Untreated Variant Research Articles

Researches Concerning Effectiveness of the Seed Treatment in Maize Crop for Controlling the Maize Leaf Weevil ( Tanymecus dilaticollis Gyll ) at NARDI Fundulea

In this paper, author collective present results and methodology of the insecticides testing against maize leaf weevil, in laboratory conditions. Year by year at NARDI Fundulea, in field conditions, it has tested insecticides used both like seed and vegetation treatment for control ling of the maize leaf weevil. Because climatic conditions from the spring are not favorable for this pest every year, laboratory testing is one of the best methods for evaluate of the insecticides used like seed treatment. At eight days after insects are added in the pots with maize plants, highest adults mortality and lowest attack intensity has registered in case of plants emerged from the seeds treated with products on base of thiametoxan ( Cruiser 350 FS ) , clothianidin ( Poncho 600 FS ) or thiametoxan+teflutrin ( Force Zea ) . In case of seeds treated with product on base of imidacloprid ( Nuprid 600 FS 8,0 l/t ) , even if the insects mortality was lower, the attack intensity has low values. All plants from the untreated variant were destroyed. At treated variants, saved plants percent were at least 90 %. Seed treatments provide a satisfactory protection of the maize plants, in first vegetation stages against maize leaf weevil.

Properties of thermally modified medium-density fibreboards

Abstract Thermal treatment of solid timber and oriented strandboards (OSB) improves durability against fungal decay and dimensional stability (swelling and shrinking). It is not clear whether thermal treatment of medium-density fibreboards (MDF) has the same effects. In this work, four variants of phenol-formaldehyde (PF)-bonded MDF with varying contents of resin and hydrophobing agent were thermally post-treated according to the Mühlböck procedure at three different maxi-mum temperatures. The short-term properties internal bond, modulus of rupture, modulus of elasticity, thickness swelling and equilibrium moisture content and the long-term property creep behaviour of treated variants and of one untreated variant have been tested. The results are presented and discussed in comparison with the respective European standards. Altogether, the thermal treatment had a positive effect on most of the tested mechanical short-term properties. The moisture-related properties, i.e., thickness swelling and equilibrium moisture content, were also positively influenced. The creep behaviour of heat-treated MDF could also be improved by thermal modification.

Sliding tribological properties of untreated and PIII-treated PETP

Poly(ethylene terephthalate) (PETP) was treated by plasma immersion ion implantation (PIII or PI 3) in nitrogen. The surface changes were characterised by XPS and water contact-angle measurements. Sliding tribological properties of untreated and nitrogen PIII-treated PETP against conventional low carbon structural steel S235 were studied under dry and water-lubricated conditions by a pin-on-disc tribometer. XPS results suggested the evolution of surface composition and bonding towards those of amorphous hydrogenated carbon-nitride. Water contact-angle decreased implying increased surface wettability. At a very low Pv factor (0.0075 MPa m s −1) for the nitrogen PIII-treated PETP the dry friction coefficient was smaller than, while the lubricated friction coefficient was similar to, the corresponding value of the untreated variant. At higher Pv factors (near 0.1 MPa m s −1), however, both the dry and lubricated friction coefficients were higher for the treated sample than for the untreated variant, suggesting an increased adhesion component of friction for the nitrogen PIII-treated PETP in this region.

Effect of Biological and Biochemical Silage Additives on Final Nutritive, Hygienic and Fermentation Characteristics of Ensiled High Moisture Crimped Corn

