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.
January 2012. Members were asked by a grower in Cambodia why the leaves of the cassava were yellow.
More details were requested about this condition. Is the condition limited to one plant, or many; what is the weather situation: has it been dry recently; how old are the plants; has the land been intensely cropped (and with what?), or is this the first crop after a fallow; are there several varieties affected, is the condition seen on one only or many plants; has any fertilizer been applied, and, if so, what?
It was said to have spread t many plants in the field, slome are close together, others not. Tfhe plants arre now 5 months old. Before the land was planted to Jatropha. After 1 month fertiliazer was applied (15-15-15 NPK) at 330 kg per ha.
The symptoms were not of virus.
A comment from Jane O’Sullivan, at UQ, Brisbane (Associate)
That’s a rather spectacular example of vein-clearing. It looks from the photos as if surrounding plants are not similarly affected. I don’t think it’s nutritional.
It looks like it may have been transient in appearance – only middle leaves are affected (but younger leaves may yet develop it). Is it possible that a normally benign virus became a problem in particular weather conditions? I’m just speculating – it’s not my area!