Check before planting crop

I TOOK this photo last week (right) of one of our paddocks with wheat planted in it.

Not flash and not going to eventuate into anything much, apart from brolga food.

This paddock is fairly smooth and was in perfect soil condition for planting a winter cereal crop.

What to do now with it for summer may be a question.

In these cases you hope that no pre-plant residual herbicide like chlorsulforon (glean) or Flame has been applied.

With our dry conditions, the breakdown of these two well respected weed control products will certainly be slowed down and the label suggestions of plantback time could well be extended.

So when it does rain enough to plant a summer crop, you really do need some idea of the level of herbicide left in your various paddocks, apart from a label information. It is going to be difficult to just plant on the first rain with a potentially susceptible crop species going by the label only.

These dry conditions do not provide you with any sensitive plant growth to make a determination if any herbicide is left in the soil.

By this I mean that apart from extrapolating the label details, the only other way to determine if the herbicide remaining in the soil is at a low enough concentration to not impact on the crop you want to grow, is by assessing weeds germinating and growing.

And to perform this task, we will need rain to stimulate weed seed germination and growth.

For example if chlorsulfuron had been applied in May, then the sensitive weeds I would be looking for in these early spring and summer months, would be mintweed or pigweed.

These two weeds would provide you with some confidence that the chlorsulfuron herbicide had degraded enough that crop plants like grain sorghum or mungbeans could be grown.

Never as simple as just finding one mintweed plant and two pigweed plants in a one hundred acre paddock, so there is no way that I would make a safe to plant call, with the two summer crops mentioned above with these low weed numbers.

It has got to be much more definite than just two or three weeds in the entire block.

I know we are all keen to plant something, however, I suggest taking extra care with previous residual herbicides applied in the preceding months and their most likely extended breakdown times to sensitive crops.

PHOTO: FILE SUMMER CROPS: Paul McIntosh said before planting summer crops such as sorghum, paddocks must be checked for herbicide left in the soil.

PHOTO: CONTRIBUTED This wheat crop won't amount to much more than brolga food.