CHICKPEA growers and consultants are being advised to ‘monitor closely and act promptly’ to reduce the disease risk in this year’s crops and land the 2017 harvest safely.
NSW Department of Primary Industries (NSW DPI) senior plant pathologist Dr Kevin Moore said the risk of Ascochyta, Phytophthora, Sclerotinia and Botrytis diseases was high this season in the wake of wet conditions during 2016.
Speaking at Grains Research and Development Corporation (GRDC) Updates across Queensland and northern NSW recently, Dr Moore warned growers to be vigilant about checking crops and where necessary implement in-crop management strategies to reduce disease.
“It may well be a waiting game for many growers at the moment, but fungal diseases like Ascochyta blight are largely influenced by seasonal conditions, so while growers need rain they won’t have disease problems,” Dr Moore said.
“So, in some ways the dry conditions have worked in growers’ favour by reducing the disease risk, but rain events between now and harvest could change the situation in paddocks rapidly.
“Growers need to have management strategies in place and they need to monitor crops closely and consult with their advisors ahead of any significant forecast rain events to assess the economic benefits of a fungicide treatment.”
Ascochyta blight has already reared its head in chickpea crops in parts of northern and north central NSW and southern Queensland this season.
These detections in May and early June included paddocks planted to Kyabra and the recently released PBA Seamer variety.
Although the outbreaks could have involved seed borne Ascochyta, Dr Moore said many paddocks planted to chickpeas in 2017 already contained the Ascochyta fungus because they were chickpea-on-chickpea or because they were inoculated with wind borne infected chickpea residue during harvest in 2016.
Avoid back-to-back crops
For years Dr Moore has warned against planting back-to-back chickpeas, saying growers risked up to 100 per cent crop losses if conditions favoured disease development.
“These cases highlight the risks of planting chickpea back into its own residue. Other risks are Sclerotinia and Phytophthora, which unlike Ascochyta, cannot be controlled in-crop,” he said.
If serious disease outbreaks were to occur, they would pose costly and long-term implications for the entire grains industry.
“The first implication is the increased risk of the pathogen becoming more virulent and aggressive,” he said.
“Secondly, it places increased pressure on the resistance genes in new varieties as crops are subject to earlier infection and potentially more disease cycles within a season; and thirdly, we could see an increased risk of the pathogen developing resistance to fungicide.”
Dr Moore said the best practice recommendations for disease control in chickpea crops were to maintain a 1-in-4 year rotation; avoid planting next to last year’s chickpea stubble if possible; ensure all planting seed is pickled and follow the recommended in-crop Ascochyta fungicide strategy for the variety being grown.
This season where Ascochyta blight infection is suspected, growers are advised to have the disease positively identified.
Dr Moore said they should then apply a registered fungicide based on chlorothalonil or mancozeb before and as close as possible to the next rain event.
The Grains Research and Development Corporation (GRDC) has released a Know More video to help growers with Ascochyta blight identification and management, which is available on the GRDC’s YouTube channel or by following this link.
Dr Moore will also be presenting the latest information on landing the 2017 chickpea harvest safely at the GRDC and NSW DPI AgQuip Breakfast Research Forum at the Commonwealth Bank AgQuip Field Days at Gunnedah, NSW, on August 23.
Places at the breakfast are limited and growers should contact Liz Tydd NSW DPI on 02 6763 1454 or firstname.lastname@example.org to register and receive instruction for the early site entry.