Pre-harvest Application of ReTain (Aminoethoxyvinylglycine, AVG) Influences Pre-harvest Drop and Fruit Quality of ‘Williams’ Pears

Abstract

Williams' is the highly quality pear cultivar mostly produced in the Eğirdir region of Turkey. ReTain (15% aminoethoxyvinilglycine, AVG) is a plant growth regulator used to control pre-harvest drop and increase fruit weight and firmness. The objective of this study was to determine the responses of AVG treatments on the preharvest drop and fruit quality of 'Williams' pear. Pear trees of the cultivar 'Williams' were sprayed 30, 21 and 7 days before commercial harvest (DBH) with AVG, at doses of 100, 125 and 150 mg L-1 , and assessed for pre-harvest drop, yield, maturity, delay in harvest, fruit quality, ethylene production and respiration rate at the harvest time. Fruit samples were analyzed for fruit quality parameters which are: fruit width, fruit weight, soluble solids content (SSC), titratable acidity (TA), fruit firmness, fruit colour, fruit macro and micro elements content. Maturation of the 30 and 21 DBH AVG-treated fruits were delayed 3-4 days compared to the 7 DBH AVG-treated and control groups. The pre-harvest drop decreased with all AVG applications by approximately 38-100% in comparison with the control group fruits. AVG treatments increased fruit size (7-10%), fruit weight (26-41%) and fruit firmness (2-16%) of 'Williams' pear. AVG application reduce ethylene production and respiration rate and it was found that the applications enhance the ethylene production and respiration rate by approximately (100%) compared to the control fruits on the harvest date. Results of this study indicated that 30 DBH and 21 DBH AVG-treatments at 100 mg L-1 can be recommended for 'Williams' pear cultivar on both pre-harvest fruit drop, as well as in harvest date and fruit quality.

Yield, Fruit Quality, and Storability of ‘Canino’ Apricot in Response to Aminoethoxyvinylglycine, Salicylic Acid, and Chitosan

“…Increased levels of WL during storage could also be a result of increased rates of respiration [ 65 ]. Previous reports have also indicated that AVG improved fruit firmness in sweet cherry [ 13 ], pear [ 21 ], and apple [ 12 , 22 ]. In addition, SA-treated fruit recorded a small reduction in WL ( Figure 2 ), which was associated with improved fruit firmness ( Figure 3 ).…”

“…In this regard, the applications of SA and chitosan were generally the second and third most effective treatments, compared to the control. It has been reported that the application of AVG significantly delayed starch degradation and reduced SSC, but enhanced acidity in sweet cherry [ 13 ], pear [ 21 , 34 ], and apple [ 12 , 22 ]. Similarly, SA was proven to delay the ripening and senescence process of plum [ 46 ], apricot [ 20 , 49 ], and mango fruit [ 40 ], represented by low SSC and high organic acid contents.…”

“…Foliar application of plant biostimulants [ 18 ], potassium [ 5 ], abscisic acid (ABA) [ 19 ], chitosan, oligochitosan, and salicylic acid (SA) [ 20 ] effectively reduces the deterioration rate and improves apricot fruit quality and storability. Preharvest foliar applications to control fruit diseases using aminoethoxyvinylglycine (AVG) [ 21 , 22 ], SA [ 23 , 24 ], and chitosan [ 25 , 26 ] have also been claimed to diminish ethylene production. In this aspect, transcriptome testing (RNA sequencing) has been used as a valuable tool to study the molecular mechanism of fruit quality changes in apricot [ 2 , 27 , 28 ], persimmon [ 9 ], kiwifruit [ 29 , 30 ], pummelo [ 31 ], and banana fruit [ 32 ].…”

“…For instance, application of AVG at 125 mg·L −1 decreased ethylene production rates and postponed the climacteric peak, while application at 250 mg·L −1 severely reduced ethylene production by 2–6-fold at the climacteric peak [ 34 ]. Previous reports have shown the role of AVG in reducing fruit drop, improving total yield [ 22 ], and maintaining the fruit quality of apricot [ 35 ], apple [ 22 , 36 ], sweet cherry [ 13 ], and pear [ 21 ].…”

Preharvest Applications of Aminoethoxivinylglycine in Mangifera indica L. “Ataulfo” Variety in Two Contrasting Environments

“…It also influences the reduction of fruit drop [7], the improvement of the total yield [8], and the maintenance of fruit quality in apricots [9], apples [10], sweet cherries [11], and pears [12]; the response of different cultivars can vary significantly [13] and also depends on the dose applied [14].…”