RESPONSE OF GARLIC PLANTS TO NITROGEN AND SULPHUR FERTILIZATION

Abstract

Garlic (Allium sativum L.) is an important vegetable crop grown in the world. It is valued for its distinctive pungent flavor and is an essential ingredient of the cuisine in many regions of the world. Hence, the present studies were undertaken in a field experiments were conducted at Agricultural Research Station El-kasasin, Ismailia Governorate, Egypt, (30o 33׳ 31״ N- 30° 56׳ 7״ E, elev. 15.8 m) during two seasons of 2013/2014 and 2014/2015 to evaluate growth, yield and its components, as well as chemical constituents in cloves and bulb storability of garlic (Allium sativum L.) cv. Sids-40 under three levels of nitrogen (90, 120and 150 kg N/fed) and four levels of elemental sulphur (0, 50, 100 and 150 kg S fed-1).The experiment was laid out in split plot design with three replications assigning nitrogen levels in the main plots and sulphur levels in sub-plots. The results of this study revealed that application of nitrogen and sulpher and their combinations had significant effects on most of the studied characters. The maximum plant height (80.91cm), leaf number (11.96), bulb diameter (6.40cm), and number of cloves per bulb (21.33) and bulb yield (8980 kg fed-1) were observed with N150S150 treatment. While the minimum plant height (52.64cm), leaf number (7.91), weight of bulb (58.40g) and projected yield (6620 kg fed-1) were observed under N90S0 treatment. S at 150 kg fed-1 and nitrogen at 90 kg/fed recorded the minimum physiological loss in weight (%) for garlic during the storage period (6 monthes). However increasing nitrogen and decreasing sulphur level had adverse effect on storability of bulbs. Sulphur fertilization increased the Allicin concentration from 13.87mg g-1 in the control treatment to 26.59mg g-1 dry weight at 150 kg S fed-1 after 2 weeks of storage period. Allicin decreased gradually in the garlic cloves during the storage period (12 weeks).