Response Of Onion (Allium Cepa) Crop To Foliar Application Of Humic Acid Under Rain-Fed Conditions

Humic acid is an organic chemical contains many elements which increase the availability of nutrient elements by holding them on mineral surfaces and consequently affect plant growth and yield positively. This experiment was carried out to see the effect of spraying humic acid at various concentrations (0, 500, 750 and 1000 mg L-1) and frequency (G1: at 21days after transplanting, G2: two times sprays of Humic acid at 21 and 35 DAT andG3: three times sprays of Humic acid at 21, 35 and 45) on growth of onion (Allium cepa L. Giza 20). A field experiments were carried out during the two seasons of 2014/2015 and 2015/2016. Foliar application of Humic acid significantly increased all growth characters (i.e. Number of leaves, leaf length, leaf diameter, neck diameter, fresh weight of leaves, root length and number, bulb length and diameter and fresh weight of plants) compared to untreated control plants. Among different times of Humic acid applications, Triple spray of humic acid (G3) was better than double (G2) or single spray (G1) in terms of having significantly higher number of leaves, leaf length, leaf diameter, neck diameter, fresh weight of leaves, root length and number, bulb length and diameter and fresh weight of plants. It is concluded that spraying onion with humic acid at 1000 mg L-1 resulted in higher growth and yield. (C) 2018 Friends Science Publishers