The aim of this study was to determine the effect of different biological and biochemical additives on the final nutritive quality, fermentation process and concentration of mycotoxins of ensiled high moisture crimped corn. We created four variants for the experiment: control (UC), A1, and A2 (biological stimulators with the active principle of lactic acid bacteria) and variant B (combined additives with the active principle of lactic acid bacteria, benzoate sodium and active enzymatic complex of cellulases). After 6 months of storage in laboratory conditions, we determined in experimental silages the content of dry matter ranging from 608.9 to 613 g kg-1. The significantly lower content of crude fibre was detected in silages with additives. In silages ensiled with additives we detected the highest content of nitrogen-free extract in variant B (834.3 g kg-1 of DM, P < 0.05). A similar effect was determined also in the content of starch; significant differences were detected in variants A1 and B (P < 0.05) compared to the control variant. We detected a significantly (P < 0.05) higher content of total sugars in trial silages; the highest content was in variant A2 (6.1 g kg-1 of DM). In the trial variants we determined significantly the lowest content of acetic acid in variant B (2.82 g kg-1 of DM). In case of butyric acid, whose content in the control variant was 0.22 g kg-1 of DM, we detected the lowest content in variant A1 conserved with homo- and heterofermentative species of lactic acid bacteria. The lowest content of ammonia was determined in silages of variant B (0.074 g kg-1 of DM). We found lower concentrations of DON and FUM (P > 0.05) after the application of biological and biochemical silage additives. In concentration of T-2 toxin we detected a significantly (P < 0.05) lower value in variant A1. In concentration of AFL we found significant differences between variants A1 and B, as well as in concentration of OT between untreated control variant (UC) and variants conserved by additives. Application of silage additives influenced the nutritive and hygienic quality of the conserved fodders.

The influence of thermal shock and pre-sprouting of seed potatoes on formation of some yield structure elements

For earlier potato yield formation we used pre-sprouting and thermal treatment which both add to the physiological age of potato. At the same time, pre-sprouting is a very time- and energy-consuming procedure. We investigated if thermal treatment could replace pre-sprouting and how it affects the growth and development of potato haulms and tubers. For that purpose an experiment was conducted in 2000–2002 to examine the opportunities for growing potatoes by using different methods of pre-planting treatment of seed tubers. Early, middle and late maturing potato varieties (two Estonian varieties and one Latvian) were used, each being subdivided into three variant categories: untreated, thermal shock and pre-sprouting. The experiment indicated that one or the other of thermal shock or pre-sprouting shortened the time to emergence by up to 10 days. With pre-sprouting, the formation of tubers started as soon as 45 days after planting and with thermal shock 50 days after planting, i.e., 5–10 days earlier than in the untreated variant. Thermal shock of seed tubers had the greatest effect on the number of tubers per plant, while pre-sprouting increased the average weight of tubers. Both pre-sprouting and thermal shock had a strong effect on the weight of the haulms in varieties with a longer growth period.

PROTECTION COMPLEXES’ INFLUENCE UPON ONION YIELD UNDER WESTERN FIELD CONDITIONS

The information concerning yield losses represent the best synthesis of the effects exerted by pathogen agents and pests upon onion crop. These information originate in the observations performed during 2003-2005 in the untreated control variant, compared to the variants in which we have applied protection complexes and also in the comparisons between the variants with the experience mean ( M ) and with the protection complexes mean (M cp). Yield differences compared to the control variant (Mt) are between 8.93-17.83 t/ha. The yield achieved in all seven variants is statistically assured, and the significances of yield differences are very significantly positive. Analyzing the significance if yield differences, by reporting it to the experience mean (M ), we may notice an evident differentiation per variants of the significance degree, namely a very significantly positive significance is available in only three variants (V5, V6 and V3). In V1 the significance is just positive, while in the variants V2 and V4 there is no significance, and in variants V7 and V8 it is very significantly negative. When the reference of yield differences was made only to the yield average achieved under the influence exerted by the protection complexes, excluding the yield achieved in V8 – untreated control variant, the situation changed dramatically, namely the yield has statistical cover only in two variants, difference significance being very significantly positive in V5 (Ridomil Gold MZ 68 0,25 % + Victenon 50 WP 0,075%) and distinctly significantly positive in V6 (Ridomil Gold Plus 42,5 WP 0,3% + Mospilan 20 SP 0,025%). There is no significance in the variants V3, V2 and V1, and in the variants V7 and V4 yield difference significance is very significantly negative, respectively distinctly significantly negative. As a general conclusion, we may say that the protection complexes from V5 (Ridomil Gold MZ 68 0,25 % + Victenon 50 WP 0,075%) and V6 (Ridomil Gold Plus 42,5 WP 0,3% + Mospilan 20 SP 0,025%) had the best effects in fighting against the two diseases (onion downy mildew - Peronospora destructor (Berk.) Casp and bulb rot - Botrytis allii Munn.) and the pest (onion fly – Delia antiqua Meig.), fact also proved by the level of yields achieved, by their statistical cover and the highest assessment degree of yield difference significance. The weakest effect in fighting against the two diseases and the pest belonged to the protection complex from V7 (Dithane M45 0,2% + Fastac 10EC 0,02%), because the significance of yield differences compared to M and M cp is very significantly negative.

