18 June 2024. Paul McIntosh, Pulse Australia and WeedSmart.
I have been in NSW this last week doing presentations to an agronomy group, discussing fungicides and application timing for the future growing weeks of our pulse crops.
I showed how effective fungicides like chlorothalonil can be, in our chickpea crops to control or more likely, prevent that debilitating chickpea disease called Ascochyta Blight.
Yield decreases of 53% and 89% of Kyabra and Drummond chickpea varieties respectively is quite alarming, where no fungicide was applied in one trial zone in the presence of disease.
These two varieties are good varieties, however with zero tolerance to Asco and in potentially constant showery conditions, diseases like Ascochyta can run riot.
On the other side, varieties like Boundary, Hattrick and Seamer that have some resistance to this disease lost less than 10 % yield in these trials and no fungicide applications.
So, the take home message of my presentation was to know your variety status for diseases be it Chickpeas or Faba beans and make sure after examining your risk level and plan your mix and rotate fungicide mode of actions and apply just before any rain events. As an added complication, Ascochyta Blight is changing its variants or strains across the country and these highly aggressive isolates could add more weight to getting our fungicide application process correct.
It did amaze me that reports from these mostly North NSW agronomists, that there appeared to be a lax attitude by the some in the actual farming community to the increasing possibility of higher levels of actual fungicide resistance. A similar attitude evidently exists for laxness in relation to WHP or Withholding periods and MRLs (Maximum Residue Levels). This is really asking for trouble in your marketing spaces.
So, if just adopting regular prophylactic spraying days and/or just applying the same mode of action fungicide, these ploys are fraught with danger of disease resistance becoming widespread and costly.
When you look at the history of Herbicide or Insecticide resistance, the continued efficacy keys are to only spray on thresholds with the recommended label rates and rotate your chemistry or mode of action, for every sequential application event.
No difference in our fungicide plans and I know we have a very slim number of different modes of action in our registered fungicide range. As I said to the group in NSW, the possibility of increased fungicide resistance really does scare /concern me.
So, for us in the northern part of the main Desi chickpea growing region of Australia, make sure you get it correct in your disease prevention strategies across all your pulse crops.
Picture: A Faba Bean crop in QLD in 2023.