Growth analysis and qualitative traits pumpkin (Cucurbita pepo L.) affected by application of chemical and organic fertilizers

Background and objectives: Production and use of fertilizers in common agriculture have been many environmental problems. While the application of organic fertilizers instead of chemical fertilizers have a important role in soil fertility, increase quality of production and safety of agricultural ecosystems. Pumkin, is an important annual herbaceous plant belongs to the Cucurbitaceae family due to a high percentage of protein accumulation, especially oil in seeds are good nutritional value. Therefore, the aim of this study was to investigate the effect of different sources of fertilizer and combination of qualitative and quantitative characteristics in pumpkin.
Materials and methods: In order to study growth analysis and qualitative traits pumpkin, affected by application of chemical and organic fertilizers, a field experiment was conducted based on RCBD with three replications during the 2010-2011 growing seasons in Gorgan University of Agricultural Sciences and Natural Resources, Iran. The treatments included N: (control), N1: 66-66-99 kg/ha NPK, N2: 132-132-198 kg/ha NPK, N3: 300-200-200 kg/ha NPK, H: 30 t/ha manure, HN1: ( 1/2 H + N1), HN2: (N2 + 1/2 H), HN3: (N3 + 1/2 H), C: 30 t / ha municipal compost, CN1:(1/2 C + N1), CN2: (1/2 C + N2), CN3: (1/2 C + N3) and HN: (1/2 C + 1/2 H). In this study, crop growth rate, relative growth rate, seed yield, biological yield, harvest index, oil content, linoleic and oleic acid were measured.
Results: The results showed that use of chemical fertilizer with FYM increased physiological indices. Application Integrated treatment of 132-132-198 kg NPK + 15 tons of manure per hectare, produced the highest seed yield with an average of 1044 and 1148 kg per hectare respectively in first and second year of the experiment. The highest oil content and harvest index also was obtained of integrated treatment of 132-132-198 kg NPK + 15 tons of manure per hectare in two years, respectively. Application of FYM (H) produced the highest fruit weight, biological yield, linoleic and oleic fatty acids. Application of chemical fertilizers in high level (300-200-200 kg NPK per hectare) produced the least oil content among different level of chemical fertilizers.

Conclusion: In total, the results showed that use of extensive chemical fertilizers had negative effect on all traits in except harvest index. Application of 15 ton / ha manure + 132-132-198 kg ha NPK can be enhanced the qualitative and quantitative yield of pumpkin seeds and it considered a step towards achieving sustainable agriculture.