Influence of Calcium, Potassium and Watering Regimes on Blossom End Rot in Two Varieties of Tomato (Solanum lycopersicum) in Mandera County, Kenya

Blossom end rot (BER) is one of the physiological disorders of economic importance in tomato farming since it significantly reduces yield and thus affects profit margins. Most tomato disorders are due to mineral deficiencies and unbalanced nutrition. Improving the supply of specific nutrients and uniform soil moisture can reduce their occurrences. This study was conducted to evaluate the influence of watering regimes, Calcium (Ca) and Potassium (K) on blossom end rot occurrence in two tomato varieties in Maslah and Guul sites. The trials were laid out in a randomized complete block design (RCBD) in split-split plot arrangement with watering regimes (daily, thrice and twice a week) as main plots, tomato varieties (Riograde and Rionex) as sub plots, and 3 levels of Ca and K (0 Kg/ha, 25 Kg/ha, 50 kg/ha) as the sub-sub plots and replicated three times. Calcium treatments had the lowest score of blossom end rot compared to control. In Guul, the highest BER score (2.83) was observed under the control treatment while the lowest score (1.06) was recorded on the 50 kg/ha, Ca rate. Similar results were observed in Maslah with the control having the highest score of BER (3.22) while Ca 50 kg/ha scored lowest (1.11). No statistical differences were observed in the K treatments in the two study sites, however it was notable that lower rates of K reduced the blossom end rot incidences. Water stress led to increase in severity of the BER in the two study sites. In Guul, the highest score was in minimal watering regime (twice a week) of 2.36 score and lowest was at optimal watering regime (daily) of 1.08 score whereas in Maslah the highest blossom end rot score was in minimal watering regime (twice a week) of 3.19 and the lowest score of 1.19 on medium watering regime (Thrice a week).Therefore, optimal application of Ca, K, at 50 kg/ha with adequate and uniform soil moisture can improve management of blossom end rot in tomatoes thus raising farmer’s returns.