DIFFICULT PLANTING conditions will mean a patchwork potato crop, with resulting disease and management problems, growers have been warned.

Protracted potato planting this season will leave crops at vastly different growth stages, according to Solanum agronomist, Simon Bowen.

This is going to make irrigation and blight management even more tricky, he said.

“Growers must treat crops on a field-by-field basis; blanket treatments will create too many compromises – badly affecting yield and quality.”

One problem will be late-planted crops going through their most susceptible stage to blight infection at a time when surrounding crops could be well established.

“Growers applying a contact protectant fungicide to a crop at full canopy, for example, can not afford to simply overspray the fast growing establishing crops,” said Mr Bowen.

They will still need a systemic fungicide, he added.

Equally, early-planted, slow emerging crops will have been exposed to blight pressure over a long period at their most vulnerable time.

“Crops may have been sitting still for a long time, but as they pick-up growth it is the crucial time to be using systemic products,” advised Mr Bowen.

The mix of crop growth stages could make it easier for growers with limited irrigation resources to target water applications at precisely the right time to minimise the effects of common scab, however.

“It is essential growers keep tabs on every field individually, and manage each growth stage accordingly,” said Mr Bowen.