Effect of planting date and density on yield and yield components of Medicinal plant pumpkin (Cucurbita pepo L.)

To study the effects of planting date and planting density on quantitative traits of medicinal plant, Schneider squash (Cucurbita pepo L.), an experiment was conducted at research field of Ferdowsi University of Mashhad, in year 2012. A split plot arrangement based on Randomized Complete Block Design with three replications was used. Treatments consisted of three planting date levels (1 May, 11 May and 21 May) and two density levels (2.5 and 4 Plants per m-2) which were allocated to main plots and sub plots, respectively. At the end of the growing season, the seed yield, fruit yield, number of fruits (per ha-1), number of seed (per m-2), number of seed per fruit, seed weight per fruit, 1000- seed weight and harvest index were measured. Results showed that the second planting date (11 May) results in highest amount of the quantitative study traits. The density of 2.5 plants per m-2, compared to the density of 4 plants per m-2, could result in highest yield and yield components. The interactions of planting date and density were not significant in terms of fruit and seed yield but among the other yield components, significantly affect the number of seed (per m-2), the number of seed per fruit and the seed weight per fruit at the probability level of 5%. Overall this study showed that the optimum planting date and suitable density can play an important role in increasing fruit and seed yield of the pumpkin plant, considering the usefulness of this plant in the food, cosmetics, and medicinal industry.