Chemical Removal of Premature, Unwanted Azalea Buds

Spray applications of 4.2% Off-Shoot-0 (a mixture of methyl ester of fatty acids C₆, C₈, C₁₀, and C₁₂) effectively destroyed flower bud scales and flower parts on the azalea (Rhododendron simsii Plachon.) cultivars ‘Prize’ and ‘Kingfisher’. The addition of ethephon to Off-Shoot-0 did not increase the destruction of bud scales and flower parts. Dikegulac-sodium and oxathiin alone or in combination with ethephon did not significantly destroy scales or flower parts. Destructive chemical pinching agents such as dimethyl dodecylamine and n-undecanol usually were as effective as Off-Shoot-0 in killing bud scales but not flower parts. Cultivars differed slightly in their response to chemicals designed to destroy unwanted flower buds.