*2.4. Irrigation and Fertilizer Application*

In pots, 65% field capacity was maintained on a weight basis during the experiment. To fulfil the requirement of crop nutrients (187N, 75P, and 225K kg ha<sup>−</sup>1) urea, K2HPO4 and K2SO4 were applied.

#### *2.5. Harvesting and Samples Analyses*

Harvesting was done at the time of fruit maturity. Samples were digested for the determination of biochemical attributes. The number of bitter gourds was counted manually. For fruit length, standard measuring tape was used. For determination of yield per plant, fruits were collected and weighed on the analytical balance. With the help of diacid mixture nitric acid and perchloric acid (2:1 ratio), the tissues of the plant were digested for P and K analyses [49]. Phosphorus in the samples was determined by using ammonium molybdate and ammonium metavanadate yellow color method [50]. However, for analyses of K in samples, the digested solution was run on flame photometer [51]. For determination of nitrogen, samples were digested in concentrated H2SO4, and digestion mixture (K2SO4 (100):CuSO4.5H2O (10):FeSO4 (1)). Distillation was performed in Kjeldahl distillation apparatus, using boric acid as a collector [52].
