Effects of calcium nitrate levels and soaking durations in cocopeat on the growth and yield of potato (Solanum tuberosum L.) apical rooted cuttings

Abstract

This study evaluated the effects of treating cocopeat with calcium nitrate (Ca(NO3)2) at different soaking durations on potato (Solanum tuberosum L.) Apical Rooted Cuttings (ARCs) growth and yield parameters. A greenhouse pot experiment was carried out at the Climate and Water Smart Agriculture Centre of Egerton University, Kenya. An air-dried cocopeat 1.5 kg per treatment, was treated using five soaking durations (12, 24, 36, 48 and 72 hours) × four levels of Ca(NO3)2 (0, 60, 100 and 150 g) soaked in 15 litres of water. Soil and the untreated cocopeat were used as positive and negative controls, respectively. The treatments were arranged in a completely randomized design with three replicates. The results showed that there was no significant (P>0.05) interaction effect of Ca(NO3)2 × soaking duration for the number of branches and normalized difference vegetative index. The main effect of 150 g Ca(NO3)2 gave the highest average number of branches (16.13), NDVI (0.89) and plant height (73.51 cm) followed by 100 g of Ca(NO3)2. Soaking duration of 36 hours economically produced the highest growth parameters 12.75 and 61.46 cm an average number of branches and plant height, respectively. Significant (P<0.001) interaction effects were observed for the plant height and all the yield parameters. The interaction of 100 g Ca(NO3)2 and soaking for 36 hours gave the highest mini-tuber yield of 464.67 g plant-1 and an average number of tubers of 21.67 tubers plant-1. Therefore, 100 g Ca(NO3)2 and a soaking duration of 36 hours to treat 1.5 kg of air-dried cocopeat is recommended for higher ARCs yield and yield parameters.