Pollination And Guttation In Sweet Melon Cucumis Melo L. Grown Under Field And Greenhouse Conditions In Nairobi County, Kenya

ABSTRACT

Sweet melon (Cucumis melo L.) is a plant that produces a fleshy edible fruit and belongs to the family Cucurbitaceae. As an economic crop, the sweet melon is highly consumed by the urban population in Kenya. The pollination ecology of the crop is not well understood. Effective pollination is essential for fruit set and overall productivity of sweet melons. The use of pest control products can adversely impair pollination provision through direct decimation of pollinators or their repellence from flowers. Guttation, which refers to secretion of water through pores in the leaves, can act as a mode of exposing pollinators to pesticides. This study aimed at investigating pollination ecology and guttation fluid production in sweet melons grown under field and greenhouse conditions. Experiments were conducted under field and greenhouse conditions at Kenya Agricultural and Livestock Research Organization-Kabete site situated along Waiyaki way, Nairobi County. A completely randomized design with three replicates was used for the field experiments to identify pollinators, determine the best pollinators in greenhouses and assess guttation production. Treatments were honey bee pollination, stingless bee pollination and the control experiment with no pollinators. Sampling of guttation fluid on sweet melon leaves was done at dawn using a small spoon and a syringe. The consumption of guttation water by bees in the field was also observed. To identify pollinators in the open-field, insect visitors were captured and identified using the dichotomous key and their duration of visit on sweet melons flowers in the field and greenhouses were observed and recorded using a stopwatch. Data on number of visits and durations of visits was subjected to one way analysis of variance (ANOVA), to determine the significant difference between honey bees, butterflies and hoverflies. Data on weight of fruits and number of developed seeds collected from the honeybees, stingless bees and control greenhouses was subjected to one way ANOVA, and means compared using Turkey’s test to determine the best pollinator of greenhouse sweet melons. Results showed that honey bees were the most common insect visitors on sweet melon flowers in the field. Honey bees (Apis mellifera) also spent more time on the sweet melon flowers than butterflies (Papilio dardanus) and hoverflies (Syrphys ribesii). There was a significant difference (P