Words by Bill Cabout, Ruralco Assistant Retail Manager.
This update looks at what is happening on farm over the next three months regarding agri-chemicals. We will be looking at cereals, ryegrass, white clover, and fodder beet.
Cereals
The next three months are very important to get right with your agri-chemical applications to maximise quality and yield. These crops are all at different growth stages or have yet to be planted, so timing of agrichemical applications is based on what growth stage the crop is at as well as what weed and disease pressure is happening now and in the future. It’s better to try and prevent disease from happening in the first place, as opposed to applying fungicide once disease is present. By this stage it is often too late, and the yield will be affected.
Basic Programme for Autumn Sown Wheat
This year most autumn sown crops are well advanced and are at GS (Growth Stage) 20 or later. By this stage seed treatment is no longer active and an insecticide should have been applied along with an early fungicide and relevant herbicide if necessary.
This is a good time to also apply Complete ZMC. This product is 50% zinc, 19% manganese, 5.8% copper and 2.3% nitrogen with a slow release formulation that ensures continued fertilisation of young crops. A low use rate of 0.5 Lt /ha is used, and trials show an increase in yield from using this product. Mid Canterbury has known areas of zinc and manganese deficiency and this is an ideal product to help reduce these problems.
If controlling brome grass the 2nd Rexade spray needs to be applied. The 1st Rexade spray should have been applied at around GS 13-14.
At GS 30-31 a PGR (plant growth regulator) is applied along with a triazole fungicide. If not using Rexade, a wild oat spray will be needed as well. Plant growth regulators are used to control stem length to prevent lodging.
At GS 32-33 further fungicide is applied. Choice of fungicide depends on the weather conditions and whether Septoria is present or not. If it is wet and/or Septoria is present, a SDHI fungicide will be required. If there is no Septoria present and it is dry, other cheaper fungicides can be used. Remember Septoria has a relatively long latent period of 14-42 days depending on temperature. This means that the crop will be infected well before signs of infection are visible so often a preventative approach is best rather than waiting for the disease to appear. At GS 39 flag leaf fungicide is applied. It is important that the flag leaf is protected as a lot of the potential yield comes from this development period. A SDHI fungicide is typically used at this stage.
Because Septoria is resistant to some fungicides, SDHI fungicides are used to control it, but they need to be used with a triazole fungicide to help prevent further resistance.
Spring sown wheat will be planted over the next few weeks. A pre-emergence herbicide is not normally used but once the crop is emerged an insecticide is normally needed to control aphids to prevent BYD virus. Once the crop reaches GS 20 a similar programme is followed as above, but the crop will move through the growth stages a lot quicker.
Autumn and spring sown barley have a similar programme to wheat but will use the relevant herbicides, insecticides, fungicides and PGRs suitable for barley.
For full programmes please talk to your Ruralco seed rep.
Ryegrass
Ryegrass seed crops will currently be being grazed, or, if that’s not possible they will be mown. Once this has been done they are closed and there will be no more stock on them until after harvest. Closing date depends on the variety flowering date which takes place from late September onwards. At GS 32 a PGR is sprayed on to stop lodging. Once the ear starts emerging a fungicide programme is started. Late weeds also can also be controlled at this time.
For a full programme please talk to your Ruralco seed representative.
White Clover
Once the white clover has emerged it is a matter of controlling weeds. What is used is based on the growth stage of the clover plant, as well as the previous weed history of the paddock and what weeds are currently present.
Contact your Ruralco seed rep to understand what options are available.
Fodder Beet
Sowing time for this crop is approaching and some may have even planted, as planting seems to be happening earlier each year. For a high yielding crop, good weed control is essential.
If possible, the use of the stale seedbed technique before planting is a good idea. Poor plant numbers mean a reduction in yield, so for good germination a good seedbed is essential. Once the crop is planted a pre-emergence herbicide is used, typically 2 lt/ha ethofumesate and 150 ml /ha of clomazone as well as an insecticide such as Attack or Lorsban. Once the fodder beet has emerged an early post-emergence spray is applied as well as another insecticide.
For a full programme please talk to your Ruralco seed representative.
Monitoring store grain
Monitoring grain during storage is a valuable tool in maintaining quality. This becomes more important the longer the grain remains in storage because seed quality deterioration increases in speed over time, and early in storage insects are sparse and not easily noticed. Temperature and seed moisture content are important indicators of grain quality that influence insect and mould activity. Once grain is in storage, monitoring for insects and mould once a month will give early notice of any problems occurring and action can then be taken to control these problems.