23 okt Efficacy trials towards slugs in the North Zone in caged systems
Agrolab’s trial stations in southern Sweden and Denmark conduct efficacy trials of molluscicides in caged systems, to evaluate the control of slugs in different crops. The cages are designed of euro pallet frames filled with soil, placed in Greenhouses and each cage resembles one plot. A known number of plants and slugs are planted/added in each cage, and as the slugs are very mobile, certain measures are required to prevent them from escaping. This is done by creating a barrier of copper tape on the inner walls of the pallet frames. When the slug tries to escape across the copper, a slight electric shock occurs between the slug and the copper, and though it does not kill them it is unpleasant. This showed to be effective as the slugs will avoid crossing the tape and therefore will turn the other way. To secure the survival of the slugs, and thereby increase the success rate, it is important to keep the micro climate in the cages moist, as this is the most beneficial environment for the slugs. Efficacy of molluscicides in these trials is evaluated by assessing plant damage and count throughout the trial duration. Treating the cages with molluscicide should ensure a lower number of plants are damaged by the slugs and the strong alluring properties of the molluscicide pellets attract the slugs first and thereby the mortality rate of the slugs in the cage increase. A lower or no density of molluscicide pellets results in higher vitality of the slugs and they will happily damage all the plants in the cage. This setup of a molluscicide trial has proved to be a very reliable trial design and the results are highly usable for both registration and marketing purposes!
Author: Maja Johannsson and Heidi Louise Sørensen