THE EFFECT OF SEED TREATMENT ON THE MAIN PATHOGENS PRESENT IN WHEAT AGROECOSYSTEMS

Wheat crop (Triticum aestivum L.) from Poaceae family is affected by many diseases that cause yield losses. The present paper addresses a topic of economic, agrotechnics and social importance of wheat crop (occupying the first place among the Romanian cultivated crop, feeding 35 to 40% of world population). The study had as main objective product testing like Yunta 246 FS (imidacloprid 233 g/l + tebuconazol 13 g/l), Team Micorriza Plus (Glomus intraradices 150 spore/g + Glomus mosseae 150 spore/g + organic matter 56% and Rhizosphere Bacteria 107 UFC/g) and Condor (Trichoderma spp. 1 x 109 spore/g + Glomus sp. 10 spore/g + Rhizosphere Bacteria 1 x 107 UFC/g and organic matter 7%) applied in the pathosystem wheat/pathogens. The research was conducted in the western part of Romania, in 2010-2012, experience was placed after Latin rectangle method with 10 variants (they are different by product and dose applied) and the data were statistically interpreted. Results showed the presence of pathogens Septoria tritici, Drechslera tritici repentis and Drechslera teres in experimental variants. Statistical analysis showed that the most effective chemical mixture was imidacloprid + tebuconazol at the highest dose tested (3 l/t). Regarding the non-chemical product testing, the product Condor gave positive results. The highest values of quality parameters (protein and gluten) were obtained in the variants treated with Yunta 246 FS.

The effectivenes of Trichotim in control of Cydia pomonella L. in western Romania

In the last years a significant attack increasing of codling moth was observed in the western part of Romania. In order to reduce the population of this pests a bioproduct was used named Trichotim based on entomophagous insect Trichogramma sp. Trichotim is a Romanian product certified in year 2000 with the purpose to control the pests present in various cultures such us cabbage, vineyards and fruits plantations. The study was expanded over two years (2008 and 2009), in a super intensive apple orchard of Didactical Experimental Station part of University of Agricultural Sciences Timisoara. In order to control the codling moth, the product Trichotim was used three times correlated to pest biology (two releasing of Trichogramma wasps in the time of first generation and one release in the time of second generation of the pest), releasing 300.000 wasps/ha in total, where 250.000 wasps in first generation time of the codling moth respectively 50.000 wasps in the time of second generation of the pest. The releasing of entomophagous species Trichogramma succeeded at two days after maximal flight values of Cydia pomonella L. The flight curves was realized based on pheromonal traps ATRAPOM placed in tree canopy in stage BBCH 69 (end of flowering, all petals fallen). In order to assess the efficacy of Trichotim the observation was conducted 14 days before fruit harvesting. In the plots where 300.000 wasps were released, the fruits were attacked in percent of 12,33% (efficacy 87,67%) in year 2008 and respectively 14,66% (efficacy 85,33%) in 2009. In untreated plots (control) the fruits were attacked in percent of 23% in 2008 respectively 27,33% in 2009.

The influence of weather and geographical conditions on flight dynamics of WCR adults

Since the appearance of western corn rootworm (Diabrotica virgifera virgifera Le Conte) (Coleoptera: Chrysometidae) in Romania, many researchers have been made, in more or less success. In this study we try to clarify the ecology of the species in order to predict its evolution and its potential area of distribution. In Romania, this species was signalled for the first time in 1996, in western part of country neighbouring with Hungary. This region is an important area for maize production for seed and silage. Together, the climatic conditions, altitude and their influence on species behaviour and distribution have become more apparent. Their habitat and survival strategies are strongly dependent on local weather patents and altitude. In order to investigate the potential impact of weather and altitude on pest populations, a clear understanding of the nature and characterization of pest is required. In general, most pest species are influenced by warm, rainfall and altitude. Taking into consideration our data from the years 2008 and 2009, we can emphasize a very serious influence of air temperature, rainfall and altitude on WCR flight dynamics in adults. Dry and warm conditions generally lead to increasing of insects' number. Our data shown positive correlations between air temperature (daily mean) and adults number captured on pheromone traps (daily mean), but the there are limits from which these become negative. The same trend was recorded in previous research period (2004-2006). The rainfall is an important factor that influences adults' dynamics in maize fields. Excessive rainfall leads to adults' number decreasing. Our daily observations showed a decreasing number of beetles while rainfall increases. Regarding the altitude, we observed a decreasing number of WCR adults at once the attitude increase. For capture of adults we used pheromone traps, in 3 replications (T1, T2 and T3) at difference altitude where maize was grown. Significant relationship of WCR flight dynamic with weather and geographical conditions were found. Activities were carried out under the PN-II-ID-PCE-2007-1/RO project.

Weed control in conventional and transgenic maize with resistance to glyphosate

The researches were conducted in order to observe the behaviour of conventional and glyphosate resistant transgenic maize to different weed control methods. In this paper, the obtained results are presented. The study was conducted in experimental years 2008-2009 in the frame of Didactical Station USAMVB Timisoara. In order to conduct this study, 4 variants cultivated with conventional maize DKC 5143 and 8 variants cultivated with transgenic maize DKC-MON88017 with resistance against Diabrotica virgifera virgifera and to glyphosate. The efficacy of weed control methods was assessed, as well as the herbicide selectivity to cultivated maize hybrid. The weed coverage degree in control plot (V2) was 304 weeds/sqm in the first year and 465 weeds/sqm in the second year. In the variants cultivated with transgenic maize the control was up to 90% much more than control percent achieved in conventional variants. Although, in order to achieve an efficient control (higher than 95%), even to transgenic maize, two glyphosate sequential treatments has to be done. The yield results were positive correlated to the different control methods. However those were affected by climatic conditions recorded in experimental years.

The exosome and RNA quality control in the nucleus

To control the quality of RNA biogenesis in the nucleus, cells use sophisticated molecular machines. These machines recognize and degrade not only RNA trimmings--the leftovers of RNA processing--but also incorrectly processed RNAs that contain defects. By using this mechanism, cells ensure that only high-quality RNAs are engaged in protein synthesis and other cellular processes. The exosome--a complex of several exoribonucleolytic and RNA-binding proteins--is the central 3'-end RNA degradation and processing factor in this surveillance apparatus. The exosome operates with auxiliary factors that stimulate its activity and recruit its RNA substrates in the crowded cellular environment. In this review, we discuss recent structural and functional data related to the nuclear quality-control apparatus, including the long-awaited structure of the human exosome and its activity.