Ammonium thiosulfate and 6-benzyladenine improve the crop load and fruit quality of 'Delicious' apples

2007 ◽  
Vol 47 (5) ◽  
pp. 635 ◽  
Author(s):  
S. A. Bound ◽  
S. J. Wilson

Four trials were conducted over 3 years to assess the effect of ammonium thiosulfate (ATS) as a blossom thinner of ‘Delicious’ apple trees. In addition to determining the optimal concentration of ATS and the effectiveness of multiple applications, the effect on fruit quality was assessed. A program using ATS at bloom and 6-benzyladenine (BA) applied postbloom was examined. Multiple applications of ATS reduced crop load more than a single application. A concentration of 1.0% (v/v, 5800 mg/L) applied twice during the flowering period is recommended, with the first application at 20% bloom and the second at 80% bloom. Fruit firmness and sugar content were increased by ATS, and a positive relationship between fruit weight and sugar content and between fruit weight and firmness was demonstrated. ATS can also be effectively combined in a program with BA with the added benefits of increases in fruit size, firmness and sugar content; however, caution is advised to prevent over-thinning.

2014 ◽  
Vol 24 (4) ◽  
pp. 424-427
Author(s):  
Fatih Ali Canli ◽  
Murat Sahin ◽  
Nurettin Temurtas ◽  
Mustafa Pektas

Applications that could improve apricot (Prunus armeniaca) fruit size and quality would enhance their marketability. In this study, the effects of preharvest benzyladenine (BA) and BA plus gibberellin (GA) applications on fruit quality of ‘Alyanak’ apricot were investigated. BA (50, 100, and 150 ppm) and BA + GA4+7 (12.5, 25, and 50 ppm) were applied at the beginning of pit hardening stage. When fruit reached their maturity, samples were harvested and evaluated in terms of: weight, size, firmness, soluble solids content (SSC), acidity, and pH. Fruit treated with BA were significantly heavier and larger than fruit not treated, and there were significant differences in fruit size within the BA-treated fruit. The heaviest and the largest fruit were obtained from 100 to 150 ppm BA concentrations. BA + GA4+7 treatments did not affect fruit size. Application of 100 ppm BA and 25 ppm BA + GA4+7 increased fruit firmness at harvest. SSC, pH, and acidity were unaffected by the applications. The results obtained in this study showed a practical benefit of a single application of BA at the end of pit hardening for improving apricot quality. Fruit treated with the optimum dose of BA (100 ppm) were larger and firmer than untreated fruit.


2020 ◽  
Vol 165 ◽  
pp. 03061
Author(s):  
Huiyi Zhang ◽  
Huizhi Li ◽  
Huaer Wang ◽  
Changwen Duan ◽  
Haonan Zhang ◽  
...  

The effect of DA-6 treatments with different concentrations on the maturity and fruit quality of ‘Aikansui’ pear was studied. The results showed that the effect of treatment at 35 mg •L-1 was the best, followed by 30 mg •L-1. The treatment of 35 mg •L-1 could increase the sugar content of the fruit, reduce the content of titratable acid, and advance the maturity of the fruit to the greatest extent. The 30 mg •L-1 treatment had the most significant effect on the increase of fruit weight and the Vc content.


1962 ◽  
Vol 42 (4) ◽  
pp. 602-610 ◽  
Author(s):  
Jack A. Freeman ◽  
Frances C. Mellor

Comparison of the effect of two strains of mottle virus, two strains of veinbanding virus, and latent-A virus, alone and in combination, on vigor, yield and quality of British Sovereign strawberry plants grown under two planting systems showed: 1. Vigor was reduced by infection by a single virus and still further reduced by two viruses; 2. Yield was reduced by virus infection, especially during the first fruiting year when plants were grown under the hill system; 3. Fruit size was reduced only by virus combinations; 4. Fruit quality was affected only by veinbanding, which increased the total acid content and tended to reduce sugar content.


