Effects of goat manure, NPK-fertilizer, insecticides and fungicides, and compost on potato yield at the Yasubi Rural Extension Centre.

Abstract

Two preliminary field trials were conducted at the Yasubi Rural Extension Centre in the South Fore Census Division of the Okapa District in the Eastern Highlands Province as a part of the ongoing research to develop a low input potato production system(s) for the Okapa SMAFSP area. In Trial 1. conducted during the dry period of March - July, application of goat manure increased marketable tuber yield and numbers significantly (P<0.01). Tuber yield increase was almost 200%. There was no response to either mixed NPK-fertilizer or routine spraying of insecticides and fungicides. In Trial 2. conducted during the wet period of November-March, application of 500 kg/ha of mixed NPK-fertilizer increased total tuber yield significantly (P<0.01). Increasing the fertilizer rate from 500 to 750 kg/ha did not increase the total tuber yield significantly (P<0.05) Application of additional P as triple superphosphate (TSP) and N as urea failed to influence total tuber yield significantly (P<0 05). There was no response to application of compost and the possible reason for this is discussed.