Effect of Fertilization NPK-Nano and Humic Acid on Some Vegetative Growth Characteristics and Mineral Content of Apple Seedlings (Malus Domestica) Cv. Ibrahimi.

The research was carried out in lathhouse on one-year-old apple seedlings of the Ibrahimi variety in the Karma-Fallujah region for the 2021 growing season to study the effect of methods of adding nano-fertilizer and humic acid on seedling growth. A two-factor experiment was designed according to a randomized complete block design, with three replicates and two seedlings per experimental unit, so the number of seedlings was 54. The first factor includes NPK nanofertilizer at three levels (0- and 2-ml L-1 foliar spray and 5 ml L-1 soil application). The second factor is humic acid at three levels (0 and 5 g of seedlings - 1 foliar spray and 10 g of seedlings - 1 soil application). The results of the study show that the NPK nano-fertilizer and the method of adding caused a significant effect on most of the studied traits. The treatment with a concentration of (5 ml L-1 soil application) gave the highest rate for the trait, Plant height, number of leaves, and number of branches. As for humic acid and the procedure of adding it, the treatment with a concentration of (10 g seedlings - 1 soil application) gave the highest rate for number of leaves, number of branches and the chlorophyll total phenols content of the leaves. The results show that the interaction between the levels of nano-NPK and humic acid had a significant effect in increasing the rates of the measured traits, the treatment with 5 ml L-1 of the soil application NPK nanoparticles and 5 g of seedlings-1 foliar spraying of humic acid achieved the highest rate in some measured traits, including, chorophyll and total phenols content of the leaves. The Means of the coefficients were compared according to the L.S.D. test at a probability level of 0.05. Keywords: apple, humic acid, nano-NPK, total phenols, Cv. Ibrahimi