Effect of powdery mildew attack on quality parameters and experimental bread baking of wheat

The research of powdery mildew impact on bread making quality of wheat was conducted on seven divergent wheat cultivars/lines, in factorial treatment designs (T0 - untreated and T1 - with fungicide Duett treated variants) at Križevci, Croatia. Test weight, grain protein content, wet gluten, sedimentation value and rheological parameters, as well as experimental breadbaking were examined during two years (2000 and 2001). Two years average test weight and grain protein content readings are significantly lower at untreated (T0) variants (diff. = 1.01 kg/hl** and 0.5 %** respectively). In wet gluten content there was no significant difference between the two variants, while average sedimentation value was significantly higher at untreated (T0) variant (diff. = 2.6 ml**). Farinographic indicators of quality (dough development and stability, resistance, degree of softening) as well as indicators of extensograph (energy and resistance) were also better at untreated (T0) variants. Dough yield, one of test-baking parameters, was bigger in treated (T1) variants, while the volume contribution was higher in untreated (T0) variants. Contrary to expectations, untreated resistant, moderately infected, or even susceptible variants had better quality parameters, offering speculation about eventual negative side-effect of applied fungicide Duett (epoxiconazole 12.5% + carbendazim 12.5%). Due to an interaction between numbers of different factors the speculation should be additionally checked and revised.

Small-scale dynamics of plant communities in an experimentally polluted and fungicide-treated subarctic birch-pine forest

Pollution from the Cu-Ni smelter at Monchegorsk, Kola peninsula, has resulted in major changes in the plant communities surrounding the smelter. However, very little pollution reaches northern Finland, which makes it possible to use this area for field experiments to study the mechanism of community change under pollution load. A field experiment was established to study the possible effect of pollution on the subarctic forest community, with Cu-Ni pollution and acid rain (AR) used as treatments. A fungicide (F)-treatment was also added to estimate the significance of plant-fungus interactions in community response. Floristic similarity decreased during the experiment, both within and between treatments. Cu-Ni- and AR-treatments did not have any effect on species richness. The Cu-Ni treatment reduced significantly the number of new species arrivals in plots, whereas the number of local extinctions remained constant. The heavy metal treatment resulted in a decrease in the bryophyte cover. The cover of Linnea borealis increased slightly due to the Cu-Ni-treatment, but decreased due to the AR-treatment. The F-treatment also resulted in a lower richness than in the untreated variant. Again, this effect was due to the reduced number of arrivals, whereas the number of local extinctions remained unchanged. The F-treatment also resulted in a higher cover of bryophytes and dwarf shrubs. Changes in species richness of subarctic understorey plant communities were mainly caused by the differential arrival of species under different environmental conditions. As the number of arrivals was negatively correlated to the F-treatment, the presence of (presumably positive) interactions between vascular plants and fungi may have an influence on the response of a community to pollution.

Einfluß von Witterung und Kulturpflanzenbestand auf bodenbiologische Leistungen

Summary In a long-term field experiment in a degraded black earth the carbon content in the soil, in dependence of different plant species and wheather conditions, was studied during the different vegetation periods. During 1979 and 1980 an almost uniform tendency in the change of the carbon content in the soil, i.e., the decrease of the carbon content to a minimum towards the summer and the gradual increase to the initial values up to the end of the vegetation period, was observed. The total C content in the untreated variant during the vegetation periods shows clearly that the variations of the carbon content in the soil are influenced not only by the wheather conditions, but also decisively by the special plant species cultured.