Response of Growth Inhibitor Paclobutrazol in Fruit Crops

Prunus ◽  
2020 ◽  
Author(s):  
Naira Ashraf ◽  
Moieza Ashraf

Paclobutrazol (PBZ; IUPAC name: (2RS, 3RS)-1-(4-chlorophenyl)-4, 4-dimethyl-2-(1H-1, 2, 4-triazol-1-yl) pentan-3-ol) is a triazol derivative and an antagonist of gibberellins. It has been shown to inhibit shoot growth in various perennial fruit trees. Paclobutrazol application reduced the number of shoots, transforming trees into a more desirable, spur-type growth habit as the vegetative sink was reduced. This compound induces an early and intense flowering, diminishing vegetative growth and reducing the extension of buds, allowing for ripening and the initiation of apical buds inflorescence. Besides, it also increases fruit set, the years following application as a carryover effect. An increase in return bloom is a common response to paclobutrazol treatment and has been reported for various fruit crops. Paclobutrazol is widely used to advance harvest maturity in various fruit crops and it improves fruit quality in terms of accelerated colour development, delayed and synchronized fruit maturation and control of preharvest fruit drop. It is known to improve fruit physical and fruit chemical characteristics. Fruit calcium is increased for 2–3 years due to carry over effect. It helps in the maintenance of better fruit quality during storage and influences nutrient uptake in various fruit crops including stone fruits. It has been characterized as an environmentally stable compound in soil and water environments with a long half-life under both aerobic and anaerobic conditions.

HortScience ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 401-403 ◽  
Author(s):  
Duane W. Greene

An experiment was initiated on mature `Morespur McIntosh'on M.7 rootstock to document the effects of repeated yearly applications of benzyladenine (BA) and naphthaleneacetic acid (NAA) on fruit quality at harvest, the development of storage disorders following regular air storage, and on return bloom. When analyzed over the 4-year period, thinning did not significantly reduce crop load. This result was due in large part to no thinning response one year and very poor set on all trees in another year. Thinners were effective at increasing return bloom over the course of the experiment. BA increased fruit weight but reduced red color compared with NAA treated and control trees. Fruit quality differences at harvests were attributed primarily to crop load effects. There were no fruit quality, return bloom, or storage disorders that could not be explained by treatment effects on crop load or due to previously known effects of individual thinners. The results of this experiment clearly suggest that there are no direct adverse effects following repeated use of either NAA or BA.


2020 ◽  
Vol 60 (1) ◽  
pp. 159-168
Author(s):  
V. V. Antonenko ◽  
A. V. Zubkov ◽  
S. N. Kruchina

Data were obtained on the basis of the results of research carried out on the territory of the educational and experimental farm of the Timiryazev State Agrarian University, in Moscow during 2018-2019. As a result of the surveys, the most dangerous diseases and pests of pome crops on the territory of this farm were established. The most resistant apple and pear varieties to major diseases have been identified. Peculiarities of development of alternariosis on pear are described, the harmfulness of the disease on pear and apple seedlings is noted. A possible role in the transfer of alternariosis infection from garden-protective plantations and weed vegetation to fruit trees was noted. A possible role has been established in the transport of septoriosis, powdery dew infection from dicotyledonous weeds plants. The peculiarities of the spread of infection under the influence of wind direction are noted. The results and peculiarities of the application of various methods of scaring birds in the orchard are presented. As a result of route surveys the most harmful weed plants have been identified. The possibility of using herbicides of different mechanism of action in fruit gardens for weed control has been studied. High efficiency and relative safety of application of herbicides of contact action in nursery fields, operational orchards and for control of piglets on fruit trees are shown. Recommendations are given for the use of soil and systemic herbicides of soil in seedlings beds, the first and second fields of the nursery, as well as in the process of production of large-scale planting material and operational orchards of fruit crops. The safety of the herbicides in question is established when used in accordance with the recommended methods of use.


2019 ◽  
Vol 99 (4) ◽  
pp. 444-459
Author(s):  
John A. Cline

‘Honeycrisp’ apple trees are highly prone to biennial bearing and predisposed to bitter pit. The hypothesis that tank mix sprays of ethephon (ETH), naphthaleneacetic acid (NAA), and 1-aminocyclopropane carboxylic acid (ACC) combined with calcium chloride (CaCl2) can mitigate these production problems was tested in a 3-yr study. Mature ‘Honeycrisp’ trees were treated with either three or six summer applications of 150 mg L−1 ETH or 5 mg L−1 NAA, all tank-mixed with and without CaCl2, or two or five applications of 150 mg L−1 ACC (without CaCl2). Treatments were applied at 10-d intervals and initiated between 21 and 26 June. All treatments had little effect on enhancing return bloom of ‘Honeycrisp’. NAA, ETH, and CaCl2 all influenced fruit maturity and quality at harvest to varying degrees and across years. Fruit treated with NAA were firmer compared with untreated fruit in 2 out of 3 yr, whereas overall, fruit treated with six sprays of ETH had lower fruit firmness and were more mature. NAA had less influence on fruit quality attributes at harvest than did ETH, and decreased pre-harvest fruit drop (PFD). PFD increased with ETH in 1 out of 2 yr, whereas ACC and NAA both decreased PFD in 1 out of 2 yr. Overall, ETH and NAA, with or without CaCl2, had significant but inconsistent effects on fruit quality and maturity, all dependent on the year and number of applications. Adding CaCl2 decreased fruit firmness in 2 out of 3 yr.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 343
Author(s):  
Carolina Ballesteros ◽  
Alda Romero ◽  
María Colomba Castro ◽  
Sofía Miranda ◽  
Jan Bergmann ◽  
...  

