Downy mildew is the most important pest or disease control gap in spinach in New Zealand. Where conditions favour the disease, it can result in total marketable yield loss of crops. Four field trials were undertaken to evaluate the efficacy of candidate compounds for downy mildew control and to establish the residue profile of fungicides that provide acceptable efficacy.

The six fungicide options performed better than the five biological options when applied three times at seven day intervals. However, only one chemical option had residues below 0.1 mg/kg at harvest of spinach.