Words by Bill Cabout, Ruralco Chemical Manager
This month we will look at fodder beet crops, crops, autumn sown crops, and grass grub control in pasture.
Fodder crops
Most sprays on fodder beet have been completed. If signs of disease appear such as rust, powdery mildew, cercosporin and ramularia leaf spot we can apply a fungicide. We now have a choice of two fungicides, Escolta (Cyproconazole/trifloxystrobin) types with a 42-day withholding period and Custodia (Tebuconazole/Azoxystrobin) with a 28-day withholding period.
Fodder Brassicas crops will need spraying with insecticides if the insect pressure gets too high. Damage is starting to show with both white butterfly and diamond back moth caterpillar damage being seen. We should be looking at applying an insecticide. We should also apply an aphicide to control any aphids present at the same time rather than having to come back later. We can either use older chemicals that will kill every insect, or we can use the IPM (Integrated Pest Management) approach using newer chemistry that targets the pests and leaves the beneficial insects alive.
Crops
With the changeable weather we have plenty of Glyphosate, MCPA, Glufosinate and Diquat available to help with the desiccation of crops before harvest.
For crops planted after harvest we need to look at drilling with Diazinon granules to help control grass grub. Plenty of Diazinon granules are available this season.
If there is a lot of trash, we need to look at slug control especially if the crops have been irrigated. The key to slug control is baits per square metre. We have a range of slug baits available instore.
We need to make sure we control slugs and insect pests when we drill crops to ensure successful establishment of the new crop. If we don’t by the time we realise we have a problem, it is too late, and we will have to re drill the crop. It is cheaper to control the pests than to have to buy new seed and re drill.
Autumn sown crops
Depending on the crop we need to look at the use of pre-emergence sprays to control weeds going into the winter.
Wheat: If hairgrass is a problem, we must use Genfarm Diflu-Flu, Firebird or Invado, the choice depends on our other weeds we have, as Genfarm Diflu-Flu and Firebird also has diflufenican in it. These chemicals are often used with Terbuthylazine as well for control of a greater range of weeds.
If wild oats are a problem Avadex extra can be used pre-sowing to help control them. This is an alternative if you have problems with controlling wild oats later. We also have Sakura, a herbicide from Bayer for controlling autumn germinating ryegrass, vulpia hairgrass, annual poa, soft brome, and barley grass, plus it also gives suppression of ripgut brome, prairie grass, and wild oats. This can be used instead of Genfarm Diflu-Flu, Firebird and Invado.
Barley: Genfarm Diflu-Flu, Firebird or Invado can be used as above to control weeds pre-emergent.
Ryegrass. To control a range of annual grasses and other weeds Ethofumesate is used pre-emergence in both perennial and annual ryegrass.
Grass grub control in pasture
We are coming to the time of year to control grass grub in pasture using Diazinon liquid. This must be applied to short pasture and needs to be washed in by at least 12mm of rain before it dries on the foliage for best results. This season we have plenty of stock.
With all the above scenarios talk to your Ruralco representative for the best options for you and your situation