Pseudococcus calceolariae, the citrophilous mealybug, is a species of economic importance. Mating disruption (MD) is a potential control tool. During 2017–2020, trials were conducted to evaluate the potential of P. calceolariae MD in an apple and a tangerine orchard. Two pheromone doses, 6.32 g/ha (2017–2018) and 9.45 g/ha (2019–2020), were tested. The intermediate season (2018–2019) was evaluated without pheromone renewal to study the persistence of the pheromone effect. Male captures in pheromone traps, mealybug population/plant, percentage of infested fruit at harvest and mating disruption index (MDI) were recorded regularly. In both orchards, in the first season, male captures were significantly lower in MD plots compared to control plots, with an MDI > 94% in the first month after pheromone deployment. During the second season, significantly lower male captures in MD plots were still observed, with an average MDI of 80%. At the third season, male captures were again significant lower in MD than control plots shortly after pheromone applications. In both orchards, population by visual inspection and infested fruits were very low, without differences between MD and control plots. These results show the potential use of mating disruption for the control of P. calceolariae.


2020 ◽  
Vol 266 ◽  
pp. 109311
Author(s):  
Shafa Nayab ◽  
Kashif Razzaq ◽  
Sami Ullah ◽  
Ishtiaq Ahmad Rajwana ◽  
Muhammad Amin ◽  
...  

2017 ◽  
Vol 39 (4) ◽  
Author(s):  
MATEUS DA SILVEIRA PASA ◽  
BRUNO CARRA ◽  
CARINA PEREIRA DA SILVA ◽  
MARLISE NARA CIOTTA ◽  
ALBERTO FONTANELLA BRIGHENTI ◽  
...  

ABSTRACT The low fruit set is one of the main factors leading to poor yield of pear orchards in Brazil. Ethylene is associated with abscission of flowers and fruitlets. Then, the application of ethylene synthesis inhibitors, such as AVG, is a potential tool to increase fruit set of pears. The objective of this study was to evaluate the effect of AVG, sprayed at different rates and timings, on fruit set, yield and fruit quality of ‘Rocha’ pear. The study was performed in a commercial orchard located in the municipality of São Joaquim, SC, during the growing seasons of 2014/2015 and 2015/2016. Plant material consisted of ‘Rocha’ pear trees grafted on quince rootstock ‘BA29’. AVG was tested at different rates (60 mg L-1 and 80 mg L-1) and timings [full bloom, one week after full bloom (WAFB), and two WAFB), either alone or in combination. The experiment was arranged in a randomized block design, with at least five single-tree replications. The fruit set, number of fruit per tree, yield, estimated yield, fruit weight, return bloom, and fruit quality attributes were assessed. Fruit set and yield were consistently increased by single applications of AVG at 60 and 80 mg L-1 at both one and two weeks after full bloom, without negatively affecting fruit quality attributes and return bloom.


2015 ◽  
Vol 37 (4) ◽  
pp. 1089-1104 ◽  
Author(s):  
GUSTAVO BRUNETTO ◽  
GEORGE WELLINGTON BASTOS DE MELO ◽  
MORENO TOSELLI ◽  
MAURIZIO QUARTIERI ◽  
MASSIMO TAGLIAVINI

ABSTRACT Fertilization of temperate fruit trees, such as grapevine ( Vitis spp.), apple ( Malus domestica), and pear ( Pyrus communis) is an important tool to achive maximum yield and fruit quality. Fertilizers are provided when soil fertility does not allow trees to express their genetic potential, and time and rate of application should be scheduled to promote fruit quality. Grapevine berries, must and wine quality are affected principally by N, that regulate the synthesis of some important compounds, such as anthocyanins, which are responsible for coloring of the must and the wine. Fermenation of the must may stop in grapes with low concentration of N because N is requested in high amount by yeasts. An N excess may increase the pulp to peel ratio, diluting the concentration of anthocyanins and promoting the migration of anthocyanins from berries to the growing plant organs; a decrease of grape juice soluble solid concentration is also expected because of an increase in vegetative growth. Potassium is also important for wine quality contributing to adequate berry maturation, concentration of sugars, synthesis of phenols and the regulation of pH and acidity. In apple and pear, Ca and K are important for fruit quality and storage. Potassium is the most important component of fruit, however, any excess should be avoided and an adequate K:Ca balance should be achieved. Adequate concentration of Ca in the fruit prevents pre- and post-harvest fruit disorders and, at the same time, increases tolerance to pathogens. Although N promotes adequate growth soil N availability should be monitored to avoid excessive N uptake that may decrease fruit skin color and storability.


