14 February 1997

Trace element seed dressings on some maize

SOME maize seed suppliers are this year including trace elements in seed dressings as an aid to early growth and development, especially under adverse soil conditions.

Coop de Pau includes both zinc and manganese with Seedox SC on three varieties – Botanis, Dartis, and Nancis. It says preliminary trials show the trace elements increased leaf area and root growth giving better plant establishment and more uniform plant development.

Barrenburg is including zinc but not manganese in the dressings under a polymer coating on two varieties – Aviso and CapHorn from a French breeder. Sales manager Paul Johnson is cautious about claiming yield benefits from the zinc until a third years trials results are known. But he is claiming better early vigour and a positive effect throughout the crops life. Zinc-treated seed produced plants which stayed green longer at the end of the season. "We have found cobs are better formed and have more grains, and there are strong indications of higher yield."

Francis Dunne of Oliver Seeds cites trials at Harper Adams, Shropshire, in which the plots of zinc-treated Calypso drilled May 10 gave 13% more dry matter than the same variety and seed dressing without the zinc. Cob yield was 18% higher than without the zinc.

"All I can say is that the trials were well designed and well executed and the results will be reliable," says Charles Murray of Harper Adams. "But I would emphasise that they are only one years results using only one variety."

Mr Dunne also quotes evidence of increased starch % in zinc-dressed Calypso in strip trials in Cornwall, Nottingham and York.

"We found inconsistent results with seed dressings which included zinc and manganese. But leaving out the manganese we found a positive effect.

"Zinc availability to the plant is influenced by soil temperature, low pH, high phosphate values and high concentrations of organic matter – a problem area considering the amount of slurry applied to some maize fields." &#42

John Burns

ZINCTREATMENT


ZINCTREATMENT


&#8226 Better plant established.

&#8226 Improved early vigour.

&#8226 Higher yield.