Amare Haileslassie

Economic and agronomic optimum rates of NPS fertilizer for irrigated garlic (Allium sativum L) production in the highlands of Ethiopia

Abstract Field experiment has been conducted in Yilmana Densa District during the 2014/2015 irrigation season with the objective of identifying the economical and agronomically optimum rate of the newly introduced NPS fertilizer for garlic production under irrigated smallholder farming system in the Highlands of Northwestern Ethiopia. Twelve NPS fertilizer rates, laid down on Randomized Complete Block Design with three replications were tested on local garlic variety. Accordingly, most of the growth and yield parameters were significantly affected by NPS fertilizer rates where non-fertilized plants were inferior in all parameters. Significantly highest plant height (69.23 cm) and above ground biomass (25.33 g) were recorded on garlic plants supplied with N:P2O5:S at the rate of 105:122.6:22.6 kg ha−1. Similarly, the biggest bulb diameter (4.27 cm) and the highest leaf number (13.4) as well as marketable (17.42 t ha−1) and total bulb yields (17.8 t ha−1) were recorded on plants which were supplied with 140:122.6:22.6 kg ha−1 N:P2O5:S that were similar with the effects of N:P2O5:S at the rate of 140:92:17 kg ha−1. N:P2O5:S at the rate of 140:92:17 kg ha−1 recorded the highest marginal rate of return that can be recommended to increase the yield of garlic and thus to improve the livelihoods of farmers in the study area.

Smallholders’ avocado production systems and tree productivity in the southern highlands of Ethiopia

Ethiopia is one of the top five avocado producers in sub-Saharan Africa. Despite increasing recognition for its nutritional value and economic importance, information on smallholder avocado production systems across agro-climatic zones and determinants for tree productivity are literally lacking. Therefore, the objectives of this study were to examine the determinants for avocado tree holdings by smallholder farmers and investigate the effect of avocado production systems and management conditions on fruit yield by individual avocado trees in Southern Ethiopia. Data required for the study was collected through a combination of focus group discussions, household survey and field tree inventories. The data was analyzed using descriptive statistics, analyses of variance and linear regression methods using statistical software for social sciences (SPSS version 20). In the study region, avocado is mainly grown as an integral component of the coffee- and enset-based agroforestry systems. The number of avocado trees owned by smallholder producers was related to district, sex of household head, age of household head, educational status, land holding size, pest and disease damage and access to extension services. Productivity of avocado was significantly (pxa0<xa00.05) different between production systems. The highest avocado fruit yield was observed from trees grown in the coffee and enset-based agroforestry systems. However, the smallholder producers complain that the yields of coffee and enset grown under avocado trees could be very low. The total height of avocado trees was significantly (pxa0<xa00.05) different across the different production systems. The mean heights of matured (21–25xa0years old) avocado trees were 17.57xa0±xa00.86xa0m (±SE; Nxa0=xa020) under coffee-based agroforestry system and 14.93xa0±xa01.24xa0m when grown as individual trees around homes. Proper extension support is needed to disseminate improved production techniques: encompassing proper tree spacing, tree training, pruning, soil amendments, growing optimum number of trees for successful pollination and improved harvesting.