Effect of a postbloom naphthaleneacetic acid thinning spray and hand thinning on quality and quantity of pear fruit (Pyrus communis L.) cv. Harrow Sweet

2009 ◽  
Vol 89 (6) ◽  
pp. 1109-1116 ◽  
Author(s):  
M Hudina ◽  
F Štampar

The effect of naphthaleneacetic acid (NAA) and hand thinning on quality and quantity of pear fruit (Pyrus communis L.) cv. Harrow Sweet was investigated in 2005, 2006 and 2007. The experiment included the following treatments: an unsprayed control, hand thinning to 3 fruit cm-2 of trunk cross-sectional area (TCSA), hand thinning to 6 fruit cm-2 of TCSA, NAA at 8 mg L-1 (2005-2007), NAA at 16 mg L-1 (2006-2007) and NAA at 20 mg L-1 (2007). The same treatments were applied to the same trees in each of the three years. NAA thinning did not reduce yield per tree and had no negative effect on fruit set, yield efficiency, or crop load in any of the years. In 2005 and 2006, NAA and hand thinning significantly increased fruit diameter and weight. In 2007, only NAA at 20 mg L-1 significantly increased fruit diameter and weight relative to the control. Fruit firmness was not influenced by NAA or hand thinning in 2005 or 2007, but in 2006, hand-thinned fruits were significantly less firm than control fruit. Hand thinning to 6 fruit cm-2 of TCSA increased fruit soluble solids content in 2006 and 2007. Neither NAA nor hand thinning influenced total sugars or organic acids in fruit. Key words: Yield, sugars, organic acids, HPLC

2012 ◽  
Vol 92 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Metka Hudina ◽  
Franci Stampar ◽  
Primoz Orazem ◽  
Maja Mikulic Petkovsek ◽  
Robert Veberic

Hudina, M., Stampar, F., Orazem, P., Mikulic Petkovsek, M. and Veberic, R. 2012. Phenolic compounds profile, carbohydrates and external fruit quality of the 'Concorde' pear ( Pyrus communis L.) after bagging. Can. J. Plant Sci. 92: 67–75. The practice of pre-harvest bagging has been extensively used in several fruit crops to improve the commercial value of the fruit. The purpose of this study was to investigate the effect of fruit bagging on internal and external quality of the European pear (Pyrus communis L.) cv. ‘Concorde’. Fruit quality was determined by chemical analyses (individual sugars, organic acids and phenolic compounds) and physical characteristics in 2005 and 2006. Bagging of pear fruit after June drop until harvest significantly reduced fruit length in both observed years. Fruit bagging resulted in increased firmness of the fruit only in 2006. Soluble solids content was significantly lower in bagged fruit in 2006. In 2005, bagging had no influence on firmness and soluble solids content. Bagging improved fruit surface lightness, since L* was higher in the bagged than in the control fruit in both years. Also the a* parameter was higher in bagged fruit. We noted significant influence of bagging on total sugars content. Bagging European pear fruit decreased the content of phenolic compounds in skin (catechin, chlorogenic acid, epicatechin, p-coumaric acid, quercetin 3-O-galactoside, quercetin 3-O-glucoside, quercetin 3-O-rhamnoside). The removal of bags 7 d before harvest significantly increased glucose, shikimic and fumaric acids.


2003 ◽  
Vol 9 (2) ◽  
Author(s):  
M. Hudina ◽  
A. Solar ◽  
F. Stampar

The influence of the foliar nutrition on the pear fruit quality (Pyrus communis L.) cv. 'Williams' was studied in years 1997 and 1998. We determined the contents of individual sugars (glucose, fructose, sucrose and sorbitol) and organic acids (malic, citric, fumaric and shikimic) by HPLC (High Performance Liquid Chromatography). The sizes of the fruits (diameter, length, weight) were measured as well as the amounts of soluble solids and titrable acids. The experiment comprised two treatments: the foliar nutrition and the control. In the treatment of foliar nutrition the trees were sprayed five times (from May 22 to July 7) with a foliar fertilizer, which contained 15% of P205, 20% of K20, 0.1% of Mn, 0.1% of B and 0.1% of Mo. The foliar nutrition influenced higher quantities of sugars (glucose, sorbitol, soluble solids) and organic acids (malic, citric) but had no effect on the contents of shikimic acid, pH juice and titrable acids. At the treatment of foliar nutrition a trend of decrease in the contents of fructose, sucrose, fumaric acid, boron, and zinc was noticed.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 850C-850
Author(s):  
Gregory Reighard* ◽  
David Ouellette ◽  
Kathy Brock ◽  
Duy Nguyen

