Fruit Tree Diseases in France: Botrytis cinerea

Quick read / the essentials on Botrytis cinerea in fruit growing

Botrytis cinerea, responsible for gray mold, is a pathogenic fungus that affects many fruit species, including apricot, cherry, peach, pear, and apple. This fungal disease causes considerable losses both before and after harvest, affecting the quality and shelf life of fruit. Its development is favored by humid conditions and poor ventilation in orchards, making prevention essential to limit its impact.

At Arboriverse, a specialist wholesale supplier of fruit plants , we know that the fight against Botrytis relies above all on good orchard management. Pruning should allow for better air circulation , thus reducing the humidity conducive to the fungus. Removing mummified fruit and infected branches limits the persistence of spores from one season to the next. Balanced fertilization, without excess nitrogen, prevents foliage from being too dense and therefore more vulnerable to infection. Drip irrigation , rather than sprinkler irrigation, is also recommended to avoid moisture on fruit and leaves.

In organic farming, Bordeaux mixture , applied before flowering and after leaf fall, helps limit infection. Other natural solutions, such as baking soda as a cure and talc as a preventative , are effective in limiting the spread of the fungus. In conventional farming, the use of approved fungicides can be considered, particularly during periods of high fungal pressure.

At Arboriverse, a specialist wholesale supplier of fruit plants , we select varieties that are adapted to local conditions and more resistant to disease. Buying cherry, peach, pear, and apple trees from an expert is a strategic choice for optimizing production and limiting phytosanitary risks.

Botrytis cinerea: identification, prevention and control in fruit growing

Botrytis cinerea is a pathogenic fungus responsible for gray mold, a serious fungal disease that can cause significant losses in fruit growing. It primarily affects flowers, fruits, and vegetative parts of trees, causing damage both pre-harvest and post-harvest. Its spread is favored by humidity and poor ventilation in orchards, making it a major problem in humid temperate climates.

Fruit tree species concerned

Botrytis cinerea attacks several species of fruit trees, including apricot, cherry, nectarine, peach, pear, apple and plum.

Stone fruits, such as apricot, cherry, nectarine, peach and plum, are particularly susceptible to grey mold, which often occurs during ripening and storage.

Pome fruits, such as apple and pear trees, are affected both before and after harvest, resulting in significant losses during storage.

Susceptibility to Botrytis can vary depending on the variety, climatic conditions, and cultural practices. Some species such as almond, quince, pomegranate, nashi, and medlar can also be affected, but specific information on their vulnerability remains limited.

Symptoms of the disease

Gray mold causes various symptoms depending on the organs affected.

On flowers, Botrytis cinerea causes them to wilt and turn brown, which can compromise fruit set and reduce fruit production.

On twigs and young shoots, the disease can cause brownish lesions that lead to a general weakening of the tree and, in some cases, the dieback of branches.

On fruit, the most characteristic symptom is the appearance of a soft, wet rot covered with a grayish felt made up of fungal spores. This rot spreads rapidly and causes the fruit to drop prematurely or to spoil during storage.

Means of prevention

Prevention plays a key role in the fight against Botrytis cinerea, as it is difficult to eradicate this fungus once established.

Proper orchard sanitation management is essential to limit the spread of the disease. It is recommended to collect and destroy infected plant debris, including rotten fruit that has fallen to the ground and mummified fruit that remains on the tree.

Tree pruning should be done in a way that promotes good aeration of the foliage and fruit, avoiding dense areas where moisture can accumulate. Removing dead or diseased branches also limits sources of contamination.

A balanced fertilization is necessary to avoid excessive foliage growth, which can promote a humid microclimate conducive to the development of the fungus. It is advisable not to exceed nitrogen inputs, which encourage overly dense vegetation that is vulnerable to disease.

Choosing varieties less susceptible to Botrytis can be an effective strategy for limiting infections. Some varieties have better natural resistance and should be favored in cases of high disease pressure.

Controlled irrigation is a key factor in preventing Botrytis. It is recommended to use a drip irrigation system to avoid directly wetting the foliage and fruit.

