best practice management guide for south-eastern Australia - Grains ...
best practice management guide for south-eastern Australia - Grains ... best practice management guide for south-eastern Australia - Grains ...
Pests of canola plants, which may stimulate DBM growth and development. Monitor crops regularly from flowering and podding until windrowing for caterpillars and their damage. Check by sweep-netting at 5–10 sites in the crop to determine the severity and extent of the infestation. Sometimes damaging populations can develop very rapidly. If 50 or more caterpillars per 10 sweeps are found, WA entomologists recommend increasing the monitoring to every three days. If, over the next week, the density rapidly increases to 80–100 caterpillars per 10 sweeps, spray. If the density remains about 50–70 caterpillars per 10 sweeps, keep monitoring frequently. In this latter circumstance the DBM infestation often stabilises and declines without the need to spray. Moderate levels of synthetic pyrethroid resistance have been recorded in many DBM populations collected from canola in recent years (1999–2008). The combination of moderate resistance and the sub-optimal spray coverage that is often achieved in dense stands of canola sprayed at around 100 L/ha, often results in poor control. Larvae of the cabbage centre grub. Photo: G. Baker, SARDI Native budworm moth resting with the forewings slightly parted. The outer margin of the hindwing is uniformly dark. Photo: L. Turton, NSW DPI Corn earworm moth resting with the forewings slightly parted. The pale patch, or the two spots in the dark outer margin of the hindwing, is exposed. Photo: L. Turton, NSW DPI Heliothis caterpillars (family Noctuidae); corn earworm (Helicoverpa armigera); native budworm (H. punctigera) Heliothis caterpillars, especially those of the native budworm, can extensively damage canola crops in some seasons. Infestation can occur at any time from flowering and podding until the seedheads have dried off after windrowing, but it is most common during flowering to podding. Caterpillars less than 10 mm long normally feed on the foliage, but larger ones also chew holes in the pods and eat the seeds. Loss of foliage usually does not matter, but heavy damage to the pods severely reduces yield. Occasionally, heliothis caterpillars are particularly abundant in canola crops during flowering to podding in many areas. This can be due to the combined effect of two or more of the following factors — concurrent drought conditions, concurrent heavy aphid infestation and absence of more attractive nearby crops (for example, grain legumes) to divert the egg-laying moths away from canola. Heavy aphid infestations and hot dry weather appear to favour heliothis because the egg-laying moths are attracted to the aphid honeydew as a source of food. The aphids also provide an alternative prey for predators that would otherwise feed on heliothis eggs and small caterpillars. The hot dry weather is detrimental to the wasps which parasitise the eggs and young larvae. Examine crops at regular intervals from flowering to podding for moths and young caterpillars. Moth activity alone cannot be taken as a guide for spraying. Base spray timing on careful observation of the extent of caterpillar infestation in the crop. Check plants in a large number of sites at random for caterpillars and pod damage. Sweep the borders of dense crops with a butterfly net or shake plants in thinner crops over a white fertiliser 56 Canola best practice management guide