`Coronet' peach on Lovell rootstock was planted near Clemson, S.C., in Dec. 1995 in 4 rows (= reps) 6.1 meters apart with trees 2.2 meters apart in-row. Trees were trained to a Kearney-V. In the 2nd leaf (Aug. 1997), `Ta Tao 5' buds were grafted to half (= 6-tree plot) the trees in each row. These trees received 2 `Ta Tao 5' chip buds infected with Peach Latent Mosaic Viroid (PLMVd) per scaffold at ≈0.75 to 1.15 m above ground. Dot blot hybridization confirmed that the chip buds successfully (100%) inoculated the treated trees, whereas the controls tested negative. Data collected in 2003 included bloom date, tree size, dormant and summer pruning times, fruit maturity date, fruit yield, mean fruit weight, skin color, soluble solids, flesh firmness, titratable acidity, and pH. Flowering and fruit maturity were delayed by ≈4 days in PLMVd-inoculated (PI) trees. PI trees produced larger fruit, but yield was 23% less than that of non-inoculated trees. Both fruit size and yield had been larger in PI trees in previous years. There were no differences in yield efficiency in 2003, but PI trees were 26% smaller in trunk cross-sectional area and 9% shorter. PI trees took 34% and 23% less time to dormant and summer prune, respectively and had 34% and 28% less wood removed by dormant and summer pruning, respectively than control trees. PLMVd increased fruit firmness, and PLMVd fruit lost firmness at a much slower rate. PLMVd did not significantly affect skin color, but PLMVD fruit were slightly less red. Soluble solid levels were higher in PLMVd fruit than control fruit during the first harvest, but were lower by the last harvest. Acidity was significantly higher and the soluble solids to acidity ratio significantly lower in PLMVd fruit. Control fruit had a slightly higher pH.


1993 ◽  
Vol 118 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Paul M. Chen ◽  
Diane M. Varga ◽  
Eugene A. Mielke

`Columbia' and `Gebhard' strains of red `d'Anjou' pears (Pyrus Communis L.) harvested at similar maturity exhibited different ripening behavior after monthly removal from 1C storage in air. `Columbia' fruit produced ethylene at higher rates than `Gebhard' fruit during 15 days of ripening at 20C after each corresponding storage interval, `Gebhard' fruit required a longer period of chilling than `Columbia' fruit to generate noticeable rates of ethylene during ripening. The unripened fruit of both strains contained similar amounts of ACC at each corresponding storage interval. At each corresponding ripened state, ACC content in `Columbia' fruit increased 2 to 3-fold, while that in `Gebhard' fruit changed very little. After sufficient chilling, `Columbia' fruit were capable of softening to proper ripeness, and they developed buttery and juicy texture as indicated by the apparent reduction of extractable juice (EJ) content. `Gebhard' fruit also softened but to a lesser extent than `Columbia' fruit. Ripened `Gebhard' fruit had only slightly lower levels of EJ than unripened fruit and did not develop a buttery and juicy texture after any storage intervals. Titratable acidity (TA) in fruit of both strains varied between for the 1988 and 1989 seasons but decreased significantly during storage in both years. Soluble solids concentrations (SSC) in both strains also varied seasonally but did not change during storage or ripening. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).


2019 ◽  
Vol 13 (3) ◽  
pp. 348-358 ◽  
Author(s):  
Javier Enrique Vélez ◽  
Wilson Polanía ◽  
Nicolás Beltrán

Water is a major component of plants that directly and indirectly affects physiological processes. One of the consequences of a hydric deficit in the pear fruit is modification of the aroma. No information exists on the effect of a water deficit on the sensory profile and volatile composition of this species. The objective was to determine the production of volatiles in the harvest and post-harvest of pear var. Triumph of Vienna (Pyrus communis L.) with regulated deficit irrigation (RDI). The irrigation treatments consisted of the application of water regimes that were 100 (Control), 74 and 48% of the ETc during the rapid fruit growth period. The rest of the season plants were irrigated at 100%ETc. In the deficit treatments, there were no significant reductions with respect to the control in the quality of the fruits, obtaining a water savings in 74 and 48%ETc of 26 and 40%, respectively. The esters were the volatile compounds that contribute greatly to aroma, which increased steadily during the climacteric phase. Under the limited water conditions, watering with regulated, deficit doses obtained production that was similar to that of well-watered crops, provided that it was carried out in the phenological stage of low sensitivity and that the tolerance limits of stress were not exceeded.


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