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Kruševac, Serbia

The effect of mineral nitrogen fertilization and water deficiency stress on nitrogen content in yield in dry aboveground and root mass of forage lucerne was tested at the Institute of Forage Crops, Pleven, Bulgaria (2003-04). Mineral nitrogen fertilization at the doses of 40, 80, 120 and 160 mg N kg-1 soil was tested in pot trials. Nitrogen fertilizer was applied as ammonium nitrate. Ten-day water deficiency stress at the budding stage of lucerne was imposed by stopping the irrigation till soil moisture dropped to 37-40% FC. It was found that mineral nitrogen fertilization increased nitrogen in dry aboveground mass yield - for doses of 120 and 160 mg N kg-1 soil in the conditions of optimal moisture, by 21 and 37%; for doses of 120 and 80 mg N kg-1 soil and water deficiency stress, by 12 and 14%. Mineral nitrogen fertilization had a stronger effect on nitrogen in dry root mass yield compared with that in dry aboveground mass. The negative effect of water deficiency stress on nitrogen in dry aboveground and root mass was lowest when 80 mg N kg-1 was applied to the soil. Source


The experimental study was conducted during the period of 2008-2010 at the experimental field of the Institute of Forage Crops in Pleven. The hybridization scheme included direct and back crosses covering four varieties of forage pea (Pisum sativum L.), namely two spring ones, Usatii 90 and Kamerton from Ukraine, and a winter one from Bulgaria, Pleven 10. There was analyzed the inheritance of quantitative traits such as plant height, height to first pod, pod number per plant, seed number per plant, seed number per pod, seed weight per plant and number of fertile nodes per plant of parental components (P1 and P2) and both first (F1) and second (F2) hybrid generations. The cross Usatii 90 x Pleven 10 showed the highest real heterosis effect for plant height (8.26%), pods per plant (158.79%), seeds per plant (272.16%), seeds per pod (42.09%), seed weight per plant (432.43%) and number of fertile nodes per plant (117.14%). The cross Pleven 10 x Usatii 90 had the highest real heterosis effect height to first pod (11.06%). In F2 plants, the strongest depression for plant height (5.88%), seeds per plant (57.88%), seeds per pod (55.93%) and seed weight per plant (55.99%) was in the cross Usatii 90 x Pleven 10, for height to first pod (1.47%) in the cross Kamerton x Pleven 10 and for number of fertile nodes per plant (15.91%) in the cross Pleven 10 x Usatii 90. The highest positive degree of transgression for number of fertile nodes per plant (165.64%) and seed weight per plant (162.10%) was in the cross Pleven 10 x Kamerton and for pod number per plant (102.54%) and seeds per plant (99.13%) in Kamerton x Pleven 10. The stability of the characters was determined. Low variability in F1 and F2 was found in plant height (3.97-6.85%). Variability of number seeds per plant in F1 was highest (11.86-33.23%). For all other traits, the variability varied from average to high. A lower narrow-sense heritability coefficient was observed for plant height, height to first pod, pods per plant, seeds per plant and seed weight per plant (from 0.001 to 0.230). In few cases, such as in fertile nodes per plant (0.39 and 0.81) and seeds per pod (0.44), the coefficients ofbroad-sense heritability were higher. Source


Nikolova I.M.,Institute of Forage Crops
Biological Agriculture and Horticulture | Year: 2015

Sitona lineatus L. (Coleoptera: Curculionidae) is an important pest of field vetch in Bulgaria. The response of vetch varieties to S. lineatus was determined on the basis of seedling vigour, plant phenological development and chemical analysis of the feed. The susceptibility to attack by S. lineatus of the vetch, Vicia sativa L., varieties, Liya, Loryna, Villena, Moldavskaya 82 and Vicia villosa Roth varieties, Violeta and Viola, was tested. Vetch varieties with high vitality and rapidly growing seedlings such as Liya and Loryna were considerably less preferred by S. lineatus. They were distinguished with low damage degree and leaf damage intensity. Weather conditions during the years affected population density and food activity of Sitona weevils as the harm was particularly great in the dry spring in 2013, when the plants had suppressed growth and did not develop normally. The least preferred variety with a low S. lineatus density was Liya followed by Loryna, which were characterized with the shortest vegetative season (67 days), high seedling vigour and high fibre content. The most preferred varieties with the highest density of weevils were winter varieties Violeta and Viola, which had high crude protein content. © 2015 Taylor & Francis Source


