RESUMO: A evolução da virulência de Puccinia coronata f. sp. avenae desafia a resistência genética de cultivares de aveia à ferrugem da folha. Novas fontes de resistência são constantemente necessárias para estabilizar a produção e reduzir custos. Os objetivos desse estudo foram caracterizar a resistência de seis genótipos de aveia à ferrugem da folha e avaliar o impacto produtivo e econômico causado pela doença. Foram conduzidos ensaios em dois ambientes com e sem o controle químico. A resistência foi medida via progresso da doença, taxa aparente de infecção, severidade final e tamanho da pústula. As perdas foram avaliadas em rendimento, massa de mil grãos e massa do hectolitro. UFRGS 16Q6030-2 foi imune. Em ambos os ambientes, UFRGS 166091-2 e URS Brava exibiram os maiores níveis de resistência e as menores reduções no rendimento de grãos, enquanto URS 22 teve a maior suscetibilidade, com redução superior a 70% no rendimento de grãos. Os resultados obtidos superam os impactos negativos da doença previamente relatados em aveia, particularmente em relação ao rendimento de grãos. Os dados apresentados neste trabalho ressaltam a importância da resistência genética, particularmente a parcial, na manutenção do potencial genético produtivo, na redução de contaminações ambientais pelo menor uso de fungicidas e na ampliação dos ganhos econômicos com a cultura da aveia.

ABSTRACT: The evolution in virulence of Puccinia coronata f. sp. avenae has challenged the genetic resistance to crown rust in oat genotypes. New resistance sources are constantly required for yield stabilization and costs reduction. This study aimed to characterize the crown rust resistance of oat genotypes and the disease´s productive and economic impact. Experiments were conducted in two environments, with and without chemical control. Resistance was measured by disease progress, apparent rate of infection, final severity and pustule size. Damages were based on reduction of yield, 1000 grain mass and hectoliter mass. UFRGS16Q6030-2 was immune. In both environments, UFRGS166091-2 and URS Brava exhibited the greatest level of resistance and the smallest grain yield reduction, while URS 22 was highly susceptible, reducing more than 70% of its grain yield. These results surpass the negative impacts of the disease previously reported in oats, particularly related to grain yield. The data presented in this paper highlighted the importance of genetic resistance, particularly partial resistance, for maintaining oat genetic yield potential, reducing environmental contamination with less fungicides, and increasing economic gains with oat cultivation.

Abstract The objective was to evaluate the adaptability and yield stability of different peach rootstock genotypes in subtropical climate in an experiment in Chapecó, Santa Catarina, Brazil. Twenty-one rootstocks under the scion cultivar 'BRS Libra' and one genotype from self-rooted nursery trees were evaluated. The 22 genotypes were evaluated as fruit set and fruit yield in the growing seasons 2014/15, 2015/16, 2016/17 and 2017/18. Adaptability and stability were measured by the GGE biplot method. In the four years of evaluation, plants from self-rooted nursery trees had higher fruit set, yield as well as greater stability. On the other hand, the instability of plants grown on rootstocks from species other than the scion cultivar was greater. It can be concluded that under the tested conditions, the self-rooted genotype of 'BRS Libra' is a potential alternative for peach growers.

Abstract The goal of this work was to evaluate blackberry cultivars in terms of productivity and bioactive compounds. Two experiments were conducted: in the first experiment four cultivars were evaluated (Cherokee, Guarani, BRS-Tupy and Xavante). In the second experiment, the effects of pruning management in the BRS-Tupy cultivar were evaluated with the following treatments: drastic winter pruning (zero primocane), and maintenance of two, three or four primocanes in the winter pruning. Vegetative, productive and fruit quality characteristics were determined, including measurement of bioactive compounds. Among the cultivars, the cultivar BRS-Tupy was superior in terms of productive characteristics, but for content of anthocyanins and flavonoids, the cultivar Xavante stood out (191.97 and 68.44 mg 100 g-1, respectively). Drastic winter pruning produced lower fruit quality. The number of primocanes has a directly proportional influence on the soluble solids content and productivity component. For farmers who want fruits with greater levels of bioactive compounds, the use of cultivar Xavante is recommended; however, for those who aim for productive aspects, we suggest the use of cultivar BRS-Tupy with four primocanes per plant.