RAPID GROWTH of wheat crops this season means leaf three emergence is 7-10 days ahead of last year in many areas, according to BASF.

Consequently many growers may be tempted to apply T1 sprays earlier than normal, potentially leaving an extended period before further T2 treatments can be applied, the firm said.

“The timing of T2 sprays is fixed at growth stage 37-39, so an early T1 spray will have a knock on effect on disease control that growers should be aware of,” said BASF agronomy manager, Clare Tucker.

Leaf three emergence generally occurs at GS32, but in many crops, particularly Einstein, Solstice and Robigus, it is earlier at GS31, she said.

While she acknowledged recent cool and dry weather in many places has reduced disease pressure in general, the potential for future outbreaks is still there.

“With leaf three emerging so early, it is now exposed to disease attack. There is still plenty of disease inoculum around, so if temperatures increase, disease pressure could soon come back.”

Growers should aim to protect leaf three for as long as possible, because it is a “significant contributor to yield” and could also act as a bridge for disease further up the crop, she noted.

She recommends using Tracker (epoxiconazole + boscalid) to protect against diseases such as septoria, which could be a higher threat this season.