THINNING ‘GOLDEN DELICIOUS’ APPLES USING SINGLE OR COMBINING APPLICATION OF ETHEPHON, NAA OR BA
2007, 8 (2) p. 141-146
Thinning of ‘Golden Delicious’ apples was studied after single application of ethephon 200 ppm at the balloon stage, of naphthaleneacetic acid (NAA) 10 ppm or benzyladenine (BA) 100 ppm at 10 mm fruit diameter, after sequential application of ethephon followed by NAA or/and BA or tank mixed NAA + BA application. The single application of ethephon, NAA or BA, as well as the sequential application of ethephon applied fi rst at the balloon stage and NAA or BA applied at 10 mm fruitlet diameter did not cause a signifi cant reduction of fi nal crop load nor did it cause an increase of the mean fruit weight. The treatment of tank mixed application NAA + BA at 10 mm fruit diameter and, similarly, the treatment of sequential spray of ethephon followed by tank mixture of NAA + BA had both a signifi cant effect on thinning in the studied year with the signifi cant reduction of fi nal fruit retention and the signifi cant enhancement of fruit weight. No additional thinning due to the ethephon application happened in the sequential treatments when ethephon was applied fi rst and NAA + BA mixture was applied afterward.