Appropriate canopy management, including planting density and pruning, and application of fertilizer may increase flowering success and seed and oil yields of Jatropha curcas L. Two field experiments were performed from 2009 to 2011 in Balaka, Malawi, to assess the effect of planting density and pruning regime and single fertilizer application (N, P, and K) on male and female flower number and seed and oil yields of J. curcas. Planting density influenced flower sex ratio and female flower number. Branch pruning treatments did not influence the flower sex ratio but reduced seed and final oil yield by 55 % in the following year. It is claimed that J. curcas can be grown on soils with low nutrient content, but this study revealed that yield was low for non-fertilized trees. We observed higher seed and oil yields at higher N application rates (up to 203±42 % seed and 204±45 % oil yield increase) compared with the non-fertilized control. The study suggests thatcurrently used heavy pruning practice is not recommended for J. curcas cultivation, although it needs further longer term investigation. Applying nitrogen fertilizer is effective in increasing yield.
Tag: agronomy
Effect of inoculating seeds with Bradyrhizobium japonicum on the agronomic performance of five varieties of soybean (Glycine max) in Côte d’Ivoire
Recent studies in the Nawa region of Côte d’Ivoire have indicated an acute malnutrition rate of 11.3% among cocoa producers. One of recommended actions from the studies was to diversify agriculture with nutrients rich crops. Introduction of soybean (Glycine max) cropping system could go a long way to ensure food and nutritional security in the region. The current study was conducted in two sites (Logboayo and Soubré) inthe south-west of Côte d’Ivoire, to evaluatetheeffect of IRAT-FA3 Bradyrhizobium japonicum strain inoculumon the agronomic performance of five varieties of soybean named Doko, Canarana, V3_2013,V6_2013 andIT_235. The experimental design was randomized complete block with a split plot withinoculation as the main factor and variety of soybean as subplot treatment replicated three times.Data were collected on some yield parameters and the grain yield. Results of yield showed a highly significant effect (P<0.0001) of the site and a significant effect (P=0.0316) of the variety x treatment interaction. Highest yield was recorded at Logboayo with 1838 kg ha-1 compared to 1220 kg ha-1 for Soubré. The variety V6_2013 with a yield of 1931 kg ha-1and good vegetative development could be recommended as elite variety for the farmers in the Nawa region.
A meta-analysis of the adoption of agricultural technology in Sub-Saharan Africa
Both global poverty and hunger have increased in recent years, endangering progress towards accomplishing Sustainable Development Goals (SDGs) 1 and 2. The regression has been most pronounced in Sub-Saharan Africa (SSA). Meeting the SDG targets requires achieving resilient farm productivity. Although many farm management technologies exist to improve yields, farmers in SSA largely have not adopted these approaches. A long-standing literature about technology adoption identifies multiple hypotheses as to why farmers may or may not adopt new agricultural technologies, culminating in numerous micro-econometric studies. We analyse a metadata set capturing the findings of 164 published studies specifically focusing on SSA and show that 20 out of 38, or 53%, of the determinants commonly believed to influence technology adoption lack empirical support. Eighteen determinants—primarily related to information access, wealth, group membership and social capital, and land tenure—consistently influence adoption across studies. Wealth remains a significant determinant of fertilizer adoption, despite long-running subsidies in most countries, although it is decoupled from the adoption of improved seeds and alternative crop and nutrient management technologies. We highlight the foundational determinants of adoption and offer guidance to design effective interventions that can decrease poverty and hunger towards 2030.
