Joint environmental and social benefits from diversified agriculture

Agricultural simplification continues to expand at the expense of more diverse forms of agriculture. This simplification, for example, in the form of intensively managed monocultures, poses a risk to keeping the world within safe and just Earth system boundaries. Here, we estimated how agricultural diversification simultaneously affects social and environmental outcomes. Drawing from 24 studies in 11 countries across 2655 farms, we show how five diversification strategies focusing on livestock, crops, soils, noncrop plantings, and water conservation benefit social (e.g., human well-being, yields, and food security) and environmental (e.g., biodiversity, ecosystem services, and reduced environmental externalities) outcomes. We found that applying multiple diversification strategies creates more positive outcomes than individual management strategies alone. To realize these benefits, well-designed policies are needed to incentivize the adoption of multiple diversification strategies in unison.

Fine-mesh exclusion netting reduces Drosophila suzukii (Diptera: Drosophilidae) infestation and improves organic fall-bearing raspberry yields

The economical production of small fruits has been significantly complicated by the spotted-wing drosophila, Drosophila suzukii Matsumura, throughout its invaded rage. Fall-bearing red raspberries are especially susceptible to D. suzukii, and significant efforts to mitigate their damage are undertaken by growers. Exclusion barriers made from fine-mesh netting has emerged as an organic compliant strategy to mitigate damage from D. suzukii. Identifying less susceptible raspberry cultivars may also alleviate D. suzukii damage. Key pollination complications arise from exclusion-based tactics, but properly timing exclusion establishment may provide a remedy. In a 2-yr-old fall-bearing raspberry planting containing 3 cultivars, exclusion barriers were erected at 2 phenological timings. Spinosad- and pyrethrin-based pesticides were also applied to separate rows throughout harvest and a fourth treatment group matured without management. A subsection of raspberries was harvested and examined for marketability or damage, and D. suzukii adult populations were sampled with baited traps. An exclusion barrier applied early in fruit development was the most effective pest management strategy of those we tested. Its use decreased D. suzukii captures by 75%, decreased D. suzukii-infested fruit weights by 48%, and increased marketable yield by 63% compared to the no management control; however, it also increased pollination deficient fruit weights. Exclusion netting applied later in fruit maturation also decreased D. suzukii captures, infested fruit weights, and the weight of fruits damaged by other arthropod pests but did not significantly increase marketable yield. Our results indicate that netting exclusions may hold promise for the economical production of fall-bearing raspberries.

The Impact of Plant Essential Oils and Fine Mesh Row Covers on Flea Beetle (Chrysomelidae) Management in Brassicaceous Greens Production

Brassicaceous leafy greens are an important crop for small growers but are difficult to produce due to damage by flea beetles. Flea beetles are problematic for growers as they chew many small holes through leaves rendering produce unmarketable. We tested the efficacy of several essential oils, the woven-mesh row cover ProtekNet, and the spunbonded row cover Agribon, compared to organic and conventional insecticides and no spray controls in the spring and fall of 2019. We found that the two row cover treatments (Agribon and ProtekNet) provided the best control of flea beetles and associated damage. Thyme oil was highly phytotoxic and killed the crop entirely and rosemary and neem essential oils caused mild phytotoxic burns. Organic insecticides rarely performed better than the no spray control. While conventional insecticides controlled most flea beetles, the crop was often still too highly damaged to sell. The results of our study suggest row covers offer producers an effective method of flea beetle control that reduces their dependence on insecticides for conventional and organic production.

Bird and bat predation services in tropical forests and agroforestry landscapes

Understanding distribution patterns and multitrophic interactions is critical for managing bat- and bird-mediated ecosystem services such as the suppression of pest and non-pest arthropods. Despite the ecological and economic importance of bats and birds in tropical forests, agroforestry systems, and agricultural systems mixed with natural forest, a systematic review of their impact is still missing. A growing number of bird and bat exclosure experiments has improved our knowledge allowing new conclusions regarding their roles in food webs and associated ecosystem services. Here, we review the distribution patterns of insectivorous birds and bats, their local and landscape drivers, and their effects on trophic cascades in tropical ecosystems. We report that for birds but not bats community composition and relative importance of functional groups changes conspicuously from forests to habitats including both agricultural areas and forests, here termed 'forest-agri' habitats, with reduced representation of insectivores in the latter. In contrast to previous theory regarding trophic cascade strength, we find that birds and bats reduce the density and biomass of arthropods in the tropics with effect sizes similar to those in temperate and boreal communities. The relative importance of birds versus bats in regulating pest abundances varies with season, geography and management. Birds and bats may even suppress tropical arthropod outbreaks, although positive effects on plant growth are not always reported. As both bats and birds are major agents of pest suppression, a better understanding of the local and landscape factors driving the variability of their impact is needed.

Erythema: does it indicate infection in a peritoneal catheter exit site?

The definition of a peritoneal catheter exit site infection varies from one dialysis center to another. A review of abnormal appearing exit sites (n = 334 in 169 patients) from 1/83 to 3/91 was done to compare outcome in exit sites presenting with erythema (39, 12%) to those with drainage plus erythema (72, 22%) or drainage alone (223, 67%). Resolution of the abnormality occurred in 48% of those exit sites with drainage, 62% with erythema and drainage, and 79% with erythema alone (p < 0.005). S. aureus was present in 62% of the cultured exit sites which had erythema alone, 64% with erythema plus drainage, and 41% with drainage alone, while Gram negative rods were present in 13%, 12%, and 35%, respectively (p < 0.005). Twenty-three of the 39 exit sites with erythema were not initially treated with antibiotics; 87% resolved compared with 69% of those treated immediately with antibiotics (p = ns). Seven of the 8 erythematous exit sites that did not resolve progressed to tunnel infection and/or peritonitis and required catheter removal, despite the addition of antibiotics in the three initially untreated. Six of the 8 unresolved erythematous exit sites were due to S. aureus. These results indicate that, although drainage is the commonest exit site abnormality and has the worst prognosis, peri-catheter erythema is not always benign, representing an early sign of infection in some cases.