Over the past few years there have been a number of new fungicide registrations for cucurbit crops in Canada. Each one has its own particular strengths; however it is important to find the right fit within the fungicide program.
Depending on the disease, the actual infection rates greatly between the different cucurbit crops. For example, cucumbers are highly susceptible to downy mildew while pumpkins typically have a much greater level of tolerance to this disease. The more significant diseases for each cucurbit type are listed below (Table 1. Significant Cucurbit Diseases by Crop). When planning a preventative fungicide program, it is useful to keep these diseases in mind.
A number of the new fungicide registrations are actually combinations of two older fungicide active ingredients. This gives a broader spectrum of diseases controlled. However for resistance management purposes, it is important to note the chemical groups for each component. Always rotate between fungicides from different chemical groups.