Effect of DPA [Diphenylamine] and 1-MCP [1-methylcyclopropene] on chemical compounds related to superficial scald of Granny Smith apples

C Moggia,M.A Moya-León,J.A Yuri,G.A Lobos,M Pereira

doi:10.5424/sjar/2010081-1157

C Moggia, M.A Moya-León + Show 3 more

Open Access

https://doi.org/10.5424/sjar/2010081-1157

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Abstract

Research was carried out to study the mode of action of diphenylamine (DPA) and 1-methylcyclopropene (1-MCP), on control of superficial scald of Granny Smith apples (Malus domestica Borkh.), and its relation with chemical compounds. Fruit was harvested from a commercial orchard in Chile, 182 and 189 days after full bloom and received the following treatments: DPA (2,000 ppm); 1-MCP (1.2 ppm) and control (no treatment). All fruit was stored for 4 or 6 months at 0 deg C. A completely randomized factorial design was used (2 harvest dates by 3 postharvest treatments). Monthly measurements were made on maturity indices, ethylene production rate (EPR), scald related compounds (alpha-farnesene (AF), conjugated trienes (CT), total anti-oxidants (AO)), and cell membrane stability. Following 4 and 6 months of storage, plus 7 days at 20 deg C, scald was evaluated. After 6 months, DPA-treated fruit, from both harvests, showed similar firmness, EPR and AO, compared to the control. However, AF and CT were lower, and cell membrane stability higher. Conversely, 1-MCP-treated fruit showed a noticeable EPR suppression and AF inhibition, along with higher firmness, lower CT and AO, compared to the control and DPA. Furthermore, cell membrane stability was superior to that of the control and similar to that of the DPA. Treated fruit (DPA and 1-MCP) showed an important reduction in scald compared to the control. The effect of 1-MCP on the investigated compounds and the reduction in scald, confirms that ethylene plays a major role on its development.

Highlights

Superficial scald is one of the main physiological disorders affecting stored apples (Malus domestica Borkh.), (Ingle and D’Souza, 1989; Emongor et al, 1994)
Prior to the application of the treatments, H1 fruit showed a higher ethylene production rate (EPR) than H2 (Table 1). This was not expected since EPR should be lower in less mature fruit; the result could be explained by the high variability that is usually found among ethylene measurements, suggesting that for this index, a higher number of replicates should be used
Αfarnesene levels were higher in H1, whereas conjugated trienes and total anti-oxidants were similar on both harvest dates (Table 1)

Summary

Introduction

Superficial scald is one of the main physiological disorders affecting stored apples (Malus domestica Borkh.), (Ingle and D’Souza, 1989; Emongor et al, 1994). The following research was carried out to compare the mode of action of DPA and 1-MCP on control of superficial scald of Granny Smith apples (a highly susceptible cultivar), based on their relation with ethylene production, chemical compounds and electrolyte leakage. This was achieved by applying DPA and 1-MCP treatments and determining their effect on maturity of the fruit, production of ethylene, α-farnesene, conjugated trienes, antioxidant and cell membrane stability.

Material and methods

Results

H2 Significanced