Application of a Steroidal Hormone Affects Fruit Yield and Quality in ‘Ataúlfo’ Mango (Mangifera indica L.)

In order to evaluate the effect of varying foliar applications of the brassinosteroid (BR) (CIDEF-4) prior to flowering on Mangifera indica L. cv ‘Ataulfo’ and to associate it with fruit quality and yield, the present study was conducted from September 2013 to May 2014 in a commercial orchard near Tapachula, Chiapas, Mexico. Treatments were: T1: untreated control with potassium nitrate (KNO2 2%) applied, T2: KNO2 2% plus Br (4g), T3: KNO2 (2%) plus 4 G of Br applied in two equal portions at different dates, (T4) KNO2 (2%) plus 4 G of Br applied in three equal portions at different dates. Each treatment was repeated ten times and one tree was considered an experimental unit. Flowering and fruiting variables were evaluated in the field and post harvest variables in the laboratory. Flowering was registered in ten inflorescences in each tree. Results indicate varying response to Br applications and to its effect on morphological and physiological yield variables. Yield per tree was increased with one Br application and flowering and fruit let presence increased with two applications. Postharvest fruit quality was enhanced showing more firmness and greater pectinmethylsterase activity and Brix readings. Fruits harvested from Br treated panicles showed greater weight loss.