Performance of Two Cassava (Manihot Escculenta Crantz) Genotypes to NPK Fertilizer in Ultisols of Sikasso Region, Mali

In Mali, cassava is grown on ultisols in Sikasso region situated in the southern part of the country. The yields are however low due to the low fertility of the cassava growing soils, inadequate fertilizer use and low yielding genotypes. This study aimed at determining the effect of four NPK fertilizer (15-15-15) rates (0 kg ha-1, 100 kg ha-1, 200 kg ha-1 and 300 kg ha-1) applications on growth and yield of two cassava genotypes. A randomized complete block design (RCBD) with three replicates was used in two sites during 2016/2017 cropping season. The fertilizer rates were applied in two splits of equal quantity at two weeks after planting and two months later. Data on plant height, numbers of branches, number of stem, stem diameter, number of tubers per plant, and fresh tuber weight were collected. Data collected were subjected to analysis of variance using Statistical Analysis System (SAS version 9.3). Least Significant Difference (LSD) at p=0.05 was used to separate means. The 300 kg ha-1 of NPK did achieve a significant output on both growth and yield parameters compare to the other rates. The number of tuber per plant and fresh tuber yield increased by 49% and 133% respectively in the plot which received 300 kg ha-1 of NPK compared to the controls. There was a significant correlation (r=0.6533 at P =0.0005) between the NPK fertilizer rates and fresh tuber yield in Loulouni. The results will form a basis for NPK use on cassava in the study area and policy briefs in the country

Effects of calcium nitrate levels and soaking durations in cocopeat on the growth and yield of potato (Solanum tuberosum L.) apical rooted cuttings

This study evaluated the effects of treating cocopeat with calcium nitrate (Ca(NO3)2) at different soaking durations on potato (Solanum tuberosum L.) Apical Rooted Cuttings (ARCs) growth and yield parameters. A greenhouse pot experiment was carried out at the Climate and Water Smart Agriculture Centre of Egerton University, Kenya. An air-dried cocopeat 1.5 kg per treatment, was treated using five soaking durations (12, 24, 36, 48 and 72 hours) × four levels of Ca(NO3)2 (0, 60, 100 and 150 g) soaked in 15 litres of water. Soil and the untreated cocopeat were used as positive and negative controls, respectively. The treatments were arranged in a completely randomized design with three replicates. The results showed that there was no significant (P>0.05) interaction effect of Ca(NO3)2 × soaking duration for the number of branches and normalized difference vegetative index. The main effect of 150 g Ca(NO3)2 gave the highest average number of branches (16.13), NDVI (0.89) and plant height (73.51 cm) followed by 100 g of Ca(NO3)2. Soaking duration of 36 hours economically produced the highest growth parameters 12.75 and 61.46 cm an average number of branches and plant height, respectively. Significant (P<0.001) interaction effects were observed for the plant height and all the yield parameters. The interaction of 100 g Ca(NO3)2 and soaking for 36 hours gave the highest mini-tuber yield of 464.67 g plant-1 and an average number of tubers of 21.67 tubers plant-1. Therefore, 100 g Ca(NO3)2 and a soaking duration of 36 hours to treat 1.5 kg of air-dried cocopeat is recommended for higher ARCs yield and yield parameters

Drivers of sustainable intensification in Kenyan rural and peri-urban vegetable production

Sustainable intensification promotes environmentally sound and productive agriculture. However, use of sustainable intensification practices (SIPs) is low in many sub-Sharan African countries. This study examined the adoption of SIPs in Kenyan rural and peri-urban vegetable production to understand the scale of and underlying factors in the use of SIPs. A multistage sampling technique was employed to randomly select 685 rural and peri-urban vegetable farm households. Household data was then collected and anaylsed for four practices namely improved irrigation, integrated soil fertility, organic manure and crop diversification using a pre-tested structured questionnaire. A multivariate probit model was run to model simultaneous interdependent adoption decisions. Adoption of organic manure and African indigenous vegetables (AIV) diversification was high in both rural and peri-urban areas. However, adoption of improved irrigation systems and integrated soil fertility management was low, and even significantly lower in rural areas than in peri-urban areas (p < 0.041). Similarly, adoption intensity of SIPs was lower in rural areas than in peri-urban areas. Furthermore, the findings also show complementarities and substitutabilities between SIPs. Market integration, the farm location and household income were the major factors heavily influencing the adoption of most SIPs. Policies and programmes that seek to build household financial capital base and integrate farm households into effective and efficient vegetable markets need to be formulated and implemented in order to enhance adoption of SIPs in AIV production

Inter-seasonal Effects on Selected Maturity Parameters of DK8031 Maize Grown under Varying Irrigation and Nitrogen Levels in Embu County, Kenya

