June 20, 2013
Plan and manage early wheat drilling with care
Any early wheat drilling this autumn must be planned and managed with particular care to avoid adding unnecessary extra business risk, warns Agrii trials project manager, James Southgate.
Reviewing the R&D team’s extensive drill timing work over the past four seasons at a specialist Limagrain briefing, he stressed that variety choice, T(-1) treatment, seed rates and seedbed condition are all critical factors in the success of very early sowing.
“By taking advantage of warmer soils and higher temperatures you can significantly improve establishment and yield potential by bringing wheat drilling forward to the last week in August or very early September,” he pointed out. “At the same time, you can spread your workload, reduce your seed rate and cut your autumn weather risk.
“However, you need to guard against increased disease, BYDV and lodging pressures. And you have to be aware of the serious threats posed by both dry seedbeds and reduced black-grass control.”
James Southgate is adamant that variety choice is especially critical for early drilling, pointing out that while KWS Santiago outyields JB Diego by 4% across all RL trials, the tables are turned when drilling is early. Indeed, last season at Throws Farm JB Diego delivered 1.3 t/ha (12%) more than KWS Santiago when early sown.
As well as old favourite, Claire, Agrii studies also show Horatio and Revelation performing particularly well from drilling in the first week of September.
“The right crop protection choice at T(-1) is vital where you’re drilling early too, “ he insisted. “You should prioritise early drilled seed for Deter treatment to counter the greater BYDV threat.
“Our work over a number of years underlines the major yield benefits of fluquinconazole at T(-1) too – particularly for rusty varieties and where extra competitiveness against black-grass is needed.”
While seed rates should be decreased for early drilling to reduce the risk of over-thick, more lodging susceptible crops as much as costs, James Southgate cautions against cutting back too much.
After three years of early sown Essex trials in which 100 seeds/m2 gave noticeably lower yields than 200 seeds/m2, he considers 150 seeds/m2 about as low as one should go in this part of the country, even with the best performing varieties and decent sowing conditions.
With lower seed rates reducing black-grass competitiveness appreciably, he advises particular care in this respect with varieties Agrii trials have shown to be inherently less competitive. He adds that fields known to have grass weed problems should not be drilled early as they will need the most effective pre-planting control with glyphosate.
Robust disease treatment through T0 and T1 are further essentials he identifies to combat greater Septoria and rust risks in the lusher, thicker crops that tend to result from early drilling. At the same time, these treatments will need to be accompanied by good plant growth regulation.
“Unlike the dry seedbeds that are perhaps the single biggest threat to early drilled wheats, these challenges can all be effectively managed by the right variety choice and agronomy – from T(-1) and seed rate through to spring treatment,” James Southgate concluded.
“The only solution here is not to drill wherever and whenever there is insufficient soil moisture or conditions prevent decent seedbed preparation. Seedbed conditions must always take priority over calendar date in your drilling decisions.”