With the winter wheat harvest well underway, HGCA is reminding growers to keep track of rainfall for their mycotoxin risk assessment following the onset of more unsettled weather including the potential for very heavy rain this weekend.Rainfall from growth stage 87 until the wheat is combined is a crucial determiner of mycotoxin risk. “Significant rainfall in the final days before harvest can have a big impact on the final risk score,” explains HGCA’s Dr Dhan Bhandari. At the Banbury Recommended List trial site last week, 15mm of rain fell in a downpour on Thursday afternoon despite the rest of the week being almost completely dry.“In summer, we can get localised storms with large quantities of rain in a short period of time. Because rainfall can be highly localised, it’s important to keep track of rainfall on a field by field basis to manage mycotoxin risk,” he added.When grain from different parts of a farm has different risk scores, it is important to keep it segregated if at all possible. In mixed lots, the highest risk score from any of the component parts should be used for the whole lot.The Cereal Sellers’ Checklist and the Oilseed Sellers’ Checklist, which are available as part of the Toolkit, contain helpful tips on avoiding the common pitfalls when marketing crops.