Growing oats in Western Australia for hay and grain

Acknowledgments - The authors would like to thank the Grain Research and Development Corporation (GRDC) and the Department of Agriculture and Food Western Australia (DAFWA) for funding several Oat Agronomy Projects. The information in this Bulletin is based on the work of many research scientists, development officers and plant breeders. Cut Date Risk – The sow date and variety maturity can be used to minimize the risk of all your hay being on the ground at the same time.

Insects - In high risk years for aphids (with summer/autumn green bridge or disease prone areas), anti-feeding insecticides (alpha-cypermethrin) should be applied 3 and 7 weeks after emergence, regardless , whether aphids are visible on the plant. plants. Pest control information for stored oat grain can be found on the DAFWA website www.agric.wa.gov.au and the GRDC stored grain website www.storedgrain.com.au.

Introduction

The decision to grow oats in rotation should take into account the detrimental effect of herbicide residues from previous crops. In contrast, oats for hay should only be sown in soils with moderate fertility, in the range of 80 kg/ha and less available nitrogen (N) in the top 60 cm at sowing. To avoid clogging, hay crops should be sown in paddocks where the soil is expected to have a low N mineralization rate, from previous pasture stubble and legumes.

Care should be taken if using residual herbicides for weed control in canola; straw residues must be managed to avoid contamination. Plant as late as possible in the range of optimal planting dates so that the plant will flower at its optimum.

Crop establishment

The number of plants established from a given weight of seed depends on the size of the seeds and the percentage of seeds that are viable and grow into established plants. Place a 1 m long ruler between two rows and count the number of plants along both sides of the ruler. Opening rain or seasonal break and the maturity of the selected variety dictate when oats should be sown.

The sowing time should be matched to the maturity of the chosen variety to ensure that the plant flowers at the optimum time and reaches its maximum yield potential. Crops that flower too early may not be able to grow to their maximum potential, resulting in low yields and exposing the crop to the risk of frost damage and grain discoloration from weathering.

Table 4. Maturity groups for some oat grain and hay varieties

Fertilisers and plant nutrition

The application of N too late (later than Z33) causes nitrates to accumulate in the plant dry matter which reduces hay quality. Neither variety responded to all the N applied later at Z31. The data also suggested that a late N may not have any adverse effect on grain yield, regardless of the variety. Increase in hectoliter weight and decrease in screening levels of oat grain due to potassium in the presence of nitrogen.

Potassium deficiency is likely to occur if the soil has less than 80 mg/kg K in the topsoil. If K deficiency is found in the soil by the Colwell extractable soil test, application of 40 to 80 kg K/ha as muriate of potash (90 to 180 kg/ha) can provide an economic yield increase. In deficient plants, K is redistributed to the new growth, and deficiency symptoms first appear in the older leaves.

Older leaves turn pale green, and bronze and yellow areas develop in the center of the leaf between the margin and the midvein. Sulfur deficiency in oat crops is expected to increase in the future as more compound fertilizers with lower S content are used in oat production. A soil test value of less than 10 mg/kg at the soil surface (0 to 10 cm) may indicate probably the lack of S.

However, soil S often increases down the soil profile, so knowledge of the distribution of S in the soil profile is required. Zinc concentrations in young leaves below 14 mg/kg indicate that the plant is deficient in zinc. If K deficiency is diagnosed by soil analysis, apply 40 to 80 kg/ha of K in the form of muriate of potash (90 to 180 kg/ha of KCl) near sowing.

Table 7. Change in hay yield and hay quality as nitrogen supply is increased from 15 to 80 kg N/ha at six sites sown in 2005 and 2006

Weeds

Weeds that can be controlled by pre-emergence herbicides include annual ryegrass, barley grass, silver grass, capybara, crassula, doubles, mustards, toadstool and wild radish. Grasses and weeds 15 to 25 g/ha Crop: 2-leaf stage to early tillering (see label chlorsulfuron 750 g/kg (eg Glean®) for Mortlock oats). Further information on cultivar resistance to herbicides can be found on the oat web pages ().

Herbicide recommendations can be found in the latest crop spray charts: DAFWA offices on e-weed and Planfarm Herbicide Guide.

