Words supplied by Bill Cabout, Ruralco Ashburton Store Manager.
For the next three months we are looking at final sprays for finishing off cereal and grass seed crops, getting silos cleaned before harvest, continuing post emergence sprays on fodder beet, pre and post emergence sprays on forage brassicas and weed control in new pasture.
Over the next few weeks, we are looking at putting on the final fungicide sprays to maintain disease free crops through to harvest.
Wheat. T2 Growth Stage 39– Flag leaf fungicide spray can be applied; Mixed weather has brought possible disease pressure and we should be applying a SDHI fungicide in conjunction with a triazole to protect the flag leaf as potential yield comes at this time. Follow this at full ear emergence (GS61) with a triazole + strobilurin fungicide to ensure protection from leaf rust.
Barley. T1 Growth stage 31-32. Many spring sown crops will be at or coming up to this stage. A fungicide spray of a triazole + strobilurin fungicide should be applied now. Autumn sown crops will be coming up to T2 (growth stage 39) at this time and because of the disease pressure from the mixed weather we are having, a SDHI and Triazole fungicide should be applied. Follow this at full ear emergence (GS61) with a triazole + strobilurin fungicide.
The main fungicide application timings in perennial ryegrass for stem rust control are based on the implementation of a preventative fungicide programme. The first application must be made prior to disease being visually present in the crop. The common preventative timings are at PGR application, ear emergence and at flowering with this application, include a fungicide to control blind seed disease.
For all fungicide applications consider the negative effects of fungicides on some novel endophytes and consult your company representative. Be aware of the withholding periods following fungicide application in relation to straw being sold from ryegrass seed crops.
Silo Clean Up
This is the time to get those empty silos ready to accept the new seasons harvest. Silo hygiene is a key element in controlling stored grain pests. Some key steps are:
1. Remove grain residues from empty silos and grain handling equipment to ensure an uncontaminated start for the new-season grain.
2. Clean up around silos, removing weeds and rubbish. Mow around and ensure easy access to the storage facility. This area can be sprayed with an insecticide to control any overwintering pests.
3. Completely empty and clean out your silos. We recommend spray the silos and all grain handling equipment with an applicable insecticide.
4. After the silos are cleaned and sprayed, we suggest you fumigate them out with smoke generators. These are used at one smoke generator per 333 cubic metres. (250t of wheat)
5. Grain going into the cleaned and fumigated silo should be treated with either insecticide dust or liquid to control pests during storage.
Currently most crops have had their 1st post emergence sprays of both herbicides and insecticides. Over the next few weeks, the 2nd post emergence herbicide spray will be applied as well as herbicide sprays to control grass weeds and thistles. To control grass weeds in fodder beet, we have 2 key products. Sequence from Nufarm has a registration for fodder beet with a withholding period of 63 days before grazing. Gallant is now registered for use in fodder beet crops but remember it has a withholding period before grazing of 14 weeks (98 days), plus other conditions. Make sure you read the label before applying. Gallant can also be used to control storksbill. Regular insecticides sprays are needed to control aphids. A fungicide can also be applied. These should be applied at first sign of disease with a maximum of 2 sprays per season. Remember to check the withholding period of any products used when starting to graze your crops with fungicides such as Escolta having a 42-day withholding period before grazing or Custodia, having a 28-day withholding period.
After planting, a pre-emergence spray is normally applied for weed control. Regular insecticide sprays are needed to control insect pests and normally a post emergence weed spray is required. Be careful what chemical is used at this stage as it can affect the crop grown next year. We have a product from Corteva Agriscience called Milestone used for controlling weeds in fodder brassicas that covers a good range of weeds. Corteva Agriscience also have Korvetto, a product that has a short plant-back period with excellent crop safety and kills a good range of weeds. Korvetto needs to be applied when weeds are small.
Forage brassicas are an ideal crop to use IPM (Integrated Pest Management). IPM refers to the use of cultural and biological controls as well as selective chemical insecticides that can be used to effectively control pests in crops. Selective insecticides include Transform, Pirimor, Sparta and Exirel. These products only target the pests leaving the beneficial insects such as hover flies, lacewings, ladybirds, and others to go about their business of controlling the pests.
Be proactive in controlling weeds in new pastures as what you do at this stage can affect the amount of grass produced and the longevity of pasture. There are several different options available depending on your weed spectrum.
With all the above scenarios talk to your Ruralco representative for the best options for you and your situation.