Effective program needed
Protect your chickpea plants from diseases
WITH the smaller falls of rain we are receiving it certainly is going to be putting pressure on our disease prevention fungicides in our valuable chickpea crops.
Not only do we have to contend with some rapidly declining soil moisture levels and flowering crops due to the warm conditions since planting, we also have this high level of Ascochyta spores in the region.
Residing mostly on chickpea plant particles from previous years’ record size crops, it can easily spread to even non traditional chickpea paddocks by wind storms and rain drops, plus overland flows from heavy rain events like cyclone Debbie.
As a consequence, we really need to employ an effective fungicide program pre any of these falls (even <4mm) of rain, that can spread foliar disease really easily to unprotected parts of our new chickpea bushes.
So after encouraging you to apply fungicides pre rain, I then advise you to make sure you achieve complete spray coverage in your chickpea crop as per fungicide product label.
However, what does complete or adequate coverage mean and how do you judge it before you start?
Yes, previous experience is a positive and if you have ever applied Paraquat or Sprayseed herbicides, you will certainly know about how good your coverage has been in past fallow weed control efforts.
Even positioning some water sensitive paper in various parts of your bush is an easy and practical way of pre spray judgment of coverage in your fast growing chickpea paddocks.
We are really talking about a predominantly upright and multi branched broadleaf legume plant with hundreds of small leaves that will more than double the surface area you need to cover compared to a paddock hectare rate you use with soil residual herbicides.
So leaf area index assessment at various growth stages is part of the puzzle.
There is more than one nozzle type you can use for sure and nozzles are only one
part of the ensuring adequate spray coverage equation that you need to consider.
The other big contenders are speed of sprayer, droplet generation size, including pressure and most importantly water volume.
Yes and so does boom height, weather conditions and increasingly dusty paddocks.
Too much speed and you observe your spray pattern
being bent backward especially with the smaller droplets being generated. Then it is gravity you are relying on for droplets to penetrate the bush.
If you believe that cone nozzles will give you small droplets you are right, however they will float everywhere and not necessarily on to or deep into the chickpea bush.
One key element is water volume and already I can hear the groans from boom spray operators.
It does compensate to a certain extent for low pressure, boom height inconsistencies and certainly gives you the potential of many droplets being generated with some velocity to give you that coverage over every square centimetre of chickpea bush.
So while our fungicide labels advise ensuring adequate coverage, you need to interpret and judge your application skills by not only by past success in the paddock, but the above pointers as well.
Painting literally all plant parts with the prevention type fungicides we have is the only way to protect your chickpea plants from the different foliar diseases we may experience from now till harvest time.