OTIORRHYNCHUS LIGUSTICI L. (COLEOPTERA: CURCULIONIDAE) III. MODELING SCALE FOR RESISTANCE IN ALFALFA VARIETIES

DOI: 10.7904/2068 – 4738 – III(6) – 81

Ivelina NIKOLOVA, Nataliya GEORGIEVA

 Abstract: In 2006–2009 period in the experimental field of IFC–Pleven were carried out studies with 8 alfalfa varieties included in the Official variety catalog of Bulgaria (2005): Europe (France), Prista 2 (Obraztsov Chiflik, Ruse), Prista 3 (Obraztsov Chiflik, Ruse), Prista 4 (Obraztsov Chiflik, Ruse), Obnova 10 (IFC, Pleven), Pleven 6 (IFC, Pleven), Dara (IFC, Pleven) and Multifoliate (Obraztsov Chiflik, Ruse). For evaluation of the resistance in alfalfa varieties to Otiorrhynchus ligusticiwas developed 5–graded scale based on the numbers of furrows on the root system. Withthe most strongly pronounced damage and high percentage of plants with score 3, 4 and 5 was distinguished the fourth year in alfalfa cultivation. Asmiddle resistance varieties tothe attack from O. lygusticiwere Europe, Prista 2 and Multifoliate (the index of attack was 21.7, 22.9 and 23.0% respectively) which is important for the selection and practice.

Key words: alfalfa varieties, scale for resistance, Otiorrhynchus ligustici

 

OTIORRHYNCHUS LIGUSTICI L. (COLEPTERA: CURCULIONIDAE) II. METHOD FOR DETERMINATION OF THE DEGREE OF DAMAGE BY LARVA AND BIOCHIMICAL COMPOSITION OF THE ROOT SYSTEM IN DIFFERENT ALFALFA VARIETIES

DOI: 10.7904/2068 – 4738 – III(6) – 75

Ivelina NIKOLOVA, Nataliya GEORGIEVA, Anna ILIEVA

 Abstract: During the period 2006–2009 in the experimental field of IFC–Pleven were conducted studies with 8 varieties of alfalfa included in the Official variety catalog of Bulgaria (2005): Europe (France), Prista 2 (Obraztsov Chiflik, Ruse), Prista 3 (Obraztsov Chiflik, Ruse), Prista 4 (Obraztsov Chiflik, Ruse), Obnova 10 (IFC, Pleven), Pleven 6 (IFC, Pleven), Dara (IFC, Pleven) and Multifoliate (Obraztsov Chiflik, Ruse). For determination of the damage from the large alfalfa weevil Otiorrhynchus ligustici on the root system of plants was developed methodology depending on the root area and the damage area. The area of the roots was calculated by the formula S = (π * d * L) / 2, where π is 3.14; d–diameter of the root collar, L–length of the root. The area of the furrows оn the root system was product of length and width of the furrows. With the lowest percentage of furrows and tolerant to O. ligustici were Multifoliate, Prista 2 and Europe–respectively 10.38, 11.41 and 11.68%. Highly sensitive, with high percentage of damage were distinguished Dara, Prista 4 and Prista 3 (respectively 14.28, 14.05 and 13.58%). As a result of the caused damage the content of sugars and saponins increased as depending on the sensitivity of varieties the increase was different. In the tolerant varieties to the pest the increase in sugar content was less pronounced, but in the sensitive ones–stronger. In regard to the saponins the trend was reversed–the increase in the sensitive varieties was less and in the tolerant varieties–stronger which could be explained with the defensive reaction of plants to compensate the losses from damages of the pest.

Key words: alfalfa, varieties, method of damage degree, biochemical composition, Otiorrhynchus ligustici

OTIORRHYNCHUS LIGUSTICI L. (COLEOPTERA: CURCULIONIDAE) I. COMPARATIVE STUDY OF THE RESISTANCE OF ALFALFA VARIETIES

 DOI: 10.7904/2068 – 4738 – III(6) – 68

Ivelina NIKOLOVA, Nataliya GEORGIEVA

Abstract: From studies carried out during the period 2006–2009 in the experimental field of the IFC–Pleven with 8 alfalfa varieties included in the Official variety catalog of Bulgaria (2005): Europe (France), Prista 2 (Obraztsov Chiflik, Rouse), Prista 3 (Obraztsov Chiflik, Rouse), Prista 4 (Exemplary Chiflik, Rouse), Obnova 10 (EFC, Pleven), Pleven 6 (EFC, Pleven), Dara (EFC, Pleven) and Multifoliate (Obraztsov Chiflik, Rousse) it was found that in the year of the establishment of the stand there was partial damage from Otiorrhynchus ligustici. It was found that surface of caused damage was a major sign to determination ofthe degree ofinfestation from the insect pest as it increased from second tofourth yearon average from 5.6 to 42.1 cm2.Varieties of Multifoliate, Europe and Prista 2 were the least preferred and with low values of surface of damage, number and length of the gnawed furrows. These varieties can be used as sources of germplasm resistant to Otiorrhynchus ligustici.

