A series of five trials were conducted in 2014 to determine the yield and profitability of long season wheats from early sowing opportunities and how management with fungicides and plant growth regulators may influence yield response. Trials were located at Merredin, Eneabba, Kojonup, Katanning and Esperance. They examined 12-24 wheat varieties including Magenta, Trojan, Harper, Yitpi, Calingiri and a number of potential mid to long season varieties in comparison to Mace and other competing mid to short season varieties. Disease management treatments included foliar fungicide, in-furrow fertiliser dressing (IFFD) and plant growth regulator (PGR) treatments (for full details refer to Crop Updates paper - Getting the most out of our long season wheat varieties, Shackley etal 2015).
Although Mace dominated (60%) area sown to wheat in Western Australia in 2014, Calingiri, Yitpi and Magenta were ranked in the top five. These mid to long season varieties make up 20% of the area sown in 2014, indicating a need for longer maturity types to avoid the risk of frost, to take advantage of longer seasons and with good sprouting tolerance.
Magenta and Trojan are currently the most competitive varieties when sown early to mid May in WA.
A major disadvantage of Magenta is its poor sprouting tolerance, however Trojan has moderately good sprouting tolerance (see the 2015 Wheat Variety Guide for Western Australia).
Although agronomy data on the newly released Zen is limited, long term data from NVT suggests that it is a competitive noodle replacement for Calingiri. It should be noted that although these varieties are at less risk to frost exposure than Mace when sown early May, they are still at risk. There is still a requirement for a longer season variety to fill this niche.
There is limited data on the performance of contemporary mid to long season varieties sown early May in the Merredin area. But there is a need to take advantage of early sowing opportunities without increasing the risk of frost or exposure to terminal drought or high temperatures during grain fill. Wheat agronomy and NVT trials have shown Magenta to be competitive with Mace when sown early May. Trojan’s performance in this region is uncertain, the variety tends to perform better under high yielding conditions. Estoc sown early May has performed well on the heavy loam at Merredin over the last two years in the wheat agronomy trials. There is no NVT data available for Estoc over this time frame but Yitpi was competitive with Mace in the favourable season of 2012.
Early sown wheat crops can also be more exposed to leaf diseases such as yellow spot and septoria (stagonospora) nodorum blotch. Results in 2013 and 2014 have shown massive responses to the application of fungicide (0.8 and 1t/ha) when exposed to an intense rotation (wheat on wheat at Eneabba or wheat/canola/wheat at Esperance).
Although Magenta and Trojan are considered medium to low risk for septoria (stagonospora) nodorum and yellow spot, it was not reflected in their yield performance at these sites (Table 1). Similar observations for Trojan have been observed elsewhere (M Peipi pers comm.). Monitoring and managing disease is an important management priority, especially when the leaf disease pressure is high.
If the growing conditions or variety are not conducive to lodging then the use of a PGR will have no benefit (L Forsyth pers comm.). Growing conditions at Katanning and Esperance were not conducive to lodging in 2014. Investigation of the benefits of PGR, particularly to delay flowering is being conducted by the Frost Project funded by GRDC and DAFWA (contact DAFWA Research Officer Ben Biddulph).