Assessing the potential of earthing up and integrated nutrient management on Irish potato (Solanum tuberosum L.) productivity in smallholder farming systems

Abstract

Irish potato (Solanum tuberosum L.) is a strategic food security crop in Zimbabwe which is a good source of carbohydrates. This has created the need to increase research so as to increase potato productivity. The aim of the study was to assess the effects of earthing up and nutrient management on potato growth and yield. The study was carried out in Masvingo district of Masvingo Province. The experiment was laid out as a 2*3*3 factorial design with 18 treatments replicated three times to give 54 plots. Days to maturity were observed when potato plant leaves turned yellow and 85% of the tubers were ready for harvest at physiological maturity. Results show that plant height was not significantly affected (p<0.05) by earthing up. Nutrient management significantly influenced (p<0.05) plant height with highest (31.2 ± 0.97 cm) observed from 5 t ha-1 cattle manure + 50 kg ha-1 potassium fertiliser. Days to maturity were statistically affected (p<0.05) by tillage type and nutrient management. Days to maturity increased statistically (p<0.05) with increase in application rates of cattle manure + potassium fertiliser irregardless of tillage type. Earthing up considerably influenced potato yield, with highest yields obtained from earthing up treatments amended with cattle manure + potassium fertiliser. Combining 5 t ha-1 cattle manure and + 50 kg ha-1 potassium fertiliser have the potential to improve potato growth and yields. It can be concluded that farmers adopt the use of earthing up integrated with cattle manure + potassium fertiliser at a rate of 5 t ha-1 + 50 kg ha-1can be a better option to improve potato production in smallholder farming systems.