Words by Nicola Pace, Ruralco Senior Agronomist
As we move into late autumn, the first frosts have arrived across the region, signalling a clear shift into winter conditions. Recent rainfall has been welcomed for soil moisture, but it has also made paddock access challenging, with many areas turning sticky underfoot.
Late silage is still being taken where conditions allow, while on many farms’ silage feeding has already begun to support stock as pasture growth slows. Maize harvest is now well underway, and a timely run of fine weather has enabled the last of the arable crops to be brought in.
Pest pressure is becoming more evident, with slugs active in establishing crops and grass grub present in pasture. As growth rates decline, it is important to encourage clovers and grasses to develop big enough that winter herbicide options can be applied.
With this seasonal shift, attention also turns to winter herbicide use, with propyzamide’s optimal use being earlier in the season with good soil moisture, falling soil temperatures and smaller weeds.
As with any agronomy, for further in-depth discussions or plans, please contact your Ruralco Representative.
Paddock Preparation
Most paddock preparation now is setting up for spring with weeds such as Californian thistles and twitch being best targeted in autumn, as they take reserves down to their roots. Spraying these weeds now will ensure a better kill rather than in spring when they are thinking about going to seed.
Wheat
Autumn wheats are going in the ground and with decreasing soil temperatures it’s timely to check your sowing rates as they will start to increase.
We have adequate soil moisture for pre-emergent sprays to work well, if you are late applying and the wheat is emerging, wait until it is fully up to apply as when the seedlings are emerging it can cause yellowing and stress on the crop. We can use most pre-emergent sprays up to GS21 but need to be pre-emergent of the weeds.
Another key element for wheat is to identify whether your paddocks/farm have autumn wild oats or spring wild oats (often at harvest spring wild oats will be 1 tiller and spindly) which helps plan whether you need an autumn Rexade or a spring pinoxaden/ fenoxaprop to get your wild oats.
We had high levels of yellow dwarf virus at harvest this year, so discussing with your agronomist around a diligent insecticide plan for the season will be key.
Barley
Harvest snippets show Baxter and Transformer barleys are being the most consistent across all areas, with comments from farmers with both varieties that Baxter had a lot less late secondary growth coming into harvest than Transformer.
We have fewer options for pre-emergent control in barley, with our best value being a flufenacet mixed with diflufenican. This gives adequate control and residual for both grass and broadleaf weeds, which with later sowings is key in case the weather doesn’t allow for a timely spray. Autumn sown barley seed treatments of Systiva have given proven yield increases as well as keeping the lower leaves clean, which with barley all leaves contribute to overall yield.
Every leaf on a barley plant contributes towards its overall yield, so keeping plants clean of net blotch and scald are important, so early control of these diseases is vital.
Small Seed Crops
We’ve had a favourable establishment for small seed crops this autumn with plenty of sunshine and late frosts. The key now is maintaining growth to be able to use key weed control herbicides in winter.
For grasses this can be 3-5 tillers and for clovers - 5 trifoliate.
Planning for winter sprays around grazing withholding periods is key also as diflufenican has a 6-week grazing withhold but can be timed in with a wild oat spray which also has a 6-week grazing withhold. Timing the two sprays two weeks apart allows 8 weeks of no grazing but when the temperature warms up and growth begins again post winter, there is no waiting for sprays to be done. This also takes the pressure off at ryegrass closing in case the weather is wild and windy.
We are also coming into key propyzamide timing, often, the best application timing is with our first winter rainfall while soil temperatures are dropping and the weeds are small. Waiting until later in the season can cause variable results, as weeds are larger and temperatures are rising.
Fodder beet
Insect pressure is low and any weeds present now we will live with for the season. Weed control has been incredibly difficult this year, with multiple strikes from depth making it a challenge.
If you require beet testing to support feed transitioning, please get in touch with our Ruralco Representative who can help arrange Dry Matter testing, or yield advice.
Brassicas
Caterpillars for diamond back moth and white butterfly, aphids and leaf miner are all present, however spraying now depends on when you plan to graze. When spraying with our IPM products, they work by stopping feeding within an hour of application, but it can take up to 4 days for aphids to die and 9 days for caterpillars so don’t be alarmed if they are still present. With both products, water rate is important with most labels claiming a minimum of 200L application and a non-ionic adjuvant which allows the products to be spread, then be held on the leaf which gives them time to translocate for systemic death of insects.
Pasture Management
As above- keep an eye out for slugs and grass grub, if grass grub is present in established pastures, then other than mechanical intervention such as heavy rolling or hoof n tooth, then liquid diazinon needs to be applied with 10ml of rain to be washed into the soil profile.
Maize
Maize crops have begun to be chopped, and it is important now to consider an inoculant in your stack. Pioneer research shows the use of their inoculant can reduce the dry matter lost to microbial fermentation by 3.6% compared to not using an inoculant. It also reduces the heating of the stack and reduces the days to feeding once ensiled. Therefore, showing using an inoculant makes this process far more efficient.
Soil Testing
Our full agronomy package allows us to have access to Ballance Agri nutrient specialist for soil testing, crop requirement plans and helping to get the best bang for your buck with your soil applications. Ballance have 7 self-service nitrogen silos placed around mid-canterbury which is ideal when the wind drops on a Saturday but before a rain to pop in and grab your prepaid nitrogen. For more information, please see https://ballance.co.nz/selfservicesilo or contact your Ruralco Representative.
Seed Ordering
A reminder that Ruralco have access to all major company proprietary small seed and cereal seed at very competitive prices, we can put together seed mixes, deliver seed or an agronomy package to help reduce the cost of production on farm.
With all the above scenarios talk to your Ruralco Representative for the best options for you and your situation.