Lack of rain and pests

4 April 1997

Lack of rain and pests

puts blight on output

Continuing our series of articles looking at crop management on FARMERS WEEKLYS barometer farms, we visit Cambridgeshire this week. Andrew Blake reports

DRY ditches at Wood Farm, Bluntisham, Cambs, put a question mark over harvest output. Although winter wheat and oilseed rape look well and spring peas are just emerging, lack of recent rain is worrying the Godfrey brothers.

"I estimate we have had less than 50mm (2in) since January," says Philip. His main concern is that correctly timed nitrogen dressings will not work as expected. White lines of crystals from liquid fertiliser are still showing three weeks after application this spring, he notes. "I have never seen it this dry before at this time of year."

Overall crop growth suggests the season is a couple of weeks ahead of normal. Alpine winter rape in particular made spectacular progress after receiving up to 225kg/ha (180 units/acre) of nitrogen and 20kg/ha (16 units/acre) of sulphur in three liquid fertiliser shots from January.

Even though it is dry, cereal growth regulator is vital, he believes. Early sown wheat after peas had 1.2 litres/ha of 70% chlormequat as a first split in mid March and should be ready for a second similar spray about now. "Its a cheap chemical and with our sort of inputs we cant risk lodging." All other fields are due for a single higher dose on the advice of consultant Michael Wright.

Strong winds and scorch risk meant a planned early Feb first of three N/S liquid dressings on first wheats was abandoned. "Instead we upped the rate to 80-100kg/ha of N at the end of the month."

To date the only noticeable cereal disease is mildew, to be tackled soon with low dose Patrol (fenpropidin) tank-mixed with manganese.

This seasons main fungicide programme will be Opus (epoxiconazole) based. But the farm has been promised test quantities of three new products – Ensign (kresoxim-methyl), Amistar (azoxystrobin) and Griffin (quinoxyfen).

"We will try them in 1ha strips and use our new combine yield monitor to tell us what benefit they may have given," says Philip.

Wheat weed control on 40ha (100 acres) where trifluralin replaced diflufenican in the autumn isoproturon herbicide mix was markedly poorer, he notes. An HBN herbicide with the regulator, and Starane (fluroxypyr) later on for cleavers, will be needed.

A rare visitor is wheat bulb fly on 4ha (10 acres) of C1 Rialto after peas. The crop, destined to provide home-saved seed, merited a dimethoate + LI700 dead-heart spray in early March.

Rarer still was the discovery of what were eventually diagnosed as swift moth larvae. The 40mm (1.5in) long white grubs decimated the crop in small patches in two fields of wheat after rape. "It was interesting that they were all along the same contour," says Philip. "I have never seen them before. By the time we found them the damage was done." Treatment was not considered worthwhile.

Despite cooler weather, pollen beetle in oilseed rape was deemed well worth treating with Fastac (alpha-cypermethrin) about 10 days ago. Carbendazim and Folicur (tebuconazole) were added to keep slight phoma infection in check and protect stem bases. could lead to weak flower heads.

Apron Combi treated home-saved Elan peas, drilled on Mar 10 into a near-perfect seed-bed.n

Brothers Michael (left) and Philip Godfrey found pollen beetle on Synergy hybrid rape so went in with the Fastac. A rarer discovery was swift moth larvae (inset) in Rialto wheat after rape.

"Wheres all the water gone?" Promising crops will lose yield potential quickly if the drought persists, says Philip Godfrey.


&#8226 Driest ever spring?

&#8226 Fertiliser uptake a concern.

&#8226 Season is two weeks early.

&#8226 New fungicides on trial.

&#8226 Bulb fly and swift moth worry.

&#8226 Peas off to a good start.

&#8226 Precision farming scepticism.

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