Abstract
Pineapple orange trees ware sprayed with gibberellic acid (CA) at 2.5, 5.0, 7.5 and 10.0 ppm and/or ringed on 29th .Thnuary 8th February and 18th February before blooming. Earlier ringed branches markedly increased fruit numbers per branch. This was associated with greater number of flowers, fruit set and reduced fruit drop. All treatments of GA up to 7.5 ppm increased fruit number but higher concentration at 10 ppm reduced the fruit number per branch. GA spray at 7.5 ppm combined with ringing on 29th January was the most effective treatment to improve yield.
INTRODUCTION
Sweet orange (Citrus sinensis L. Osbeck) are commercially the most important and widely cultivated species of citrus throughout the world although some good cultivars are shy bearing. Low yield of sweet oranges may be attributed to internal imbalance of growth regulators and/or other physiological factors. Application of gibberellic acid (GA) coupled with ringing operations improved cropping potential of some grape fruit cultivars (Furr and Armstrong, 1956) and many other fruits (Dennis and Edgerton, 1966). It was therefor, considered important to test several variables of GA doses and ringing in different combinations oni. pineapple cv. of sweet oranges.
Goren and Monsellse (1971) reported that ringing before flower opening in low bearing orange trees increased yield.
