Canola hit with light hail at up to 20% flower may recover with only minimal to moderate yield loss. Plants will flower longer and compensate.
However, canola that flowers longer in response to hail may be at increased risk of sclerotinia. Hail damage also allows a point of entry for diseases such as alternaria black spot and blackleg. Fungicides may help reduce the development of diseases but make sure the remaining yield potential warrants protection and conditions remain conducive to disease development. Also consider the possible impact of delayed maturity, as fall frost damage could negate the potential benefits of the fungicide application.
If applying crop enhancement products such as fertilizer and micronutrient blends on hail-damaged crops, keep in mind that there is very little research available on the efficacy of such products under these extreme conditions. Leave appropriate check strips in order to make an accurate yield comparison at harvest.