Treatment is a blow
EARLY indications from a nationwide study of on-farm take-all control suggest specialist fungicide seed treatment has had a major impact on the disease, says Monsanto.
Treatment with its Latitude (silthiofam) product is being compared with standard foliar disease and alternative take-all seed dressings.
"Initial reports show Latitude-treated strips standing out visibly from standard treatments in many cases," says study co-ordinator Geoff Hall.
"Better establishment and early growth, greater thickness and tillering and more vigorous spring root development have been the most frequent observations from the field."
Those assessments have been backed by the first take-all root assessments from the trials undertaken at the companys Cambridge laboratory at about GS 33-37.
"The assessments have revealed notably high take-all indices of over 20 for the time of year in some second wheats with standard seed dressings, confirming the extent of disease infections this season.
"This compares with medium indices of 10-15 for fluquinconazole treatment and low ratings of little more than 5 with Latitude.
No total answer
"Even Latitude treatment is unlikely to completely eliminate take-all in such a high disease pressure season," says Mr Hall.
"But with the average 0.73t/ha yield increase we recorded with feed wheats on problem sites last year, we anticipate margins over treatment costs of £20-25/ha with wheat at £65/t."
Treatment cost is typically £22/ha but obviously that depends on seed rate, he adds. "The product costs £155/t of seed treated."
Monsantos study involves up to 50 large-scale split field trials across the country. Crop growth and development observations are being made throughout the season and take-all root assessments during spring and summer.
Results from the survey are to be featured at Cereals 2002. Harvest results will also be recorded. *