Mechanical Conditioning to Control Height

Mechanical conditioning is an excellent means of regulating the growth of vegetable transplants and some ornamental bedding plants. It improves the stature, appearance, handling characteristics, and overall quality of treated plants. The application procedures reported for transplants have included wind, shaking, brushing, and more recently impedance; all of which result in physical displacement of the growing points. Brushing has been most commonly studied for mechanical conditioning in high density transplant production. Brushing reduces plant height, increases stem and petiole strength, improves insect resistance in the greenhouse, tends to improve stress tolerance and enhance stand establishment in the field, and has no effect on crop yield. Although growers using the technique have been very pleased with the quality of brushed vegetable transplants, widespread commercial application of brushing is limited by a lack of automation.