Fruit Tree Diseases in France: Entomosporium Leaf Spot

Quick read / the essentials on fruit tree blight

Entomosporium leaf spot is a fungal disease that affects several fruit tree species in the Rosaceae family, including quince, pear, apple, and nashi. Caused by Entomosporium maculatum , it appears as red or brownish spots on the leaves, which can lead to premature defoliation and compromise production. On fruit, it causes lesions that affect their quality and promote the entry of other pathogens.

At Arboriverse, a specialist wholesale supplier of fruit trees , we know that prevention is essential to limit this disease. Choosing resistant varieties is an effective first barrier. Rigorous orchard maintenance, including adequate spacing of trees to improve air circulation and avoid excess humidity, helps limit the risk of infection. Removing fallen leaves, maintaining hygienic pruning tools, and balanced fertilization are also important levers. Irrigation must be well controlled: watering at the base of the trees is preferable to avoid wetting the foliage and thus slow the proliferation of the fungus.

When intervention is necessary, several treatments exist. In organic farming , solutions such as Bordeaux mixture, lime sulfur or potassium-sulfur bicarbonate can be applied preventively and curatively. In conventional farming , specific fungicides such as those based on myclobutanil or mancozeb are used according to a reasoned program. In all cases, regular monitoring of the orchard allows for rapid intervention as soon as the first symptoms appear.

At Arboriverse, a specialist wholesale supplier of fruit plants , we offer plants adapted to the requirements of professionals, guaranteeing robustness and productivity. Buying apple, pear, quince and nashi plants from a specialist ensures efficient cultivation and limits health risks, while optimizing the profitability of your farm.

Fruit tree blight: identification, prevention and control

Entomosporium leaf spot is a fungal disease affecting several fruit tree species in the Rosaceae family. It can cause significant losses by weakening trees and affecting fruit quality. A good understanding of the symptoms and management strategies allows professional arborists to adopt effective measures to limit its impact.

Fruit tree species concerned

Entomosporium leaf spot mainly affects quince, pear, apple, cider apple, nashi (Japanese pear), and medlar. Among these species, quince is particularly vulnerable and can be severely affected.

Symptoms of the disease

The pathogen responsible for entomosporium leaf spot is Entomosporium maculatum (syn. Diplocarpon mespili ). This disease is mainly manifested by the appearance of red or brownish spots on the leaves, progressing to necrosis and premature leaf fall. On the fruits, small circular lesions may appear, causing cracks that encourage the entry of other pathogens. In cases of severe infection, massive defoliation weakens the tree and compromises its long-term production.

Means of prevention

A rigorous preventive approach is essential to limit the development of entomosporium in orchards.

Choosing resistant varieties is a first line of defense against the disease. Although some varieties have reduced susceptibility, it is important to ensure that they are suitable for local conditions before planting.

Orchard maintenance plays a key role in disease management. Collecting and destroying fallen leaves is essential to prevent fungal spores from persisting from one year to the next. Regular pruning to ensure good leaf aeration also helps limit humidity, a condition conducive to the development of the fungus.

The spacing between trees must be sufficient to ensure good air circulation and prevent rapid spread of the disease. Similarly, it is recommended to avoid overly dense plantings, which promote the maintenance of a humid microclimate conducive to infection.

Tool hygiene is an often underestimated factor. Disinfecting pruning shears and other equipment between each tree limits the transmission of spores and prevents contamination of new shoots.

Fertilizer use must be controlled. Excess nitrogen promotes rapid foliage growth, making young tissue more susceptible to infection. Balanced fertilization helps strengthen the trees' natural resistance.

Irrigation should be adjusted to avoid wetting the foliage. Watering at the base of the trees is preferable to limit humidity in the canopy and thus reduce the risk of infection.

Means of control and treatments

Different strategies can be implemented to combat entomosporium, depending on whether a biological or conventional approach is adopted.

In organic farming, several treatments are available. Bordeaux mixture can be applied at strategic times: at bud break, one month later, and then in the fall when the leaves fall. A liquid chitosan-based solution, combined with a specific organic treatment against fruit tree diseases, can be used to strengthen the trees' resistance. Copper-based fungicides, authorized in organic farming, are an effective alternative. The use of lime sulfur or a wettable potassium bicarbonate-sulfur mixture as a preventative or curative treatment can also limit the growth of the fungus.

In conventional agriculture, the use of synthetic fungicides can be considered. Products containing myclobutanil have both preventative and curative effects, while those containing mancozeb are only preventative. Bordeaux mixture, although used in organic farming, is also a commonly used treatment in conventional arboriculture. Its application must be carried out according to a precise schedule, respecting the recommended doses.

Treatments should be applied as soon as the first symptoms appear and repeated every 7 to 14 days during wet periods, when the disease is most likely to develop. Careful monitoring of trees allows for rapid intervention and prevents the spread of entomosporium within the orchard.

Integrated strategy for the control of entomosporium

Effective management of entomosporium leaf spot relies on an integrated approach combining preventive measures and appropriate treatments. Early identification of symptoms and the adoption of good cultural practices can limit reliance on phytosanitary treatments.

Adapting control strategies to climate conditions and local specificities is essential to maximize the effectiveness of interventions. Regular monitoring and careful management of inputs help maintain an optimal health balance in professional orchards.

Conclusion

Entomosporium leaf blight poses a threat to fruit crops, particularly quince and other susceptible species in the Rosaceae family. Prevention remains the best approach to limiting its impact, through appropriate cultural practices and rigorous monitoring. When treatments are necessary, their application must be reasoned, favoring solutions authorized in organic farming or conventional fungicides as a last resort. An integrated approach adapted to the specific conditions of each orchard ensures healthy and sustainable fruit production.

To summarize: how to protect your fruit trees against entomosporium leaf spot?

Entomosporium leaf blight poses a significant threat to orchards, particularly quince and pear trees. This fungal disease causes damage to foliage and fruit, reducing tree vigor and crop quality. A well-thought-out preventive strategy is essential to minimize its impact.

Arboriverse, a specialist wholesale supplier of fruit plants , supports arborists by offering suitable and rigorously selected plants. Buying apple, pear, quince and nashi plants from an expert allows you to have resistant varieties that are well adapted to local conditions, thus reducing vulnerability to disease.

Orchard maintenance is the first line of defense. It is essential to choose tolerant varieties and properly space plantings to limit moisture stagnation. Regular foliage monitoring and prompt removal of infected leaves prevent the disease from spreading from one season to the next. Pruning tool hygiene, often neglected, plays a key role in limiting contamination from one tree to another. Balanced fertilization, without excess nitrogen, promotes moderate foliage growth and naturally strengthens the trees' resistance. Irrigation must be considered: it is preferable to water at the base of the trees to prevent moisture on the foliage from creating an environment favorable to the development of the fungus.

When disease pressure becomes too high, applying appropriate treatments can limit its progression. In organic farming, Bordeaux mixture, sulfur, or alternative solutions based on sulfur lime are effective options. In conventional farming, approved fungicides can be used according to a reasoned program to limit the spread of the pathogen without disrupting the balance of the orchard. An approach combining prevention, maintenance, and targeted treatments can effectively reduce losses and ensure healthy and profitable production .

At Arboriverse, a specialist wholesale supplier of fruit plants , we put our expertise at the service of professionals by offering robust plants adapted to the requirements of fruit growing. Buying apple, pear, quince and nashi plants from a specialist is an essential investment to guarantee the sustainability and profitability of your orchard.