EFFECT OF FOLIAR SPRAYING WITH MELATONIN, POTASSIUM, AND ZINC ON SOME VEGETATIVE TRAITS AND SAPLING CONTENT OF SOME CHEMICALS IN KUMQUAT SAPLINGS

Abstract

The experiment was conducted in one of lath houses of Fruit Section belong to Department of Horticulture and Landscape Engineering, College of Agricultural Engineering Sciences, University of Baghdad, Research Station (B) for 2022 season to study effect of spraying with the growth regulator melatonin, potassium, and zinc on the growth of 3-year-old kumquat saplings Budded on lemon rootstock. A factorial experiment consisting of three factors with three replicates was conducted, using the Randomized Complete Block Design

(RCBD) experimental design. The factors were foliar spraying with melatonin, potassium sulfate, and organic zinc. The addition was made at two times: spring and autumn. The results were as follows, where the main factor of the three factors, their interaction, had a significant effect on the traits under study. The results indicate that the concentration of 20 mg L^-1 of melatonin outperformed in the following vegetative traits (plant height, stem diameter, number of branches, number of leaves, leaf area). The same factor also increased the plant content of the following chemicals (nitrogen, potassium, zinc, chlorophyll, carbohydrates). It is also observed that potassium sulfate at a concentration of 3000 mg L^-1 and organic zinc at a concentration of 1000 mg L^-1 gave the highest measurements for the same traits affected by melatonin.