EFFECT OF HARVESTING TIME AND POST-HARVEST HANDLING ON QUALITY OF PUMPKIN SEED (Cucurbita pepo L.).

Abstract

Pumpkin fruits are usually harvested by rural farmers purposely for food after which the extracted seed is used for planting, yet the age of fruit at maturity may not coincide with the seed quality. This study was done to determine the effects of harvesting time and post harvest handling of pumpkin fruit on seed quality. The field experiment was carried out in one season of the year 2015 in three sites (UOE, KTTI and AIC Cheptebo) of the North-Rift region of Kenya. Randomized Complete Block Design was used, laid out in split plot, where the main plot was the type of pumpkin and the sub plot was the harvesting stage. Pumpkin fruits were harvested at four stages (30, 40, 50 and 60 Days after Anthesis). Seeds were extracted then fermented for a period of 0, 2 and 4 days. They were then sun-dried until constant weight was obtained, then a thousand seed weight was determined. The dried seeds that had been harvested at 60 DAA were stored where they were produced (UOE, KTTI and AIC Cheptebo) for a period of three months. Seed testing for germination percentage, electrical conductivity and seedling height was done in the seed science laboratory using Completely Randomized Design. Data was obtained on Germination percentage, Seedling height, TSW, Electrical conductivity and Seedling growth rate. The data obtained was subjected to ANOVA using General Linear Model procedure for (SAS, Version 9.1.3). The treatment means for each test was compared by protected Fischer’s test Least Significant Difference (LSD) at P ≤ 0.05 level of probability. The seeds from fruits harvested at 60 DAA and fermented for a period of four days, from Cheptebo were significant on a thousand seed weight, germination and vigour at P≤0.05. Germination percentage was 90.9% for the round type and 87.6% for the oval type and TSW was 39.45 g for the round type and 29.03 g for the oval type. Electrical conductivity was lowest for seeds harvested from Cheptebo at 60 DAA. The seeds that were fermented for a longer period (4 days) gave higher germination percentage of 90% for the round type and 86% for the oval type compared to those fermented for 2 days and those not fermented. Seeds stored at UOE and KTTI for a period of three months were significant at P≤0.05 compared to those stored in Cheptebo. There was no significance at P≤0.05 between the two pumpkin types. The conclusion of this study showed that the round-shaped pumpkin fruits harvested at 60 DAA from AIC Cheptebo gave the highest Thousand Seed Weight, seed germination and vigour. The seeds fermented for a period of four days and stored in KTTI at 22⁰C showed high TSW, seed germination and vigour. It is recommended that pumpkin fruits should be planted in relatively warm areas (30-38⁰ C), like Cheptebo and harvested at 60 DAA. The seeds should be fermented for four days, dried and stored in cooler room temperatures (18-24⁰ C) at the highlands (Eldoret and Kaiboi) and further selection and breeding should be done on pumpkin local types.