A network that helps people worldwide obtain rapid advice and information on crop protection, including the identification and management of plant pests.
PestNet is a network that helps people worldwide obtain rapid advice and information on crop protection, including the identification and management of plant pests. It started in 1999. Anyone with an interest in plant protection is welcome to join. PestNet is free and is moderated, ensuring that messages are confined to plant protection.
November 2015. Pomegranate with leaves that are drying out on mature trees, sent from Maharashtra, India.
Jane O’Sullivan, from the University of Queensland if she had any idea of the cause of this bleaching symptom. This is her response:
“I’d be speculating wildly on this one. It depends a lot on whether it’s patchy or widespread, and whether it’s a problem that’s just cropped up rather than one that’s been plaguing the orchard all along and, if it’s recent, has the weather been wet or dry?
Supposing it’s associated with recent wet weather, it looks like photobleaching on younger leaves, that might be associated with iron deficiency in response to a manganese toxicity brought about by waterlogging. The plant most affected seems lower on a slope than the less-affected background plant, which would be consistent. If this is the cause, they’ll probably recover when the soil drains. If it’s a persistent problem, liming might help.
“However, it might be something else entirely. If the soil is already alkaline, it might be a direct iron or zinc deficiency, in which case liming would not be a good idea at all. They really should get a local agronomist to investigate”