Keywords: alfalfa, varieties, damage, Otiorrhynchus ligustici

 

TO THE QUESTION ABOUT THE BEHAVIOUR OF SOME RED FESCUE GENERATIONS

DOI: 10.7904/2068 – 4738 – III(6) – 59

Dimitar MITEV, Galina NAYDENOVA

Abstract: The experiment with a polyhybrid population of Red fescue was performed in the period of 1995–2004.It was set annually during the winter from 1994/95, according to the block method with four repetitions.The seeds were collected consecutively in the period after 1992.They were sowed alone and in a mixture from two different, but consecutive years.The oldest seeds were excluded gradually from the scheme and were replaced by others, which had been obtained in the year before the sowing.The behaviors of the generations (dry substance yields, botanical ingredients) are varied.The genotype variance assessment shows that the differences in the productivity are due to a proven genotype influence, i.e. the different generations behave to one another as if they are different species. When the generations from two different sowings are compared the productivity differences, which are provoked by the genotype influence, are displayed in different years since the grasslands have been used. Considering the productivity, the highest yields were obtained from grasslands created by the combination of seeds gathered in 1993 and 1994, but which were sowed in 1995/1996 and 1996/1997. The investigated generations show a remarkable ability for self–cleaning from weeds.It is found that there are divergences in that tendency. There is a self–sowing of other meadow species which are characteristic for this region. It is assumed that there is a dependence among the formed genetic material and the admission to the environmental factors, durability, the spreading ability. Probably, the particular “structural units” (…, species, population, sort, …) have a specific “energy configuration”, which is subjected to the Nature rhythm and which represents a peculiar “projection” in Time with a corresponding direction of Evolution.

Key words: Red fescue, generations, rhythm, hypotheses

REDUCED TILLAGE PRACTICES

DOI: 10.7904/2068 – 4738 – III(6) – 49

Ts. MIHOVSKY, I. PACHEV 

Abstract: Soil erosion can be considered, with different leve of severity, an EU–wide problem. Erosion is a natural geological phenomenon resulting from the removal of soil particles by water or wind, transporting them elsewhere. However some human activities can dramatically increase erosion rates. Soil organic matter assures the binding and buffering capacity of the soil, an essential determinant of erosion resistance and soil fertility. Crops grown without tillage, use water more efficiently, the water–holding capacity of the soil increases, and water losses from runoff and evaporation are reduced. In addition, soil organic matter and populations of beneficial insects are maintained, soil and nutrients are less likely to be lost from the field and less time and labour is required to prepare the field for planting. Greater water–stability of surface soil aggregates, higher microbial activity and earthworm populations and higher total carbon can be found In general, the greatest advantages of reduced tillage are realized on soils prone to erosion and drought, but significant advantages are only seen after more than 10 years of application.

 Key words: soil erosion, soil organic matter, conservation agriculture

 

INVESTIGATIONS OF CHAENOMELES JAPONICA (THUNB.) LINDL. IN THE REGION OF CENTRAL BALKANS

DOI: 10.7904/2068 – 4738 – III(6) – 43

 Teodora MIHOVA, Violeta KONDAKOVA, Penka MONDESHKA

Abstract: The characterization of genetic resources of Chaenomeles japonica (Thunb.) Lindl, spread in the region of Central Balkans, aims to assess its complex of biological, biochemical, biotechnology and metabolic properties. The fruits of this plant species are characterized by a rich content of biologically active substances having greater importance to human health and food industry. Determination of metabolic parameters of the spectrum depending on the environmental area, the method of generation and storage of fruit is defined as self–direction at the Research Institute of Mountain Stockbreeding and Agriculture–Troyan.

 Key words: Chaenomeles sp., genotype, fruits, quality, phenologycal calendar, yield, reproductive characteristics, biochemical parameters

 

COMPARATIVE TESTING OF SOME PERENNIAL DROUGHT TOLERANT LEGUME GRASSES BY FOOTHILL CONDITIONS OF CENTRAL NORTHERN BULGARIA

 DOI: 10.7904/2068 – 4738 – III(6) – 37

Vladimir LINGORSKI, Dimitar MITEV

Abstract: During the 2010–2012 period in RIMSA, Troyan (Bulgaria) the comparative testing of some perennial drought tolerant legume grasses (birdsfoot trefoil, white clover, common sainfoin, hybrid–blue lucerne and hybrid–yellow lucerne) was accomplished. It was found that best bio–productive indicators had the hybrid–blue lucerne. In the triple regime of harvesting it received 4.39 t.ha1 green mass and 1.09 t.ha1 dry matters, which exceeded the standard (birdsfoot trefoil) by 26.51% and 43.42%, respectively. Hybrid–blue lucerne, hybrid–yellow lucerne and birdsfoot trefoil predominated over weeds and weed infestation decreased from Ist to IIIrd haymaking.

