Effect of paclobutrazol on growth and flowering of lychee (Litchi chinensis)

1990 ◽  
Vol 30 (1) ◽  
pp. 131 ◽  
Author(s):  
CM Menzel ◽  
DR Simpson

The effects of either foliar (1.00-4.00 g/L) or soil applications (0.25-1.00 g/m2 tree ground cover) of paclobutrazol, during autumn, on vegetative flushing and flowering of 3 lychee (Litchi chiriensis) cultivars (Bengal, Kwai May Pink and Tai So) were investigated over 3 years at 8 sites in subtropical southern Queensland. Cultivars at these sites varied in the level of vegetative flushing prior to panicle emergence in May-August and flowering in spring. Paclobutrazol reduced flushing and increased flowering in 5 out of 8 orchards, maintained dormancy and reduced flowering in 1 orchard, and had variable effects in 2 orchards, depending on the method of application. The maximum level of flowering in paclobutrazol treated trees occurred when the control trees bloomed moderately (40-60% of terminal branches). The responses were sometimes weak when the trees were very vigorous (<30% bloom). Paclobutrazol had no significant effect or reduced flowering of heavily blooming (70-100% bloom) trees. Paclobutrazol had only a small effect on panicle development, fruit set and fruit quality at most sites. Yield reflected the flowering response to paclobutrazol, except when yields were lowered by excessive male flowering or bird damage to the fruit.

1992 ◽  
Vol 32 (1) ◽  
pp. 105 ◽  
Author(s):  
CM Menzel ◽  
DR Simpson

The pattern of panicle and flower development of lychee (Litchi chinensis Sonn.) trees was studied in subtropical Queensland (lat. 27�S.). The cultivars studied were Tai So at 3 sites, Bengal at 4 sites, Kwai May Pink at 2 sites, Salathiel at 3 sites, and Wai Chee at 2 sites. Tai So was the earliest cultivar, with panicle emergence in late May and flower anthesis in mid September. The other cultivars were 5-7 weeks later. Tai So had a longer period of flower anthesis than the other cultivars (4 weeks v. 1-3 weeks). Cultivars Tai So and Bengal generally had longer panicles than cvv. Kwai May Pink, Salathiel and Wai Chee (17-32 v. 10-14 cm), and more flowers per panicle (1800-3400 v. 400-900). Similarly, the number of fruit per panicle ranged from 7-33/panicle 2-3 weeks after the end of flowering, to 4-22/panicle at harvest. The proportion of female flowers setting fruit ranged from 2.1 to 19.5%. Similar estimates for fruit carried to harvest ranged from 0.8 to 6.8%. Variations in the times of panicle emergence, panicle development, and anthesis among the cultivars in relation to seasonal progressions in temperature affected the number of fruit set. The number of fruit set per panicle increased as the number of female flowers per panicle increased. Higher numbers of female flowers were associated with maximum temperatures during flower development of 18�C, with lower numbers at 23�C. Higher maximum temperatures during anthesis (30�C v. 24�C) increased the proportion of female flowers setting fruit.


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 50 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Isac Gabriel Abrahão Bomfim ◽  
Antônio Diego de Melo Bezerra ◽  
Alexandre Campos Nunes ◽  
Breno Magalhães Freitas ◽  
Fernando Antonio Souza de Aragão

The objective of this work was to evaluate the floral biology and pollination requirements of seeded and seedless mini watermelon varieties, and to determine the best varieties to cultivate under protected environment. Three seedless (HA-5106, HA-5158, and HA-5161) and two seeded (Minipol and Polimore) genotypes were tested. Flowers were monitored from the pre-anthesis stage to senescence, and fruit quality was also evaluated. The evaluated treatments were hand-geitonogamous pollination (MG), cross-pollination with pollen from the Polimore variety (MCP), cross-pollination with pollen from the Minipol variety (MCM), and restricted pollination. All varieties had monoecious plants with diclinous flowers, and the stigmas remained receptive throughout anthesis. Fruit set rates of 84.62% (MG), 61.54% (MCP), 48% (MCM), and 0% (restricted) were obtained for seeded varieties, but of 0% (MG), 76.36% (MCP), 82.69% (MCM), and 0% (restricted) for seedless varieties. Fruits did not differ in quality among treatments within each genotype. Therefore, all the studied varieties require a pollination agent and diploid pollen for fruit set to occur, regardless of the donor variety; and Minipol or Polimore with HA-5106 or HA-5158 are the varieties recommended for cultivation in protected environment.


2020 ◽  
Vol 100 (2) ◽  
pp. 185-201 ◽  
Author(s):  
Michelle H. Cortens ◽  
John A. Cline

Gala apple (Malus domestica Borkh.) trees are prone to heavy cropping but respond to chemical fruitlet thinners to reduce crop load and improve fruit quality. Environmental concerns over the fate of the chemical fruitlet thinner carbaryl is widely acknowledged, but crop load management options are limited. In southern Ontario, Gala trees were treated with new thinning compounds or combinations to determine post-bloom thinning efficacy and resulting fruit quality. Treatments included 6-benzyladenine (6-BA) combined with naphthaleneacetic acid (NAA) or abscisic acid (ABA), and 1-aminocyclopropane-1-carboxylic acid (ACC) alone applied at 9 mm in 2014 and 17 mm in 2015. The treatment NAA + 6-BA produced unacceptably small “pygmy” fruit when applied at 17 mm fruitlet diameter. ABA at 150 and 300 mg L−1 and ACC at 150 mg L−1, when applied at 17 mm fruitlet diameter, resulted in acceptable fruit set, crop load, and quality results in comparison with the carbaryl thinner in 1 yr. The bioregulators ACC and ABA combined with 6-BA showed commercial potential for thinning Gala fruit but require further evaluation.


2016 ◽  
Vol 41 (3) ◽  
pp. 419-432
Author(s):  
MS Alam ◽  
N Islam ◽  
S Ahmad ◽  
MI Hossen ◽  
MR Islam

The study was carried out during summer of 2012 with BARI hybrid tomato 4, planted in the Olericulture farm of Bangladesh Agriculture Research Institute, Joydebpur, Gazipur, Bangladesh to find out the response of plants to some staking and pruning treatments on yield, fruit quality and cost of production. A two factor experiment consisting of three staking methods and four level of pruning, laid out in complete block design with three repetitions. Plants were staked on inverted „V? shaped staking, high platform and string. The plants were pruned to two stem, three stem, four stem and no pruning as control. Results showed that significantly the highest total number of fruits per plant (37.1), marketable fruits per plant (33.7), yield per plant (1.68 kg) and total yield (44.6 t/ha) were produced by the plants having the treatment string staking with four stem. The highest fruit set (43.50%) was found in the plants staking with string having three stems. Plants grown on string staking allowing two stem gave the maximum length (4.71 cm), diameter (4.83 cm) and weight (53.4g) of single fruit as well as maximum fruit firmness (3.43 kg-f cm-2). From the economic point of view, it was apparent that summer tomato produced by string staking with four stem pruning exhibited better performance compared to other treatment combinations in relation to net return and BCR (2.10).Bangladesh J. Agril. Res. 41(3): 419-432, September 2016


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