Effect of Potassium Nitrate Spray on the Flowering and Fruiting of Mango Varieties Grown in Uganda

Annet Katwesige *

Ministry of Agriculture Animal Industry & Fisheries, Entebbe, Uganda.

Gabriel Ddamulira

National Crops Resources Research Institute Namulonge, Kampala, Uganda.

Sylvester Katuromunda

Department of Agricultural Production, College of Agriculture and Environmental Sciences, Makerere University, Kampala, Uganda.

*Author to whom correspondence should be addressed.


Abstract

Aims: To evaluate the effect of potassium nitrate (KNO3) on flowering and fruiting of mangoes in Uganda.

Study Design:  Randomized complete block design in a split plot arrangement.

Place and Duration of Study: National Crops Resources Research Institute Namulonge, National Semi–Arid Resources Research Institute in Serere and Bulindi Zonal Agricultural Research and Development Institute in Hoima in 2015 and 2016.

Methodology: The study was superimposed on eight-year-old mango orchards which were simultaneously planted at the three sites. Main plot treatments comprised three mango varieties (Bire, Tommy Atkins, Zillate), while sub-plot treatments comprised four concentrations of KNO3 (zero as control, 1, 2 and 4%). Data was collected on number of terminal buds induced after applying KNO3, percentage flowering, number of fruits set per 20 panicles and fruit yield per tree.

Results: Trees sprayed with KNO3 produced higher (P < .05) numbers of terminal buds than the control. Across sites, Bire produced higher numbers of buds (64.8) than Tommy Atkins (46.3) and Zillate (17.8). Flowering response was higher in Bire (28.6%) than in Tommy Atkins (20.8%) and Zillate (17.8%). Flowering response of trees sprayed with 2% KNO3 (31.4%) was higher than that of trees sprayed with 1% KNO3 (24.7%). Mean number of fruits induced per 20 panicles in trees sprayed with 4% KNO3 (8.24) was higher than that of trees sprayed with 1% KNO3 (4.8). Fruit yield of Tommy Atkins (23.01 kg/tree) was higher than that of Bire (10.97 kg/tree). Mean fruit yield of trees sprayed with 2% KNO3 (27.36 kg/tree) was higher than that of trees sprayed with 1% KNO3 (15.93 kg/tree).

Conclusion: For better fruit yields, farmers at Bulindi should grow Tommy Atkins and apply 2% KNO3. Farmers at Namulonge can grow any of the three mango varieties and apply 2 or 4% KNO3, while those at Serere can grow Tommy Atkins and Zillate, and should apply 4% KNO3.

Keywords: Mango varieties, potassium nitrate, flowering response, fruit yield


How to Cite

Katwesige, Annet, Gabriel Ddamulira, and Sylvester Katuromunda. 2022. “Effect of Potassium Nitrate Spray on the Flowering and Fruiting of Mango Varieties Grown in Uganda”. International Journal of Plant & Soil Science 34 (1):80-93. https://doi.org/10.9734/ijpss/2022/v34i130827.