Effects of Time of Earthing Up on Yield and Yield Parameters of Irish Potato (Solanum Tuberosum L.) in Zaka District, Zimbabwe

Potato (Solanum tuberosum L) is a strategic national food security crop in that can be used as a supplement for carbohydrates. It is the fastest growing staple food crop and source of income for poor smallholder farmers. There is limited documentation on effects of earthing up irish potatoes on yield and yield components in Zimbabwe. A field experiment was conducted in Zaka district of Masvingo province in Zimbabwe during the 2018/19 cropping season. The aim of the study was to investigate the effect of time of earthing up on yield and yield parameters of BP1 potato variety. The treatments consisted of four levels of time of earthing up (no earthing up (control), three, four and five weeks after plant emergence), replicated three times on a Randomized Complete Block Design (RCBD). Results on earthing-up at three weeks recorded significantly (P<0.013) the highest total tuber yield (21.97 t ha-1) which is 10% higher compared to no earthing up which recorded 14.43 t ha-1. Moreover, earthing up at two weeks had the least number of greening tuber yield (3%), 11% pest damaged tuber yield, 6% unmarketable tuber yield and 45% marketable tuber yield. This is in contrast with no earthing up which recorded 91% greening tuber yield, 25.3% on pest damaged tubers, 59% on unmarketable tubers and 10% marketable tuber yield. Based on the results, first earthing up should be done at three weeks after complete plant emergence at the study area under rain fed conditions for the production of potatoes with improved yield and better tuber quality.