Medicinal pumpkin responses to Thiobacillus and sulfur under water stress. Sadegh Masoodi and Leila Hakimi*

The present study aims to assess the effect of Thiobacillus and sulfur on morphological and biochemical properties of medicinal pumpkinproperties under deficit irrigation based on a split-plot design. For this purpose, water stress was applied as a main factor in three levels (control, no irrigation in flowering stage, no irrigation in fruiting), and Thiobacillus and sulfur fertilizers as sub-plots (250 kg/ha). The results revealed water stress significantly reduced stem diameter, fruit weight, fruit yield, and 1000-seed weight. In contrast, Thiobacillus + sulfur significantly increased fruit weight, fruit yield, 1000-seed weight, seed yield, and oil content. Furthermore, deficit irrigation and fertilizers influenced fatty acid of medicinal pumpkin. The interaction of fertilizer and deficit irrigation was significant on all seed oil compositions, fruit weight and yield as well as seed weight and yield. The fatty acid profile of the oil showed that it is composed primarily of oleic, linoleic, palmitic, stearic, and linolenic acids.