26 September 1997

Warmth brings harvest forward

WARM autumn weather has allowed maize dry matters to increase further, bringing harvest forward by two weeks.

Three of the seven FW monitored sites are now at the point of harvesting. All growers should be checking cob maturity frequently, urges Grainseed technical manager Mike Warden.

Sites at Devon and Hants are within 2% of the target harvest DM of 30% and Norfolk is now ahead of that at 31.9% DM. Even crops in the north are approaching target DMs, with a gain of over 4% last week at the Yorks site.

Mr Warden advises breaking a cob in half, removing a kernel and squeezing towards its attachment point.

"If one drop of buttermilk liquid appears, the cob should be ready given about seven days of average weather," he says.

John Morgan of the Maize Growers Association warns that cobs must not be allowed to become over-ripe. "Too mature and the grain becomes too hard and passes straight through the cow without being digested." He also advises against delaying harvest beyond the first hard frosts.

"Previously, frost was thought to reduce the green leaf area, so improving whole plant dry matter. But current advice is to cut as soon after the crop is frosted as possible and preferably before. Frost damage allows mould and bugs to attack the plant, reducing its feed value," says Mr Morgan.

&#8226 Growers should harvest as most crops are approaching optimum cob maturity, according to Julie Graham of Mommersteeg.

Cobs from the variety Lincoln- – collected at the Dairy Event – averaged 44% DM, indicating a whole crop DM of about 26%. That was 10-14 days from optimum harvest last week – so for most producers that means cutting next week, she says.

Those who wait until the normal harvest date or until plant stems are brown will find silage quality is poor. "Dont go by the calender. Check the cobs and cut when theyre ripe," Ms Graham adds.

Growers concerned that crops which are greener than usual could produce effluent should raise the cutting height to reduce the amount of stem going into the clamp. "This is a good option when forage supplies are plentiful and although raising the cutting height from 10cm to 50cm (3.9 to 19.6in) reduces yield by 8%, it will lift crop digestibility by 3%.n


Forage maize dry matter data from seven farms

Site LocationHeight aboveDrillingDM%DM%

sea level (m)dateSept 11 Sept 18

Crediton, Devon11818/425.029.1

Attleborough, Norfolk2525/431.031.9

Gelli Aur, Dyfed238/522.723.1

Winchester, Hampshire10012/426.028.3

Ticknall, Derbyshire6717/425.129.7

Castle Howard, Yorkshire759/522.526.8

Dumfries, Scotland4515/519.120.2