High grain prices are tempting at the best of times, particularly when another rotation staple is at historical lows. This it the predicament some chickpea growers are facing in the GRDC Northern Region, with high chickpea prices and low cereal prices heading into the 2017 season tempting some growers to plant chickpeas back-to-back. However, breaking rotations and going back-to-back is a particularly risky business with chickpeas, and Senior Pulse Pathologist Kevin Moore is strongly advising against chasing these high prices at the expense of integrated disease best management practice.
The release of PBA Seamer has delivered improved Ascochyta blight resistance for Northern growers. However, the recent breakdown of chickpea Ascochyta resistance in the Southern Region and evidence that the pathogen has also changed in the Northern region demonstrate that plant resistance to disease isn’t bullet-proof. Sowing back-to-back chickpea crops will provide more opportunity for the Ascochyta blight pathogen to evolve, hastening the breakdown of PBA Seamer’s resistance.
But the back-to-back message is not just about Ascochyta. Soilborne diseases like Sclerotinia and Phytophthora root rot are a much more persistent problem. These diseases are usually lethal for chickpea crops, and the only management option is through rotations with nonhost crops. Once a chickpea crop is sown into a paddock with Sclerotinia or Phytophthora, no in-crop management is available. These diseases also persist in the soil via survival structures (sclerotia and oospores) for 5-7 years, creating a much longer term problem.
Dead set on sowing chickpeas into last years chickpea stubble? Dr Moore suggests Kyabra is the variety to grow in this situation. Although Kyabra is very susceptible to Ascochyta this susceptibility will ensure that growers need to remain on top of disease control no matter what. And PBA Seamer’s resistance won’t be put under as much pressure.
- Ascochyta to be assessed in Predicta B tests – GRDC Media Release
- Minimising risk of disease in 2017 chickpea crops – GRDC Update Paper
- Managing inoculum key to reducing impact on 2017 chickpea crops – Field Crop Diseases Article
- The Northern Region Chickpea Ascochyta Diaries – Field Crop Diseases Article
Kristy Hobson, NSW DPI