Words by Bill Cabout, Assistant Retail Manager
For the next 3 months we will look at the following: fodder crops, pre-emergence sprays on autumn sown crops, grass grub control in pasture, and use of gibberellic acid to increase pasture growth.
Most sprays on fodder beet have been completed. If signs of disease appear such as rust, powdery mildew, cercospora and ramularia leaf spot we can apply a fungicide. We now have a choice of two fungicides, Escolta (Cyproconazole/trifloxystrobin) types with 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. Early on insect pressure was low, but we starting to see white butterflies flying in crops which means caterpillars in a few weeks so an insecticide will need to be applied. We should also apply an aphicide to control any aphids currently present 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.
Autumn Sown Crops
For crops planted after harvest we need to look at drilling with either Diazinon granules or chlorpyrifos granules to help control grass grub. Both Diazinon granules and chlorpyrifos granules (Suscon Green) are in plentiful supply this season.
If there is a lot of trash, we need to look at slug control especially if the crops have been irrigated. We have a range of slug baits available in store. The key to slug control is baits per square metre.
We need to make sure we control slugs and insects when we drill crops to ensure successful establishment of the new crop. It is cheaper to control the pests than to have to buy new seed and re drill.
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 have to use Firebird or Invado, the choice of which depend on our other weeds we have as Firebird also has diflufenican in it as well. These chemicals are often used with Asset (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 new herbicide from Bayer for controlling autumn germinating ryegrass, vulpia hairgrass, annual poa and soft brome plus it also gives suppression of autumn germinating ryegrass, ripgut brome, praire grass and wild oats. This can be used instead of Firebird or Invado.
Barley: Again, 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
This is the time of year to control grass grub in pasture using Diazinon liquid. This must be applied to short pasture and 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 but it always pays to get your orders in early, so you do not miss out.
We can increase the grass growth on pasture by 30-60% within a 3-week period by using gibberellic acid during the autumn period. For this to be successful there must be sufficient fertility and moisture in the soil to support this extra growth. It is often applied with liquid nitrogen to increase likelihood of success. Both granular and liquid versions of gibberellic acid are available. It needs to be applied 3-5 days after grazing. We have liquid nitrogen available in 1000L pods to go with the gibberellic acid.
With all of the above scenarios, talk to your Ruralco Representative for the best options for you and your farm.