Response of Tomato Growth to Foliar Spray and Root Drenching of Aqueous Garlic Extract: A Cocktail of Antioxidative Defenses, Chlorophyll, Carotenoid and Soluble Sugar Contents

In our previous work, aqueous garlic bulb extracts (AGE) with 100-200 mu g mL(-1) have shown considerable effects on the growth of tomato and cucumber plants, however, to investigate the effects for repetition of these applications more than once in a growing period, a pot experiment in a plastic tunnel was conducted to evaluate whether a single or a repeated application of AGE would be inducible for enhanced tomato growth. AGE was applied at the rate of 100 mu g mL(-1) as foliar spray and root drenching applications and their respective effect was determined on the growth and physiological conditions of tomato plants. Findings of the study revealed that AGE can modulate the antioxidant enzymes, chlorophyll content and soluble sugar content of the treated tomato plants. The effect however, depends upon the method of application and moreover, the repetition of treatment as root irrigation may cause adverse effects on the treated plants. AGE foliar and root application influenced plant growth parameters such as plant height, shoot fresh weight, root length, fruit size and weight. Similarly, differences were found in the antioxidative response of the treated plants; nonetheless, these treatments affected the abundance of chlorophyll, carotenoid, and the total soluble sugar contents in the plants. Current findings indicate that garlic extracts bear priming effects which could be useful to enhance certain physiological aspects of the receiver plants; the bioactive role of aqueous garlic extracts is hereby addressed to postulate a botanical stimulator for enhanced vegetable production under specialized horticultural situations. (C) 2018 Friends Science Publishers