Tailor pgr policy – Dalgety

23 February 2001




Tailor pgr policy – Dalgety

EXTREMELY variable crops mean a mix-and-match policy with pgrs will be essential this year, says Dalgety.

"Growers will need a pgr strategy that is very flexible," says pgr manager Colin Lloyd. "It is going to be a case of assessing the need field by field, crop by crop."

Many crops that have struggled to establish will benefit from an early pgr to boost rooting and tiller survival, he says.

"By getting in early you are suppressing apical dominance for a few days, buying time for the other tillers to catch up. The result is a much more even plant; you are not increasing tillering, but reducing the level of tiller abortion later."

However, such applications need to go on between GS13 and early tillering (GS23), which often coincides with cold temperatures. That creates a problem with straight chlormequat as it needs to be 8-10C for several days running for the pgr to work, he says.

An application of an activated chlormequat, such as Adjust, gets round that. "Adjust enables the cereal plant to respond under cold conditions and is effective down to 1C."

The formulation also includes a tank-mix safening system and a pH buffer. "Because of the safener up to 6-way tank-mixes can be made," he says. But because of the tender nature of many crops, separate applications should be made where possible, he adds.

On wheat recommended rate is 1 litre/ha, and for winter or spring barley the rate is 1.25 litres/ha. Cost is about £7.50/ha for wheat, compared with about £2.80 for a 1.75 litre/ha dose of straight chlormequat. But that extra cost is easily justified by better results, says Mr Lloyd. "We can consistently increase yield by 6%, even in the absence of lodging. With chlormequat responses range from 98% of control to 105%."

Later applications, around GS30-31, can be used to increase stem base strength, and Terpal (2-chloroethylphosphonic acid + mepiquat) or Sypex (2-chloroethylphosphonic acid + chlormequat) used between GS32 and GS49 used to cut crop height if lodging is still considered a risk.

Late-drilled barley like this will grow shoulder high without pgrs, warns Dalgetys Colin Lloyd. Tailoring a strategy to individual fields will be vital.

Beware barley

Late-drilled barley will need a programme of pgrs. "With winter barley it is vital to remember that the later you drill the crop the taller it will grow," warns Dalgetys Colin Lloyd. That means that a GS32-37 application of Sypex or Terpal will be needed in addition to any early pgr aimed at evening up tillers.

Beware barley

Late-drilled barley will need a programme of pgrs. "With winter barley it is vital to remember that the later you drill the crop the taller it will grow," warns Dalgetys Colin Lloyd. That means that a GS32-37 application of Sypex or Terpal will be needed in addition to any early pgr aimed at evening up tillers.


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