Effect of cut off Irrigation and Foliar Application of Kaolin Clay on Yield and Yield Components of Pumpkin Seed (Cucurbita pepo L.)

One of the most important and valuable plants in the pharmaceutical industry is the hull-less pumpkin (Cucurbita pepo L. var. Hamedani) plant, which belongs to the cucurbitaceous family. The aim of this research was to evaluate the effect of deficit irrigation and kaolin clay on yield and yield components of (Cucurbita pepo L.). Experiment was laid out as a split plot design with randomized complete block design with three replications at the field located in Siahbaz village, Khoy district, Iran. The main factors included irrigation at four levels (complete irrigation, deficit irrigation from the shoot stage, deficit irrigation from flowering stage, Deficit irrigation from seed filling stage) and sub-factor including three levels of kaolin (control, 3% kaolin, 6% kaolin) was considered. Analysis of variance showed that the effect of deficit irrigation and kaolin on number of seeds per fruit, fruit yield, 1000 grain weight, grain and biological yield, harvest index, oil and protein percentage, oil yield and protein yield were significant. Analysis of variance showed that irrigation treatment at different growth stages had significant effect on leaf number at 1% probability level, but application of kaolin and interaction of irrigation and kaolin on number of leaves per plant was not significant. The results showed that the highest grain weight (294.55 gr), grain yield (807.2 kg/ha), oil percentage (46.2) and oil yield (373.3 kg/ha) were related to complete irrigation treatment. Irrigation at grain filling stage had no significant effect. Deficit irrigation treatment at the stem stage showed the lowest of studied traits. The highest grain weight (257.07 gr), grain yield (733.7 kg/ha) and fruit yield (23.84 kg/ha) were observed in the 3% kaolin spraying treatment. Kaolin 3% increased oil yield, oil percentage, protein percentage and protein yield compared to control treatment. Interaction between deficit irrigation and kaolin consumption was not significant on any of the traits of pumpkin. According to the results of means of oil and protein yield, complete irrigation and cessation of irrigation at filling of grain, were in a statistical group and there was no significant difference with kaolin 3% and cessation of irrigation in filling of grain, the desired quantitative and qualitative yield can be achieved in Pumpkin.