Analyse de l'étalement temporel de la floraison et influence sur la variabilité intra-arbre de la chute et de la croissance précoce des pêches

2000 ◽  
Vol 80 (1) ◽  
pp. 129-136 ◽  
Author(s):  
Françoise Lescourret ◽  
O. Inizan ◽  
M. Génard

This study attempted to explain peach abscission and early growth variabilities. We assumed that flower anthesis variability was indicative of early competition for carbohydrates, presumedly determinant for fruit set and early growth. From this viewpoint, the fruits resulting from early flowers should be advantaged. In a first step, we described and analysed the pattern of flowering dates within peach trees. In a second step, we studied the relationship between this pattern and the variability of fruit abscission and growth. At the tree level, the flowers started opening from the base towards the top, but at the shoot level the flowers opened from the apex down to the base. Single flowers opened 1 d earlier than associated flowers, which opened independently. However, the relationships between either fruit set or growth and date of flowering did not fit our hypothesis. For example, fruits from the late flowers had the best set. Thus, the initial hypothesis should be rejected while the influence of other factors should be considered. Our observations suggest that post-bloom temperatures could affect fruit set and early growth. Key words: Peach, Prunus persica, flowering, fruit abscission, fruit growth, early stage of development

1990 ◽  
Vol 115 (2) ◽  
pp. 278-281 ◽  
Author(s):  
Takaya Moriguchi ◽  
Tetsuro Sanada ◽  
Shohei Yamaki

Sugar levels and composition were determined in developing `Hakuto' peach (Prunus persica Batsch var. vulgaris Maxim.) fruit. Glucose and fructose in nearly equal amounts were the predominant sugars detected during the early stage of development. Sucrose subsequently began to accumulate and was the predominant sugar in mature fruit. Sorbitol remained at a low level throughout development. The large increase in the amount of sucrose was accompanied by a rapid increase in sucrose synthase (EC 2.4.1.13) activity. Sucrose phosphate synthase (EC 2.4.1.14) was also detected in flesh extracts, but the activities were low throughout development. Acid invertase (EC 3.2.1.26) activity was highest in young fruit and declined with development. Activity, however, increased again at a later stage of development. Peach fruit contained appreciable sorbitol oxidase activity, while other sorbitol-related enzymes were barely detectable, suggesting that transported sorbitol was predominantly converted to glucose. These results suggest that the supply of glucose and fructose depends on acid invertase and sorbitol oxidase, and that accumulation of sucrose depends on-sucrose synthase.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 541f-541
Author(s):  
Mosbah M. Kushad

Seasonal variation in polyamines were evaluate during growth of fruit and seed of peach (Prunus persica L. cvs. Loring and Biscoe) starting at fruit set. In both cultivars, putrescine and spermidine increase significantly while spermine increase only slightly during the early stages of development then declined at the later stages. During pit hardening, polyamines in the flesh remained unchanged but their level in the seed continued to decrease. In both cultivars, polyamine levels corresponded to changes in fruit and seed sizes. when polyamines were vacuum infiltrated into commercially mature Biscoe fruits, flesh firmness, ethylene biosynthesis, and flesh color were significantly different from untreated tissue. The relationship between polyamines, seed development, and fruit development and ripening will be examined.


2019 ◽  
Vol 41 (4) ◽  
Author(s):  
Roseli de Mello Farias ◽  
Carlos Roberto Martins ◽  
Caroline Farias Barreto ◽  
Marcos Antônio Giovanaz ◽  
Marcelo Barbosa Malgarim ◽  
...  

Abstract In the peach tree cultivation, the producer has the challenge of obtaining good quality fruits and maintaining production in a balanced way over the years. Thinning favors these parameters and reduces the fruit load on plants. Manual thinning commonly practiced on peach trees requires high labor and increases production costs. Chemical thinning as an alternative to manual thinning, which depending on the species, time and concentration, has demonstrated high efficiency. The aim of this study was to evaluate the effect of metamitron applied at different seasons and concentrations on the chemical thinning of peach trees in southern Brazil. Experiments were conducted in a commercial peach orchard (‘Maciel’ cultivar), in the municipality of Morro Redondo, Rio Grande do Sul, Brazil, during the 2015 and 2016 harvests. In experiment 1, metamitron at concentration of 200 mg L-1 was applied at 20, 30, 40, 50 and 60 days after full bloom and manual thinning performed at 40 days after full bloom. In experiment 2, metamitron was applied at concentrations of 100 mg L-1, 200 mg L-1, 300 mg L-1 and 400 mg L-1 and manual thinning at 40 days after full bloom, in addition to control plants. Fruit abscission, fruit set, total number of fruits per plant, yield per plant, average mass and fruit diameter were evaluated. Metamitron at concentration of 200 mg L-1 has thinning effect when applied before 40 days after full bloom. Metamitron concentration of 100 mg L-1 applied at 40 DAFB promoted fruit abscission superior to manual thinning. Therefore, the application of metamitron to ‘Maciel’ peach trees close to full bloom at concentration of 100 mg L-1 results in thinning practice similar to manual thinning.


Author(s):  
Caroline Farias Barreto ◽  
Roseli de Mello Farias ◽  
Renata Diane Menegatti ◽  
Renan Ricardo Zandoná ◽  
Carlos Roberto Martins ◽  
...  

