What is the fine-grained topic of the following text: The Valle Versa, in the heart of the Oltrepo’ Pavese noted for the quality of its vineyards and wines, is an adequate terrain to welcome the new operative principle (defined as Low Volume) which the production of pneumatic sprayers and dusters is based on. Only return the topic.
Low Volume production of pneumatic sprayers and dusters in Valle Versa's vineyards