Growth characters, tree nutritional status, fruit set %, June drop %, yield and fruit quality of Valencia orange trees in
response to spraying salicylic acid at 0.0 to 400 ppm either applied once at growth start or twice at growth start and again
just after fruit setting were investigated during 2012 /2013 and 2013/ 2014 seasons.
Spraying salicylic acid at 100 to 400 ppm once or twice considerably improved all growth characters , leaf pigments,
N, P, K, Mg and Ca percentages, initial fruit set %, fruit retention %, yield and fruit quality over the check treatment. All
salicylic acid treatments effectively reduced June drop. Using salicylic acid at 400 ppm once or twice caused a significant
reduction on all the aforementioned parameters comparing with using salicylic acid at 100 to 200 ppm. Two sprays of
salicylic acid were preferable than using it once in this connection.
Treating Valencia orange trees twice at growth start and just after fruit set with salicylic acid at 200 ppm was
responsible for promoting yield and fruit quality.