Yield and Yield Components of Potato (Solanum tuberosum L.) as affected by Plant Growth Regulators and Potato Varieties at Kulumsa Agricultural Research Centre, Southeastern Ethiopia

Potato tuberization is influenced by environmental factors like light intensity, photoperiod and temperature. Changes in these factors influence the levels of endogenous plant growth regulators. The present study was done at Kulumsa Agricultural Research Centre (KARC), Southeastern Ethiopia during the< main cropping season of 2018 to determine the effect of three plant growth regulators (PGRs) (Gibberellic acid-GA 3 , Benzyl aminopurine-BAP and Benzyl adenine-BA) on yield and yield components of two potato varieties (Belete and Jalenie). Forty sprouted seed tubers with pre-treatment of the three PGRs at different concentrations were planted per plot (9m 2 ) using the recommended spacing of 75cmx30cm in an experiment using Randomized Complete Block Design (RCBD) with three replications. BAP and BA significantly (P<0.05) affected the yield and yield components of potatoes such as tuber weight, leaf area index, marketable and total tuber yield per< hectare and these results were better than the effects due to GA 3 and distilled water (control). BA at low concentration (0.1mM) increased the average tuber weight over the control by 62.80%; however, BAP increased the average tuber weight at 0.2mM over the control by 59.17%. BAP and BA at 0.1mM concentration increased the leaf area index by 54.81% and 52.9%, marketable tuber yield by 67.28% and 70.55%, and total tuber yield by 61.98% and 65.81% respectively over the control. With the current findings, BAP and BA at the lowest concentration (0.1mM) concentration could be used to pre-treat seed tubers to obtain better tuber yield and yield components.