Response of Four Varieties of Courgettes (Cucurbita pepo) to Powdery Mildew (Sphaerotheca fuliginiea) Disease

Abstract

Courgettes are known to be good source of Potassium, an important intra-cellular electrolyte that helps in reducing blood pressure problems. Powdery mildew disease has become a stumbling block to yield, quality and production of Courgettes in both greenhouse and field production. A study was conducted to screen different varieties of Courgettes; Hybrid Squash STAR 8021, Hybrid Squash Ambassador, Dark Green Zucchini, Squash Black Beauty against powdery mildew inoculum. This was carried out at the School of Agriculture and Biotechnology – University of Eldoret, greenhouse and laboratory where four varieties of were planted in a Completely Randomized Design (CRD) with 3 replicates each. Fresh Diseased plant materials were then collected from CHEPFRESH and isolated to obtain inoculums by scraping the conidia of a virulent isolate into sterilized distilled water. Courgettes in the greenhouse were then transferred to the laboratory at stage of 16th day after germination for inoculation. Inoculation was done by spraying using a hand sprayer until run-off. There was no use of chemicals in the management of the disease. Data was collected on height of plant at intervals of 1 week, number of fruits per plant, days to flowering and disease severity rated at 0-5 rating scale 8 days after inoculation. The quantitative data collected was subjected to Analysis of Variance (ANOVA) using Genstat Version 14.1 and means separated using Duncan’s Multiple Range Test. From the results there was a difference between the four varieties on their response to disease where Hybrid Squash STAR 8021 (highly susceptible), Hybrid Squash Ambassador (susceptible), Dark Green Zucchini (resistant), Squash Black Beauty (moderately susceptible). On number of fruits, Hybrid Squash STAR 8021 had the highest mean (8.250) and Dark Green Zucchini with the lowest mean (3.750).