Effect of application of humic acid and zinc at different concentrations and their interaction on some vegetative growth characteristics of chilli pepper Capsicium annuum L

The field experiment was carried out in one of the agricultural fields in Mansouriya Al-Shatt/Diyala Governorate with the aim of studying the effect of foliar feeding with humic acid and zinc on some vegetative growth of pepper plants. A factorial experiment was designed according to a complete randomized block design with three replicates. The first factor included humic spray concentrations (0, 6, 12) g. L-1, The second factor was spraying zinc sulphate concentrations (0, 1, 2) g. L-1. The results showed that foliar fertilization with humic acid at the level of 12 g. L-1 was significantly superior in giving the highest averages for all vegetative traits, as there was a significant superiority in the trait of plant height, chlorophyll, number of branches, and leaf area, which reached 44.70 cm, 65.17 SPAD, 5.00 branches. plant-1, and 74.25 dm2, respectively. Zinc spraying at 2 gm.L-1 was superior in plant height and chlorophyll with an average of 44.31 cm and 62.70 SPAD, respectively, while the concentration of 1 gm.L-1 for zinc spraying gave the highest average in the number of branches with an average of 4.55 branches.plant-1, while the comparison treatment for zinc spraying was superior in leaf area with an average of 72.99 dm2. The interaction between the two experimental factors had a significant effect on all studied traits.