Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Grow non-crop plants that produce chemicals that attract natural enemiesNatural enemies: Four studies from China, Germany, India and Kenya tested the effects of growing plants that produce chemicals that attract natural enemies. Three (including one replicated, randomised, controlled trail) found higher numbers of natural enemies in plots with plants that produce attractive chemicals, and one found that the attractive plant also attracted natural enemies in lab studies. One found no effect on parasitism but the plant used was found not to be attractive to natural enemies in lab studies. Pests: All four studies found a decrease in either pest population or pest damage in plots with plants that produce chemicals that attract natural enemies. Yield: One replicated, randomised, controlled study found an increase in crop yield in plots with plants that produce attractive chemicals. Crops studied were lettuce, orange, safflower and sorghum.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F724https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F724Thu, 30 May 2013 13:11:05 +0100Collected Evidence: Collected Evidence: Use chemicals to attract natural enemiesParasitism and predation (by natural enemies): One review and two of five studies from Asia, Europe and North America found that attractive chemicals increased parasitism. Two studies, including one randomised, replicated, controlled trial, found greater parasitism for some but not all chemicals, crops, sites or years and one study found no effect. One study showed that parasites found pests more rapidly. One study found lower egg predation by natural predators. Natural enemies: Five of 13 studies from Africa, Asia, Australasia, Europe and North America found more natural enemies while eight (including seven randomised, replicated, controlled trials) found positive effects varied between enemy groups, sites or study dates. Four of 13 studies (including a meta-analysis) found more natural enemies with some but not all test chemicals. Two of four studies (including a review) found higher chemical doses attracted more enemies, but one study found lower doses were more effective and one found no effect. Pests: Three of nine studies (seven randomised, replicated, controlled) from Asia, Australasia, Europe and North America found fewer pests, although the effect occurred only in the egg stage in one study. Two studies found more pests and four found no effect. Crop damage: One study found reduced damage with some chemicals but not others, and one study found no effect. Yield: One study found higher wheat yields. Crops studied were apple, banana, bean, broccoli, Chinese cabbage, cotton, cowpea, cranberry, grape, grapefruit, hop, maize, oilseed, orange, tomato, turnip and wheat.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F754https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F754Thu, 08 Aug 2013 13:40:59 +0100