CONTROL OF BULBING IN GARLIC
Experiments were carried out to quantify the factors responsible for failure of bulbing in late-planted crops and to investigate ways to overcome this problem.
Results indicate that poor bulbing in late-planted crops in Bangladesh was probably due to increasing air and soil temperatures at the end of the season. Temperatures above 20°C had adverse effects on growth and development. Results also demonstrated the possibility of accelerating growth by either precooling treatments or by the use of growth regulators. Seed cloves treated either at 5 or 10°C for 15–30 days before planting showed accelerated initiation, development, and maturity of bulbs relative to those of cloves stored at 15 and 20°C. Preplanting treatment of cloves by 24-h immersion in aqueous solution of growth retardants (Cycocel and Paclobutrazol) enhanced initiation, development, and maturity of garlic bulbs, whereas, gibberellic acid delayed bulb formation and maturity, but enhanced leaf growth. The stimulatory effects of growth retardants on bulb growth and development were counteracted by subsequent application of gibberellic acid. It was concluded that growth retardants could be used as substitutes for the cold requirement of garlic.
The possible applications of these findings to environmental conditions in Bangladesh are discussed, and proposals are made for improving production of garlic through the use of cold storage and growth regulators.