Effect of Prohexadione calcium, 6-benzyl amino purine and 6-furfuryladenine on vegetative growth and fruit quality in apple

It is well established that the climatic change is alteringyield in fruit trees. This adversity reflects, among others, extremetemperature modifications in northern Mexico. This effect modifiesnegatively the physiology of apple trees (Malus domestica Borkh.),originating excessive shoot growth and a decrease in flower bud formation.In this study, Prohexadione-Ca (P-Ca), 6-benzyl amino purine(BAP) and N6-furfuryladenine (kinetin) were evaluated on shootand reproductive growth in Golden Delicious apple trees in ArteagaCoah., Mexico. A completely randomized design with 12 treatmentswas used. These were: Control, Prohexadione calcium (Ca-P) at dosesof 150, 300 and 450 mg/L, cytokinins (CK) [6-benzylaminopurine(BAP) + N6-furfuryladenine (kinetin)] at concentrations of 150 and300 mg/L, and combinations of these bioregulators to the doses mentioned.The experimental unit consisted of two trees per treatment.Variables evaluated were: shoot growth, fresh weight, vitamin C, andcarotenoid concentration in fruit and return bloom. P-Ca drasticallyreduced shoot growth and increased return bloom. Carotenoids andvitamin C concentrations were increased in fruits with this retardant.Cytokinins applied individually or in combination with P-Ca causedincrements on flower bud formation, fruit weight, and carotenoid andvitamin C concentrations in harvested fruits.