Inhibition of Botrytis cinerea growth and suppression of botrytis bunch rot in grapes using chitosan

Abstract

Chitosan inhibited growth of Botrytis cinerea in liquid culture and suppressed grey mould on detached grapevine leaves and bunch rot in commercial winegrapes. Germination of B. cinerea was completely inhibited in malt extract broth containing chitosan at concentrations greater than 0AE125 g L )1. However, treated conidia were able to infect detached Chardonnay leaves and pathogenicity was not affected, even after incubation for 24 h in chitosan at 10 g L )1. When added after conidial germination, chitosan inhibited B. cinerea growth and induced morphological changes suggestive of possible curative activity. The effective concentration of chitosan that reduced mycelial growth by 50% (EC 50 ) was 0AE06 g L )1. As a foliar treatment, chitosan protected detached Chardonnay leaves against B. cinerea and reduced lesion diameter by up to 85% compared with untreated controls. Peroxidase and phenylalanine ammonia-lyase activities were also induced in treated leaves. In vineyard studies, Chardonnay winegrapes exhibited 7AE4% botrytis bunch rot severity at harvest in 2007 after treatment with an integrated programme that included chitosan sprays from bunch closure until 2 weeks preharvest, compared with 15AE5% in untreated controls and 5AE9% with fungicide treatment. In the following season, botrytis bunch rot severity was 44% in untreated Chardonnay at harvest and the integrated programme (21%) was less effective than fungicides (13AE8%). However, in Sauvignon blanc winegrapes, the integrated and the fungicide programme each reduced botrytis bunch rot severity to 4% and were significantly different from the untreated control (11AE5%). This study provides evidence that suppression of botrytis in winegrapes by chitosan involves direct and indirect modes of action.

Antifungal Effect of Chitosans and Chito-oligosaccharides against Early Blight of Tomato

“…glycine. In the in vitro experiments, growth of the test fungus was successfully inhibited by chitosan treatment, varying from partial inhibition at low concentration to complete inhibition at high concentrations, which is in agreement with the findings of Reglinski et al, (2010), Abd-Alla andHaggag (2010), El Hassni et al, (2004) and Munoz and Moret (2010).…”

Potassium silicate and chitosan application for gray mold management in strawberry during storage

“…A direct antifungal effect of chitosan has been observed in B. cinerea,. The growth of this pathogen was completely inhibited if 125 g L À1 of chitosan was added to the culture medium (Reglinski et al, 2010). Strawberry fruit from plants treated with chitosan in the field in doses of 0.5, 1 and 2% showed a reduced incidence of postharvest rot (Mazaro et al, 2008).…”

“…Strawberry plants of the cultivar 'Camarosa' are larger than those of the cultivars 'Aromas', 'Seascape' and 'Oso Grande', which are considered compact plants (Duarte Filho, 2006). Chitosan has a direct effect on B. cinerea (Reglinski et al, 2010); however, contact of chitosan with the fungus is necessary to achieve this effect. When the products are sprayed on the larger 'Camarosa' plants, they often do not reach the surface of the fruits, which are usually located on the lower parts of the plant.…”

Evaluation of Host Resistance to Botrytis Bunch Rot in Vitis spp. and Its Correlation with Botrytis Leaf Spot

“…In Vitis spp., B. cinerea can incite bunch rot, also known as gray mold, in addition to cane and leaf spot. Annual losses caused by Botrytis can range from 10% to 44% (preand postharvest), with most loss occurring postharvest (Droby and Lichter, 2007;Reglinski et al, 2010). Disease management requires regular applications of fungicides to minimize reductions in yield and quality, in addition to cultural practices, such as canopy thinning.…”