Boron deficiency-Cocoa

Symptoms
Young leaves are smaller in size, pale, thickened and brittle. Leaf apex is lost, multiple new growth starts, leaves may be distorted. Tips and margins become necrotic. Older leaves are not affected.

Reasons
Boron deficiency. Boron deficiency is a well-known micronutrient disorder of cocoa. B is very mobile in the soil and can be easily leached from the rootzone. Cocoa has a high demand for boron, the recommended level in leaves is above 25 ppm. There is only a narrow range between boron deficiency and toxicity, however. Adequate B supply enhances flowering, fruit set and disease resistence.

Symptoms
Young leaves are smaller in size, pale, thickened and brittle. Leaf apex is lost, multiple new growth starts, leaves may be distorted. Tips and margins become necrotic. Older leaves are not affected.

Reasons
Boron deficiency. Boron deficiency is a well-known micronutrient disorder of cocoa. B is very mobile in the soil and can be easily leached from the rootzone. Cocoa has a high demand for boron, the recommended level in leaves is above 25 ppm. There is only a narrow range between boron deficiency and toxicity, however. Adequate B supply enhances flowering, fruit set and disease resistence.

Symptoms
Young leaves are smaller in size, pale, thickened and brittle. Leaf apex is lost, multiple new growth starts, leaves may be distorted. Tips and margins become necrotic. Older leaves are not affected.

Reasons
Boron deficiency. Boron deficiency is a well-known micronutrient disorder of cocoa. B is very mobile in the soil and can be easily leached from the rootzone. Cocoa has a high demand for boron, the recommended level in leaves is above 25 ppm. There is only a narrow range between boron deficiency and toxicity, however. Adequate B supply enhances flowering, fruit set and disease resistence.