EFFICACY OF FOLIAR APPLICATION OF TWO NAPHTHALENEACETIC ACID SALTS FOR OLIVE FRUIT THINNING
Olive fruit populations are successfully decreased using the ammonium salt of naphthaleneacetic acid (NAA-NH4). California olive growers have used NAA for about 30 years. Several salts of NAA have been manufactured for numerous agricultural applications throughout the world. The original clearance for NAA use took place in the 1950's, recent environmental Protection Agency (EPA) policy calls for re-clearance of agricultural chemicals, such as NAA, that were approved using less vigorous procedures in the past. Currently, AMVAC Corporation holds the manufacturing rights for NAA in America. It is their desire to develop one of the four NAA salts (ammonium, potassium, sodium, and amide) for all applications, thereby reducing EPA clearance costs. The olive industry has used NAA-NH4 for fruit thinning yet the potassium salt of NAA would be the least expensive of the four salts to develop for AMVAC. Direct comparison of the potassium and ammonium salts at two concentrations on two varieties in three different locations in California, showed that equal chemical fruit thinning performance can be achieved from both NAA salts.
Martin, G.C., Connell, J.H., Freeman, M.W., Krueger, W.H. and Sibbett, G.S. (1994). EFFICACY OF FOLIAR APPLICATION OF TWO NAPHTHALENEACETIC ACID SALTS FOR OLIVE FRUIT THINNING. Acta Hortic. 356, 302-305