12 May 1995



IMPROVED application of CIPC sprout suppressant in potato stores is being researched at Sutton Bridge and at processors stores.

The work is testing a computer model developed by Silsoe Research Institute which shows that particle size is vital for even chemical distribution, especially in box stores.

"Fogging box stores can result in uneven application," says Dr Storey. That means that although the correct amount can be blown into store, there is a risk that maximum residue levels will be exceeded on certain tubers, he explains. "When fogged, chemical rises to the top of the store and large particles fall quickly to cover the top of the boxes so little reaches the rest of the stack. Smaller particles percolate through the store better giving a more even cover."

CIPC rates are also being examined to find out what levels give effective control, and for how long. Further development should make it possible to predict the optimum range of particle size for any given store, allowing contractors to tune their equipment to the right range, says Dr Storey.