Effect of the application of prohexadione-calcium on the growth of ‘Packham’s Triumph’ and ‘Hosui’ pears (Pyrus communis L.)

Abstract

The necessity of controlling the vegetative growth of fruit trees is a growing concern for farmers since vigorous plants tend to have lower fruit yields. The use of chemicals that inhibit the vegetative growth of plants, such as prohexadione-calcium (PCa), an inhibitor of gibberellins which is currently used as a growth regulator for apple trees, is an agricultural practice aimed to help in reducing pruning time and cost. Pear trees grafted on vigorous rootstocks tend to present high rates of vegetative growth, hindering fruit production. Thus, this work aimed to evaluate the effect of the application of different doses of the plant growth regulator PCa on the vegetative growth, pruning time, radiation incidence, and productive and quality parameters of ‘Packham’s Triumph’ and ‘Hosui’ pears grafted on vigorous rootstocks. Two PCa applications were carried out, the first after the falling of petals (2009-10-10), and the second twenty-one days after the first (2009-11-02). The observed results showed a significant effect of PCa in reducing the vegetative growth of the pear trees and the pruning time in both cultivars. The effect on photosynthetic active radiation (PAR) was observed only in the ‘Packham’s Triumph’ variety, not being observed for the ‘Hosui’ pear trees. No statistical difference was observed relative to the quality parameters and yield of the fruits, in both cultivars, showing that PCa application has not caused any deleterious effect on fruit development.

Growth, Yield and Quality Performance of Pear (Pyrus communis L.) cv. ‘Santa Maria’ under High Density Planting

“…The less shoot growth in the high fruiting year was due to less amount of carbohydrate for shoots as it was used for fruit formation [52]. Observed that, there were differences in the one-year-old shoot growth between pear cultivars 'Packham's Triumph' (34.3 cm) and 'Hosui' (80.4 cm) [13]. Reported 1-year-old shoot length as following 'Santa Maria'/QA (35.56 to 49 cm), 'Santa Maria'/OHF333 (15.69 to 37.90 cm) [17].…”

Ca2+ mediates transcription factor PuDof2.5 and suppresses stone cell production in pear fruits

“…Calcium is a secondary messenger that participates in cell signaling pathways and is closely related to cell wall development, which plays an important role in regulating fruit quality (Wójcik et al, 2014). Modulation of calcium has been reported in terms of the fruit quality of several pear species (Sajid et al, 2019;Zudaire et al, 2019;Dalzochio et al, 2021). Meanwhile, Ca 2+ also regulates the lignin synthesis process.…”