Effects of vermicompost, bio-nitrogen (Barvar 1), and bio-phosphorus (Barvar 2) fertilizers on the yield and yield components of medical pumpkin (Cucurbita pepo L. var. styriaca)

Abstract

Medical pumpkin (Cucurbita pepo L. var. Styriaca) contains valuable edible oils and compounds that are used to prevent and treat prostate cancer. To evaluate the effects of vermicompost (no application, 5, and 10 t ha-1) as the main factor, biological nitrogen (no application and application of Barvar 1), and biological phosphorus (no application and application of Barvar 2) as sub-factors on the yield and yield components of medical pumpkin, an experiment was conducted as a split-factorial based on a randomized complete block design with three replications in Islam Abad-e-Gharb, Kermanshah province, in 2015. Studied traits included male to female flower ratio, number of fruits plant-1, number of seeds fruit-1, average dry fruit yield, stem length, number of days to flowering, seed yield, and seed oil yield and percentage. Vermicompost had a significant effect on the number of seeds fruit-1, dry fruit yield, and flowering date. The highest oil yield (30 kg ha-1) was obtained from the combination of bio-phosphorus application and non-application of vermicompost treatments, and the highest seed yield (195 kg ha-1) was obtained from the combination of bio-nitrogen, non-application of bio-phosphorus, and non-application of vermicompost treatments. A combination of non-application of bio-phosphorus and bio-nitrogen and application of 5 t ha-1 vermicompost treatments resulted in the least male to female flower ratio (39); however, the highest one (66) was obtained in the combination of non-application of bio-nitrogen, application of bio-phosphorus, and 10 t ha-1 vermicompost. In general, the highest seed and oil yield was obtained from a single application of bio-nitrogen and bio-phosphorus fertilizers, respectively.