2020 ◽  
pp. 242-245
Author(s):  
Виктория Сергеевна Кириченко ◽  
Нина Александровна Бабинцева ◽  
Надежда Александровна Тихомирова

Основным направлением повышения продуктивности насаждений плодовых культур будет смена технологических подходов по эксплуатации садовых экосистем, основой которых является загущенное размещение плодовых деревьев, изменение формы кроны с ограничением их размеров, подбор сортов, подвоев, отвечающих требованиям плотного размещения деревьев с высокой продуктивностью, хорошим качеством плодов. Цель исследований - изучение влияния формы кроны на структурные параметры, степень облиственности и трудоемкость затрат труда при обрезке для создания интенсивных садов на слаборослых подвоях. Были проведены трехлетние полевые опыты по схеме: 1 вариант - стройное веретено (контроль); 2 вариант - безлидерная уплощенная крона; 3 вариант - трёхлидерная крона; 4 вариант - французская ось при плотности посадки 2500 дер./га (4 х 1 м). Объектом исследований являлись сорта яблони Бреберн, Джалита, Ренет Симиренко на подвое ЕМ IX в саду с капельным поливом. Работа проводилась по методикам полевых опытов с плодовыми культурами. Установлено, что высокая ростовая активность наблюдалась у сорта Ренет Симиренко независимо от формы кроны, где параметры варьировали от 0,71 м до 1,06 м. Структура плодообразующей древесины дерева зависит от биологических особенностей сорта и формы кроны. На третий год после посадки сада в кронах деревьев свободного веретена и французской оси сформировано наибольшее количество генеративных образований от 20,3 и 24,7% (Джалита, Бреберн) до 23,3 и 25,6% (Ренет Симиренко). Трудоемкость обрезки зависит от сорта, формы кроны и структуры обрастающей древесины. Максимальные затраты труда применяет один человек на обрезку деревьев сорта Джалита с трехлидерной кроной (25,6 чел.-час./га) и безлидерной уплощенной кроной (22,9 чел.-час./га). На обрезку сада деревьев с кроной по типу французской оси требуется 1,0 и 1,4 дня одному человеку или 7,2 (Джалита) и 9,5чел.- час./га (Ренет Симиренко), что в 1,9 и 2,2 раза меньше, чем на обрезку деревьев по типу стройного веретена (контроль). Область применения - садоводческие с.-х. предприятия всех форм собственности, садоводы - любители, специалисты The main direction of improving the productivity of plantations of fruit crops will be a change of technological approaches to the use of garden ecosystems, based on dense placement of fruit trees, changing the shape of the crown cap size, selection of varieties, rootstocks, meeting the requirements of a dense distribution of trees with high productivity, good fruit quality. The purpose of the research was to study the effect of crown shape on structural parameters, the degree of foliage and labor coefficient of pruning for the creation of intensive gardens on dwarf rootstocks. We carried out three-year field experiments according to the scheme: option 1 - slender spindle (control); option 2 - leaderless flattened crown; option 3 - triple leaders crown; option 4 - French axe, when planting density was 2500 trees/ha (4 х 1 м). The varieties ‘Braeburn’, ‘Dzhalita’, ‘Renet Simirenko’ on the rootstock EM IX in the garden with drip irrigation were the object of research. The study was performed according to the techniques of field experiments with fruit crops. It was found that high growth activity was observed for the variety ‘Renet Simirenko’, regardless the form of the crown, with parameters ranged from 0.71 m to 1,06 м. The structure of carpogenous wood depended on the biological characteristics of variety and crown shape. In the third year after planting the garden in the trees of control and French axe the greatest number of generative formations from 20.3 and 24.7% (‘Dzhalita’, ‘Braeburn’) to 23.3 and 25.6% (‘Renet Simirenko’) were developed. The complexity of pruning depended on the variety, the crown shape and the structure of the overgrown wood. Maximum labor cost one person spends for pruning the variety ‘Dzhalita’ with triple leader crown (25.6 man-hour/ha) and leaderless flattened crown (22.9 man-hour/ha). Pruning trees with French axe type of crown required 1.0 and 1.4 days per one person or 7.2 (‘Dzhalita’) and 9.5 man-hour/ha (‘Renet Simirenko’), which was 1.9 and 2.2 times less than the pruning according to the control. The scopes of the research are horticultural agricultural enterprises of all forms of ownership, gardener amateurs and experts.


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