Author(s):  
Le Van Ut ◽  
Vo Thi Bach Mai

Effects of gibberellic acid (GA3) and urea on Queen pineapples (Ananas comosus (L.) Merr.) growth in the field were discussed in this study. Pineapples were sprayed with GA3 (at the concentration of 1, 5, 10, 20, 40, 60, 80 and 100 mg.L-1) or urea (at the concentration of 1, 5, 10, 15, 20, 25 and 30 g.L-1) on day 0 and day 3 at the beginning of growth period (50% dried flowers). Fruits were sampled every 15 days from day 0 to day 75 for assessment on fruit weight, fruit size, and fruit quality. Besides, fruits (which were sprayed with GA3 at the concentration of 40 mg.L-1 or urea at the concentration of 15 g.L-1) were sampled on the 15th day from the day which processed to determine the size of cells. The results showed that the treatments with four highest concentration of GA3 (40, 60, 80 and 100 mg.L-1) or urea (15, 20, 25 and 30 g.L-1) significantly increased fruit weights and fruit sizes. In addition, the treatments of GA3 in high concentration (40 - 100 mg.L-1) stimulated the increase of sugar content and vitamin C content in the fruit flesh compared to the control. The treatments of urea at different concentrations did not alter the fruit quality index. Exogenous GA3 at the concentration of 40 mg.L-1 or urea at the concentration of 15 g.L-1 stimulated the increase of fruit weight without decreasing the fruit quality. In which, exogenous GA3 at concentration 40 mg.L-1 increased the fruit weight by enlarging flesh cell.  


2008 ◽  
Vol 14 (1-2.) ◽  
Author(s):  
E. Szűcs ◽  
T. Kállay

Long term fertilisation trials were combined with storage experiments with 'Jonathan' apple trees and fruits to study influence of tree nutrition on quantity and quality of crop. The site of experiments is a typical Carpathian-basin environment with loamy silt soil, high lime content and arid summers. Conclusions has been drown from six years' set of data. Augmented levels of soil fertilisation increased cropping capacity of apple trees, however, the fruit load has not met with cropping capacity in every year. More the def cit came into view in crop load, less the fruit quality resulted in. The deficit in cropping capacity, however, could not have been determined with simple rates as fruit weight per trunk circumference or similar. Better determination was obtained where foliar nutrient contents were correlated to crop per tree figures. In general terms, the N and Ca content in leaves increased with yields when K and P content formulated reciprocally. When storage quality of 'Jonathan' apple fruits were related to crop load (kg/tree), influence of crop deficit became visible. As the crop load and foliar nutrient levels interacted, the fruit quality (number of disordered apples after 6 month of storage) subjected of both physiological phenomena. Higher determination degree were obtained when crop load was assessed together with single or multiple foliar analysis data.


2018 ◽  
Vol 14 (4) ◽  
pp. 161-166
Author(s):  
Scheila Lucia Ecker ◽  
Clevison Luiz Giacobbo ◽  
Leandro Galon ◽  
Adriana Lugaresi ◽  
Gian Carlos Girardi

The objective of this work was to verify the influence of planting density on productivity and fruit quality of the fig tree. The design was used in three blocks, the plants of the cultivar Roxo de Valinhos were submitted to three planting spacings: 5 x 0.5 m; 5 x 1.0 m; and 5 x 1.5 m. The evaluated characteristics were: length of branches; average weekly growth of branches; fruit size; average fruit weight;soluble solids (°Brix); yield of mature fruits; productivity of green fruits; accumulated productivity; and dry mass of fruits.The length of the branches was not influenced by planting spacing, the plants conducted at lower densities presented higher productivity, both of green fruits and accumulated productivity.Plants submitted to lower planting density produced fruits with higher dry matter, but these were smaller in size, but without significant difference for those submitted to lower density. It wasconcluded that productivity is directly affected by fig planting density, but not all the qualitative aspects of the fruits were affected.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 613b-613
Author(s):  
Esmaeil Fallahi ◽  
John K. Fellman

