Use of Bioregulators to Control Vegetative Growth of Fruit Trees and Improve Fruiting Efficiency

1984 ◽  
pp. 93-99 ◽  
Author(s):  
MAX W. WILLIAMS
Keyword(s):  
Vegetative Growth ◽  
Fruit Trees

scholarly journals Chemical Control of Excessive Vegetative Growth of Fruit Trees with Emphasis on Stone Fruit Species

1985 ◽  
Author(s):  
Amnon Erez ◽  
M.W. Williams ◽  
Yosef Ben-Tal ◽  
B. Avidan ◽  
E.A. Curry ◽  
...  
Keyword(s):  
Vegetative Growth ◽  
Chemical Control ◽  
Fruit Trees ◽  
Stone Fruit ◽  
Fruit Species

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

2021 ◽  
Vol 10 (8) ◽  
pp. e3110816801
Author(s):  
Odair Ângelo Dalzochio ◽  
Wendel Paulo Silvestre ◽  
Gabriel Fernandes Pauletti
Keyword(s):  
Growth Regulator ◽  
Vegetative Growth ◽  
Fruit Trees ◽  
Fruit Production ◽  
Quality Parameters ◽  
Agricultural Practice ◽  
Pyrus Communis L ◽  
Pear Trees ◽  
Prohexadione Calcium ◽  
Different Doses

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.

scholarly journals The INFLUENCE OF TEMPERATURE AND FUNGAL COMMUNITY ON GROWTH AND SPORULATION OF Diaporthe FROM FRUIT PLANTS

2020 ◽  
Vol 19 (5) ◽  
pp. 71-79
Author(s):  
Barbara Anna Abramczyk ◽  
Ewa Dorota Król ◽  
Ewa Dorota Zalewska ◽  
Beata Zimowska
Keyword(s):  
Vegetative Growth ◽  
Growth And Development ◽  
Pathogenic Fungus ◽  
Extreme Temperature ◽  
Fruit Trees ◽  
Climatic Conditions ◽  
Effect Of Temperature ◽  
Influence Of Temperature ◽  
Fruit Plants

The purpose of this experiment was to determine the influence of temperature and fungi colonizing fruit plants on Diaporthe, a pathogenic fungus in Poland. The biotic series method was used to test in vitro the effects of the fungi colonizing fruit trees on isolates of Diaporthe. Among the 13 fungal species tested, six inhibited the growth and development of Diaporthe; while another two species were neutral and the rest showed the lack of limiting impact in relation to the pathogen. Fungi present in the shoots of fruit plants was able to limit the growth and development of Diaporthe spp., both in chemically-protected and non-protected orchards. Studies on the effect of temperature indicated that the optimum temperature for vegetative growth of isolates of Diaporthe ranged from 20°C to 30°C, and for conidial sporulation from 25°C to 30°C. However, the ability of Diaporthe sp. to survive at extreme temperature (–20°C and +35°C) enables their vegetative growth in climatic conditions worldwide.

scholarly journals Prohexadione-Ca in Fruit Trees: Modes of Action of a Multifunctional Bioregulator

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 851D-851
Author(s):  
Wilhelm Rademacher*
Keyword(s):  
Vegetative Growth ◽  
Disease Incidence ◽  
Crop Protection ◽  
Acc Oxidase ◽  
Fruit Trees ◽  
Pathogen Resistance ◽  
Convincing Evidence ◽  
Gibberellin Biosynthesis ◽  
Fruit Drop ◽  
Open Canopy

APOGEE and REGALIS have recently been introduced in a number of countries for use in pome and other fruit trees. These products contain 27.5% and 10% of prohexadione-Ca (ProCa), respectively. As a result of inhibiting excessive vegetative growth, less summer and dormant pruning is required, the ratio between vegetative growth and fruit formation is improved, and crop protection is facilitated due to the reduction of tree row volume and a more open canopy. Additionally, a lowered incidence of diseases such as fire blight and scab is observed, which is not due to a direct bactericidal or fungicidal effect of the compound. Further, the compound may reduce fruit drop early in the season. Prohexadione is a structural mimic of 2-oxoglutaric and ascorbic acid. Therefore, distinct dioxygenases are blocked, which require these compounds as a co-substrate. Such enzymes catalyze late steps in gibberellin biosynthesis. After treatment with ProCa, less growth-active gibberellins are formed and treated plants remain more compact. ProCa also affects ACC oxidase, another dioxygenase. The resulting reduction of ethylene formation, in addition to the availability of more assimilates for fruit growth, is most likely the cause of reduced fruit drop. 2-Oxoglutaric acid-dependent dioxygenases are also involved in the metabolism of flavonoids and their phenolic precursors: In shoots of apples and pears, ProCa causes considerable changes by inhibiting flavanone 3-hydroxylase. Convincing evidence is now available that ProCa triggers pathogen resistance by inducing the formation of 3-deoxyflavonoids, in particular luteoforol, with phytoalexin-like properties. Morphoregulatory effects caused by ProCa are only of secondary relevance for the reduction of disease incidence.

scholarly journals Recovery of Declined Pear Tree Vitality through Grafting with Scions from a Vigorous Cultivar

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 595c-595
Author(s):  
Hsin-Shan Lin ◽  
Jia-Shing Lin
Keyword(s):  
Relative Humidity ◽  
Vegetative Growth ◽  
Fruit Trees ◽  
Temperature Tolerance ◽  
Heavy Load ◽  
Tree Vitality ◽  
Quick Recovery ◽  
Environmental Status ◽  
Pyrus Serotina ◽  
Higher Temperature

Taiwan, located in subtropic regions, naturally is not an ideal region for temperate-zone fruit trees' production due to the supra-optimum temperature, heavy rainfall, and higher relative humidity in summer and insufficient chilling in winter. Higher relative humidity and temperature in summer and autumn months cause excessive vegetative growth, resulting in poor flowerbud initiation and formation. Typhoon invasions result in the severe damage of twigs as well as the loss of quality and yield of fruits. In order to overcome these natural barriers, Hengshan (Pyrus serotina Rehd.) pear has been selected as a major cultivar for lowlands in Taiwan. It has low-chilling requirement and higher temperature tolerance. Branches of Hengshan are pulled and tied to a horizontal wire net to adapt to the environmental status. This trellis system enhances flowerbud initiation through the retardation of vegetative growth. It also induces numerous water shoots. Scions from high-chilling cultivars grown at a high altitude on mountains are grafted onto water shoots of Hengshan pear trees. The system has been successful in the production of both high-chilling pears in June and the Hengshan pears in August, and has made production of both pears an important industry in Taiwan. Heavy load and trellis systems, however, result in hastening the senescence of Hengshan trees. Vitality of trees could be restored by grafting scions from a vigorous cultivar, P. koehnei, onto the terminal position of the branches. The practice resulted in several advantages including: 1) uniform growth of branches, 2) redistribution of water shoots, 3) inducing formation of calluses on old damaged trunks, 4) quick recovery of mealybug-damaged branches, 5) rejuvenation of branches, and 6) termination of dormancy.

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