Spray timing

A spray timing experiment in 2000 using a mixture of Compass + Carbendazim illustrates the importance of spray timing:

		% control of sclerotinia
Early flowering	27 April	97
Mid-flowering	9 May	72
Late flowering	16 May	14
Early + Late flowering		99
Untreated control had 3.5% plants with sclerotinia.

There was no significant yield response to controlling this low incidence of sclerotinia.

Spray timing for other diseases

Yield loss can occur when diseases affect the pods. Dark pod spot (alternaria) and light leaf spot are the most important pod diseases and these can be controlled with fungicides applied at timings for sclerotinia. Use a broad-spectrum fungicide for sclerotinia control where light leaf spot and/or or alternaria are active on the upper leaves. Lodged crops are particularly prone to alternaria problems and should also be treated with a broad-spectrum fungicide.

Treatments should be used to protect pods for 6-8 weeks. Fungicide dose should follow label guidelines to ensure that treatments provide good control up to harvest.

Traditionally alternaria was controlled with an end of flowering spray - this can still be justified if alternaria is present on the pods at that stage.