Sahelian conditions.
种球技术是一种简单且经济实惠的种子颗粒技术，它使用当地可获得的材料，如沙子、壤土、木灰和种子，以加强作物的早期建立。它已被证明对珍珠粟(Pennisetum glaucum, L.)有效。R.Br)。萨赫勒地区的自给生产本研究的目的是优化高粱(sorghum bicolor (L.))的种球技术。Moench)在温室条件下。通过盆栽试验，确定了低磷有效度和正常土壤磷有效度下的最佳粒数、种子数量和养分含量。经鉴定，高粱最佳种球配方为:砂80 g +壤土50 g +水25 ml +种子20粒左右。氮磷钾矿物肥最多可添加1.5 g作为营养物。与对照处理相比，种子球显著提高了生长19 d高粱幼苗的根、梢生物量变量和养分吸收。基质磷水平越低，种球生物量增强效果越好，即可能是由养分有效性引起的。下一步是在萨赫勒条件下的农场实地测试。
{"title":"Optimisation of the seedball technology for sorghum production under nutrient limitations","authors":"C. Nwankwo, L. Herrmann","doi":"10.17170/KOBRA-202102113204","DOIUrl":"https://doi.org/10.17170/KOBRA-202102113204","url":null,"abstract":"The seedball technology is a simple and affordable seed-pelleting technique that uses locally available materials such as sand, loam, wood ash and seeds to enhance early crop establishment. It has been shown to be effective for pearl millet ( Pennisetum glaucum (L.) R.Br. ) subsistence production in Sahelian environments. The objective of this study was to optimise the seedball technology for sorghum ( Sorghum bicolor (L.) Moench) under greenhouse conditions. Series of pot experiments were conducted in order to identify optimal size, seed number as well as nutrient content under low- and normal-soil phosphorus availability. The identified optimal seedball formula for sorghum is: 80 g sand + 50 g loam + 25 ml water + about 20 seeds. As maximum 1.5 g NPK mineral fertiliser can be added as nutrient compound. Compared to the control treatment, seedballs significantly improved root and shoot biomass variables as well as nutrient uptake of sorghum seedlings grown for 19 days. The lower the substrate P level, the better the biomass enhancement effect of seedballs, i.e. likely caused by nutrient availability. The next step is on-farm field testing under Sahelian conditions.","PeriodicalId":54889,"journal":{"name":"Journal of Agriculture and Rural Development in the Tropics and Subtropics","volume":"122 1","pages":"53-59"},"PeriodicalIF":0.0,"publicationDate":"2021-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45718091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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