Nutrition
Phosphorous deficient wheat
Nitrogen
Paddocks with deep soil and high natural nitrogen fertility would be suitable for growing dryland durum wheat. Generally, if Prime Hard (PH) wheat can be grown with high frequency then durum should be a feasible proposition.
Where nitrogen fertility has declined substantially, application of sufficient nitrogen fertiliser to produce the desired grain protein may be a significant production cost which will be economic only where substantial premiums are paid.
When the premium for durum exceeds that for PH wheat, application of high rates of nitrogen fertiliser may become profitable. Soil sampling to the full depth of root exploration prior to sowing should be a good guide to the available soil nitrogen supply. For the production of a 3.0 t/ha crop with 13% protein, access to 140 kg /ha N is necessary.
Phosphorus
This nutrient is important in growing tissue where cells are actively dividing; i.e. seedling root development, flowering and seed formation.
Use a soil test to determine phosphorus status. Long fallows due to crop rotation or drought may accentuate phosphorus deficiency through absence of mycorrhizae - phosphorus fertiliser should be used in this situation.
Where needed, apply phosphorus with the seed at planting.
Zinc
Compared to bread wheats, durums can be more sensitive to low zinc levels. Elongated necrotic lesions (small dead patches) on the lower leaves may indicate the onset of zinc deficiency. If the soil is known to be low in zinc, a 1% aqueous solution of zinc sulphate heptahydrate should be applied as a foliar spray 2-4 weeks after emergence.
Zinc sulphate monohydrate applications can provide four to five years supply of this essential micronutrient. Apply at 15 kg/ha on sandy and sandy-loam soils or 30 kg/ha for clay and clay-loam soils and incorporate some months before sowing.
Where phosphorus fertilisers are required, products that are coated with zinc provide a very efficient method of increasing crop recovery of applied zinc. A range of zinc-fortified fertilisers are now available. Consult with an agronomist for details and recommendations.
Harvesting
Harvesting of wheat
Durum wheats are marginally more difficult to thresh than most bread wheats, so concave adjustments on the header may be necessary. Care needs to be exercised when threshing a durum crop as the very hard grain has a higher tendency to fracture than bread wheat.
Crops should be harvested as soon as the grain is ripe. Buyers of durum grain consider grain appearance important and pay premiums for large, well-filled vitreous grain with a low percentage of mottled and bleached seeds.
Ensure all grain handling equipment (e.g. headers, bins, augers and silos) is clean. Presence of foreign seeds can downgrade the grain.
Grain storage and disposal
Durum wheat must be segregated. On-farm storage is necessary if immediate delivery to GrainCorp Australia depot or buyer storage cannot be arranged.
Growers are able to deliver durum wheat to selected GrainCorp Australia depots. This service will be available if enough durum is produced to justify segregation. Interested growers are advised to notify AWB Ltd and GrainCorp Australia of their intentions to grow durum wheat. It is still advisable for growers to arrange a pre-plant contract with millers, to ensure prompt delivery and payment.
