After 14 days after full bloom, the pear trees were treated as follows:
1) with BA at dose of 50, 100, 150 ppm;
2) with BA+GA, each compound at dose of 12.5, 25, 50 ppm.
At harvest, the fruits were evaluated for size and quality characteristics.
The highest concentrations of BA + GA (25 and 50 ppm) and the intermediate of BA (100 ppm) increased fruit size for weight, diameter and length.
Higher values of weight and length of the fruits were obtained from plants treated respectively with 25 and 50 ppm of BA + GA. Treatment with 25 ppm of BA + GA has increased by 20.2% the weight of the fruit compared to untreated plants (58.7 g vs. 48.8 g). However, it was found an important decrease of production in the plants treated with 25 and 50 ppm of BA + GA, respectively by 54% and 60%.
In plants treated only with BA at a concentration of 100 ppm it was detected a significant increase in fruit size (+ 11.3%) without reduction in yield.
Moreover, plants treated with these growth regulators have produced pears with a higher soluble solids content than the untreated plants.
Treatment with these hormones did not affect the pH of the fruits and plants treated with BA and BA + GA produced pears darker, greener and less yellow.
The scientists conclude that BA treatment at concentration of 100 ppm can be considered a proper cultivation practice to improve quality and size of pears of low yielding summer varieties without negative impacts on yield and on the shape of pears.
Source: Canli F.A., Pektas M., ‘Improving fruit size and quality of low yielding and small fruited pear cultivars with benzyladenine and gibberellin applications’ , 2015, European Journal of Horticultural Science, Vol. 80 (3) 103-108. http://www.pubhort.org/ejhs/80/3/2/index.htm