Sensitivity monitoring of Phakopsora pachyrhizi populations to triazoles in Brazil.

Asian soybean rust (ASR) reported in 2001 in South America spread to Brazilian producing areas and is considered one of the main diseases of the crop. Fungicides used for the control belong to QoI (strobilurins) and SBI (azole) compounds. A weaker efficacy of straight azole was observed at some regions in the end of the crop season 2006/2007. To determine whether the problem observed was due to the resistance, a sensitivity monitoring test was carried out in 2008/2009 to detect possible changes in the EC50 values of the fungus population. The test was done according to FRAC methodology. Leaves samples infected with Phakopsora pachyrhizi were sent from nine Brazilian states, in a total of 36 populations, and the spores collected were inoculated in detached leaves treated with fungicides. The triazoles tested were cyproconazole, metconazole, tebuconazole, and prothioconazole (0; 0.125; 0.25; 0.5; 1.0; 2.0; 4.0; 8.0; 16.0; 32.0 ppm). Disease severity was evaluated 15 days after inoculation. The EC50 values were estimated by Proc Probit, SAS®. Differences in EC50 values among the populations were statistically significant (P < 0.01). The EC50 for cyproconazole and metconazole ranged from 0.06 to 1.37 ppm and from 0.02 to 3.89 ppm, respectively. For tebuconazole, EC50 ranged from 0.02 to 1.28 ppm. For prothioconazole, there wasn’t a distribution of EC50 values because, with 0.25 ppm, the populations tested didn’t develop symptoms of ASR. The results showed an oscillation of EC50 values in the P. pachyrhizi population from different locations during the crop season

Screening for emerging metabolites by ESI-QTOF in arabica coffee under different roasting levels.

P.FC.6

Ensaio Nacional de aveias forrageiras 2009 - análise conjunta.

Com objetivo de avaliar a capacidade produtiva de forragem de genótipos de aveias brancas e pretas, foram conduzidos experimentos em oito locais do Brasil (Cruz Alta, Passo Fundo e Três de Maio no Rio Grande do Sul; Lages e Canoinhas em Santa Catarina; Londrina e Ponta Grossa no Paraná e São Carlos em São Paulo)

Resistance to thrips (Enneothrips flavens) in wild and amphidiploid Arachis species.

Thrips (Enneothrips flavens) is a pest that causes severe damage and yield losses to peanut crop if not properly controlled. The main control method currently used by farmers is biweekly application of insecticides during crop development, which, in addition to its toxicity, is very costly. Thus, new sources of resistance must be identified in order to reduce the use of insecticides and effectively manage the pest. This study aimed to evaluate the occurrence and symptoms of E. flavens infestations in 12 accessions of 10 wild species of Arachis and nine amphidiploids, as well as to compare their morphoagronomic characteristics to those of commercial cultivars. To this end, we conducted experiments during two summer seasons, using a randomized block design with four replications. We conducted evaluations of the severity of infestation, noting visual symptoms of E. flavens and morphological and reproductive characteristics of the Arachis plants. Results indicated that wild accessions V 7635 (A. vallsii), V 13250 (A. kempff-mercadoi), K 9484 (A. batizocoi), Wi 1118 (A. williamsii), V 14167 (A. duranensis) and V 13751 (A. magna) are the most promising for obtaining useful new amphidiploids. Among the amphidiploids, An 12 (A. batizocoi x A. kempff-mercadoi) 4x, An 9 (A. gregoryi x A. stenosperma) 4x, and An 8 (A. magna x A. cardenasii) 4x showed high level of resistance to E. flavens. The identified thrips resistant wild and amphidiploid Arachis species may be used in future breeding program to produce thrips resistant peanut cultivars