FOLIAR APPLICATION OF SOME GROWTH BIOREGULATORS AND THEIR EFFECT ON THE YIELD AND NUT QUALITY IN PECAN.

The pecan [Carya illinoinensis (Wangenh.) K. Koch.] is a deciduous species with high economic importance and nutritional value that exhibits alternate bearing. The mitigation of alternate bearing through the floral initiation of pistillate flowers is very important to improve the yield and nut quality. The aim of this research was to evaluate the effect of the application of some growth bioregulators on the yield and nut quality in pecan. The application of gibberellic acid (GA3 - 50 mg L-1), thidiazuron (TDZ - 10 mg L-1) and prohexadione calcium (PCa - 500 mg L-1) was carried out during two years (2017 and 2018) on young Western Schley pecan trees from an orchard located in Chihuahua, Mexico. The foliar application of growth bioregulators minimized alternate bearing by maintaining the number of fruits set before harvest between the evaluation years. Between the evaluated production cycles, the data obtained indicate that the application of growth bioregulators affected the yield, although the nut weight per kilogram remained similar with TDZ (5.6 and 5.7 g). PCa was the best treatment for both parameters. Likewise, significant variation in the alternate bearing index with respect to the control was observed. On the other hand, the kernel percentage showed the best behavior between years and treatments with the use of GA3 and PCa. The use of the evaluated growth bioregulators could be an agronomic management strategy to minimize alternate bearing in Western Schley pecan trees. [ABSTRACT FROM AUTHOR]