Effects of Aminoethoxyvinylglycine and Naphthaleneacetic Acid on Ethylene Biosynthesis, Pre-Harvest Fruit Drop and Fruit Quality of Apple

Abstract

Cultural control of pre-harvest drop has relied upon plant growth regulators. To investigate the effects of plant growth regulators on pre-harvest drop and fruit quality, 150, 300 and 600 mg L -1 aminoethoxyvinylglycine (AVG) and 20 mg L -1 NAA were sprayed to 'Red Chief' apple trees at 4 week before anticipated harvest date. Untreated trees were kept as control. Results revealed that all AVG treatments increased the fruit removal force and significantly delayed pre-harvest drop and fruit maturity. Pre-harvest drop generally was unaffected by NAA. Internal ethylene concentration decreased with increasing AVG concentrations. Fruits treated with 150, 300 and 600 mg L -1 AVG showed increased fruit firmness and titratable acidity and reduced soluble solids content. Red colour development and starch degradation were retarded by all AVG treatments. Fruits treated with AVG (300 and 600 mg L -1 ) had lower fruit mass, fruit width and fruit length. The effect of NAA on all quality parameters was similar to the control treatment. AVG treatments decreased pre-harvest drop by fifty percent relatively to control.

Postharvest quality of ‘Brookfield’ apple field-treated with naphthalene acetic acid alone or combined with other growth regulators

“…3i), however, a benefit was obtained by applying NAA plus Ethephon in the preharvest by standardizing fruit maturation (Brackmann et al 2014). Ozkan et al (2016) verified less flesh firmness of 'Red Chief ' apple in treatment with application of 20 mg•L -1 of NAA compared whit different AVG concentrations, in the two evaluated years, which is in agreement with the results of this study.…”

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 ).…”

“…Previous findings revealed that PFD is diminished with delayed fruit ripening using AVG that reduced ethylene biosynthesis via the inhibition of ACC synthase activity [ 22 , 60 , 61 ]. It was reported that spraying apple trees with AVG four weeks before harvest delayed the fruit ripening rate and decreased PFD by 50% [ 12 ]. Preharvest application of SA also decreased PFD [ 62 ].…”

“…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.…”

“…Both enzymes increase ethylene biosynthesis, resulting in higher rates of respiration [ 11 ]. The higher rate of ethylene production improved the fruit ripening and senescence process and led to the formation of the abscission zone and, hence, fruit drop [ 12 , 13 ]. The ACS is a pyridoxal phosphate (PLP)-dependent enzyme that catalyzes the synthesis of 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor for ethylene, from S -adenosyl methionine [ 14 ].…”