Grain moisture and the weather : what can the records tell us?

The expansion of cereal production in areas along the south coast has exposed harvesting problems associated with high grain moisture. A grain delivery standard of 12 per cent moisture means that, in the absence of grain drying facilities, harvesting times in the field are restricted to those hours when grain moisture falls below this figure. Grain moisture, however, remains the major problem and for planning purposes, producers require an estimate of the harvesting time available in a given year. This will depend on all the climatic variables which affect grain moisture. These include rainfall and dew which deposit water directly onto the ear, and more importantly the relative humidity of the atmosphere. In this article we discuss the patterns of rainfall and their possible consequences. Another article in this issue describes research in progress on relative humidity and grain moisture