Yield and Tissue Calcium Concentration of Mango (Mangifera indica L.) Fruit as Influenced by Calcium Source and Time of Application
N. M. Bitange *
Department of Plant Science and Crop Protection, University of Nairobi, P.O. Box 29053-00625, Kangemi, Nairobi, Kenya.
G. N. Chemining’wa *
Department of Plant Science and Crop Protection, University of Nairobi, P.O. Box 29053-00625, Kangemi, Nairobi, Kenya.
J. Ambuko
Department of Plant Science and Crop Protection, University of Nairobi, P.O. Box 29053-00625, Kangemi, Nairobi, Kenya.
W. O. Owino
Department of Food Science and Technology, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 6200-00200, Nairobi, Kenya.
*Author to whom correspondence should be addressed.
Abstract
The effect of varied calcium sources, applied at different times and rates, on the yield and calcium concentration of mango fruit were investigated. “Van Dyke” mango cultivar tree of 10 years old was sprayed with calcium chloride, calcium nitrate, easy gro and water (control). The calcium sources were sprayed at the rates of 1%, 1.5% , 2% or 0% (control) during three different stages of fruit development i.e. fruit set, 30 days after fruit set and 30 days to physiological maturity. The experiment was carried out during 2017 and 2018 seasons at Karurumo, Embu County, Kenya. This orchard has been found to have low calcium levels. These experiments were laid in a completely randomized block designs with a split, split plot arrangement replicated three times. The results indicated that spraying with calcium significantly affected the weight, breadth, number and the total weight of fruits/tree. The concentration of calcium in the fruit flesh was also significantly increased by the application of calcium and a direct relationship between calcium concentration and yield attributes was reported. Calcium chloride (2.0%) sprayed at fruit set was the most effective in enhancing the fruit weight, breadth, number of fruits and the total weight of fruits. Application of calcium at fruit set was found to be the most effective in enhancing the yield. Further investigations need to be done to determine the effect of these calcium sources on the quality of fruits and the optimal rate as there was an increase in the yield with an increase in the rates.
Keywords: Mango, calcium chloride, calcium nitrate, easy gro, yield.