11 June 2024. Paul McIntosh, Pulse Australia and WeedSmart.
I have just returned from two jam-packed information days at Tamworth for the excellent Crop Consultants Australia or CCA cropping solutions seminar.
One of my major take home messages is about pesticide resistance-insecticide resistance to be precise. After listening to Lisa Bird, the Senior Entomology Research Scientist from the DPI in NSW, I am more convinced than ever that insecticide resistance issues like we experienced in the late 1980’s and 1990’s with our very common Helicoverpa Armigera in sorghum, cotton and increasing hectares of pulse crops, has no way finished with us yet.
Of course, I am referring to the new Australian incursion of Fall Armyworm (FAW). Not an incursion due to lack of Biosecurity checking, as these damn insects simply flew into the north of Australia, after migrating across half the world from the United States over the last few years. Quite spectacular it would be, if they did no damage to mainly our grass type crops like maize, grain sorghum and millets in our broadacre summer ag scene, however they really have showed their true damaging colours this last summer season.
Unfortunately, our mainstay of control on the very damaging larvae or grub stage of this insect, is our current suite of insecticide - and some of the older ones like SP’s and Carbamates do not work very effectively. Insecticide resistance levels on many insects is increasing and new modes of action insecticides are not plentiful and just like new herbicides mode of actions, are not around every corner.
A the approaching winter of 2024 when Heliothis Armigera starts to chew into our very valuable chickpea crops, many of us will simply reach for the best registered insecticide drum in the shed and go an spray those foliage and pod eating beggars.
What I suggest is that you take the foot of our precious conventional larval insecticides pedal, that we will mostly use in Queensland like Indoxacarb and Chloraniloprole and particularly consider applying a biological insecticide like Vivus Max or NPV in this early grub infestation stages, when it is basically vegetative plant material, and grubs are present.
Now in my four decades of agronomy in the paddock, I have (sort of) broken many label registration rules, particularly in my early agro days. Being somewhat wiser now, I can see big problems with increasing levels of insecticide resistance for not only FAW, but also reduced control of Heliothis larvae which is our usual problem. I highly recommend that you do not break the label or IRMS rules by reducing rates or spraying outside the window. What I challenge all agros to do, with support from farmer clients, is to consider the future seasons where resistance levels are so high and control % are so low, that you cannot grow a particular crop due to financially non-controllable insects like H. Armigera or Fall Armyworm.
I have applied Vivus Max or Nucleopolyhedrosis virus to many vegetative/early flowering chickpea crops before and whilst it did not control all the larger grubs , it really did allow future insect spray decisions to be more effective and invariably turned two conventional insecticide applications to only one or even zero sprays over that reproductive stage of chickpea crops.
This is the future challenge I present to you all to adopt in our very large area of chickpea crop in the winter of 2024.
A droughted virus infected sad chickpea crop in 2019