Response of Application Time and Method of Inorganic Phosphorus Fertilizer on Irish Potato ( Solanum tuberosum L.) Production at Bore and Anasora Area, Southern Oromia, Ethiopia

Abstract

Optimizing fertilization brings tangible benefits such as higher yields and lower fertilizer costs, but also assures the sustainability of agricultural businesses. Appropriate nutrient application at critical time is often a crucial and increase rapidly during the tuber bulking phase and then slow as the plant matures. In recent years, however, some producers have applied some or all of the fertilizer in a concentrated and in inefficient form at a time carelessly. There is a limiting knowledge regarding time and appropriate method of application. The field trials were conducted during 2016 and 2017 main cropping season at the Bore Agricultural Research Centre on site and Ana sora on farm which is located in Guji Zone of Southern Ethiopia to evaluate the best P application time and method. The treatments consisted of Five (5) levels of application time (pre-planting (10DBP), at planting, at first weeding, at first earthingup and second earthingup stage (45DAP) and three (3) levels of application methods (band placement (localized placement or spot application), side dressing and broadcasting) will be arranged in RCBD with factorial arrangement of three replications. Sprouted tubers was planted on plot size of 2.1mx 3.5m and spacing of 30cm between plants and 70 cm between rows. The plot consists of five rows and seven plants per single row, totally 35 plants per plot. A distance of 0.6m and 1.4m was left between plots and blocks, respectively. Data were collected on growth, yield, yield components and disease incidence and severity. The two years combined data analysis results revealed that the interaction effect of fungicides and potato varieties had influenced significantly (P<0.05) response on days to 50% flowering, 50% maturity, plant height, number of tubers per hill, stem number per plant, marketable tuber yield and unmarketable tuber yield and total tuber yield. The highest economic yield (50.2 t ha-1 and 49.98 t ha-1) was obtained from the combined use of phosphorus at planting with banding. Generally, as a conclusive and recommendation, Irish potato growers at Bore, Ana sora and surrounding area need to grow Irish potato by applying phosphorus fertilizer at time of planting with banding method of application thereby phosphorus recovery can be improved for better use of plants.