Research on slug behaviour - two projects

Abstract

The influence of soil moisture on slug activity was studied both in the field and in the laboratory. Low moisture levels were shown to restrict slug activity and the presence of a rehydration refuge had no effect on the restriction of movement.

A number of electrical methods of assessing soil moisture content proved satisfactory and weight loss from polyacrylamide gel cylinders was shown to give an accurate indication of evaporation in the field. A visual assessment of soil moisture content was also tested.

Other environmental variables were shown to restrict activity on a microclimate scale, principally temperature, both air and soil, and to a lesser extent humidity and windspeed. A limit model was developed which used this information to predict slug activity. Other models were developed from data collected from two sites, one in Northumberland and a second in North Yorkshire which used meteorological measurements more readily available to growers. The model was validated against information collected from five sites around the UK in 1990 and was 73% successful in predicting slug activity at those sites.