Regulating Vegetative Growth of Deciduous Fruit Trees in the Nursery by Adjuvant-Mediated Uptake of Gibberellin Biosynthesis Inhibitors Applied as Trunk Paints

2018 ◽  
pp. 553-559
Author(s):  
Eric A. Curry
Keyword(s):  
Vegetative Growth ◽  
Fruit Trees ◽  
Gibberellin Biosynthesis ◽  
Biosynthesis Inhibitors ◽  
Deciduous Fruit

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 Vegetative Growth Responses of Citrus Nursery Trees to Various Growth Retardants

2010 ◽  
Vol 20 (1) ◽  
pp. 197-201 ◽  
Author(s):  
Smit le Roux ◽  
Graham H. Barry
Keyword(s):  
Vegetative Growth ◽  
Foliar Application ◽  
Shoot Length ◽  
Internode Length ◽  
Citrus Limon ◽  
Gibberellin Biosynthesis ◽  
Growth Responses ◽  
Biosynthesis Inhibitors ◽  
Nursery Trees ◽  
Prohexadione Calcium

As part of a larger study to improve rind color of citrus (Citrus spp.) fruit, this initial study was conducted to determine the concentration of various gibberellin-biosynthesis inhibitors required to elicit a biological response in citrus trees, as measured by vegetative growth. Paclobutrazol and GA3 were included as control treatments at concentrations known to elicit growth-retarding or growth-promoting effects, respectively. Repeated (×4) foliar applications of GA3 (at 64 ppm) increased growth of ‘Eureka’ lemon (Citrus limon) shoots by 63%, with no significant effect on rootstock and scion diameters. Repeated foliar applications of prohexadione-calcium (ProCa) at various concentrations (100, 200, 400, or 800 ppm) as well as uniconazole (at 500 or 1000 ppm) and paclobutrazol (at 0.25%) had no effect on rootstock or scion diameters 8 months after the first application. The high concentrations of ProCa (800 ppm) and uniconazole (1000 ppm), and the paclobutrazol treatment (0.25%) reduced shoot length compared with the control. Uniconazole at 1000 ppm resulted in the most growth retardation, which resulted in 34% shorter shoot length than the control. Although the number of nodes on the longest shoot did not differ from the untreated control, internode length differed significantly among treatments. ProCa at 400 and 800 ppm, uniconazole at 1000 ppm, and paclobutrazol at 0.25% significantly reduced internode length relative to the control by 31%, 56%, 50%, and 28%, respectively. Vegetative growth of ‘Eureka’ lemon nursery trees was retarded following the repeated (×4) foliar application of gibberellin-biosynthesis inhibitors. ProCa at 400 to 800 ppm and uniconazole at 1000 ppm were identified as prospective treatments for further field studies to test their effects on rind color enhancement of citrus fruit.

scholarly journals Evaluation of N-P-K-Ca-Mg dynamics in plum (Prunus salicina Lindl.) var. Horvin under nursery conditions

2020 ◽  
Vol 14 (3) ◽  
pp. 334-341
Author(s):  
Francisco Orduz-Ríos ◽  
Karen Victoria Suárez-Parra ◽  
Pablo Antonio Serrano-Cely ◽  
Pablo Cesar Serrano-Agudelo ◽  
Nicolás Forero-Pineda
Keyword(s):  
Fruit Trees ◽  
Vegetative Development ◽  
Vital Part ◽  
Foliar N ◽  
Early Stages ◽  
Prunus Salicina ◽  
Tropical Highlands ◽  
Deciduous Fruit ◽  
Successful Establishment ◽  
Nutritional Balance

Temperate fruit trees are a vital part of the economy of the Cundiboyacense highlands in Colombia. The nursery stage is important because it guarantees development at the final grow site. Little is known about the fertilization processes and nutritional dynamics of deciduous fruit trees in the early stages. This research aimed to evaluate the dynamics of N-P-K-Ca and Mg, along with SPAD units, in grafted plum (Prunus salicina) var. Horvin plants under the conditions of tropical highlands, which were evaluated at different growth points (cm), from grafting to transplant. The foliar N concentrations were the highest, followed by the K, P and Mg concentrations. Macronutrient concentrations in the first-stage of grafted nursery plants require nutritional balance for vegetative development and successful establishment at the definitive grow site.

scholarly journals CHR: An Integrated Software Tool for chilling requirements

2020 ◽  
Author(s):  
Chen Chen ◽  
Wanyu Xu ◽  
Ningning Gou ◽  
Lasu Bai ◽  
Lin Wang ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Software Tool ◽  
Fruit Trees ◽  
Cold Weather ◽  
Chilling Requirements ◽  
Deciduous Fruit ◽  
Heat Requirement ◽  
Integrated Software ◽  
User Friendly ◽  
Analyze Data

Abstract Background Bud dormancy in deciduous fruit trees enables plants to survive cold weather. The buds adopt dormant state and resume growth after satisfying the chilling requirements. Chilling requirements play a key role in flowering time. So far, several chilling models, including ≤ 7.2 °C model, the 0–7.2 °C model, Utah model, and Dynamic Model, have been developed; however, it is still time-consuming to determine the chilling requirements employing any model. This calls for efficient tools that can analyze data. Results In this study, we developed novel software Chilling and Heat Requirement (CHR), by flexibly integrating data conversions, model selection, calculations, statistical analysis, and plotting. Conclusion CHR is a tool for chilling requirements estimation, which will be very useful to researchers. It is very simple, easy, and user-friendly.

scholarly journals Evaluation of Definitive Water Status Using the ‘Water Stress Indicator Sheet’ in Deciduous Fruit Trees

2016 ◽  
Vol 15 (4) ◽  
pp. 401-407 ◽  
Author(s):  
Kunihisa Morinaga ◽  
Kenichiro Koga ◽  
Hiroto Iga ◽  
Naoto Endo ◽  
Yuichiro Fujii ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Status ◽  
Fruit Trees ◽  
Stress Indicator ◽  
Deciduous Fruit
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