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    Statistical Analysis of Non-Replicated Experiments in Farmers’ Fields. A Case of Balanced Fertilization Trials for Bean in Burundi
    (2019-05-01) Joaquin Sanabria; Wendt John
    Very often agricultural experiments in smallholder farms are conducted without actual replications due to land restrictions. Using fields as replications and performing the ANOVA with a randomized complete block design (RCBD) model can result in misleading conclusions about treatment’s performance due to a biased error variance matrix estimated under the wrong assumption of independence between fields. A better alternative is using the spatial variability modeling features of the GLMM to generate an error term to perform unbiased hypothesis tests. Non-replicated trials to estimate bean response to three fertilization treatments were conducted across 175 farmers’ fields in Burundi. Yields were used to compare the performance of an ANOVA using a GLMM where the exponential autocorrelation pattern of the residuals was used to model the error variance-covariance matrix against an ANOVA following a RCBD model where the fields are handled as blocks. The fields were grouped in three clusters prior to the ANOVA. AIC and the Generalized Chi-Sq./DF ratio values for the model involving spatial modeling were 165.3 and 1, respectively. The same fit statistic values from the RCBD model were 330.1 and 0.1, respectively. The near-half magnitude of AIC in the spatial model relative to the RCBD model indicates higher model goodness of fit for the spatial model. The 0.1 value for the Generalized Chi-Sq./DF ratio in the RCBD model suggests underdispersion and violation of the independence-between-fields assumption. Detection of a significant CLUSTER*TREATMENT by the spatial model corroborates the superiority of the ANOVA model involving spatial variability.
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    Foliar fertilization: possible routes of iron transport from leaf surface to cell organelle
    (2020) Hina Malhotra; Renu Pandey; Sandeep Sharma; Bindraban, Prem S.
    Iron (Fe) plays a pivotal role in plant nutrition as well as human health. Foliar application is being adopted as an economic, targeted and environment friendly alternative over soil fertilization. However, dependency of foliar fertilization on crop species, environment, Fe compound and Fe status of plant makes it a complex practice. Though a large body of evidence is available on Fe movement from root to shoot, very little is known on its movement from the leaf surface (extracellular) to various organelles (intracellular). This article presents possible pathways of foliar-fed Fe including crossing leaf physical barriers to reach the apoplast, crossing the plasma membrane, moving through plasmodesmata, phloem loading and unloading and storage in intracellular compartments. We have also emphasized on various chelating agents present in intracellular environments along with membrane-bound proteins aiding in Fe movement. Further, genes involved in Fe uptake and transport from leaf surface are discussed. At organelle level, presence of importer/exporter in outer membranes or bound Fe (Fe(II) to Fe(III)) form needs to be identified. The long-distance transport of Fe in phloem supports the existence of unknown oxido-reductases. The understanding of Fe mobilization pathways from foliage to sink tissues might also assist in molecular biofortification.
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    Impact of Evaporative cooling technology & Post-harvest treatments on shelf life and quality of tomato of two different harvesting stages (Solanum lycopersicum var. Pearson
    (2021) Sayed Samiullah Hakimi; Ravinder Raina; Yashpal Singh Saharawat
    The Zero Energy Cool Chamber (ZECC) is the needed evaporative cooling system introduced as one of the economical small scale on-farm storage in Afghanistan for enhancing the shelf life of tomato and other fresh crops. Tomato is one of the highest value crops, and due to excellent flavor, higher juice, and pulp content of tomato fruits of “Pearson” variety makes it further valuable. Hence, this study aims to understand the effect of ZECC and postharvest treatments on shelf life and quality of tomato’s fruits harvested at turning and light red colors’ stages. Fruits were treated with different concentrations of CaCl2 and mint leaf extract solutions and kept in both ZECC and ambient storages. The shelf life of tomato fruits extended up to 29 days under T4 (turning color fruits + 6% CaCl2 + ZECC). Under the same treatment, the highest firmness as 840.0 grcm-2 and the lowest PLW, Decay Losses and TSS were recorded as 1.80%, 0.0% and 4.400 brix, respectively; on the 20th day of the storage. The lowest shelf life under T11 (Light red color fruits + distilled water dip + Ambient condition) was about 8 days. As a result, the ZECC as an evaporative cooling system significantly enhanced the shelf life and maintained the quality of tomato fruits harvested at the turning color stage treated with 6% CaCl2.
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    Private Agricultural R&D: Do the Poor Benefit?
    (2021) Anderson, J.R; R. Birner; L. Nagarajan; A. Naseem; Carl .E. Pray
    Private agricultural research and development can foster the growth of agricultural productivity in the diverse farming systems of the developing world comparable to the public sector. We examine the extent to which technologies developed by private entities reach smallholder and resource-poor farmers, and the impact they have on poverty reduction. We critically review cases of successfully deployed improved agricultural technologies delivered by the private sector in both large and small developing countries for instructive lessons for policy makers around the world.
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    Can farming provide a way out of poverty for smallholder farmers in central Mozambique?
    (2018) Wilson Leonardo; Gerrie W.J. van de Ven; Argyris Kanellopoulos; Ken E. Giller
    Given that agriculture is a key economic activity of the majority of people living in rural Africa, agricultural development is at the top of the agenda of African leaders. Intensification of agriculture is considered an entry point to improve food security and income generation in sub-Saharan African (SSA). We used a farm optimization model to perform ex-ante assessment of scenarios that could improve gross margin, a farmer's objective, and maize sales, a national policy objective to improve food security, of large and small farms in maize-based farming systems in two posts representative of rural Mozambique (Dombe and Zembe Administrative Posts in Central Province). For selling maize, farmers first had to be maize self-sufficient. We explored two options for increasing agricultural productivity: (i) extensification, to expand the current cultivated area; and (ii) intensification, to increase input use per unit of land. We considered two scenarios for each of the two options. Extensification: current situation (SC1), hired labour (SC2) and labour saving (SC3). Intensification: land-saving (SC4) and combined improvement (SC5). For each scenario, we maximized gross margin and maize sales for large and small farms and assessed the trade-offs between the two goals. We further explored the impact of increasing labour and land availability at farm level beyond the current observed levels. SC4 substantially increased both gross margin and maize sales of large and small farms in both posts. Minor trade-offs were observed between the two goals on large farms whereas we saw synergies between the goals for small farms. In Dombe, the gross margin of large farms increased from $ 5550 to $ 7530 y-1 and maize sales from 12.4 t to 30.4 t y-1. In Zembe, the annual gross margin increased from $ 1130 up to $ 2410 per farm and annual maize sales from 5.1 t up to 9.5 t per farm. For small farms in Dombe, the gross margin increased from $ 1820 to $ 2390 y-1 and maize sales from 3.0 t to 9 t y-1. In Zembe, the annual gross margin increased from $ 260 to $ 810 and annual maize sales from 2.0 t to 3.6 t per farm. With the most optimistic scenarios and conditions of more hired labour and labour-saving technologies, both farm types substantially increased both gross margin and maize sales. We conclude that with available resources, the possibilities for increasing gross margin and maize sales are greater where agroecological conditions are more favourable and are much higher for larger farms. Without interventions that allow small farms to access more labour and land, intensification of agriculture is likely to happen only on farms of better-resourced households, indicating the need for alternative forms of on- and off farm income generation for poorer farmers. The contribution of agriculture to national food security has to come from the large farms, requiring policy support.