Effect of foliar application of humic acid levels and nano-fertilizer application on some quantitative and qualitative traits of pumpkin (Cucurbita pepo L.) in climatic conditions of Khorramabad area, Iran.

The present study was carried out to evaluate the effect of spraying different levels of humic acid and nano-fertilizer in Khorramabad region in a temperate climate during 2017-2018 cropping year. It was carried out in a factorial arrangement based on completely randomized block design with three replications. The examined factors included humic acid in three levels (control, seed coating with humic acid and humic acid foliar application as H1, H2 and H3 respectively) and foliar application of nano-fertilizer in four levels (control, one, two, and three times nano-fertilizer spraying as N1, N2, N3 and N4 respectively). The results of mean comparison showed that non-application of humic acid and nano-fertilizer treatments had the lowest fruit yield (28400 kg ha^-1). Also, by increasing the number of nano-fertilizer application, the fruit yield of pumpkin was elevated. The results showed that there was no significant difference between treatments of one, two and three times the application of nano fertilizer, however, the highest amount of protein and oil yield were 182.7 and 384.9 kg ha^-1 in three treatments which obtained in nano-fertilizer application and the least amount of oil and protein was obtained in control treatment (distilled water). Overall, the results showed that three-time application of nano-fertilizer with humic acid foliar application as well as seed coating with humic acid could significantly improve the quality and quantity of pumpkin seeds. Therefore, using these fertilizer in the climatic conditions of Khorramabad is recommended. [ABSTRACT FROM AUTHOR]