Abstract

Aim: The aim of this study was to determine the contribution of biotic pollination on avocado fruit set and yields.

Method and Materials: The experiment was set out at Murang’a County for three seasons from August 2015 to March 2017 in 12 farmer fields, each with five randomly selected trees. On each tree, two randomly selected terminal branches with inflorescences of the same age and size were labelled, one bagged with a mosquito net(1.2mm mesh size) to deny insect visits and another left open for unlimited visitation. Data collected included identity of flower visitor and the number of individuals observed visiting per each species. Additionally, fruit set and yield data were collected. Data were analyzed using Student’s T-test in Genstat12th Edition.

Results: Common visitors were Apis mellifera (87.3%), Chrysomya putoria (5.3%), Eristalis tenax (3.1%) and Polistes sp. (2.7%). There was high significant difference (P <0.001) in fruit set per terminal branch with bagged having 9.38 fruits and un-bagged with19.85 fruits. Further, highly significant difference(P= 0.002) existed in fruit yield per terminal branch; 0.165 and 0.464 fruits on bagged and un-bagged, respectively, translating to 64.5% pollination deficit. Significant differences also existed for seed weight (P=0.001), seed cavity equatorial diameter (P=0.001) and fruit equatorial diameter (P=0.035).

Conclusion: It was confirmed that bee pollination remains key role in avocado production, thus bee colony management is critical in avocado orchards for high and quality yields.

Statistics