Morphology of immature stages, biological parameters and life table of Microtechnites bractatus (Hemiptera: Miridae) on different host plants

ABSTRACT The garden fleahopper, Microtechnites bractatus (Say) (Hemiptera: Miridae), is associated with several cultivated plant species and, despite its economic importance, little is known about its development and performance in such hosts. We described here, the morphology of immature stages, and evaluated the biology of M. bractatus in beans, potatoes, white clover, alfalfa, and wheat. The bioassays were carried out in the laboratory under controlled temperature (25±2ºC), humidity (UR70±15%), and photoperiod (12L:12D). The eggs of M. bractatus are elongated and slightly curved, without respiratory projections and light yellow in color, becoming dark at the end of the incubation period. Nymphs present an oval-shaped body, a reddish color that intensifies along with the development and dimorphic wing pads in the fifth instar. In the bioassays, the host plants influenced the biological aspects of M. bractatus, both in the immature and adult stages. Nymph survival was higher in clover and alfalfa, while in wheat, it was lower. Clover-fed insects had the longest longevity. The fecundity parameters and egg viability were favored in insects that fed on clover and alfalfa. The fertility life table showed that feeding M. bractatus with clover provides a higher net reproduction rate (R0) and a higher finite ratio of population increase (ʎ). This study contributes to bioecological and behavioral studies on M. bractatus and provides data for the recognition and characterization of individuals in the immature stage.

Competition of onion genotypes in the soil and climatic conditions of Guarapuava, State of Paraná

The use of genotypes more adapted to climatic conditions can contribute to increase the yield of onion producers. The goal of this study was to evaluate the agronomic performance of 15 onion genotypes in the soil and climatic conditions of Guarapuava, state of Paraná. The study was conducted in the experimental area of Horticulture, Cedeteg campus, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, state of Paraná, Brazil, from July to November 2018. The experimental design used was randomized blocks, with four replications, and the treatments consisted of four commercial cultivars Optima F1, Bella Dura, Sirius F1, Soberana F1 and eleven experimental genotypes N1, N2, N3, N4, N5, N6, N7, N8, N9, AF4241 and AF4243. Biometric characteristics of the plants, production components and early flowering were evaluated. Plants presented between 6 and 9 leaves, in which N1, N3, N4 and N6 had less than 7 leaves, differing statistically from the others. The cultivar Optima F1 and the genotypes N2, N3, N5, N6, N7 and N8 presented the tallest plants, with 66.1 to 76.0 cm. The pseudostem diameter did not differ significantly between genotypes, showing values between 15.2 and 20.4 mm. Total productivity was higher in genotypes N2, N6, N5, N4, N3, N7 with values from 43.6 to 50.3 t ha-1. The highest average bulb mass was found in N2, N4, N6, Sirius F1, Optima F1 and Soberana F1

Competition of onion genotypes in the soil and climatic conditions of Guarapuava, State of Paraná

The use of genotypes more adapted to climatic conditions can contribute to increase the yield of onion producers. The goal of this study was to evaluate the agronomic performance of 15 onion genotypes in the soil and climatic conditions of Guarapuava, state of Paraná. The study was conducted in the experimental area of Horticulture, Cedeteg campus, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, state of Paraná, Brazil, from July to November 2018. The experimental design used was randomized blocks, with four replications, and the treatments consisted of four commercial cultivars Optima F1, Bella Dura, Sirius F1, Soberana F1 and eleven experimental genotypes N1, N2, N3, N4, N5, N6, N7, N8, N9, AF4241 and AF4243. Biometric characteristics of the plants, production components and early flowering were evaluated. Plants presented between 6 and 9 leaves, in which N1, N3, N4 and N6 had less than 7 leaves, differing statistically from the others. The cultivar Optima F1 and the genotypes N2, N3, N5, N6, N7 and N8 presented the tallest plants, with 66.1 to 76.0 cm. The pseudostem diameter did not differ significantly between genotypes, showing values between 15.2 and 20.4 mm. Total productivity was higher in genotypes N2, N6, N5, N4, N3, N7 with values from 43.6 to 50.3 t ha-1. The highest average bulb mass was found in N2, N4, N6, Sirius F1, Optima F1 and Soberana F1, wit

Genetic divergence among processing tomato hybrids and formation of new segregating populations / Divergência genética entre híbridos de tomate industrial e formação de novas populações segregantes

ABSTRACT Tomato is the most important vegetable species and has a strong bottleneck effect in its domestication and evolution. In exploring the existing genetic variability in commercial germplasm, germplasm has been proven to be an excellent alternative to obtain inbred lines in order to provide superior new hybrids in the future. In this sense, the objective of this study was to estimate the genetic distance among commercial processing tomato hybrids via agronomical and quality postharvest fruit traits with the aim of suggesting promising crosses for the formation of base populations for tomato breeding. Ten hybrids of processing tomato were evaluated in a complete randomized block design with three replicates. In total, eleven agronomic and postharvest fruit quality traits were evaluated. The genetic distances were estimated between the hybrids using the generalized Mahalanobis () and Gower () distances. The genetic distance among tomato hybrids was determined using a graphic projection of the first two canonical variables. The presence of significant genetic variability among the hybrids (P <0.05) was demonstrated and was sufficient for the selection of the best hybrids before the breeding process. The hybrid Laura stood out for its postharvest characteristics and was the most divergent genotype compared to the others evaluated. The most promising crossings for the formation of segregating populations with superior genetic merit are Kátia x Laura, Vênus x Laura, Fascínio x Laura, AP-533 x Laura, Tinto x Laura, AP-529 x Laura, Supera x Laura, Granadero x Laura, Granadero x AP533, Granadero x Ap529 and Granadero x Kátia.

