Horticulture crops as a source of green crop protection products

The horticulture sector and the pesticide industry want to make crop protection more sustainable. In June 2014, a Green Deal was agreed that focuses on the (rapid assessment and) introduction of green crop protection products, including plant extracts.

The horticulture sector and the pesticide industry want to make crop protection more sustainable. In June 2014, a Green Deal was agreed that focuses on the (rapid assessment and) introduction of green crop protection products, including plant extracts.

Plants are naturally resistant or insensitive to most illnesses and diseases and could therefore supply an important raw material for the production of green crop protection. For this reason, the Centre of Expertise for Plant Compounds commissioned a literature study into the protective effects of plant extracts. That resulted in an extensive overview of some very interesting plant genera.

In a follow-up study, 20 ornamental plants were selected from this database and are now being cultivated commercially in the Netherlands. In the top sector project ‘Ornamental horticulture in the Bio-based Economy’ conducted by KCP, FloraHolland and Wageningen UR, these 20 crops were cultivated illness-free and without use of crop protection. Extracts were then made from the leaves, flowers and sometimes even the roots. The project also included a number of extracts from KCP’s extract library. All of these extracts were tested by Wageningen UR for their effectiveness against powdery mildew, botrytis, aphids, spider mite and thrips.

The initial results of the project are promising. For the fungi and insects that were studied, one or more extracts were found with a good crop protection effect. This project was followed up in 2016 by a validation of the effects, which also involved several cultivars. The technical and economic feasibility of the production and extraction of plant extracts (albeit from residual flows or from plants cultivated specifically for this purpose) for the crop protection industry is also important.

KCP is also working with a number of private companies on the development of a business case to extract a compound from the pressed juice of tomato stalks that can be used as a green pesticide. The pressed juice of tomato stalks produces a pesticide effect on a number of fungi but contains too many aggregrates for the pressed juice to be used directly. That is why various extracts were taken in a series of trials and were all tested for their effectiveness as fungicides. The most effective extract has now been isolated and the main plant compounds that produce this crop-protection effect have been identified. Here, too, the follow-up study is focusing on the reproducibility of the results and the technical and economic feasibility.