12 April 2002

Early maize drilling OK if theres enough water

By Jessica Buss

MAIZE growers who are confident that they can secure enough moisture to ensure a good maize germination can drill now, even though it is still early.

A good seed-bed will also be essential, says MGA agronomist Simon Draper. "The big questions are will it stay dry, as growers cannot afford to lose moisture, and will it warm up to allow quick germination of the seed?"

Maize seed needs to germinate quickly to survive. High seed losses can occur if it stays in the ground for too long because soil temperatures are too cold.

Seed loss also occurs when there is not enough moisture. "Maize seeds must remain moist for two to three weeks to ensure a good germination. But when maize seed is half wet and then dries it can die.

"Where land is being ploughed before drilling there may be enough moisture, but seed-bed temperatures may be colder and germination could be slow. Where ground has been ploughed early it is likely to be warmer, but it may also be dry and it may, therefore, be better to wait for rain."

Mr Draper also suggests a number of tactics for keeping moisture in soil. "Ideally, maize prefers to be drilled at about 1in deep, but it can go in 3-4in when that will allow it to stay moist. But at this depth the seed-bed is colder and soil could be too cold to ensure rapid germination.

"Precision drilling will also help to trap moisture. Cereal drills tend to have a coulter which leaves soil fluffy, so moisture escapes and rain is needed to keep the seed moist."

In most years, rolling in seed is unnecessary as any form of soil compaction causes maize to struggle. However, under dry conditions rolling may be the only method to hold the soil moisture, he adds.

Another way to ensure a good germination in dry conditions is to increase the seed rate by 10% to cover any losses. "Starter fertiliser, containing nitrogen and phosphate, may also be more beneficial when drilling early, although there is limited data to prove it works."

Weed control using the pre-emergence spray atrazine can also be difficult in dry weather, says Mr Draper. "Atrazine is being withdrawn from sale in France next year and it is perhaps only a matter of time before we see its sale limited in this country.

"It could, therefore, be useful to achieve a good, cheap clean up on fields, before it disappears. But only in conditions where it will work. In dry conditions it is better to incorporate it into the seed-bed before drilling, but it still needs adequate moisture," he warns. &#42

High maize seed losses can occur when the soil is too dry or cold, warns Simon Draper.

&#8226 Can drill now.

&#8226 Seed needs moisture.

&#8226 Care with weed spray.