Effect of Chemical Thinning Season Using Metamitron on Peaches ‘Sensação’ Quality

Abstract

Aims: The objective of this study was to evaluate peach fruits quality after chemical thinning using metamitron at different times in the South of Brazil. Study Design: The experimental design was in randomized blocks, with five replications of three plants, fruits were harvested and evaluated the central plant in the plot, and twenty fruits were evaluated in each replicate.

Influence of the Period of Peach Tree Chemical Thinning on Fruit Quality

“…No direct relation could be established between periods of chemical thinning and peach pulp firmness, since physiological responses varied among crops. These results agree with Farias et al (2017), who observed that pulp firmness was affected between periods of application of metamitron to peach tree thinning and the crop. However, pulp firmness did not exhibit any differences after the application of metamitron to apple tree thinning in four different periods (Gabardo et al, 2017).…”

“…Therefore, the lower the ripening index, the less amount of chlorophyll (Andrade et al, 2015), due to pectin solubilization (Zhang et al, 2010;Pegoraro et al, 2015). Data collected by this study agree with the ones found by Farias et al (2017), who observed that the ripening index of peaches yielded by cultivars 'Sensação' was lower when plants were thinned manually and with metamitron on the 20th and 30th DAFB. However, when chemical thinning with metamitron was carried out on the 50th and 60th DAFB, peaches had higher RI values (Table 1).…”

“…In this year, peaches from manually thinned plants which underwent chemical thinning with metamitron on the 20 DAFB had the highest pH values. However, different doses of metamitron in peach tree thinning (Farias et al, 2017) and of ethephon in plum tree thinning (Pavanello & Ayub, 2012) did not lead to any difference in fruit pH. According to Alcobendas et al (2013), pH of peach juice may be related to the location of the fruit in the plant.…”

“…However, few have shown satisfactory thinning effects. In order to carry out chemical thinning of peach trees, some products, such as 6-benzyladenine, gibberellins, ethylene and metamitron (Meitei et al, 2013;Giovanaz et al, 2014;Giovanaz et al, 2016;Farias et al, 2017;Barreto et al, 2018), have been investigated. Metamitron may be an efficient alternative to peach tree thinning (McArtney et al, 2012).…”

“…Regarding peach tree cultures, there is very little information on chemical thinning with metamitron and on its effects on the quality of fruits, since the efficiency of chemical thinning depends on the cultivar, application period and product doses (Gabardo et al, 2017;Farias et al, 2017). Therefore, this study aims at evaluating the quality of peach tree fruits after chemical thinning with metamitron at different application periods in the south of Brazil.…”