Evaluation of the Effects of Fertilizers on the Productivity of Selected Potato Varieties Grown On the Taita Hills, Kenya

Abstract

Potato is an important food and cash crop whose yield is limited by biotic and abiotic factors. Of these factors, poor soil fertility and recommendation of nutrients matched with the respective suitable variety at specific agro ecological zone is rare as the case in the Taita Hills in Kenya. Thus, this study evaluated various NPK 17:17:17 fertilizer rates of 250, 500 and 750 kg ha-1 with or without cattle manure on four popular potato varieties (Tigoni, Shangi, Kenya Mpya and Dutch Robjin) for two seasons to establish the suitable high-yielding climate smart variety and fertilizer rate for the Taita Hills.The varieties indicated significant difference (p<0.05) in the yields in both seasons.The Shangi achieved high yields of 22 tons per hectare, compared to Kenya mpya that had the lowest tuber yield of 12 tons per hectare low. Generally, the potato grown in the long rains season of March to June performed better than the short rains season crop of October to December, thus long rains season being more suitable for higher tuber yields. The tuber yield was significantly different between the seasons (p≤ 0.000), among the varieties (p ≤0.000), among the treatment (p ≤ 0.002) and application of significantly increased the yields by 2.5 tonnes at 250 kg/ha, 3.4 tonnes at 500 and 4.3 tonnes at 500kg/ha. Shangi variety generally showed higher yields as compared to the other varieties. Shangi performed better than Dutch Robjin with about 6000kgha-1 and NPK application of 250kg, 500kg NPK increased the yields of potato by about 2500 and 3400 kg respectively as compared to no fertilizer. The application of 750kgha-1 NPK plus 7000 kgha-1 of cattle manure led to higher yield as compared to the application of 7000kgha-1 cattle manure alone, 250kgha-1 fertilizer alone or no fertilizer respectively. Hence, fertilizer use together with cattle manure practice is recommended for the Taita hills and Shangi variety is the most appropriate for the Taita hills