Controlling Citrus Rootstock Sprouting in the Nursery Using Tre-Hold

Tests were conducted to determine whether Tre-Hold , a commercially available sprout inhibitor for newly planted trees in citrus groves, could be used to prevent axil lary bud growth on citrus rootstock seedlings in the nursery. Tre-Hold® was applied at formulated concentration (1X), one-half (V2X), and one-fourth (1AX) to container-grown green house seedlings before budding and full concentration (1X), three-fourths (3/4X), and one-half (V2X) to field-grown seed lings after budding. When Tre-Hold® was applied to green cit rus tissue, no phytotoxicity occurred. It was possible to control dormancy of individual buds without affecting adja cent buds. Full and V2X concentrations of the formulated product prevented rootstock sprouting of container trees and 1X, 3AX, and V2X prevented sprouting on field-grown trees. Full concentration of Tre-Hold® was found to prevent scion bud healing of container-grown trees when the seedling was treated before budding. Application a few days before un wrapping and after the scion bud had healed did not affect bud healing or budling growth in the field nursery.