Recurrent deficit irrigation and fruit harvest affect tree water relations and fruitlet growth in ‘Valencia’ orange

Background. Partial rootzone drying is an irrigation strategy known for increasing water use efficiency without significantly affecting tree water status. ‘Valencia’ oranges have a very long development period and nearly mature fruit and new fruitlets may be present at the same time on the tree, competing for water and assimilates. Objectives. The present study investigates the effect of recurrent deficit irrigation and fruit harvest on tree water status and fruitlet growth of ‘Valencia’ orange. Methods. Forty-eight adult trees were exposed to three irrigation treatments for seven years (2007-2013): irrigation with 100% of ETc (CI), continuous deficit irrigation (DI, 50% of CI) and partial root-zone drying (PRD, 50% of CI on alternated sides of the root-zone). In spring 2014, stem water potential (Ψstem) and continuous measurements of sap flow and fruitlet growth were recorded before (May) and after (June) the harvest of mature fruit. Results. No differences in Ψstem were found among irrigation treatments, while Ψstem was lower in June than in May at midday. In both May and June, sap flow density (not sap flow per tree) was higher in DI than in CI and PRD trees suggesting more efficient water uptake/transport in the former. In May, DI and PRD fruit showed lower daily relative growth rate (RGR) than CI fruit due to a possible shortage of carbon and nutrients. After removing mature fruits, differences among irrigation treatments were canceled. Sap flow was directly related to fruit RGR at low sap flow rates, but inversely related to RGR at high sap flow rates. Conclusions. Our data show that the presence of maturing fruit does not impact the water status of ‘Valencia’ trees, while it may transiently limit fruitlet growth (by source limitation) in deficit irrigated trees

Intensive Case Management for Addiction to promote engagement with care of people with severe mental and substance use disorders: an observational study.

Co-occurring severe mental and substance use disorders are associated with physical, psychological and social complications such as homelessness and unemployment. People with severe mental and substance use disorders are difficult to engage with care. The lack of treatment worsens their health and social conditions and increases treatment costs, as emergency department visits arise. Case management has proved to be effective in promoting engagement with care of people with severe mental and substance use disorders. However, this impact seemed mainly related to the case management model. The Intensive Case Management for Addiction (ICMA) aimed to improve engagement with care of people with severe mental and substance use disorders, insufficiently engaged with standard treatment. This innovative multidisciplinary mobile team programme combined Assertive Community Treatment and Critical Time Intervention methodologies. The aim of the study was to observe the impact of ICMA upon service use, treatment adherence and quality of support networks. Participants' psychosocial and mental functioning, and substance use were also assessed throughout the intervention. The study was observational. Eligible participants were all the people entering the programme during the first year of implementation (April 2014-April 2015). Data were collected through structured questionnaires and medical charts. Assessments were conducted at baseline and at 12 months follow-up or at the end of the programme if completed earlier. McNemar-Bowker's Test, General Linear Model repeated-measures analysis of variance and non-parametric Wilcoxon Signed Rank tests were used for the analysis. A total of 30 participants took part in the study. Results showed a significant reduction in the number of participants visiting the general emergency department compared to baseline. A significantly decreased number of psychiatric emergency department visits was also registered. Moreover, at follow-up participants improved significantly their treatment adherence, clinical status, social functioning, and substance intake and frequency of use. These promising results highlight the efficacy of the ICMA. The intervention improved engagement with care and the psychosocial situation of people with severe mental and substance use disorders, with consequent direct impact on their substance misuse

Controle biológico no Brasil: situação, desafios e oportunidades.

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Efeito da radiação ultravioleta-B sobre a germinação de conídios de Botrytis cinerea e colonização em discos de morango.

