Postharvest fungal infections, particularly by Botrytis cinerea, can cause up to 50% losses in fruits and vegetables, and the overuse of synthetic fungicides has led to resistant pathogen strains. We hypothesized that hexane (Hex) and methanolic (MeOH) extracts from peanut (P) and pecan nut (PN) shells possess antifungal properties effective against B. cinerea in strawberries. To test this, we conducted both in vitro and ex vivo assays using strawberries inoculated with B. cinerea, comparing two controls (T0: water; T1: commercial synthetic fungicide) with four treatments—Hex-P, MeOH-P, Hex-PN, and MeOH-PN—at 1000 and 2000 ppm (in vitro) and 4000 ppm (ex vivo). Total phenolic content (TPC) and antioxidant activity (AA) were also measured. MeOH-P and Hex-PN extracts at 2000 ppm significantly inhibited fungal mycelial growth in vitro. In ex vivo assays, MeOH-P reduced both disease incidence and severity comparably to the synthetic fungicide. MeOH-PN exhibited the highest TPC and AA. These findings support the potential use of MeOH-P extract as a natural alternative to synthetic fungicides for controlling B. cinerea in strawberries during postharvest storage.
The aim of this work was to improve the understanding about the relationship between solar radiation and temperature exposure during crop and tomato fruit susceptibility to postharvest chilling injury. Two preharvest treatments were applied: direct sunlight exposed plants (Ex) and shaded plants (Sh). After harvest, fruit were stored at 10⁰C and 4⁰C for ten days. Then, fruit were removed from the chambers and stored at room temperature for four days. Several determinations were carried out: total mineral and calcium content, fruit quality and postharvest parameters, ions leakage and thiobarbituric acid reactive species content and chilling injury index (CII). Ex fruit had higher values of chilling injury index than the Sh fruit, and at the same time, fruit under 4⁰C storage treatment presented a more marked damage than those stored at 10⁰C, demonstrating that accumulated radiation in the field, as a result of a higher solar radiation exposure, is a critical factor affecting postharvest chilling injury susceptibility. The lower calcium content in the Ex fruit could be one of the causes of their response to chilling.
17 September 2020 in The Journal of Horticultural Science and Biotechnology
The aim of this work was to study the effect of postharvest light treatment as a potential degreening method on ‘Okitsu’ Satsuma mandarin (Citrus reticulata Blanco). Furthermore, a possible synergistic effect of light and ethephon treatment was also evaluated. For this, mature green fruit were harvested and treated. The treatments were: 1) exposing the fruit to increasing periods of time of photosynthetically active radiation (PAR); 2) the combination of a traditional ethephon degreening method with the most effective PAR treatment. The results show that 12 h and 24 h of PAR treatments were the most favourable to obtain the better effects of degreening, not affecting the rest of quality parameters. The combination of the 24 h of PAR and ethephon treatments was not effective to degreen the fruit. The present work is the first step in the approach to the study of PAR treatment as a degreening method on citrus and, according to the results, we consider it could be a promising degreening treatment on ‘Okitsu’ mandarin.