16 February 1996

Routine net blotch spray raises yields

NET blotch-infected barley could be worth treating routinely in the autumn, says Doug Stevens of Morley Research Centre.

Puffin yielded nearly 0.5t/ha (0.2t/acre) more at Morley last year when treated for the disease at that time. "It is unusual to get a response from varieties suffering from net blotch only. We will see if the phenomenon continues."

The disease is difficult to predict and control, he notes. "It can go through a life cycle, from infection to sporulation, in two days. The disease can explode very quickly. Unfortunately, we do not fully understand what favours an outbreak."

Opus (epoxiconazole) gives best control but other conazoles like Sanction (flusilazole) are not far behind, says Mr Stevens. Full rates are the most profitable. &#42