Words supplied by Bill Cabout, Assistant Retail Manager.
In this issue of the Agri-link, we will be looking at what is happening on-farm over the next 3 months regarding agrichemicals. The focus will be on cereals, ryegrass, white clover, and fodder beet.
The next 3 months are vital for getting agrichemical applications right to maximise quality and yield in these crops. These crops are all at different growth stages or 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. With disease, it is often better to look at a programme to prevent it rather than apply fungicides once the disease is seen. It is often too late at this stage as the damage has already been done and yield is affected.
Basic Programme for Autumn Sown Wheat
This year, most autumn sown crops are well advanced and are at growth stage (GS) 20 or later. By this stage, the seed treatment has run out and an insecticide should have been applied along with an early fungicide and relevant herbicides if necessary.
This is a good time to also apply Complete ZMC. This product is 50% Zn, 19% Mn, 5.8% Cu and 2.3% N with a slow release formulation that ensures continued fertilisation of young crops. A low use rate of 0.5Lt/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 second Rexade spray needs to be applied. The first Rexade spray should have been applied at around GS 13-14.
At GS 30-31 a plant growth regulator (PGR) is applied along with a triazole fungicide. If not using Rexade a wild oat spray will be needed to be used as well. PGR’s 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 need to be used. If no Septoria is present and it is dry, cheaper alternative 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. Often a preventative approach is best rather than waiting for the disease to appear and then trying to cure it. At GS 39 flag leaf fungicide is applied, t is important that the flag leaf is protected with most of the potential yield coming from this time. Normally a SDHI fungicide is used at this stage. SDHI fungicides are used to control Septoria as it is resistant to some other fungicides, but they need to be used with a triazole fungicide to help prevent further resistance. There have been some new fungicides released this year for the control of fungal diseases in wheat. Talk with your local Ruralco Representative to see if these will fit into your programme.
Spring sown wheat will be planted over the next few weeks. A pre-emergence herbicide is not normally used but once the crop has 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 using the relevant herbicides, insecticides, fungicides, and PGR’s suitable for barley.
Ryegrass seed crops will be currently grazed. If crops are unable to be grazed, they will be mown. Once this has been done, they are closed (no more stock on them until after harvest). Closing date depends on the variety flowering date. This takes place from late September onwards. At GS 32 a PGR is sprayed on to stop lodging. Once the ear[AP1] starts emerging a fungicide programme is started. Late weeds also can be controlled at this time.
Once the white clover has emerged it is a matter of controlling weeds. Herbicide choice is based on the current growth stage, previous weed history of the paddock and which weeds are present.
Sowing time for fodder beet is approaching fast, with planting seeming to happen 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. This is an ideal season to apply this technique as the weather has made it easier to cultivate paddocks after other crops. Poor plant numbers mean a reduction in yield, therefore to achieve good germination of fodder beet a good seedbed is essential. Once the crop is planted a pre- emergence herbicide is used normally 2lt/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.
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 deterioration in seed quality early in storage is slower and insects are sparse and not easily noticed. Temperature and 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.
For further information or a request for an agri-chemical program, please contact your Ruralco Representative.