Cereal growers should be prepared to invest in their crops this season to maximise the profit opportunity presented by high grain prices.
Dr David Ellerton, technical director of the ProCam Group, said the buoyant market meant it was much easier to justify spending more on crop inputs, provided that increased yield.
At last week’s ProCam conference in Newmarket, he illustrated the point from trials conducted in 2007 on 10 winter wheat varieties. “We compared two fungicide programmes, one costing £46/ha and the other at £77/ha. The main difference between the two was that the more expensive programme used higher dose rates and included strobilurins.”
That programme gave a yield increase of 1.5-2.0t/ha, said Dr Ellerton. “So an extra £30 on crop inputs resulted in £300-worth of additional production. The investment was wise and shows what can be achieved with the right fungicide approach.”
Similarly, a four-spray protectant regime lifted output by 1-2.25t/ha compared with a basic two-spray triazole programme. “Starting with a T0 spray, including a protectant product with the T1 and T2, bringing in a strobilurin at T2 and completing the season with a T3 spray, gave a yield response worth £200/ha over the two-spray regime.”
Responses to strobilurins were much greater than expected in 2007, Dr Ellerton admitted. “That was due to their brown rust activity, which was needed last year. The average response to a strobilurin was 0.8t/ha, which was worth £73.60/ha then. Today, the same response is worth £135.20.”
Sclerotinia sprays in oilseed rape also provided a good return. “We had an unusual year, with disease levels being the highest since recording began in 1987. There were two separate germination events, so an epidemic developed.”
On high-risk sites, growers recorded 2t/ha responses from spraying, he recalls. “That was worth £600/ha, from just one spray. We also saw that two sprays worked well in some places.”
Even the average yield response of 0.36t/ha was worth more than £59/ha in 2007. “At 2008 prices, the same response is worth £108/ha.”
An understanding of what lay behind these results was crucial to this season’s decision-making, Dr Ellerton stressed.
At the start of last season, septoria risk was high. Most programmes were built on either prothioconazole or epoxiconazole, plus chlorothalonil.
However, the warm, dry spring limited septoria spore production, but favoured brown rust. The emphasis on septoria-based strategies allowed rust to build.
Dr Ellerton advised growers to be more vigilant when checking for brown rust symptoms and to take more account of varietal susceptibilities.
“Growers should also make greater use of the rust-active triazoles, such as tebuconazole and cyproconazole, as well as non-triazoles like strobilurins, fenpropimorph and mancozeb.”
Spray intervals should be kept tight at 3-4 weeks, he added. “And be prepared to add in intermediate triazole-based sprays if the disease reoccurs.”
Sclerotinia affected a third of oilseed rape crops in 2007, which meant there was likely to be more inoculum around this year, said Dr Ellerton.
“There was an early germination at the beginning of March, then another one in late April. So both early and late flowering crops were hit, with some sites having two separate germinations.”
Growers should spray at early to mid-flowering where crops were at risk. “Choose your fungicide carefully and maintain high doses,” he advised. “Be prepared to spray twice at early and mid-flowering if there’s high pressure. Remember – the value of the yield response will be much higher this year.”