Determination of the effects of different harvest times and phosphorus doses on yield and some primary and secondary metabolites in field peas (pisum sativum var. arvense)

This research was carried out in Isparta in 2022 and 2023 vegetation periods to determine the effects of harvest time and phosphorus doses on the yield and quality values of forage pea and some primary and secondary metabolites in dry grass and seeds. Taskent forage pea variety was used in the study. A total of 20 different subjects were examined in the study planned with 5 different phosphorus doses (0, 4, 8, 12 and 16 kg/da) placed in main plots and 4 different harvest times (beginning of flowering, 50% flowering, full flowering and seed harvest period) in sub-plots. The trial was carried out in randomized blocks according to the split plot trial design with 3 replications. In the study, green forage yield, dry hay yield, seed yield, crude protein ratio, crude protein yield, crude ash, NDF, ADF, TDN, RFV, free amino acid amount, oil ratio and composition, total phenolic compounds amount, phytic acid amount and antioxidant activity (DPPH-CUPRAC methods) analyses were performed. When the two-year average results obtained from the study were evaluated, the increase in phosphorus doses increased the green forage, dry hay, crude protein ratio, crude protein yield, TDN, RFV, total phenolic compounds, antioxidant activity, phytic acid, free amino acid and oil ratio values, while it decreased the NDF and ADF ratios, and its effect on the crude ash ratio was found to be insignificant. As the harvest time progressed, green forage, dry hay, crude protein yield, NDF and ADF ratios, TDN, RFV, antioxidant activity, phytic acid amount and oil ratio increased; crude ash ratio, crude protein ratio, TDN, RFV, total phenolic compounds and free amino acid amounts decreased. It was determined that the leaves and seeds of forage pea were rich in unsaturated fatty acids and the dominant components were linoleic acid and oleic acid.