Means of control and treatments

When an infection is detected, it is crucial to intervene quickly to limit the spread of the fungus.

In organic farming, several strategies can be implemented. Collecting and destroying infected parts is an essential measure to reduce fungal pressure.

Applying biocontrol products is an interesting alternative. Baking soda is used as a curative to block the growth of the fungus, while talc acts as a preventative by forming a physical barrier on the fruits and leaves.

Willow bark infusion, known for its natural antifungal properties, can be sprayed regularly to strengthen the resistance of trees.

In conventional agriculture, the use of fungicides is sometimes necessary to protect orchards against Botrytis.

Copper sprays, especially copper hydroxide, are more effective than copper sulfate or copper oxychloride. They should be applied in three stages: just before leaf fall, before bud swell, and just before flowering.

Sodium bicarbonate can also be used as a curative, at a rate of 3 to 10 g/L, with a maximum of eight applications per season spaced ten days apart.

Talc, applied as a preventative measure, blocks the growth of the fungus and limits fruit contamination. It should be used every two to three weeks, with three to five applications per season.

Conditions favorable to the development of the disease

Botrytis cinerea thrives in specific climatic conditions. It grows mainly in humid and cool environments, with temperatures between 15 and 25°C.

Prolonged periods of rain followed by cloudy, humid days favor the proliferation of the fungus. Dense or poorly ventilated orchards are particularly susceptible to this disease.

Wounds on fruit, whether caused by insects, mechanical shock or extreme weather conditions, provide entry points for Botrytis and increase the risk of infection.

Impacts and monitoring of the orchard

Gray mold can cause significant economic losses, particularly by reducing fruit quality and shelf life. In severe cases, it can compromise the harvest and affect the profitability of orchards.

Careful monitoring of the orchard is essential to quickly detect the first symptoms of the disease. Particular attention must be paid to climatic conditions and the stages of fruit development.

Conclusion

Botrytis cinerea is a ubiquitous pathogen that poses a serious threat to fruit production. Its management relies primarily on prevention, combining good sanitation, appropriate pruning, and cultural practices that limit excessive moisture.

When an infection occurs, rapid action is necessary to limit its spread. Biological and conventional solutions must be rigorously applied to ensure effective protection of orchards.

An integrated approach, combining prevention, monitoring and targeted treatments, helps to minimize losses and guarantee quality fruit production.

To summarize: how to protect your fruit trees against Botrytis cinerea?

Gray mold is a disease that weakens fruit trees and reduces harvest quality. Its management relies on good prevention, eliminating sources of infection, and appropriate treatments to prevent its spread.

Arboriverse, a specialist wholesale supplier of fruit plants , supports growers by offering plants rigorously selected for their vigor and adaptation to growing conditions. Buying cherry, peach, pear and apple trees from a specialist supplier is a wise investment to ensure a healthier and more sustainable crop.

Orchard maintenance plays a vital role in combating Botrytis. Proper pruning , which promotes good aeration of the foliage, helps limit humidity and prevent the development of the fungus. Removing contaminated fruit and branches , as well as cleaning the orchard at the end of the season, significantly reduces fungal pressure. Reasonable fertilization , avoiding excess nitrogen, strengthens the natural resistance of the trees.

When treatments are necessary, several options exist. In organic farming, Bordeaux mixture as a preventative measure , combined with baking soda as a cure , effectively limits the spread of the fungus. Talc as a physical barrier prevents spores from adhering to fruit and foliage. In conventional farming, the application of specific fungicides helps protect orchards during periods of high risk, while ensuring that pre-harvest deadlines are respected.

Increased orchard monitoring and rapid intervention can help control the infection before it gets out of hand. At Arboriverse, a specialist wholesale supplier of fruit plants , we put our expertise at the service of producers by offering healthy and resistant plants , ensuring quality and sustainable production. Buying cherry, peach, pear and apple plants from a specialist is a key strategy for strengthening crop resilience against disease and ensuring optimal yields.