Effects of Humic Acid Applications on Growth and Yield of Garlic (Allium sativum L.) in Kandahar, Afghanistan

Garlic (Allium sativum L.) is one of the most important vegetable crops and a common culinary spice used daily by most people around the world. Humic acid can enhance garlic growth and yield, and previous studies have reported that its application improves these traits. Although the effects of humic acid combined with other nutrients on the growth and quality of garlic have been studied, further comprehensive investigations are still needed, especially in Afghanistan's bioclimatic conditions. Therefore, the study aimed to examine the effects of humic acid on the growth and yield of garlic. The specific objective of the study was to determine the optimal amount of humic acid for promoting the growth and yield of garlic in Kandahar. A filed experiment was conducted at the research farm of Afghanistan National Agricultural Sciences and Technology University (ANASTU), using Randomized Complete Block Desing (RCBD) with five treatments T0 (no Humic acid), T1 (10 Kg ha-1 Humic acid), T2(15 Kg ha-1 Humic acid), T3 (20 Kg ha-1 Humic acid), and T4 (25 Kg ha-1 Humic acid) each replicated trice. The results showed that plant height, No. Leaves of plant-1, and leaves length increased significantly by 30.40%, 28.21%, and 19.97% respectively, compared to the control at harvest; moreover, Bulb weight, bulb polar diameter, bulb equatorial diameter, No. Of cloves bulb-1, cloves weight, cloves length, clove diameter, and bulb yield also significantly increased by 68.79%, 59.42%, 20.72%, 17.38%, 26.50%, 36.36%, 47.28%, 71.09 %, respectively, in comparison to the control. It is concluded that the highest growth and yield of garlic was recorded in the treatment where 25 kg ha-1 Humic acid was applied.