Changes in phenological attributes, yield and phytochemical compositions of guar (Cyamopsis tetragonoloba L.) landaraces under various irrigation regimes and planting dates

Guar (Cyamopsis tetragonoloba L.) is an annually legume with high adaptability in arid and semi-arid regions has various applications in different industrials as well as in animal food. A field experiment was carried out as split split plot arrangement in randomized complete block design with three replications to evaluate the influence of planting dates (April 30th and May 31') and irrigation regimes [(two times of irrigation: after sowing and flowering (Ir-1) three times of irrigation: after sowing, flowering and seed formation (Ir-2), and four times of irrigation: after sowing, flowering, seed formation and prior to harvesting (Ir-3)] on biochemical features (e.g. protein and fat contents, antioxidant activity, and amino acid constituents), phytochemical properties (e.g. total phenol and galactomannan contents), phonological traits (e.g. number of days to flowering, podding and harvesting), and yield components (e.g. seed yield, number of branch/plant, seed/plant, pod/plant, 100-seed weight) of three local landraces (Pishen, Grembite and Saravan) of guar plant. According to the ANOVA, some traits such as plant height, number of branches/plant, pod/plant, seed/plant, pod length, 100-seed weight, gum and protein contents, viscosity, and seed yield were significantly (P < 0.01) affected by experimental factors and/or by their two-way interactions. However, there were no significant changes in total phenol and crud fat contents, antioxidant activity and amino acid constituents of different guar landraces under employed treatments. The late planting date showed a longer growth cycle than the early one. Pishen showed the maximum plant height, while Grembite recorded the highest pod/plant, branch/plant, seed/plant, pod length, 100-seed weight, seed yield, gum percent and viscosity. The two-way interaction between May planting x Ir-3 exhibited the maximum seed/plant in Grembite. The Pearson's correlation analysis revealed that protein, viscosity, plant height, number of branches, pod/plant, seed/plant, pod length and 100-seed weight positively correlated with seed yield, while fat showed negatively significant correlation with the seed yield. The major amino acid constituents of seed powder were glutamic acid, aspartic acid and arginine. Thus, Grembite could be introduced as a promising landrace upon experimental treatments in case of studied region.