Abstract
The effect of non-volatile (as a paste) and volatile compounds from five Allium species on the bud dormancy of grapevine cuttings ('Muscat of Alexandria' and 'Kyoho') were examined. Painting freshly grated paste from the five, garlic, Chinese chive, rakkyo, onion and Welsh onion on the upper cut surface of single-bud cuttings of dormant grapevines did not accelerate budbreak, whereas volatile compounds from these plants hastened it. The effect was greatest with volatile compounds from etiolated Chinese chive, followed by non-etiolated Chinese chive, rakkyo, garlic, and onion. The advancement of budbreak by these compounds was less than that by diallyl di- and trisulfide substances in garlic. Volatile compounds from garlic, etiolated Chinese chive, and rakkyo were less effective when the preparations were boiled. A 12 hr- or 24 hr-exposure to volatile compounds of garlic, etiolated Chinese chive, and rakkyo promoted budbreak to the same extent as did commercial garlic oil. Temperature had no effect on budbreak when cuttings were exposed to volatiles from non-etiolated Chinese chive for 24 hr, although high temperature induced budbreak in cuttings treated with garlic volatiles. Chinese chive and rakkyo promoted budbreak in grapevines ; the substances were supposed to be volatiles similar to those in garlic.
