Abstract
A device for mechanical stimulation was developed to produce tomato seedlings at a high planting density. 1) The device could be moved automatically and enabled to change freely the operation time, traveling velocity and height. By this device, mechanical stimulation was applied near the growing points of the seedlings at the 2nd leaf stage for 20 days, the traveling velocity was 10 m/min, and the frequency one stroke per 30 min. 2) The mechanical stimulation of the seedlings exerted a favorable effects on the uniformity of stem length and the improvement of the percentage of dry matter as well as the prevention of spindly growth, without affecting adversely the dry matter production and the formation of flower buds. 3) It was possible to produce tomato seedlings at a high planting density by mechanical stimulation. Maximal planting density was about 1, 000 plants per m2 for seedling production at the 4th-5th leaf stages, and about 400 plants per m2 at the 6th-7th leaf stages. 4) Although seedlings in tissue-culture display considerable individual variations in growth at the early stage, mechanical stimulation exerted favorable effects on the uniformity of stem length and fresh weight of the seedlings.
