14 May 2024. Last updated 14 May 2024.
The importance of chickpea inoculation
A couple of things have come across my desk over the past week that caught my eye. The first concerning issue was the apparent current shortage of registered and effective fungicidal seed dressing to be applied to the chickpea planting seed. I refer to Thiram and P Pickle T as being the two registered seed dressing treatment products we normally use in our chickpea industry.
My concern is that either a product shortage or even just a “she’ll be right mate” attitude will lead to chickpea seed being planted with no fungicide on it. When you have a close look at a chickpea seed, it has many little nooks and crannies. Obtaining 100% coverage with a fungicide for Ascochyta or Botrytis Grey Mould seed borne disease control is not that easy.
Having said this, variety selection becomes even more important for disease tolerance in chickpeas, particularly with new biotypes appearing in our Ascochyta disease spectrum.
So, the chickpea seed is planted bare, with live bacteria in the peat inoculant applied a few hours before sowing, the seed germinates and pushes through the topsoil. Any microscopic disease isolates on parts of the seed can begin to flourish in the moist cool soil from the un-treated or poorly treated chickpea seed. All of a sudden, your newly emerged seedlings start to die, and some do not even emerge.
Hoping for the best and instead of having the recommended 20 to 30 plants per sq metre emerged, you have a scrappy 10 or 15 small non thrifty seedlings looking at you. Do you replant or leave it be is the next question?
So, if you decide to leave it be, you need to make very sure your post emergent fungicide applications start very early in the crops life to protect it from more disease spread. These fungicidal regular applications for most varieties are going to come under pressure this coming winter cropping season, particularly if our rain events are regular and this includes a potentially wet spring.
This poorly treated chickpea planting seed is not a good situation, especially if the paddock you have planned for and chosen to plant your chickpeas in is clean of previous chickpea stubble/volunteers and now diseased seed is introduced by the planting operation.
One final point I will make is in respect of Rhizobia Bacteria and the inoculation process, is that chickpeas need nitrogen to grow and produce high protein seeds in their pods. It may surprise you to know that for a chickpea crop to produce 2 tonnes per hectare, it requires around 160kgs per ha of nitrogen. This is not just removal out the gate of our high protein legume grain, as all legume plants need Nitrogen to grow and reproduce. Now this nitrogen can come from the NdfA (Nitrogen derived from the Atmosphere) process through correctly inoculated seed, or it can come from your previous expensive applied nitrogen sources or even mineralisation. It makes sense to use the free service that effective nodules on your root system (like the photo above shows) is the preferred method of feeding your high protein chickpea crop.
Reiterating my key points here, is to use high quality well treated chickpea seed, ensure good inoculation and importantly examine your varietal choice in this potentially wetter winter and spring.
Our favourite winter legume; the chickpea, with a reasonable root system and a fantastic live nodulation level, which would score 5 in any inoculation manual.