Fall Armyworm (FAW), Spodoptera frugiperda, is prevalent in Zimbabwe, causing significant damage to maize and yield losses. Three synthetic insecticides (Nemesis, Ecoterex and Lamda-cyhalothrin) belonging to different chemical groups and neem bio-pesticide (Neem Leaf Extract) were tested for their efficacy against FAW under laboratory and field conditions. The aim of the study was to assess the effect of neem bio-pesticide and synthetic insecticides on the population of FAW larvae, level of leaf damage and maize grain yield in comparison with untreated control plants. In laboratory experiment, neem biopesticide and the three synthetic insecticides resulted in significantly higher FAW larval mortality (p < 0.05) at 24, 48 and 72 hours after application of treatments as compared with the untreated plants. Neem bio-pesticide and the synthetic insecticides caused highest percentage of larval mortality (> 90%) at 72 hours after treatment application. In the field, both bio-pesticide and synthetic insecticides resulted in significantly higher efficacy (p < 0.05) against fall armyworm larvae, reduced the level of leaf damage and increased maize grain yield as compared to the untreated control plants. The untreated maize plants were found to be extensively damaged by FAW as compared to those treated with insecticides and neem bio-pesticide. The highest efficacy was recorded on plants treated with Nemesis, followed by Neem Leaf Extract, Ecoterex and lastly Lamda-cyhalothrin, respectively. The neem bio-pesticide and synthetic insecticides which were used in this study showed high efficacy against FAW larvae and can be recommended to be used as components for integrated pest management (IPM) plans for FAW under smallholder farmer conditions in Zimbabwe and the rest of Africa.

A field experiment was conducted in 2018/2019 growing season at the Scientific Industrial Research and Development Center under irrigated conditions using the simple alpha lattice (7 ∗ 7) design, with three replications. The objective of the study was to determine the performance of 44 elite rice lines that were selected and shared from elite doubled haploid germplasm and five cultivars were used as checks. All evaluated genotypes exhibited significant variation in the traits measured except for number of grains/panicle, total tillers/plant, and effective tillers/plant. Elite line 70462 was found to be the highest yielding, with yield advantage of 66% over the high yielding local check (Nerica 7). High values for broad sense heritability were recorded for days to 50% heading, panicle length, culm length, number of filled grains/panicle, 1000-grain weight, grain length, grain shape, and grain yield and indicated lesser influence of environment in expression of these traits, hence amenable to simple selection. Correlation analysis revealed that grain yield manifested significantly positive correlation with filled grains/panicle contributing the highest correlation (r = 0.784), followed by culm length (r = 0.605), spikelet fertility/panicle (r = 0.677), grain length (r = 0.551), 1000-grain weight (r = 0.518), panicle length (r = 0.449), and number of grains/panicle (r = 0.328). Based on grain yield, number of filled grains/panicle and spikelet fertility/panicle, panicle length, and earliness, lines 70462, 60143, 70383, Arica 3, Sahel 177, 6040, 70537, 60409, and 70476 had the best performance. Selection of these traits would be more effective for yield improvement in rice and these promising lines could be used in the varietal development and can be tested in multilocational trials and on-farm trials in Zimbabwe with the possibility of release and commercialization.