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.
July 2015. Photos of badly distorted papaya plants from India.It started with one or two plants in the field and now it is 20% of about 9000 plants.And farms nearby also had the problem. Samples were sent to the Jawaharial Nehru University for virus identification but none were found. The soil pH is 7.5-7.9, dissolved salts in the water is around 550, and the herbicides used are glyphosate and paraquat. In the cotton fields, selective herbicides are used.
Members asked if the farmer had used herbicide on the papayas or on the previous crop.It seemed not. There was also a suggestion of boron deficiency, and a question about the source of the water, especially if farmers were using the same source. It seems that bore water was being used. Phytophthora crown rot was mention as a possibility.
Another member said, if there is no evidence of herbicide damage, either on the crop or on weeds nearby, the the next thing that comes to mind is eriophyiid mites, although it was not known if there was one that attacked papaya.Treat some of the plants with a miticide, even sulphur may be sufficient and see whether the plants grow out of the condition.
Later in the month, a post was sent from the farmer saying that he had visited an area about 90kms from his farm. There farmers were planting 300 acres of papaya. They plant mostly in June, whereas we plant in March/April when the temperatures are high and lower RH. He noticed that those plantations that were planted in March had the same problem that we did, but those plant later in June were fine. In June, the conditions are different as its the start of the monsoon, with reduced temperatures.