Plant-parasitic nematodes, a threat to Australian cotton?

Abstract

Plant-parasitic nematodes are the number one cotton disease in the USA that accounts for a loss of more than 550 million bales of cotton in 2022. The reniform nematode is widespread in the Central Queensland region. QDAF monitors the status of the reniform nematodes in various cotton-growing regions, although there is no economic study that estimated the yield loss caused by nematodes in Australia. In recent years, cotton seedlings with very weak and rotting root systems have been noticed in reniform nematode-infested fields, and reniform nematode is also suspected to play some detrimental role in such poor roots. Reniform nematodes have also been found infecting the root system of mungbean which is a common rota on crop that also grows as a volunteer crop in cotton fields. There are no nematicides or resistant varieties against reniform nematodes. Our glasshouse trial has shown that the silicon-treated seedlings are resistant to the reniform nematode which require further exploration. QDAF has been providing technical support to collaborating partners such as CSIRO and Bayer to conduct field trials for the management of reniform nematode. There is a strong need for future research on monitoring of nematode population, yield loss caused by nematodes, resistant varieties, rota on crops with the ability to reduce nematode population in the soil, field hygiene, and plant defence-mediated resistance for the sustainable management of plant-parasitic nematodes.