Table 9 lists the herbicides that are registered for use in emerged oat crops to control either grasses or broad-leafed weeds

Diseases

Infection at all stages of growth can be harmful, but infection that occurs early in crop growth has the greatest potential for crop damage. In high-risk years for aphids (with a summer/autumn green bridge or in disease-prone regions), anti-feeding insecticides (alpha-cypermethrin) should be applied 3 and 7 weeks after emergence, regardless of whether aphids are visible on the plants. In many cases, disease symptoms can be mistaken for nutrient deficiencies, herbicide damage, or soil limitations.

Disease symptoms on roots are usually characteristic and when combined with paddock symptoms, accurate diagnosis can be achieved. The potential for damage from various key root and crown diseases can be tested with a soil test. Plants affected by nematodes may be more prone to attack by fungi that cause leaf and root disease.

The female nematodes appear as pinhead-sized immature cysts on the root surface (Photo: . Vivien Vanstone DAFWA). Oats can be very sensitive to CCN, so only a low nematode count can cause significant damage to an intolerant variety. With resistant varieties, the nematode population can be reduced in one or more seasons.

Root lesion nematode can be managed with rotations and other cultural practices, but cannot be eradicated. Suspected root disease or crop nematode problems can be confirmed by laboratory soil and/or root analysis. Pre-season soil tests can be used where paddock history is not adequate for future use planning.

Figure 10. Leaf rust in oats (Photo: Pamela Zwer, SARDI).

Insect and allied pests of oats

Plants are most vulnerable to the effects of the virus within the first 8-10 weeks after emergence. Feeds at night, found in net-lined tunnels in the ground, usually with the plant part forward. Theba pisana) White Italian snails have white shells, mostly with broken brown bands in the line of the spiral.

Most insects (except snails) are found under the track during the hottest part of the day. However, at night or in cool conditions, insects move out from under the lane and onto the top of the lane, where they are more likely to be harvested or baled with the grain. Moreover, no insecticides are registered for this use, as this can lead to chemical contamination of the grain and rejection by national and international grain markets.

Experiments have shown that direct-harvested grain contains fewer stray insects, but if grain is harvested at night, more stray insects may be found in the harvested grain. If slugs are present in folds, they may be found sheltering in the head of the crop at harvest, and as a result become a grain contaminant. Test for the presence of insects by checking samples of the stored grain with a grain sieve from the top and bottom of the silo or pits in the silo headspace.

Corn insects reduce the quality of oats by reducing grain germination, eating and contaminating feed for livestock, and re-infecting machinery. When treating stored grain, growers should be aware of Maximum Residue Limits (MRL) for 60 chemicals introduced by Japanese buyers in 2006 and likely to be introduced by some other buyers. Much of the information in this section comes from the research conducted by several Department of Agriculture and Food entomologists who have worked on cereal pests for many years.

TABLE 10. Identification of oat pests and cultural control options

Harvest

Making quality hay

The optimum cutting time recommended by most processors is at the water-ripe stage (Z71) or earlier. If more than half of the paddock is in the water-ripe stage, now is the perfect time to mow. Mowing hay a week later than the water-ripe stage reduces quality, but is still within the acceptable range of export standards.

Hay cut before the watery stage has the highest quality, but the penalty for the. Change in hay quality at mowing was delayed by two weeks from the water-ripe stage (data is an average of six varieties). While mowing hay after the watery mature stage can result in a higher hay yield, the hay is of lower quality.

In the hay varieties, Brusher A generally reached the water-ripe stage first, followed by Marloo, Swan, Winjardie and Kangaroo A and finally by Wintaroo A. Wandering A, another popular variety cut for hay, reached the water-ripe stage slightly reached earlier than Carrolup. Cut hay crops at the water-ripe stage (Z71) as this is the best compromise between hay yield and hay quality.

When Winjardie is planted in late May, it reaches water maturity 7 days later than Carrolup. Seasons of lower than average temperature may result in a later time to water ripening (up to a week later than the estimated date). Flowering date trials conducted at Katanning and Northam show large differences in the predicted date oat varieties will reach water maturity due to location.