2018/10/29 by Venzon, Madelaine, Henrique Brum Togni, Pedro, Silvio Souza Leite Amaral, Dany +4
#0 #Conservation biological control #Extrafloral nectar #Medicinal plants #Nos-crop plants #Plant diversification
paper · doi:10.15454/1.540802127114748e12
Farming landscape diversification with plant providing multiple ecosystem services is a strategy for agroecosystem sustainability. Pest population regulation, via natural enemy increment, is one of the multiple ecosystem services associated to plant diversification. For instance, the leguminous Inga spp., used in coffee agroforestry systems for shade, improvement of soil fertility, wood and human and animal feeding, produces extrafloral nectar that attract and increase survival of coffee pest natural enemies, thereby decreasing pest population. In vegetable gardens, the use of aromatic, medicinal and non-crop plants can repel pests and attract natural enemies. The maintenance of non-crop plants reduces weeding and the need for seed acquisition. In chili pepper, a crop used as a study model and typical for small farmers, the conservation of billygoat-weed (Ageratum conyzoides), beggar-tick (Bidens pilosa) and sowthistle (Sonchus oleraceus), reduces pest ocurrence. Their flowers provide food resources that increase predator survival. These food can also be used by predatos in periods of prey shortening, thereby keeping them in the cropping areas. Nevertheless, non-crop plant may harbor pests. In those cases, they can be selectively eliminated by manual weeding. Basil (Ocimum basilicum), used as food and as medicinal, repels several pests and attracts natural enemies. In the vegetative stage, basil attracts a generalist predator (green lacewings). During periods of prey shortening, the predatory larvae survive feeding only on pollen and nectar of basil. Thus, the presence of basil can sustain predator population before pest population built up in the crop area. Coriander (Coriandrum sativum) is a condimentary plant, rustic, and resistant to several pests and diseases. During vegetative stage, coriander releases volatiles that mask the odours from the main crop, which difficult pest crop recognition. These volatile also attract several predators, such as ladybeetles. When flowering, natural enemies can feed on pollen and nectar of coriander, increasing their survival. Varronia currasavica, known as “erva baleeira” or “maria-pretinha”, is a perennial bush, native from Brazil, and it has medicinal proprieties. It is known as trap-crop for the citrus borer. It flowers all year around, and the flowers attract several pollinators and natural enemies. Thus, keeping this plant in cropping areas will assure the presence of these beneficials.