Maize is a staple food and a source of carbohydrates to a large proportion of people in Kenya. The performance of crop plants such as maize depends on a number of factors such as climate, soil characteristics and plant species. The maturity parameters such time to tassel, milk stage, physiological maturity and biological maturity are consequently affected which in turn has an influence on crop performance. A study was carried out at University of Embu Demonstration Farm that lies at 03° 30′ S latitude, 37° 30′ E longitude, and altitude 1480 m above sea level, soils being Humic Nitisols. To evaluate the effects of seasonal weather variability on maturity parameters of DK8031 maize, a CRBD in a split plot experimental arrangement was set up in which four irrigation levels (I) and five nitrogen fertilizer rates (N) were allocated the main and subplot treatments in two seasons, respectively. The results revealed that the irrigation levels and nitrogen rates significantly (P&lt;0.05) affected the time to reach the 50% tasseling, 50% milk stage and 50% physiological maturity, ranging from 69 to 73, 99 to 107 and 128 to 140 days after planting, respectively. In all cases, Season I (cool and less rainfall, 530.3 mm) crop took longer to reach any the three developmental stages, compared to Season II (warm and more rainfall = 605.6 mm). The time variation in reaching the developmental stages was attributed to the seasonal weather conditions. Farmers can opt to plant their maize crop in Season II to take advantage of the shorter period the crop takes to mature

Feeding preferences of the field cricket Scapsipedus icipe (Orthoptera: Gryllidae) for different species of Commelina

The field cricket, Scapsipedus icipe Hugel and Tanga (Orthoptera: Gryllidae) is edible and could be used to reduce malnutrition in Sub-Saharan Africa. As the demand for cricket products is increasing, there is a need to find cost-effective ways of rearing this cricket using locally available and affordable sources of food. This study evaluated the feeding preferences of the field cricket S. icipe for 11 species of dayflowers (Commelina spp.; Commelinaceae), using no-choice and multiple-choice experiments in controlled environments. Leaf feeding rates and the nutrient content and phytochemicals of the plants were determined. The ANOVA results indicate significantly higher feeding rates when offered Commelina petersii and C. forskaolii, than Commelina sp. and C. purpurea in no-choice experiments. Multiple-choice experiments ranked C. petersii as the most preferred species followed by C. forskaolii and the two reference species, C. benghalensis var. benghalensis (non-hybrid variant) and C. benghalensis (hybrid variant). The Spearman correlation and PCA revealed positive significant associations between leaf feeding and Ca and NDF content of leaves and a negative significant association between Ca and NDF. A high Ca/low NDF content was recorded for C. petersii and a low Ca/high NDF content for C. purpurea. The beta regression analysis and a biplot identified six phytochemical constituents influencing leaf feeding: phenols, alkaloids, tannins, glycosides, saponins and anthraquinones. Phenols stimulate feeding by S. icipe on C. petersii and C. forskaolii, whereas the tannins and alkaloids in Commelina sp. and C. purpurea, acted as deterrents. Nutrient content and phytochemicals are two important factors determining the suitability of species of Commelina for the field cricket S. icipe. Based on the results of this study, the leaves of C. petersii are highly recommended as a source of food for the mass rearing of this field cricket (S. icipe) and boosting entomophagy in Sub-Saharan Africa

Livelihood and climate trade-offs in Kenyan peri-urban vegetable production

Trade-offs between livelihood and environmental outcomes due to agricultural intensification in sub-Saharan Africa are uncertain. The present study measured yield, economic performance and nitrous oxide (N2O) emissions in African indigenous vegetable (AIV) production to investigate the optimal nutrient management strategies. In order to achieve this, an on-farm experiment with four treatments – (1) 40 kg N/ha diammonium phosphate (DAP), (2) 10 t/ha cattle manure, (3) 20 kg N/ha DAP and 5 t/ha cattle manure and (4) a no-N input control – was performed for two seasons. Yields and N2O emissions were directly measured with subsampling and static chambers/gas chromatography, respectively. Economic outcomes were estimated from semi-structured interviews (N = 12). Trade-offs were quantified by calculating N2O emissions intensity (N2OI) and N2O emissions economic intensity (N2OEI). The results indicate that, DAP alone resulted at least 14% greater yields, gross margin and returns to labour in absolute terms but had the highest emissions (p = 0.003). Productivity-climate trade-offs, expressed as N2OI, were statistically similar for DAP and mixed treatments. However, N2OEI was minimized under mixed management (p = 0.0004) while maintaining productivity and gross margins. We therefore conclude that soil fertility management strategies that mix inorganic and organic source present a pathway to sustainable intensification in AIV production. Future studies of GHG emissions in crop production need to consider not only productivity but economic performance when considering trade-offs