Volume estimation models for avocado fruit
Avocado (Persea americana Mill.) is an important horticultural crop and proved to be a very profitable commercial crop for both local consumption and export. The physical characteristics of fruits are an important factor to determine the quality of fruit produced. On the other hand, estimation of fruit volume is time-consuming and impractical under field conditions. Thus, this study was conducted to devise cultivar-specific and generalized allometric models to analytically and non-destructively determine avocado fruit volume of five wildly distributed avocado cultivars. A significant relationship (P ≤ 0.01) was found between fruit diameter, length, and volume of each cultivar. Our best models (VM2 –for cultivar specific, and VM7-generalized model) has passed all the rigorous cross-validation and performance statistics tests and explained 94%, 92%, 87%, 93%, 94% and 93% of the variations in fruit volume of Ettinger, Fuerte, Hass, Nabal, Reed, and Multiple cultivars, respectively. Our finding revealed that in situations where measurements of volume would be inconvenient, or time-consuming, a reliable volume and yield estimation can be obtained using site- and cultivar-specific allometric equations. Allometric models could also play a significant role in improving data availability on avocado fruit physical appearance which is critical to assess the quality and taste of fresh products influencing the purchase decision of customers. Moreover, such information can also be used as a ripeness index to predict optimum harvest time important for planned marketing. More importantly, the models might assist horticulturists, agronomists, and physiologists to conduct further study on avocado production and productivity through agroforestry landuse system across Ethiopia.
iSDAsoil: The first continent-scale soil property map at 30 m resolution provides a soil information revolution for Africa
Open access, high-resolution soil property maps have been created for Africa at 30 m resolution, using machine learning trained on over 100,000 analysed soil samples. Combined with other field-level information, iSDAsoil enables the possibility of site-specific agronomy advisory for smallholder farmers. © 2021 Miller et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Agronomic gain: Definition, approach, and application
Meeting future global staple crop demand requires continual productivity improvement. Many performance indicators have been proposed to track and measure the increase in productivity while minimizing environmental degradation. However, their use has lagged behind theory, and has not been uniform across crops in different geographies. The consequence is an uneven understanding of opportunities for sustainable intensification. Simple but robust key performance indicators (KPIs) are needed to standardize knowledge across crops and geographies. This paper defines a new term ‘agronomic gain’ based on an improvement in KPIs, including productivity, resource use efficiencies, and soil health that a specific single or combination of agronomic practices delivers under certain environmental conditions. We apply the concept of agronomic gain to the different stages of science-based agronomic innovations and provide a description of different approaches used to assess agronomic gain including yield gap assessment, meta-data analysis, on-station and on-farm studies, impact assessment, panel studies, and use of subnational and national statistics for assessing KPIs at different stages. We mainly focus on studies on rice in sub-Saharan Africa, where large yield gaps exist. Rice is one of the most important staple food crops and plays an essential role in food security in this region. Our analysis identifies major challenges in the assessment of agronomic gain, including differentiating agronomic gain from genetic gain, unreliable in-person interviews, and assessment of some KPIs at a larger scale. To overcome these challenges, we suggest to (i) conduct multi-environment trials for assessing variety × agronomic practice × environment interaction on KPIs, and (ii) develop novel approaches for assessing KPIs, through development of indirect methods using remote-sensing technology, mobile devices for systematized site characterization, and establishment of empirical relationships among KPIs or between agronomic practices and KPIs.
Chromosome evolution and the genetic basis of agronomically important traits in greater yam
The nutrient-rich tubers of the greater yam Dioscorea alata L. provide food and income security for millions of people around the world. Despite its global importance, however, greater yam remains an “orphan crop.” Here we address this resource gap by presenting a highly-contiguous chromosome-scale genome assembly of greater yam combined with a dense genetic map derived from African breeding populations. The genome sequence reveals an ancient lineage-specific genome duplication, followed by extensive genome-wide reorganization. Using our new genomic tools we find quantitative trait loci for susceptibility to anthracnose, a damaging fungal pathogen of yam, and several tuber quality traits. Genomic analysis of breeding lines reveals both extensive inbreeding as well as regions of extensive heterozygosity that may represent interspecific introgression during domestication. These tools and insights will enable yam breeders to unlock the potential of this staple crop and take full advantage of its adaptability to varied environments.