Key words: legume grasses, drought tolerance, Central Northern Bulgaria.

 

INFLUENCE OF FOLIAR ТОР–DRЕSSING WITH ОRGANIC FERTILIZER ON SOME BIOPRODUCTIVE FORAGE PARAMETERS ОF ANNUAL SUMMER CEREAL–LEGUMINOUS MIXED CROP

DOI: 10.7904/2068 – 4738 – III(6) – 32

Vladimir LINGORSKI

 Abstract: During the 2010–2012 periods in the Research Institute of Mountain Stockbreeding and Agriculture (RIMSA) in Troyan the effect of foliar fertilizing with the organic fertilizer BioLIFE on the green and dry mass yields and weed infestation of annual summer spring cereal–leguminous mixture was established. The following doses of foliar fertilizer were tested as variants in a mixed crop of fodder maize and white lupine: 1. Untreated with BioLIFE (Standard); 2. Treatment with BioLIFE–2 l/ha; 3. Treatment with BioLIFE–3l/ha; 4. Treatment with BioLIFE–4l/ha. It was found that the application of 4 l/ha BioLIFЕ increased the obtained green and dry mass by 20.43 and 24.45% more than the untreated standard crop. The exceeding in the productivity of the same variant, as against the obtained ones at the lower doses of foliar fertilizer was by 21.17%, 10.36% and 26.63%, 11.51% respectively. These variants were superior to the standard in yielding capacity of green and dry mass by 7.39–14.98% and 8.65–19.99%, respectively. The weed infestation of the mixture sowing was lower for the treatment with foliar fertilizer and the tested doses did not influence it significantly.

Key words: summer mixture, foliar fertilizer, green and dry mass, weeds infestation.

 

EFFECT OF PRESOWING TREATMENT OF SEEDS WITH INSECTICIDES ON PARAMETERS RELATED TO NODULATION AND NITRATE REDUCTION IN SOYBEAN [GLYCINE MAX (L.) MERR.]

  DOI: 10.7904/2068 – 4738 – III(6) – 24

Anna ILIEVA and Viliana VASILEVA

Abstract: Effect of pre-sowing treatment of seeds with insecticide preparations on parameters related to nodulation and nitrate reduction in soybean was studied in pot trial at the Institute of Forage Crops, Pleven, Bulgaria (2003–2004). It was found that insecticide preparations Gaucho 600 FS (imidacloprid), Carbodan 35 ST (carbofuran) applied for pre-sowing treatment of seeds at the doses of 1, 2 and 3 L/100 kg seeds, and Promet 400 CS (furathiocarb) (standard) at the dose of 3 L/100 kg seeds, had no suppressive effect on the root length, dry root mass and specific nodulating ability of plants. When used Gaucho 600 FS at the dose of 1 L/100 kg seeds, root mass was most developed, the largest number of nodules was formed, and specific nodulating ability was highest. The common tendency for decrease of nitrate reductase activity in leaves and significant increase in stems was found. Nitrate reductase activity increased in leaves, stems and roots in treatment with Carbodan 35 ST applied at the dose of 3 L/100 kg seeds. Chlorophylls а+b/carotenoids ratio exceeded this of the control only in treatment with Gaucho 600 FS at the dose of 1 L/100 kgseeds.

 Key words: nodulation, nitrate reductase, plastid pigments, presowing treatment, insecticides, soybean. 


DENSITY AND REDUCTION OF THE STAND AT ALFALFA VARIETIES (MEDICAGO SATIVA L.)

DOI:10.7904/2068 – 4738 – III(6) – 18

Natalia GEORGIEVA, Ivelina NIKOLOVA

 Abstract: With purpose to study the density and reduction of stand at 9 alfalfa varieties (Europe, Prista 2, Prista 3, Prista 4, Obnova 10, Pleven 6, Dara, Multifoliate and Dama)during 2006–2009 period in IFC–Pleven is carried out an experimental activity. The average density of stand at studied alfalfa varieties during the first year of development was 1313 plants/m2. The reduction during next three years was disproportionately and was the strongest pronounced during the second year–by 58.3% to the density of the stand in the previous year. During the third experimental year the reduction of alfalfa was still strong pronounced albeit with a lower value (51.1%) and during the fourth year it was 5 times less than that during the previous two years at average value of 10.6%. In the end of four–year experimental period the reduction at different varieties was in limits from 68.6% (Obnova10) to 85.7% (Dara) at average value for the species of 81.8%. It is established correlations with high negative value among the stand density and root mass weigh/plant (r=–0.811) and diameter of root collar (r=–0.692), and a correlation with medium negative value between the stand density and number of stems/plant (r=–0.488).

Key words: alfalfa, varieties, stands density, reduction