News Release

Sowing whatever the weather

Reports and Proceedings

New Scientist

GOOD news for farmers. A special coating means seeds can be sown early in the season without fear that a cold spell will damage them. That should extend sowing seasons and increase yields.

Farmers only have a narrow window for sowing seeds. If they plant crops too early their yields will suffer if a frost comes along. So Landec Ag of California has developed coatings that stop seeds germinating until conditions are right. The coating is made of inert fatty polymers that keep water out when cold, but break down above a certain temperature. When coated seeds are planted in cold soils, they stay dormant until the soil warms up.

The coatings can be tailor-made for particular crops depending on their optimal germination temperature, says Landec's chief executive Tom Crowley. So far coatings have been created for maize seeds and soybeans, which have been tested since 1995 in small pilot projects across the US (New Scientist, 18 November 1995, p 24).

Now Landec Ag has carried out the first large-scale test of coated seeds. Last year, around 150 farms planted coated maize seeds on more than 1000 hectares. Farmers who planted their maize two to four weeks earlier still got yields equivalent to or better than those who planted on the right date, the company says.

This year 500 farms will be planting a total of 8000 hectares with the coated seeds, Crowley says. That's only a tiny fraction of the 31 million hectares of maize in the US. The seeds will cost farmers an extra $20 to $25 per hectare, so the increased yields and productivity will have to be worth at least this much, says agronomist Dale Hicks of the University of Minnesota.

As well as allowing early planting, Landec Ag hopes its coatings will help farmers get two crops from the same field each season. At the moment very few farmers use relay cropping, in which soybeans are planted in fields of growing wheat in late spring. By the time the wheat is harvested, the soybean seedlings are already well established and have time to mature before the end of the growing season.

The problem is that here too there's a narrow window. Plant the soybeans too early and they interfere with the wheat; leave it too late and the machinery can damage the wheat crop. Landec Ag, however, has developed a coating that delays the germination of soybean seeds, allowing them to be planted earlier.

###

Author: Sylvia Pagan Westphal, Boston

New Scientist issue: 23rd March 2002

PLEASE MENTION NEW SCIENTIST AS THE SOURCE OF THIS STORY AND, IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO: www.newscientist.com

"These articles are posted on this site to give advance access to other authorised media who may wish to quote extracts as part of fair dealing with this copyrighted material. Full attribution is required, and if publishing online a link to www.newscientist.com is also required. Advance permission is required before any and every reproduction of each article in full - please contact angela.bourton@rbi.co.uk. Please note that all material is copyright of Reed Business Information Limited and we reserve the right to take such action as we consider appropriate to protect such copyright."


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.