RESUMO O tomateiro é a cultura hortaliça mais importante e sofreu um forte estreitamento de sua base genética ao longo da sua evolução e domesticação. Explorar a variabilidade genética existente em germoplasma comercial têm se mostrado uma excelente alternativa para obtenção de novas linhagens que proporcionará novos híbridos no futuro. Neste sentido, o objetivo deste trabalho foi estimar a distância genética entre híbridos de tomateiro para processamento industrial por meio de variáveis agronômicas e de qualidade pós-colheita dos frutos, com intuito de sugerir cruzamentos promissores para a formação de populações-base para o melhoramento do tomateiro. Foi conduzido um experimento com dez híbridos de tomateiro para processamento em delineamento experimental de blocos completos casualizados com três repetições. Ao todo foram avaliadas onze características de natureza agronômica e de qualidade pós-colheita dos frutos. As distâncias genéticas entre os híbridos foram estimadas por meio da distância generalizada de Mahalanobis () e Gower (). A divergência genética entre os híbrido foi estudada por meio da projeção gráfica dos genótipos utilizando-se as duas primeiras variáveis canônicas. Foi comprovada a presença de variabilidade genética significativa (P<0,05) entre os híbridos, viabilizando a realização da seleção dos melhores híbridos para os objetivos do melhoramento. O híbrido Laura se destacou para características pós-colheita e foi o genótipo mais divergente perante aos demais avaliados. Pensando-se em formar populações-base com ampla variabilidade genética as combinações de híbridos simples mais recomendadas é Kátia x Laura, Vênus x Laura, Fascínio x Laura, AP-533 x Laura, Tinto x Laura, AP-529 x Laura, Supera x Laura e Granadero x Laura.

Produtividade e rendimento comercial de bulbos de cebola em função da densidade de cultivo / Productivity and commercial yield of onion bulbs in function of growth density

A distribuição adequada das plantas de cebola (Allium cepa L.) na lavoura torna-se necessária devido a influência sobre a competição por água, luz e nutrientes, determinando o tamanho dos bulbos e a produtividade total. Objetivou-se, no trabalho, avaliar a produtividade e os padrões comerciais de bulbos de cebola, em função da densidade de plantio adotada. As mudas de cebola foram produzidas em bandejas de poliestireno de 200 células, com substrato comercial Plantimax®. O experimento foi instalado em delineamento experimental de blocos casualizados (DBC) com 4 repetições, com parcelas de 2 m². Utilizou-se a cultivar Buccaneer, nas densidades de 50, 75 e 100 plantas m-2. Foram avaliadas a produção comercial, a produção total e a massa média de bulbos. Observou-se que a densidade de 100 plantas m-2 proporcionou a maior produtividade (92,20 t ha-1). No entanto, a menor densidade de plantas avaliada proporcionou bulbos com a maior massa média (171g). As densidades de 50 e 75 plantas m-2 apresentaram os maiores valores distribuídos na classe 4 (> que 70 até 90 mm de diâmetro) e 3 cheio (> que 60 até 70 mm de diâmetro), respectivamente. A densidade de 100 plantas m-2 proporcionou uma maior quantidade de bulbos na classificação 3 cheio. Os resultados obtidos demonstraram que o aumento na densidade de plantas proporcionou uma maior produtividade, uma menor massa média de bulbos e uma maior produção na classificação comercial 3 cheio, considerada ideal para comercialização em função da preferência pelos consumidores.

The adequate distribution of onions (Allium cepa L.) within a crop becomes necessary due to their influence on the competition for water, light, and nutrients, which determines the size of the bulbs and the total yield. The goal of this work was to evaluate the yield and commercial pattern of onion bulbs as a function of the crop density employed. The onion seedlings were produced on polystyrene trays with 200 cells filled with commercial substrate Plantimax®. The experiment was carried out according to a randomized block design (RBD), with four replications and 2-m² plots. The cultivar Buccaneer was evaluated in densities of 50, 75, and 100 plants m-2. The commercial bulb yield, the total yield, and the average mass of bulbs were evaluated. The density of 100 plants m-2 provided the greatest yield (92.20 t ha-1). However, the lower density of plants provided bulbs with the greatest average mass (171g). Densities of 50 and 75 plants m-2 presented the greatest values distributed in class 4 (> 70 up to 90 mm of diameter) and 3 full (> 60 up to 70 mm of diameter), respectively. Density of 100 plants m-2 provides a larger amount of bulbs in the 3-full classification. The results obtained in this experiment showed that an increase in the density of plants provided greater yield, smaller average mass of bulbs and greater production in the commercial 3-full classification, which is considered ideal for the market due to the consumers' preference.