Mango trees productivity and quality as affected by Boron and Putrescine

•Foliar spray of 'Zebda' mango trees with boron (0.3%) or Putrescine (0.45 mM) increased fruit set and yield.•Fruit quality parameters were also improved.•Low percent of fruit abscission associated with high activity of antioxidant enzymes in fruit petiole.•Fruit petioles had high contents of reducing sugars, free auxin, phosphorous and potassium.•Low contents of free amino acids, free phenolics and nitrogen were also detected in fruit petioles.

Field experiments were conducted to study the effect of Boron (B) and Putrescine (PUT) on fruit drop percentage and quality of 'Zebda' mango during 2013 and 2014 seasons. Results indicated the beneficial effect of high concentration of B (0.3%) and PUT (0.45 mM) in decreasing the percentage of fruit drop and improving fruit quality. Fruit yield was increased by 19.2 and 16.2 kg tree−1 under B (0.3%) compared to the control in the first and second seasons, respectively. The reduction in fruit abscission was correlated with high activity of antioxidant enzymes (peroxidase, superoxide dismutase and catalase) in fruit petiole (FP). Also FP treated with B and PUT showed high contents of reducing sugars, free auxin, phosphorous and potassium as well as low contents of free amino acids, free phenolics and nitrogen. For fruit quality, total chlorophyll concentration in fruit peel was increased and 'L', 'a' and 'b' color values were affected by PUT (0.45 mM) and B (0.3%) treatments. Both treatments increased pulp (%), TSS (%) and TSS/TA ratio and decreased fruit firmness. It could be concluded that application of boron (0.3%) or Putrescine (0.45 mM) to 'Zebda' mango trees three times was effective in increasing fruit setting and yield in addition to improving fruit quality parameters.