Two field experiments were conducted during the two successive winter seasons of 2006/2007 and 2007/2008 in the Vegetable Private Farm at El-Khattara village, Sharkia Governorate to evaluate the effect of sulphur quantity and its application time, on yield, quality and storability of garlic under sandy soil conditions using drip irrigation system. This experiment included ten treatments, as follows : (1) Control ( without sulphur), (2) 100 kg S/fed at soil preparation (SP), (3) 200 kg S/fed at SP, (4) 300 kg S/fed at SP, (5) 100 kg S/fed as 50 % at SP+50 at 30 days after planting (DAP), (6) 200 kg S/fed as 50 % at SP+50 at 30 DAP, (7) 300 kg S/fed as 50 % at SP+50 at 30 DAP, (8) 100 kg S/fed as 50 % at SP+25 at 30 DAP+ 25 at 60 DAP, (9) 200 kg S/fed as 50 % at SP+25 at 30 DAP+ 25 at 60 DAP, (10) 300 kg S/fed as 50 % at SP+25 at 30 DAP+ 25 at 60 DAP.
All applied sulphur quantity at different tested application times and doses had significant enhancing effect on garlic plant growth ( roots, bulb, leaves and total dry weights/ plant), plant nutrients uptake and bulb quality at harvesting time (total carbohydrate, total sugars, S, DM volatile oil and pungency percentages in bulbs) comparing to unfertilized control plants. Also, sulphur fertilized plants resulted bulbs able to store for long times with minimum percentages of emaciation, sprouting and weight loss during storage period as compare to bulbs resulted from unfertilized plants. The superior treatment which resulted the highest values represented bulb yield of grade 1, 2, exportable, marketable, and total yield /fed as well as average bulb weight was 200 kg S/fed as 50 % at SP + 50% at 30 DAP. It recorded 27 and 29 % increases in total yield over control treatment during the two tested seasons, respectively. The highest sulphur use efficiency (SUE) as Kg bulb production/ Kg S fertilizer was recorded under treatments effect of 100 Kg S/ fed as 100 % at SP or 200 kg S /fed as 50 % at SP + 50 % at 30 DAP.