M. Salerno

Effectiveness of Aureobasidium pullulans and Candida oleophila against postharvest strawberry rots

Abstract Many yeasts, including yeast-like fungi, were selectively isolated from fruits and vegetables. In several assays performed on strawberries, table grape berries and kiwifruit, the yeast-like fungus Aureobasidium pullulans L47 and the yeasts Candida vanderwaltii L60 and C. oleophila L66 were the most effective antagonists of Botrytis cinerea and Rhizopus stolonifer . Isolates L47 and L66 were utilized in trials on strawberries grown under plastic tunnels. They were applied at flowering (full bloom and late petal fall) and at fruit maturity (just before or after harvest). Isolate L47 was the most effective against both B. cinerea and R. stolonifer . Both antagonists were more active when applied at the flowering stage, with isolate L47 more effective than vinclozolin. The antagonist population was consistently high on flowers and developing fruits, and on cold-stored strawberries. Isolates L47 and L66 showed a low sensitivity towards some fungicides in culture and were able to grow at temperatures between those of cold storage and 33 °C. Competition for nutrients seems to be the main mode of action.

Effect of short hypobaric treatments on postharvest rots of sweet cherries, strawberries and table grapes

The effectiveness of short hypobaric treatments against postharvest rots was investigated by exposing sweet cherries, strawberries and table grapes to sub-atmospheric pressures (0.25, 0.50, and 0.75 atm) for different times (from 1 to 24 h). Postharvest rots of sweet cherries and strawberries arose from natural infections, whereas small table grape bunches and artificially wounded single berries were inoculated with Botrytis cinerea after hypobaric treatment. Sweet cherries exposed to 0.50 atm for 4 h had the lowest incidence of gray mould, brown rot and total rots, while a 1 h treatment was not effective. On strawberries, the greatest reductions of gray mould and Rhizopus rot were observed on fruits treated for 4 h at 0.25 and 0.50 atm, respectively. On table grape bunches treatment with 0.25 atm applied for 24 h significantly reduced the incidence of gray mould. In experiments performed with artificially wounded single table grape berries exposed to 0.50 atm for 24 h and then inoculated, the percentage of infected fruits and the diameter of the lesions were significantly reduced, in comparison with the controls. As a sub-atmospheric pressure of 0.25 atm did not affect radial growth of B. cinerea and Monilinia laxa, induced resistance was likely to be responsible for the observed reduction in decay.

Abiotic diseases of olive

SUMMARY Several non-parasitic diseases are of primary significance for olive trees growing in the Mediterranean area and other warm-temperate regions of the world. As for other crops, they are generally poorly understood and often completely unrecognized, especially in olive which is considered a crop of marginal lands. The origin may rest with a lack/excess of essential nutrients or an excess of non-essential elements; it may be an unsatisfactory environment: too cold or hot, too wet or dry, or too windy; there may be unsuitable soil characteristics such as poor physical condition, water-logging, salinity, improper pH, and so on. Also pollution in the environment, spray and fire damage, and climatic extremes like lightning, hail, and snow can cause heavy losses to olive. This review focuses on the most important disorders of olive caused by environmental, physical, and chemical stresses that can affect the normal physiological processes in trees. An integrated view is utilized to highlight interactions with plant healthiness, production, and quality.