15 July 2024. Paul McIntosh, Pulse Australia and WeedSmart.
Had a toss-up this week about whether I should pen an article on chickpea and the practical aspects of foliar diseases or the benefits of successful inoculation in respect to chickpeas and other legumes.
The diseases in chickpea won out, as we can probably expect disease issues like Ascocyhta Blight (AB) and even Phytophthora Root Rot (PRR) in these wet times. PRR I will not cover today as there is not much you can do about this root rotting disease, except stop any soil saturation events of rain or irrigation.
Last Tuesday I was part of a webinar on this subject of chickpea foliar diseases, so I started my presentation session on this well attended zoom meeting by outlining risk assessment of Ascochyta Blight or Asco infections in your crop of chickpeas.
With the last few years of not many hectares of chickpeas in Queensland or Nth NSW, the carryover of disease particles spread around the region would be fairly low. These particles or fragments of chickpea or even dust from headers can carry diseases like Asco and others for many miles and it can take some years for full breakdown.
Next item on the risk list is variety choice and whilst our varieties have generally gone from a moderately susceptible level to susceptible levels, we certainly have not gained much there.
Third item on my risk assessment list is your planting seed treatment. There was much angst about the lack of supply of Thiram or P Pickle T for use on chickpea planting seed, so I suspect with the high prices being offered by exporters for chickpeas at harvest time in November and December, significant areas of our favourite winter legume would be bare seed apart from the inoculant.
After crop emergence - that is when the farmer, and especially the agronomist adds all these factors up and decide on a plan of disease prevention and disease spread, by applying a fungicide option before any rain events.
Why do I say applying fungicides before rain events?
That is because when rain drop falls, on impact on a diseased bit of plant parts or even microscopic dust bits, it propels millions of disease spores into the air. Include a small breeze or worse on a windy showery day, there is your spread factor through your crop and even the neighbours next door. I have witnessed this event heaps of times over the last 25 odd years we have been battling Asco.
So, to protect all your chickpea leaves and stems of your plants, you really need to apply a coating of fungicide all over the green parts and even flowers of your crop, so that when the Asco disease spores are airborne and come to land on your painted with fungicide leaves, the spore actually dies due to inability to send its germination tube into the plant surface.
When agronomists and farmers ask me should I spray my chickpea crop for foliar disease, then I look at the above risks and I also consider the very lucrative pricing for our product and then I ask them is it going to rain?
Big questions, and not sure we have all the answers especially predicting the rainfall as chief spreading agent, apart from other spreading issues like kangaroos, farm dogs and even olde agronomists moving through the wet from dew crop.
Therefore, thorough field inspections are extremely important, invariably with a magnifying glass, as it takes time and money to spray all the hectares of chickpeas we have this season. However, rewards are positive both financial and as a good break crop in our northern farming systems.
That’s all folks.
Chickpea leaf with AB Disease.
Chickpea plant broken from AB Disease.