No abstract

Aphidius colemani (Viereck) was reported in Brazil before the Biological Control Program of Wheat Aphids (BCPWA) when Mediterranean genotypes were introduced from France and Israel. This species was re-described as a complex called A. colemani group composed of three species. Consequently, uncertainty remains about which parasitoid of the group is occurring in southern Brazil. This study has two main objectives: (i) re-examine the species status of A. colemani group collected during the introduction of parasitoids and from a 10-year (2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018) monitoring program in wheat fields in northern Rio Grande do Sul (RS), Brazil; (ii) describe the variation in the population density of parasitoids and its association with meteorological factors during this period. We examined 116 specimens from the Embrapa Wheat entomological collection, and those collected in Moericke traps in Coxilha, RS. All the parasitoids of the A. colemani group from the BCPWA period were identified as Aphidius platensis (Brèthes). In traps, 6541 cereal aphid parasitoids were collected, of which 61.9% (n = 4047) were from A. colemani group and all those were identified as A. platensis. Temperature was the factor that effected population density with the highest number of parasitoids recorded in the winter months. Sex ratio changed between years varying from 0.50 to 0.97. The parasitoid A. platensis was the only species in the A. colemani group sampled during 10 years of monitoring.

Statistical analysis is considered an important tool for scientifi c studies, including those on seeds. However, seed scientists and statisticians often disagree on the nature of variables addressed in germination experiments. Statisticians consider the number of germinated seeds to be a binomially distributed variable, whereas seed scientists convert it into a percentage and often analyze it as a normally distributed variable. Th e requirement for normal adjustment restricts the models of analysis of variance that can be used. Lack of fi t requires nonparametric tests, but they are known by their inferential problems. Generalized Linear Models (GLM) can provide better fi t to germination variables for any species, including Lychnophora ericoides Mart., because they allow wider probability distributions with fewer requirements. Here we suggest the use of relative germination besides absolute germination for species with seed development problems, such for L. ericoides and others from the campos rupestres. Th is paper introduces the most current statistical advancements and increases the possibilities for their application in seed science research.

We compared the goodness of fit and efficiency of models for germination. Generalized Linear Models (GLMs) were performed with a randomized component corresponding to the percentage of germination for a normal distribution or to the number of germinated seeds for a binomial distribution. Lower levels of Akaikes’s Information Criterion (AIC) and Bayesian Information Criterion (BIC) combined, data adherence to simulated envelopes of normal plots and corrected confidence intervals for the means guaranteed the binomial model a better fit, justifying the importance of GLMs with binomial distribution. Some authors criticize the inappropriate use of analysis of variance (ANOVA) for discrete data such as copaiba oil, but we noted that all model assumptions were met, even though the species had dormant seeds with irregular germination.

The objective of this study was to evaluate the influence of pollinating insects on canola productivity for different commercial hybrids, Hyola 61 and Hyola 433, in Minas Gerais State, Brazil. The studies were conducted at the Fazenda Experimental Água Limpa of the Federal University of Uberlândia. To evaluate the influence of pollination by bees on the production of canola seeds, an experiment was carried out to exclude floral visitors and compare canola seed production following four treatments: (a) autogamy in Hyola 61, (b) autogamy in Hyola 433, (c) open pollination in Hyola 61, with insects having free access, and (d) open pollination in Hyola 433, with insects having free access. Flowers that were available for pollination had 25% and 18.8% heavier pods and 22.5% and 20.6% more seeds per pod in Hyola 61 and Hyola 433, respectively, than those bagged without pollination. The results show that the cross-pollination process, fostered by pollinator visits, positively influenced some parameters related to production, presenting an advantage in relation to canola autogamy in Cerrado Mineiro.Serviços de polinização na produção de sementes de canola no Cerrado de Uberlândia, Estado de Minas Gerais, Brasil RESUMO. O objetivo desse estudo foi avaliar a influência da polinização por abelhas na produtividade de canola em diferentes híbridos comerciais, Hyola 61 e Hyola 433, em Minas Gerais. Os estudos foram conduzidos na Fazenda Experimental Água Limpa da Universidade Federal de Uberlândia. Para avaliar os efeitos da polinização de abelhas na produtividade nas sementes de canola, realizou-se um experimento com exclusão dos visitantes florais, comparando a produção em quatro tratamentos: (a) autogamia em Hyola 61 e (b) autogamia em Hyola 433; (c) polinização aberta em Hyola 61 e (d) polinização aberta em Hyola 433 com acesso livre de insetos. As flores disponíveis para polinização apresentaram 25% e 18,8% sílicas mais pesadas e 22,5% e 20,6% mais sementes por sílica em Hyola 61 e Hyola 433, respectivamente, do que aquelas privadas de polinização. Os resultados apontaram que o processo de polinização cruzada, favorecida pela visita de insetos polinizadores, influenciou positivamente alguns parâmetros relacionados a produção, demonstrando-se vantajosa em relação à autogamia da canola no Cerrado Mineiro.Palavras-chave: Apis mellifera; Brassica napus; tropicalização; produtividade.

Este trabalho teve como objetivo avaliar o efeito do silício nas características físicas e química dos frutos e na incidência de insetos-praga em Physalis peruviana. O experimento foi realizado em delineamento em blocos casualizados, com três tratamentos sendo T1- testemunha (ausência de silício); T2- Agrisil® (8 g L-1 de SiO2) e T3- Insecto® (40 g L-1 de SiO2 derivado de terra diatomácea), com 14 blocos para análises entomológicas e 10 blocos para caracterização dos frutos. O silício promoveu incremento no diâmetro longitudinal (40 g L-1 de SiO2) e transversal (8 g L-1 ou 40 g L-1 de SiO2) dos frutos com cálice, e também no diâmetro transversal sem cálice (8 g L-1 de SiO2). Em contrapartida, não foram constatados efeitos significativos entre as fontes de silício e a testemunha para o diâmetro longitudinal sem cálice e teor de sólidos solúveis. Quanto à entomofauna, não houve diferença significativa entre os tratamentos quanto à incidência de ninfas de mosca-branca, cigarrinha verde e o coleóptero (sp. 1). Por outro lado, o silício (8 g L-1 ou 40 g L-1 de SiO2) promoveu menor incidência da fase adulta da mosca-branca, provavelmente devido a não preferência dessa fase do inseto pelas plantas tratadas com silício. Assim, conclui-se que a adubação foliar silicatada contribui para o incremento das características físicas dos frutos e reduz a incidência dos adultos de mosca-branca em P. peruviana.

No abstract

The genotypes evaluation in a germplasm bank is essential to determine their commercial or usefulness, as potential parents, in a breeding program. We aimed to detect the genetic diversity of 42 tomato genotypes of cherry type, belonging to the germplasm bank of the Federal University of Uberlândia and, also evaluate their behavior. The experiment was conducted in a greenhouse in randomized block design with 42 treatments and two replications. Ten quantitative traits of agronomic importance were evaluated. The genetic divergence was obtained by multivariate analysis, using the Mahalanobis distance with different clustering methods (UPGMA and Tocher). The hybrids performance was compared by Scott-Knott (p= 0.05) and Dunnett’s test (p= 0.05). UPGMA and Tocher grouped the genotypes similarly, representing genetic divergence satisfactorily. The genotypes UFU 29, UFU 21 and UFU 07 were more productive, earlier and also divergent from the pre-commercial treatment (UFU 200), being able to be used as potential parents.