-Potato (Solanum tuberosum L.) breeding for PVY resistance is of utmost importance, in view of

A micropropagação da amoreira-preta pode gerar plantas livres de vírus e em curto espaço de tempo. Com o objetivo de aprimorar técnicas de propagação in vitro de amoreira-preta, testaram-se diferentes meios de cultivo e concentrações de 6-belzilaminopurina (BAP) e ácido indolbutírico (AIB). O primeiro experimento constou da cv. Brazos inoculada em 3 diferentes meios, combinados com cinco concentrações de BAP. O segundo experimento constou da cv. Tupy inoculada em 4 meios de cultivo, combinados com cinco concentrações de AIB. O pH do meio foi ajustado para 5,8 antes da adição de 6 g cm-3 de ágar e da autoclavagem a 121 °C e 1 atm por 20 min. Após a inoculação, os explantes foram mantidos por 70 dias, em sala de crescimento a 25 ± 1 °C, irradiância de 35 mmol m–2 s–1 e fotoperíodo de 16 h. Os experimentos foram inteiramente casualisados, utilizando-se três explantes por repetição e 12 brotações por tratamento. Verificou-se maior número de brotos da cv. Brazos em meio de cultura MS. Comprimento e número de raízes dessa mesma cultivar foram estimulados em meio Roubelakis e MS adicionados de 0,5 mg dm-3 de BAP. Foi observada a formação do sistema radicular das brotações em todos os meios empregados, porém melhores resultados de ‘Tupy’, na ausência de AIB deu-se nos meios Knudson, NN e MS.

This study aimed to develop a warning system platform for coffee rust incidence fifteen days in advance, as well as validating and regionalizing multiple linear regression models based on meteorological variables. The models developed by Pinto were validated in five counties. Experiments were set up in a randomized block design with five treatments and five replications. The experimental plot had six lines with 20 central plants of useful area. Assessments of coffee rust incidence were carried out fortnightly. The data collected from automatic stations were adjusted in new multiple linear regression models (MLRM) for five counties. Meteorological variables were lagged concerning disease assessment dates. After the adjustments, two models were selected and calculated for five counties, later there was an expansion to include ten more counties and 35 properties to validate these models. The result showed that the adjusted models of 15–30 days before rust incidence for Carmo do Rio Claro and Nova Resende counties were promising. These models were the best at forecasting disease 15 days in advance. With these models and the geoinformation systems, the warning platform and interface will be improved in the coffee grower region of the south and savannas of the Minas Gerais State, Brazil.

<p>Chemical control is the main weed management system in coffee crop. Herbicides alternatives controlling grass weeds in infested coffee areas are limited, mainly due to the few options of registered herbicides. Thus, it is important to evaluate selective post-emergence herbicide to control these important weeds in coffee crop. The objective of this work was to evaluate the selectivity, efficiency and agronomic viability of the herbicide IHH 0513 (Quizalofope-P-ethyl 50g ai L^-1) compared to Glyphosate on grass control in coffee crop. Two experiments were carried out in randomized blocks with four replications in the municipality of Lavras and Santana da Vargem (MG - Brazil) in a commercial coffee crop cultivar “Mundo Novo” and “Catuai” to evaluate the herbicide effectiveness in the crop rows. The experimental design was a randomized block design with seven treatments and four replications. Treatments consisted of  IHH 0513 doses (Quizalofope-P-ethyl  25, 50, 75 and 100 g ai ha^-1) compared to the standard GLI OVER (Glyphosate 480 g ia L^-1) at the dose of 1680g ai ha^-1 + Iharol at 0.5% v/v. Application occurred when sourgrass and goosegrass were at the beginning of development with up to 4 tillers (early vegetative stage) and in a second trial, at advanced stages of development (highly branched and /or flowering). Control assessments in percentage were performed at 7, 14, 21 and 28 days after application (DAA) of the treatments. A note of phytotoxicity was given by the EWRC scale (1964). The control of weeds was evaluated in each experimental plot using the visual notes scale of FRANS et al. (1986), where: 0% represents no control, and 100% total control of the species in question, compared to the population present in the non-weed control. In general, the dose of 1500 and 2000 mL per hectare of IHH 0513 (75 and 100 g ai ha^-1) for the weeds at early vegetative stage presented the highest levels of controls (above 90%). The dose of 2000 mL per hectare (100 g ai ha^-1) was efficient at 28 DAA to control more developed plants. No symptoms of phytotoxicity caused by the IHH 0513 product were detected at any dose tested.  Quizalofop-P-ehtyl can be recommended for integrated weed management in coffee for sourgrass and goosegrass.</p>