Nutritional/Physiological Disorders:Calcium Deficiency
- Deficiency symptoms appear in the younger leaves owing to low mobility of calcium within the plant.
- Early foliar symptoms include yellow stripes parallel to leaf midrib and crinkling of leaves (Image1,2).
- Leaf thickening and marginal interveinal chlorosis as the plant grows.
- If the deficiency is severe, the leaves develop serrated or saw like margins and are completely deformed.
- Heart leaf exhibits chlorosis followed by necrosis (Image3).
- Prolonged and severe deficiency prevents the emergence of new leaves and ultimately the plant dies.
When plants outgrow their calcium or boron supply it results in deformed, bunchy and yellow leaves at the center/top of the plant resembling bunchy top disease. Deformation of the flag leaf can also be induced by
- poorly placed herbicide applications such as glyphosate and can be erroneously confused with deficiencies of Ca, Zn or B. Similarly, symptoms of viral attack can be mistaken for deficiencies of these elements. To confirm that the plant does not have banana bunchy top disease, check closely for symptoms such as Morse code and petiole streaking that represent the bunchy top disease.