Abstract The objective of this work was to evaluate the effect of chemical thinning with metamitron on fruit of the Maciel and Sensação peach (Prunus persica) tree cultivars, as well as to identify its relation to the carbohydrate content in their branches. The experimental design was randomized complete blocks, and the treatments were trees with no thinning, manual fruit thinning, and chemical thinning with 200 mg L-1 metamitron applied at 20, 40, and 60 days after full blooming. The evaluated variables were: abscission percentage, yield per plant, number of fruit, presence of lignin in fruit, and carbohydrate content in the branches. The carbohydrate content was evaluated in trees with and without chemical thinning seven days after the application of the product. The use of metamitron promotes fruit thinning in the ‘Maciel’ and ‘Sensação’ peach trees, with a decrease in the carbohydrate content in their branches. Metamitron application 20 and 40 days after full blooming favors fruit abscission in both studied cultivars.


2009 ◽  
Vol 134 (2) ◽  
pp. 236-243 ◽  
Author(s):  
Dongyan Hu ◽  
Ralph Scorza

Since the first report of the ‘A72’ semidwarf peach [Prunus persica (L.) Batsch] tree in 1975, no new information has become available on this genotype. We evaluated the growth habit and verified the inheritance of ‘A72’ in a population of 220 progeny derived from self-pollination. Detailed tree and branch measurements revealed a unique forked-branch (FBR) character of the ‘A72’ (Nn) phenotype. The progeny segregated into 1 NN:2 Nn:1 nn. NN trees were indistinguishable from standard peach trees, Nn were FBR, and nn were dwarf. Hybrids between ‘A72’ and columnar (brbr) peach trees confirmed that FBR is inherited as a monogenic trait that appears to express incomplete dominance. ‘A72’ (Nn) trees were later blooming than sibling NN trees. The relationship (linkage or pleiotropy) between the growth habit of ‘A72’ and late bloom is not known. The structure of ‘A72’ trees presents new opportunities to breeder/geneticists, physiologists, and horticulturists to further explore the plasticity of peach tree growth and architecture that can be achieved through breeding. Applications of the ‘A72’ growth habit for commercial fruit production and as an ornamental, particularly in the dwarf form (nn) and in combination with the columnar tree (brbr) form, present opportunities that await exploration.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 496c-496
Author(s):  
R.C. Ebel ◽  
D.G. Himelrick ◽  
A. Caylor ◽  
J. Pitts

The surfactant “Surfactant WK” (dodecyl ether of polyethylene glycol) was applied to peach trees [Prunus persica (L.) Batsch] at full bloom over 3 years. Blossoms died rapidly, so that within 2 days dead blossoms could be distinguished easily from live blossoms or set fruit. There were strong (R2 > 0.87), linear correlations between concentration of “Surfactant WK” applied and percent blossoms removed and fruit set, which were similar over the 3 years. Trees were hand-thinned according to commercial practices after treatment. There was similar cropload, fruit weight and yield across treatments at harvest indicating no negative effects by the chemical on productivity. There was only slight limb damage at the highest concentrations of “Surfactant WK”, which over thinned blossoms. We recommend that based on the effectiveness, consistency, and lack of significant phytotoxicity, “Surfactant WK” be re-evaluated as a thinning chemical for peach trees.


Author(s):  
Roseli de Mello Farias ◽  
Caroline Farias Barreto ◽  
Renan Ricardo Zandoná ◽  
Carlos Roberto Martins ◽  
Paulo Mello-Farias ◽  
...  

Abstract: The objective of this work was to evaluate the effect of thinning with metamitron on the fruit yield and quality of 'BRS Kampai' peach (Prunus persica) trees. The experiment was carried out in the municipality of Eldorado do Sul, in the state of Rio Grande do Sul, Brazil, in the 2016 and 2017 crop years. Treatments consisted of the application of 100, 200, 300, and 400 mg L-1 metamitron and of hand thinning 40 days after full bloom, besides control plants. Fruit abscission, effective fructification, number of fruits, and fruit yield per plant were evaluated. Regarding fruit quality, fresh fruit biomass, epidermis color, pulp firmness, soluble solids, total phenolic compounds, and antioxidant activity were assessed; fruits were also classified into diameter classes. For fruit abscission, the effect of the application of 100 mg L-1 metamitron is similar to that of hand thinning. Fruit yield and mean mass in all treatments with metamitron are similar to those obtained by hand thinning. The application of metamitron does not affect the fruit quality of peach trees. Chemical thinning with metamitron may be an alternative to hand thinning in peach trees used for the production of fruits for fresh consumption.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1119c-1119 ◽  
Author(s):  
Michael Maurer ◽  
Thomas DeWitt ◽  
Gary Ritenour

Mature 7-year-old `Raycrest' peach trees (Prunus persica [L.] Batsch) were treated at prebloom and late postbloom with foliar sprays of lactidichlor ethyl at 0, 25, 50, 75 and 100 mg·liter-1. A trunk girdled treatment was also included. Lactidichlor ethyl treatments had no effect on fruit set, fruit size and maturity. Girdling trees 30 days postbloom increased fruit size and enhanced maturity, but had no effect on fruit set. These results suggest that fruit size and maturity are enhanced by girdling.


1982 ◽  
Vol 13 (1) ◽  
pp. 23-27
Author(s):  
Hugh G. Clarke

Problems with selection procedures for sales staff are discussed. It is difficult to assess the variety of characteristics required for success in sales in an interview, but most interviewers undervalue information that can be gained from direct observation. The author proposes the use of 'action profiling', to assess personality based on body movement. Careful observation of postural movement (big body movements) and gestural movements (smaller limb movements) can provide information on motivational characteristics (assertion) and task orientation (perspective) of individuals. A brief overview is given of research on the relationship between body movement and personality, and the author gives his adaptation of these theories to interpreting behavioural-action tendencies in sales staff. It is proposed that action profiling techniques, although still in an early stage of development, could make a valuable contribution, in conjunction with existing techniques, to improved selection of 'the right person' for the sales job.


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