Vasileva V.,Institute of Forage Crops
Bulgarian Journal of Agricultural Science | Year: 2014

Changes in some charatcteristics of chemical composition of aboveground and root mass of soybean after presowing treatment of seeds with insecticides were studied in a pot trial carried out at the Institute of Forage Crops, Pleven, Bulgaria (2003-2004). Soybean cultivar Pavlikeny 121 was used and the next insecticide preparations were tested: Gaucho 600 FS (600 g.L-1 imidacloprid) (1, 2 and 3 L.100 kg-1 seeds), Carbodan 35 ST (350 g.L-1 carbofuran) (1, 2 and 3 L.100 kg-1 seeds), and Promet 400 CS (400 g.L-1 furathiocarb) (3 L.100 kg-1 seeds) (standard). It was found that Gaucho 600 FS at the dose of 1 L.100 kg-1 seeds increased crude protein content in aboveground mass by 14.0 g.kg-1 dry matter (DM) and in root mass by 22.6 g.kg-1 DM as compared to untreated control. Crude fiber content in aboveground mass increased by 28.0 g.kg-1 DM when Carbodan 35 ST at the dose of 3 L.100 kg-1 seeds was applied and decreased in root mass by 74.5 g.kg-1 DM for the same insecticide at the dose of 2 L.100 kg-1 seeds. Calcium content in aboveground mass was by 1.9 g.kg-1 DM higher as compared to untreated control for Gaucho 600 FS at the dose of 1 L.100 kg-1 seeds. When Carbodan 35 ST at the dose of 1 L.100 kg-1 seeds was applied, phosphorus content in aboveground mass increased by 0.20 g.kg-1 DM and in root mass by 0.28 g.kg-1 DM for Gaucho 600 FS at the dose of 1 L.100 kg-1. Chemical composition of plant biomass did not include the amount of possible residues after the using of insecticides. © National Centre for Agrarian Sciences. All rights reserved. Source


Nikolova I.M.,Institute of Forage Crops
Irish Journal of Agricultural and Food Research | Year: 2015

Trials were conducted in 2011 and 2012 at the Institute of Forage Crops, Pleven, Bulgaria, in order to study the imaginal and possible ovicidal effect of some insecticides against Bruchus pisorum under field conditions. Treatments with insecticides were started after the appearance of the first pea weevils eggs on pods located on the bottom two nodes. It was found that treatment with acetamiprid; thiacloprid; thiacloprid+deltamethrin; 50 g cypermethrin+480 g chlorpyrifosethyl, 50 g cypermethrin+500 g chlorpyrifosethyl and zeta-cypermethrin resulted in the cessation of additional oviposition on the lower nodes by Bruchus pisorum, due to the toxic effect of the insecticides on the pea weevil. It was found that spraying with acetamiprid and zeta-cypermethrin was the most effective. These insecticides significantly reduced the proportion of infected pods in comparison with the proportion of pods with eggs before the treatment by 30.2 and 27.4% and by 15.8 and 24.0% in 2011 and 2012, respectively. The use of acetamiprid and zeta-cypermethrin was also associated with the lowest percentage of infected seeds (21.7 and 23.6%, respectively), with the lowest percentage of infected seed in infected pods (40.5 and 42.5%, respectively) and the highest weight of 1000 infected seeds (161.94 and 182.04 g, respectively). It was concluded that the management of pea weevils in the crop with acetamiprid and zetacypermethrin can lead to satisfactory results when spray timing is chosen when the first eggs are visible. © 2015, Teagasc. All rights reserved. Source

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