Effects of three times and five rates of urea application on productivity, tree growth, soil nitrate movement, nutrient partitioning, and postharvest fruit quality of `Redspur Delicious' apple on M.7 rootstock over several years were studied. Time of application did not have significant effects on most fruit quality factors or yield. However, significant differences were observed for quality and yield measurements among different quantities of N. Fruit firmness decreased with every increment in N increase. Trees with N at 0.045 kg/tree had lower yield and higher fruit firmness than those with higher quantities of N. Fruit weight and color decreased with each increment increase in the quantity of N. Trees with N at 0.045 and 0.18 kg/tree had significantly better (more red) color and lower fruit N and leaf N than those with higher quantities of N. Bud tissue nutrients were affected by quantity of N application. Fruit from trees with N at <0.18 kg/tree had lower soluble solids. High N increased fruit ethylene and respiration. Nitrogen application affected 2-methyl butyl acetate of fruit. Monitoring nitrate movement through the soil showed that application of N at >0.45 kg/tree, particularly in fall resulted in excess levels of nitrate, increasing the possibility of underground water contamination. Applying N at ≤0.32 kg/tree did not result in excess soil nitrate at 1.52-m depth.


HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1305-1308 ◽  
Author(s):  
David Sugar ◽  
Don C. Elfving ◽  
Eugene A. Mielke

The effects of prohexadione-calcium (P-Ca) on fruit size and return bloom in three pear cultivars were evaluated in Medford and Hood River, Ore., and in Cashmere, Wash. A variety of treatment dosages and timings was applied to 4- and 5-year-old trees in 2 years of study. Fruit weight of `Bosc' and `Red Anjou' pears was not affected by P-Ca treatments at any location in either year. However, decreased weight of `Bartlett' pear fruit was associated with all P-Ca treatments in 1999 in Medford except for 83 ppm applied at 2.5 to 6.0 cm shoot growth (first treatment) plus 2, 4, 6, and 8 weeks after first treatment (WAFT) and 125 ppm applied at 2.5 to 6.0 cm growth plus 4 WAFT. `Bartlett' fruit weight was reduced in Medford in 2000 by all treatments except 125 ppm applied at 2.5 to 6.0 cm growth plus 4, 8, and 12 WAFT. In Cashmere in 2000, mean weight of `Bartlett' and `d'Anjou' fruit was reduced by treatments with 83 or 125 ppm applied at 2.5 to 6.0 cm growth plus 2, 4, and 6 WAFT and of `Bosc' pear by all treatments that included more than a single application of P-Ca. Crop load was not significantly different among treatments at any location. Return bloom in the year following P-Ca treatment was reduced in `Bosc' pears by some to most treatments at all locations in both years. In contrast, return bloom was reduced in `Bartlett' and `Anjou' pears only in Hood River in 1999.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 841D-842 ◽  
Author(s):  
Terence L. Robinson* ◽  
Christopher B. Watkins

In 2001 and 2002, we imposed a wide range of croploads (0-15 fruits/cm2 of TCA) on 4- and 5-year-old Honeycrisp/M.9 trees by manual hand thinning soon after bloom to define appropriate croploads that give adequate repeat bloom and also the best fruit quality. At harvest each year we evaluated fruit ripening and quality. Samples were stored for 5 months in air at 38 °F and 33 °F and evaluated for fruit firmness and storage disorders. Cropload was negatively correlated with tree growth, return bloom, fruit size, fruit red color, fruit sugar content, fruit starch content, fruit firmness, fruit acidity, fruit bitter pit, fruit senescent breakdown, fruit rot and fruit superficial scald, but was positively correlated with leaf blotch symptoms, fruit internal ethylene concentration at harvest, and fruit soggy breakdown. There was a strong effect of cropload on fruit size up to a cropload 7, beyond which there was only a small additional effect. Although there was considerable variation in return bloom, a relatively low cropload was required to obtain adequate return bloom. Fruit red color was reduced only slightly up to a cropload of 8 beyond which it was reduced dramatically. The reduced fruit color and sugar content at high croploads could indicate a delay in maturity of but, fruits from high croploads were also softer, had less starch and greater internal ethylene. It that excessive croploads advance maturity. Overall, croploads greater than 10 resulted in no bloom the next year, and poor fruit size, color and flavor, but these fruits tended to have the least storage disorders. Moderate croploads (7-8) resulted in disappointing return bloom and mediocre fruit quality. For optimum quality and annual cropping, relatively low croploads of 4-5 were necessary.


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