Drought

Symptoms: Slowing down of shoot and fine root growth, leaves wilt, curl up and dry out, hang down and fall off.

Mechanisms: The first effect of water stress is a reduction in cell growth and leads to a slowing down of shoot and fine root growth. This is because the stomata close to limit transpiration, which blocks exchanges with the atmosphere and therefore the absorption of CO2, photosynthesis and consequently growth. If the water deficit persists, cavitation and embolism of the vessels appear, which disrupt the functioning of the entire conductive system and lead to the wilting of the foliage. In this case, for deciduous species, the leaves dry out, curl up, hang down and then fall off. When the vascular system is completely embolised, the tissues, especially the meristems, are no longer supplied with water. The cells eventually empty themselves of their contents and die.

The chestnut tree is not very resistant to a lack of water as soon as it occurs at a depth of less than 50-60 cm (stagnant or circulating waterlogging), its initial response is to close the stomata to limit transpiration. The available water capacity should not be less than 120 mm. The most suitable soil textures are sandy loam, silty loam and sandy loam, which are relatively aerated.

For more information on drought, see the e-Phytia Forest application: Drought.