Effect of nutrient stock solutions on the growth and yield of apical rooted cutting (Solanum tuberosum L.) varieties in a hydroponic system

There is limited information on adequate application rates of nutrient stock solutions in hydroponic seed potato production systems in Kenya. This has led to low yields of apical rooted cuttings (ARC) potato varieties due to either nutrient deficiencies or toxicities. This study evaluated the effects of varied nutrient stock solution concentrations (NSSC) on the growth and yield of potato apical rooted cuttings varieties. Two greenhouse experiments were conducted at the Climate and Water Smart Agriculture Centre of Egerton University, Kenya. The experiments were laid out in a split-plot of a randomized complete block design, where the main plot comprised three nutrient concentrations, i.e., 75% (N75), 100% (N100) and 125% (N125) of the ADC-Molo’ nutrient formulation. The subplots were allocated the four potato varieties ( Shangi, Wanjiku, Nyota and Unica ). The results revealed significant ( p  ≤ 0.05) effects of NSSC application rates on the growth and yield attributes of ARCs. The N125 gave the tallest plants, highest normalised difference vegetation index (NDVI), plant survival rate and fresh and dry matter (DM %) yields of aboveground biomass (AGB) in both experiments. Nyota produced taller plants, and gave higher NDVI values, higher fresh and DM weight of AGB. The highest numbers of minitubers/plant (8.67 to 9.93) as well as yields (9.97-13.08t/ha) were observed under 125% NSSC in both experiments. Nyota variety gave the highest minitubers/plant while Unica gave the highest yield. Therefore, to achieve high growth and yields of ARCs under a hydroponic system, seed potato producers should use 125% of the ADC Molo nutrient formulation.