RESUMO: O ultravioleta é um fator de grande impacto na agricultura e está intimamente relacionado à camada de ozônio, a qual vem sendo reduzida paulatinamente, em consequência das atividades antrópicas. A camada de ozônio está sendo degradada, principalmente, por ação dos clorofluorcarbonos (CFC) utilizados pelo homem alterando assim a intensidade de radiação ultravioleta na superfície terrestre em especial no comprimento de onda da radiação ultravioleta B (UV-B). O objetivo do trabalho foi avaliar a resistência de conídios de Botrytis cinerea à radiação UV-B. Foram testados 13 isolados do patógeno, onde uma suspensão contendo 105 conídios mL-1 de cada isolado foi preparada e uma alíquota de 20 ?L foi colocada no centro de uma placa de Petri contendo BDA. Os conídios foram expostos à radiação UV-B 5,6 kJ m-2 a uma irradiância de 823 mW m-2. Também foi avaliada a esporulação de B. cinerea em discos de folha de morangueiro em meio de cultura paraquat-clorofenicolágar (PCA). Os isolados apresentaram germinação relativa entre 15% e 90%, sendo que os isolados com maior resistência à radiação UV-B foram o LQC 162, LQC 150 e LQC 159. No teste da esporulação foi observado maior diferenças entre os isolados quanto a formação de conidióforos do patógeno sendo os isolados LQC 150 e LQC 157 superiores aos outros isolados. Foi selecionado o isolado LQC 150 para ensaios posteriores onde será comparada a tolerância desse isolado com isolados de agentes de controle biológico deste patógeno quanto a tolerância a radiação UV-B

Biotic and abiotic factors associated with soil supressiveness to Rhizoctonia solani.

Crop management may modify soil characteristics, and as a consequence, alter incidence of diseases caused by soilborne pathogens. This study evaluated the suppressiveness to R. solani in 59 soil samples from a microbasin. Soil sampling areas included undisturbed forest, pasture and fallow ground areas, annual crops, perennial crops, and ploughed soil. The soil samples were characterized according to abiotic variables (pH; electrical conductivity; organic matter content; N total; P; K; Ca; Mg; Al; H; S; Na; Fe; Mn; Cu; Zn; B; cation exchange capacity; sum of bases and base saturation) and biotic variables (total microbial activity evaluated by the CO2 evolution and fluorescein diacetate hydrolysis; culturable bacterial, fungal, actinomycetes, protozoa, fluorescent Pseudomonas and Fusarium spp. communities). The contribution and relationships of these variables to suppression to R. solani were assessed by path analysis. When all samples were analyzed together, only abiotic variables correlated with suppression of R. solani, but the entire set of variables explained only 51% of the total variation. However, when samples were grouped and analyzed by vegetation cover, the set of evaluated variables in all cases accounted for more than 90% of the variation in suppression of the pathogen. In highly suppressive soils of forest and pasture/ fallow ground areas, several abiotic variables and fluorescein diacetate hydrolysis correlated with suppression of R. solani and the set of variables explained more than 98% of suppressiveness

Efeito da radiação UV-B sobre a capacidade antagônica de Clonostachys rosea a Botrytis cinerea em discos de folha de morango.

Resumo:: As atividades antrópicas estão alterando a concentração de gases na atmosfera, o ozônio da troposfera é um dos afetados e consequentemente a incidência de raios ultravioleta B (UV-B) na superfície da Terra tem sido alterada. A sensibilidade à radiação UV-B é uma das limitações do uso de agentes de biocontrole a campo. O objetivo deste trabalho foi avaliar o efeito da radiação UV-B em um isolado de Clonostachys rosea e quantificar a capacidade antagônica a Botrytis cinerea em discos de folhas de morango. Foram utilizadas quatro concentrações de conídios de C. rosea e quatro diferentes doses de radiação UV-B, sendo metade dos discos irradiados desafiados com conídios de B. cinerea. As concentrações de conídios de C. rosea acima de 105 conídios mL-1 apresentaram maior tolerância a radiação UV-B e apresentou nível de controle do patógeno superior a 75%, mesmo com a exposição à radiação. De acordo com os resultados, além de mostrar menor crescimento sob radiação UV-B, conídios de C. rosea apresentaram menor capacidade antagônica ao patógeno. Estudos adicionais são necessários para observar a tolerância de isolados de B. cinerea à radiação UV-B e assim, sugerir que um ambiente com radiação UV-B aumentada possa favorecer o patógeno