Gleberson Guillen Piccinin

Insecticide Treatment and Physiological Quality of Seeds

The use of high-quality seeds enhances the probability of success of a crop. Another important factor is the use of techniques which target the improvement of seed field performance. Applications (seed dressing) of fungicides, inoculants, insecticides and micronutrients on seeds are practices most used by farmers for several years. These products have provided more favorable conditions to crop’s growth as well as its development. Chemical treatment on seeds have been one of the most common techniques in use on current farming due to its low-cost technology, low-environmental impact, and, in general, a significant effect on yield (Zambolim, 2005). High quality seed is one of the essential prerequisites to achieve higher crop productivity. Seed physiological quality is influenced by genetic traits inherited from their parent trees, as well as germination and vigor, which are affected by environmental conditions, harvesting methods, drying process, processing, storage and packing (Zambolim, 2005). Nevertheless, storage of insecticide treated seeds may cause significant reduction on both germination and vigor as demonstrated by a number of authors (Bittencourt et al., 2000); (Gotardo et al., 2001). This fact might be related to deterioration caused by the use of insecticides, which induce the formation of free radicals and subsequent oxidative stress (Braguini, 2005). Chemical treatment on seeds has become an important procedure on agricultural production by a number of reasons. Firstly, by using this kind of treatment, many pest insects attacking not only seeds but also in some cases the aerial part of plants can be efficiently controlled. Secondly, these products can be handled in either protected or controlled environment regardless of climatic conditions, therefore, reducing additional and unwanted machinery movement in the land for cultivation. These arguments are added to the fact that, in that referred kind of treatment; small quantities of products are used per area unit, which implies lower risks of environmental contamination. In addition, chemical treatment is a procedure of simple implementation and low cost (Goulart, 1999; Machado, 2000).

Agronomic performance and yield components of soybean cultivars in two sowing dates in the region of Caiuá Sandstone.

This work was conducted with the aim of assessing the agronomic performance and yield components of soybean (Glycine max (L.) Merrill) cultivars in two sowing dates and three crop seasons in the Caiuá Sandstone region. The evaluated cultivars were BRS 255 RR, CD 202, CD 214 RR, BRS 232, BRS 246 RR, CD 208, BRS 262 and CD 218 in three crop seasons (2005/2006, 2006/2007 and 2007/2008) settled in two sowing dates (10/27 and 11/10). The trials were arranged in randomized block design, with four replications. The agronomic characteristics and yield components assessed were: number of days for maturation, insertion height of the first pod, number of pods per plant, 100 seed weight and grain yield. The first sowing date favored increasing the number of days for maturation of virtually all agricultural cultivars in three crop seasons, compared with the second sowing date. For all the evaluated cultivars 1 Pesquisador Dr. em Produção Vegetal pela Universidade Estadual de Maringá, UEM, Maringá, PR. E-mail: mcezarbarbosa@ yahoo.com.br 2 Profs. Drs. do Depto de Agronomia, UEM, Maringá, PR. E-mail: albraccini@uol.com.br; cascapim@uem.br 3 Prof. Dr. Universidade Federal do Paraná, UFPR, Campus Palotina, PR. E-mail: lpalbrecht@yahoo.com.br 4 Discente do curso de Pós-Graduação em Agronomia, UEM, Maringá, PR. E-mail: guillen.piccinin@hotmail.com 5 Prof. Dr. do Depto de Agronomia, Universidade Estadual de Londrina, UEL, Londrina, PR. E-mail: claudemircca@uel.br * Autor para correspondência ARTIGOS/ARTICLES

Adaptability and stability of canola hybrids in different sowing dates

Canola is an important crop in the world market, mainly for its oil being used for human consumption and biodiesel production, being a great economical option for the farmer, which are the reasons to the increase in its cultivation in Brazil. This study aimed to evaluate the adaptability and stability of canola hybrids, depending on the sowing dates. The canola hybrids (Hyola 61, Hyola 76, Hyola 411 and Hyola 433) were evaluated in three sowing dates (04/10, 04/25 and 05/10) in the agricultural years of 2013 and 2014, under a randomized complete block design with five replications. The response variables analyzed were seed yield and oil content. Adaptability and stability of the hybrids were evaluated by three methods: Wricke’s ecovalence (1962); confidence index (ANNICCHIARICO, 1992) and method of maximum ideal deviation (LIN; BINNS, 1988). The methodology proposed by Wricke (1962) highlighted as stable the hybrids Hyola 61 for seed yield and Hyola 411 for oil content. In the methodology proposed by Lin and Binns (1988) and Annicchiarico (1992), the hybrids with higher general adaptability and stability were Hyola 411 and 433. These hybrids presented the highest means for seed yield and oil content with predictable and responsive behavior to changes in sowing dates tested in the region of Maringa-PR.

Co-inoculação e modos de aplicação de Bradyrhizobium japonicum e Azospirillum brasilense e adubação nitrogenada na nodulação das plantas e rendimento da cultura da soja

As new cultivation techniques arise, crops require the development of new technologies and management practices that aim higher yields with lower production cost. Thus, the objective of this study was to evaluate the efficiency of co-inoculation and different ways of application of Bradyrhizobium japonicum and Azospirillum brasilense and nitrogen fertilization on nodulation and yield of soybean. The experiment was established in November 2013 in an area located in the Iguatemi Experimental Farm, of State University of Maringa (UEM). The design was a randomized block with four replications. The treatments consisted of a control, fertilization with nitrogen (200 kg N ha -1 ), standard inoculation in seeds (liquid and peat inoculant), co-inoculation on seed and co-inoculation at sowing, using different doses of inoculant B. japonicum and A. brasilense. The following determinations were carried out in the field and in the laboratory: number of nodes at flowering, mass of nodules at flowering, the shoot dry mass, nitrogen content in the shoot, grain nitrogen content, number of pods/plant, thousand grain mass and yield. The results showed that inoculation through seed treatment with liquid inoculant presents an adequate option to farmers, in the conditions of this experiment. Nitrogen fertilization did not increase yield and yield components, being unnecessary.

Management Practices for Insect Resistance in Bt Maize

The failure to reduce the population of a phytophagous species recognized as a key pest in a given situation usually occurs by not using the principles of Integrated Pest Manage‐ ment (IPM). The control of insect pests in agriculture has been done mainly through the application of chemical insecticides. However, chemical insecticides has lost effectiveness due to the selection of populations of resistant insects and cause adverse environmental effects. The main resistance management programs (IRM) strategy is the use of ‘high dose/refuge’, which involves the use of high dose of Bt protein in plants, promoting high mortality of heterozygotes associated with the planting of refuge, ie, a proportion of the crop in which it must be planted a non-Bt variety, allowing the survival of susceptible in‐ dividuals. The emergence of Bt crops is an important step between the tactics available for pest control in various crops such as maize, canola, cotton and, in the near future, soy‐ beans.

Use of Biotechnology in the Control of Insects-Prague

Productivity gains in agriculture are satisfactory with the use of genetically modified plants and the dependency of application of insecticides on crops becomes smaller over the years. The consequences of the development and marketing of corn genetically modified (GM) have been profound, and in 2011 the area planted in the United States of America (USA) with at least one GM trait corresponded to more than 88% of was over acreage.