Four Year Study Highlights Better Second Wheat Management Value

September, 2004 - Optimising both drilling date and seed treatment can boost second and subsequent wheat yields by as much as 1.49 t/ha, according to the results of a four-year Allied Grain study published this week (September 8).

The comprehensive study, conducted at the company's Haywold trials site in Yorkshire, examined the performance of 21 varieties grown as second, third and fourth cereals over four contrasting seasons under six different drilling date and seed treatment regimes.

Overall, early October drilling gave an average 0.42 t/ha benefit over sowing in the second week of September, with a clear advantage in three of the four years (Table). The greatest benefit from later drilling (1.12 t/ha) was obtained in the past season, following especially challenging earlier establishment conditions, while a disadvantage of 0.15 t/ha was recorded in 2002/3 when later sowings were hard hit by the spring drought.

The specialist take-all fungicide, Latitude (silthiofam) proved the most effective seed treatment in all four years, giving an average yield benefit of 0.72 t/ha over a single- purpose dressing. The advantage ranged from 0.97 t/ha in a second cereal in the notably high take-all year of 2000/1 to 0.38 t/ha in a fourth cereal in the most recent, lower take-all season.

"Not surprisingly, October drilling proved a greater advantage in the absence of the specialist take-all treatment," explained Allied Grain technical manager, Jim Carswell. "Equally, Latitude treatment gave a greater benefit with September sowing.

"Most importantly, though, the best performance clearly came from a combination of October drilling and the most effective take-all control. Over the four years, the average yield advantage from this regime was a very attractive 1.13 t/ha - ranging from 0.48 t/ha in 2002/3 to fully 1.49 t/ha in the past year.

"Latitude-treated September sowings did outperform October sowings receiving only a standard single-purpose seed dressing," he pointed out. "But the average benefit of 0.30 t/ha was only around a quarter of the gain from combining specialist seed treatment and October sowing."

"We've also seen clear differences between varieties in their responses to the different autumn management regimes," Jim Carswell added. "In the past, we've found Deben, Sabre and Consort to be some of the most reliable performers as second and subsequent wheats. Among the newer varieties Gladiator, Einstein and Cordiale look to be particularly promising, albeit currently on the evidence of a single year."

"Generally, it's safe to say that delaying drilling and using a specialist seed treatment can give significant returns across most of today's leading wheats where take-all is a potential problem."

Table: Allied Grain Trials 2001-2004 (Average yields across all varieties and years)

SPD* Seed Treatment SPD + Latitude Seed Treatment Average Latitude Benefit Sept Drilling 10.13 t/ha 10.93 t/ha 10.53 t/ha 0.80 t/ha Oct Drilling 10.63 t/ha 11.26 t/ha 10.94 t/ha 0.63 t/ha Average 10.38 t/ha 11.09 t/ha 0.72 t/ha Oct Drilling Benefit 0.50 t/ha 0.33 t/ha 0.42 t/ha Oct Drilling + Latitude Benefit 1.13 t/ha

^*Single-purpose seed dressing