Innovative agronomic practices for sustainable intensification in sub-Saharan Africa. A review
Africa’s need to double food production and feed the burgeoning human population, without compromising its natural resource base, has raised the momentum for sustainable agricultural intensification on the continent. Many studies describe agronomic practices that can increase productivity on existing agricultural land without damaging the environment and without increasing the agricultural carbon footprint. However, there is limited information on specific practices with the greatest potential to contribute to sustainable intensification on smallholder farms in sub-Saharan Africa, while simultaneously keeping the carbon footprint low. The objectives of this review were to (1) identify good agronomic practices with potential for contributing to sustainable intensification across sub-Saharan Africa, (2) synthesize available information on benefits and synergies from these technologies, and (3) discuss bottlenecks in their adoption in order to obtain insights that inform the formulation of supportive policies. Agroforestry, cereal-legume intercropping, conservation agriculture, doubled-up legume cropping, fertilizer micro-dosing, planting basins, and push-pull technology were identified as key agronomic innovations widely promoted in sub-Saharan Africa. We show that these innovations can build synergies and increase resource use efficiency while reducing agricultural carbon footprint. We outline the benefits, trade-offs, and limitations of these practices and discuss their potential role in strengthening food sovereignty and climate change adaptation and mitigation.
Population status of Boswellia papyrifera woodland and prioritizing its conservation interventions using multi-criteria decision model in northern Ethiopia
Boswellia papyrifera woodland provides considerable economic, ecological and socio-cultural benefits in the drylands of Ethiopia. However, its populations are in rapid decline due to human pressure and environmental degradation. As a consequence, the species is now considered being endangered, demanding an urgent conservation intervention to sustain its existence. This study was carried out in the Abergele district, northern Ethiopia, with objectives to characterize the current population structure of B. papyrifera and prioritize its potential conservation intervention alternatives using Analytical Hierarchy Process (AHP) modelling techniques. The woody species related data were collected from 33 sample plots randomly established in the study area. Data related to the potential intervention alternatives and their evaluating criteria were collected from experts, personal experiences and intensive literature reviews, and then validated using stakeholders’ focus group discussion. Four candidate alternatives were then considered for the AHP: 1) free grazing with no tapping resting period (FGNTR), 2) free grazing with a rotational tapping (FGRT), 3) area exclosure with medium tapping resting period (AEMTR), and 4) area exclosure with long tapping resting period (AELTR). The results showed that the population structure of B. papyrifera is unstable and is characterized by low density (266 trees ha−1), absence of regeneration and saplings (DBH<10 cm) due to different interrelated disturbances such as overgrazing, over tapping, pests, agricultural expansion and poor managements. The overall priority ranking value of all stakeholders using the AHP techniques also indicated that AEMTR (with overall rank value of 0.352) and AELTR (0.294) as the best alternatives strategies, respectively, for sustainable B. papyrifera woodland conservation. For the success of these strategies, their economic impacts at their early implementation stages (5–10 years) should be minimized by collecting different non-timber forest products from the woodland. Continuous capacity building training on sustainable utilizations and managements of B. papyrifera woodland should also be provided for all relevant stakeholders.
Propensity to adapt to climate change: insights from pastoralist and agro-pastoralist households of Laikipia County, Kenya
Climate change is a reality in Africa’s drylands. Pastoralists are engaging and embracing a range of adaptive strategies to adjust to these changes. The socioeconomic factors driving them to engage in a portfolio of multiple adaptation strategies have not been adequately addressed in the existing literature. A multivariate probit model was used to analyze them as determinants of adaptive capacity that promotes or hinders adaptation to climate change. Adaptation is represented by uptake of multiple strategies (irrigation, livestock migration, fodder production, and improved livestock breeds) by households, a demonstration of a household’s ability to diversify and adapt to the effects of climate change. The household asset base, particularly social capital represented by government assistance, stands out as it positively influenced by the uptake of four out of five adaptation strategies; that is, irrigation, livestock manure, fodder production, and improved breeds. Information heavily supports the adaptation process as it influenced all the five adaptation strategies analyzed but has a heterogeneous effect, supporting households to either adopt or reject a strategy. Crop-based information positively determines uptake of yield-enhancing strategies while relevant information for livestock activities contributes to the uptake of livestock-based strategies. These findings suggest that mainstreaming agricultural innovations, building a household asset base, and facilitating access to agronomic and climatic information will enable dryland communities to better adapt to climate change.