Pests of canola bag or plastic tray. Newly hatched heliothis caterpillars are 1–1.5 mm long with dark heads and dark-spotted, whitish bodies. Young caterpillars are 10–20 mm long and pale yellow, greenish or brownish with dark heads, conspicuous upper body hairs and often have narrow, dark stripes along the back and sides of the body. The threshold for treatment is five or more 10 mm long pod-feeding caterpillars per square metre. (Below) Heliothis caterpillar and pod damage in canola. Photo: R. Colton, NSW DPI Cabbage white butterfly (centre) and looper caterpillar (bottom). Photos: G. Baker, SARDI Egg and six larval instars of native budworm. Photo: G. Baker, SARDI (Below) Rutherglen bugs feed on the pods, reducing the weight and oil content of the seeds. Photo: R. Colton, NSW DPI (Above) Rutherglen bug nymphs can cause similar damage to that caused by adults. Photo: R. Colton, NSW DPI Canola best practice management guide 57
- Page 5 and 6: Introduction 1. Introduction Don Mc
- Page 7 and 8: Grain quality 2. Grain quality Rod
- Page 9 and 10: Grain quality Erucic acid The level
- Page 11 and 12: The canola plant and how it grows 3
- Page 13 and 14: The canola plant and how it grows S
- Page 15 and 16: Crop rotation and paddock selection
- Page 17 and 18: Crop rotation and paddock selection
- Page 19 and 20: Crop rotation and paddock selection
- Page 21 and 22: Crop establishment 5. Crop establis
- Page 23 and 24: Crop establishment Certified seed i
- Page 25 and 26: Crop establishment Dry sowing in dr
- Page 27 and 28: Crop establishment Sowing depth - g
- Page 29 and 30: Canola in the low-rainfall cropping
- Page 31 and 32: Nutrition and soil fertility 7. Nut
- Page 33 and 34: Nutrition and soil fertility Nitrog
- Page 35 and 36: Nutrition and soil fertility Sulfur
- Page 37 and 38: Nutrition and soil fertility Molybd
- Page 39 and 40: Nutrition and soil fertility Mangan
- Page 41 and 42: Weed management 8. Weed management
- Page 43 and 44: Weed management of the herbicide to
- Page 45 and 46: Weed management Burning windrows ca
- Page 47 and 48: Pests of canola 9. Pests of canola
- Page 49 and 50: Pests of canola Cutworm caterpillar
- Page 51 and 52: Pests of canola Lucerne flea. Photo
- Page 53 and 54: Pests of canola Controlling snails
- Page 55: Pests of canola Winged aphids migra
- Page 59 and 60: Diseases of canola 10. Diseases of
- Page 61 and 62: Diseases of canola Figure 10.1 2009
- Page 63 and 64: Diseases of canola Alternaria leaf
- Page 65 and 66: Diseases of canola Downy mildew on
- Page 67 and 68: Grazing and fodder conservation 11.
- Page 69 and 70: Grazing and fodder conservation Gro
- Page 71 and 72: Irrigation management 12. Irrigatio
- Page 73 and 74: Irrigation management Terraced cont
- Page 75 and 76: Bees and pollination 13. Bees and p
- Page 77 and 78: Windrowing and harvesting 14. Windr
- Page 79 and 80: Windrowing and harvesting Windrowin
- Page 81 and 82: Windrowing and harvesting Severe wi
- Page 83 and 84: Windrowing and harvesting Timing of
- Page 85 and 86: Post-harvest management 15. Post-ha
- Page 87 and 88: Marketing 16. Marketing Dick Benson
- Page 89 and 90: Marketing because of a sudden colla
- Page 91 and 92: Acknowledgements Acknowledgements T
Pests of canola<br />
bag or plastic tray.<br />
Newly hatched heliothis caterpillars are 1–1.5 mm long<br />
with dark heads and dark-spotted, whitish bodies. Young<br />
caterpillars are 10–20 mm long and pale yellow, greenish or<br />
brownish with dark heads, conspicuous upper body hairs<br />
and often have narrow, dark stripes along the back and<br />
sides of the body.<br />
The threshold <strong>for</strong> treatment is five or more 10 mm long<br />
pod-feeding caterpillars per square metre.<br />
(Below) Heliothis caterpillar and pod damage in canola.<br />
Photo: R. Colton, NSW DPI<br />
Cabbage white butterfly (centre) and looper caterpillar (bottom).<br />
Photos: G. Baker, SARDI<br />
Egg and six larval instars<br />
of native budworm. <br />
Photo: G. Baker, SARDI<br />
(Below) Rutherglen bugs feed on the pods, reducing<br />
the weight and oil content of the seeds. <br />
Photo: R. Colton, NSW DPI<br />
(Above) Rutherglen bug nymphs can cause similar<br />
damage to that caused by adults.<br />
Photo: R. Colton, NSW DPI<br />
Canola <strong>best</strong> <strong>practice</strong> <strong>management</strong> <strong>guide</strong><br />
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