INFLUENCE OF FOLIAR K, Mg AND MICRO-NUTRIENTS ON THE YIELD, QUALITY AND ESSENTIAL OIL CONSTITUENTS OF GARLIC IN SANDY SOIL

Abstract

Two field experiments were conducted under newly reclaimed sandy soils irrigated by drip irrigation system at El-Bostan area, Nubaria region, during the winter season's 1999/2000 and 2000/01. The study aimed to determine influence of foliar application of potassium fertilizer (With (K1) or without (K0)) accompanied with different mixtures of micronutrients and Mg {M1 (Fe + Zn + Mn), M2 (M1 + Cu) and M3 (M2+Mg)} and concentrations (control, 25, 50, 75 and 100 g/100L H2O) on garlic "Aspani" cultivar growth, productivity, quality, macroand micronutrients concentration, essential oil content and constituents.The results showed significant effect for the main effects and interaction of the studied parameters (potassium, nutrients mixtures and concentrations) on vegetative growth characters (plant height, leaf number and leaf area), yield and its components (bulb fresh weight, average clove number and weight and bulbs yield) and bulbs features (neck diameter, bulb diameter, bulbing ratio, TSS% and dry matter%). Main effects and interactions indicated that foliar application of potassium (K1) and M3 mixture with increasing foliar spray concentration up to 100g/100 L H2O increased all Aspani garlic plant growth, yield and bulb features presenting importance of adjusting nutrients supplying.Foliar application is particularly useful under conditions where nutrient uptake from the soil is restricted. Garlic leaves and cloves N, P, K, Mg, Fe, Zn, Mn and Cu concentrations were significantly affected by interaction of K treatments, nutrient mixtures and concentrations. The differences were located in each nutrient due to application of K1 in increasing order of M3  M2  M1 and with increase the concentration. The oil percentage was found to slight gradually increase with increasing the level of fertilizer inside each mixture of M1, M2 and M3. Nutrients mixture in M3 treatments was the superior with K1. Ten constituents identified in the essential oil of garlic 'Aspani' cultivar by using Gas chromatography-mass spectrum technique (GC-MS). They were di-allyl disulfide (di-propenyl disulfide) as major component, the intermediate components were allyl sulfide, methyl allyl tri-sulfide and Allyl tri-sulfide and the rest were minor. Effect of K and different mixtures and concentrations on the percentage of the volatile oil constituents showed the same trend with volatile oil percentage i.e. potassium fertilization significantly increased the essential oil constituents percentage. Also there were differences resulted from adding different mixtures of M1, M2 and M3. As for the main effect of different concentrations of foliar spray application could be also notes that, the percentage of essential oil constituents slight progressively increased by increasing the concentrations of fertilizers.