Assessment of the effectiveness of maize seed assistance to vulnerable farm households in Zimbabwe

The publication describes outcomes of a study to assess the effectiveness of a large-scale crop seed relief effort in Zimbabwe during 2003-07. Aims of the effort, which was supported by the British Department for International Development (DfID) and coordinated by the Food and Agricultural Organization (FAO) regional office in Harare, included broader diffusion of open-pollinated maize varieties (OPVs), as opposed to hybrids. Based on the findings of the study, the authors recommend that, to increase benefits to vulnerable groups, participants in such efforts should effectively disseminate information on selecting and recycling seed, supported by training and field demonstrations, and should target relatively well-endowed farmers initially. Recommendations also included promotion of OPVs by commercial seed companies and developing a simple, farmer-friendly system for naming varieties.Agricultural development, Technical aid, Farm income, Food production, Maize, Open pollination, Hybrids, Zimbabwe, Crop Production/Industries, International Development,

Quality protein maize—Bridging the malnutrition gap

United States Agency for International Developmen

Genetic evaluation of seedling heat tolerance in sorghum

Surface temperatures of tropical soils at planting time, where sorghum (Sorghum bicolor) is a traditional crop, can exceed 50 oC for hours. Seedling heat tolerance is critical for adequate crop establishment in the semi-arid tropics. Improvement of seedlings heat tolerant genotypes would reduce crop losses due to sufficient plant populations. The objectives of this study were to estimate seedling tolerance to heat, determine individual parental contribution and estimate additive, dominance and epistatic effects for seedling tolerance. In our experiments, seedling heat tolerance termed heat tolerance index (HTI) was defined as a ratio of resumed coleoptile growth after a controlled heat shock, compared to normal growth. Genetic parameters of HTI were determined by crossing four lines with varying HTI, with three tester lines, and deriving F1, F2, F3, BC1 and BC11 families forgeneration means analysis. Line IS20969 from Egypt showed the highest HTI of 0.71, while 290R, an experimental line from the University of Nebraska was the lowest at 0.51. Additive and dominance effects contributed to coleoptile elongation under normal conditions, but only additive effects were significant in recovery growth. Epistatic effects were present in both conditions. General combining ability (GCA) effects for HTI were highly significant in both conditions, but specific combining ability effects were negligible. These results indicate that it is possible to improve seedling heat tolerance and, thus, improve sorghum variety and hybrid plant populations in tropical areas where hot soil temperatures occur

Africa RISING science, innovations and technologies with scaling potential from ESA-Zambia

United States Agency for International Developmen

Africa RISING genetic intensification in Central Tanzania and Zambia

United States Agency for International Developmen

Exploiting Grain-Filling Rate and Effective Grain-Filling Duration to Improve Grain Yield of Early-Maturing Maize

Early-maturing maize (Zea mays L.) genotypes yield 15 to 30% less than late-maturing genotypes. One strategy for improving grain yield in the early-maturing group involves assessment of grain-filling traits as secondary traits for selection for high grain yield. In this study, we investigated the possibility of using grain-filling rate and duration for improving grain yield in early-maturing tropical maize. Forty-four hybrids generated using North Carolina design II were evaluated at CIMMYT-Zimbabwe during the 2011/2012 season under irrigated and nonirrigated environments. Although grain-filling rate and effective grain-filling duration were negatively correlated, several hybrids were distinctly above the trend line. The earliest-maturing hybrid took 127 d to reach physiological maturity and produced grain yields comparable to those of the medium-maturing genotypes (7 t ha−1). It had a high grain-filling rate of 2.40 g per plant d−1 (18% higher than those of the low-yielding hybrids) and a relatively longer effective grain-filling duration. Grain-filling rate and effective grain-filling duration had high coefficients of genetic determination, positive correlations with grain yield, low error terms, and low genotype × environment interactions, making them appropriate selection traits for improved grain yield. The study shows that it is possible to develop high-yielding early- to medium-maturing maize hybrids based on favorable combining ability values for grain-filling rate and duration

Variability of Grain-filling Traits in Early Maturing CIMMYT Tropical Maize Inbred Lines

Grain-filling rate (GFR), effective grain-filling duration (EGFD) and total grain-filling duration (TGFD) are important physiological traits of maize (Zea mays L.) grain yeild (GY) formation. To devise effective breeding strategies, the genetic nature of these traits is pre-requisite for improvement in early maturing maize

Does cooperative membership increase and accelerate agricultural technology adoption? Empirical evidence from Zambia

Open Access Article; Published online: 20 Jun 2020In developing countries, agricultural cooperatives are increasingly being used to promote improved agricultural technologies and alleviate food insecurity and poverty. However, little is known about the role of agricultural cooperatives in accelerating the adoption of improved agricultural technologies. Using a comprehensive balanced household panel and varietal data, this study applied the difference-in-difference model to identify factors affecting farmers’ decision to become cooperative members and the impact of cooperative membership on the adoption of improved maize, inorganic fertilizer and crop rotation. Furthermore, the study used the inverse probability weighted regression adjustment model to analyze the impact of cooperative membership on the speed of adoption of improved maize varieties. We found that cooperative membership increased the probability of technology adoption by 11–24 percentage points. Results further indicated that the average time to adoption was about 8 years, but it was shorter for cooperative members. The results showed that, on average, cooperative membership increased the speed of adoption of improved maize by 1.6–4.3 years. Generally, the results suggest the need for policies which promote farmer organizations such as cooperatives coupled with effective extension services for faster and greater adoption of improved technologies

Current warming will reduce yields unless maize breeding and seed systems adapt immediately

The development of crop varieties that are better suited to new climatic conditions is vital for future food production1, 2. Increases in mean temperature accelerate crop development, resulting in shorter crop durations and reduced time to accumulate biomass and yield3, 4. The process of breeding, delivery and adoption (BDA) of new maize varieties can take up to 30 years. Here, we assess for the first time the implications of warming during the BDA process by using five bias-corrected global climate models and four representative concentration pathways with realistic scenarios of maize BDA times in Africa. The results show that the projected difference in temperature between the start and end of the maize BDA cycle results in shorter crop durations that are outside current variability. Both adaptation and mitigation can reduce duration loss. In particular, climate projections have the potential to provide target elevated temperatures for breeding. Whilst options for reducing BDA time are highly context dependent, common threads include improved recording and sharing of data across regions for the whole BDA cycle, streamlining of regulation, and capacity building. Finally, we show that the results have implications for maize across the tropics, where similar shortening of duration is projected