Grey mould, which is caused by the Botrytis cinerea bacteria, is one of the most harmful diseases that can affect many plant varieties before and after harvesting. In this case, natamycin – as a natural antifungal agent – can help prevent the onset of grey mould and prolong the shelf life of fruits and vegetables.
Grey mould: characteristics
One of the factors most heavily involved in the appearance of grey mould is moisture and sudden changes in temperature. Botrytis Cinerea not only attacks healthy plant tissues, but also those which are already infected and even dead tissues. Furthermore, its spores are capable of remaining in the soil for years until they find favourable conditions for development.
Grey mould does not only affect the fruit – it can attack the entire plant: the leaves dry out quickly and the stems become brittle. The microscopic morphology of the mycelium, the terminal growth points and the spores also lead to adverse growth. The edges of the mycelium become rough, the terminal growth points wilt and the spores become deformed.
Application of natamycin in plants affected by grey mould
Applying natamycin to plants affected by grey mould, at both room temperature and at low temperatures, prevents the growth of the bacteria responsible for growth of the mould, but it is more effective at low temperatures.
The treatment can be applied both before and after harvesting the fruits, although the mould rate is lower if applied beforehand. After immersion with natamycin, the fruit is harder after 80 days of storage, and Botrytis cinerea disappears from the surface of the fruit. Furthermore, the ethylene (ETH) generation rate in the fruit is also reduced by pretreatment involving immersion with natamycin, phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD).
In conclusion, treatment with natamycin before harvesting can significantly help to control grey mould and improve the quality of the fruit during subsequent storage. In view of the above, it is highly advisable to design measures to reduce surface grey mould, because by doing so fruit suppliers can provide a better quality product.