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The effect of different herbicide on the number and activity of living microorganisms in soil
76-82Views:119Sustainable plant growth, considering the difficulties of weed elimination, cannot be effective without the application of herbicides. However, these chemicals have enormous ecological implications, including effects on the microbiological communities of soils. It is advisable to use herbicides that have minimal secondary effects on the environment and soil-living microorganisms. In contrast, herbicides with prolonged growth stimulating or inhibiting effects are not suitable, because both types have strong influences on the number and activity of bacteria, thus causing changes in the ecological equilibrium.
Preceding small plot experiments, laboratory tests were carried out to study the effect of herbicides used in maize cultures on the number of bacteria and growth of microscopic fungi.
Substances that were observed to have stronger influences were applied in small plot experiments set up in the experimental garden of the Department of Plant Protection of the University of Debrecen. We studied the effects of four herbicides (Acenit A88EC, Frontier 900 EC, Merlin SC and Wing EC) on the microbiological properties of the soil. These herbicides were used in different concentrations in maize culture, and we investigated the effects in different soil layers.
In the laboratory experiments, we determined the total number of bacteria and microscopic fungi and examined the growth of Aspergillus niger, Trichoderma sp. and Fusarium oxysporum on peptone-glucose agar containing herbicides.
During the small plot experiments, soil samples were collected 3 times a year from 2-20 cm depth. The total numbers of bacteria and microscopic fungi were determined by plate dilution method, while the method of most probable number (Pochon method) was used to determine the numbers of nitrifying bacteria and cellulose decomposing bacteria. To evaluate the microbiological activity of the soil samples we measured carbon-dioxide release (after 10 days incubation), nitrate production (after 14 days incubation) and the concentration of C and N in the biomass.
We can summarize our results as follows:
• In laboratory experiments, herbicides caused a decrease in the number of bacteria and inhibited the growth of microscopic fungi.
• Frontier 900 EC and Acenit A 880 EC had the strongest inhibiting effect on microorganisms.
• In small plot experiments, herbicide treatment decreased the total number of bacteria and microscopic fungi.
• Herbicides caused a significant increase in the number of nitrifying and cellulose decomposing bacteria.
• Different herbicides containing the same active compound had similar influences on soil microoorganisms.
• A significant increase was observed in the physiological processes of tolerant microorganisms surviving the effects of herbicides -
The influence of biostimulators in the growth of some shrubs
49-52Views:58More sensitive than Mimosa pudica and more beautiful than any adornment detached from nature by man, the azalea (Azaleea
indica) gathers through its shapes a real symphony of colours and enchanting hues, of elegant shapes, having no rival in the flower world.
The azalea can multiply through seeds and vegetatively: seedlings, grafting, layering.
The widest reproduction method remains that through semilignified seedlings, a method that can be used throughout the year
avoiding the months less favourable for propagation by seedlings, with poor light: November and October. The best results are given by the
spring propagations by seedlings (February-March) and the summer propagations by seedlings (July-August). The rooting can last for 12-14
weeks until the seedlings can be transplanted in flower pots without risks.
A wide application in horticultural practice is the use of growth substances, that take part in the faster formation of roots and in a
higher percent for species of plants, that, normally, root with difficulty through seedlings. Under this aspect, many synthetical compounds
have proved to be very active (IAA, NAA, IBA, 2,4,5-T acid etc.) (3,4). -
Production of novel fermented milks
303-305Views:172The objective of this research was to test the influence of various natural substances on acid production, growth, and viability of characteristic microorganisms in yogurt and probiotic fermented dairy foods. Oligofructose, inulin, honey, and the dried biomass of Spirulina (Arthrospira) platensis were found to stimulate the growth rate and acid production activity of the major thermophilic diary cultures tested and, in addition to this, the presence of the aforementioned substrates also improved the survival of starter bacteria in fermented milk products during storage. The reduced production time of cultured milks resulted in increased production efficiency. The stimulatory and/or protective effect of oligofructose,
inulin, honey, and Spirulina on Bifidobacterium spp. is probably the most important finding of this study because bifidobacteria do not grow well in milk and they have low survival rates in conventional fermented milks. Some of the bioactive substances tested were also capable of exerting an antifungal effect on spoilage yeasts and molds, and improving the nutritional and sensory properties of the final product, thus providing a new opportunity for manufacture of functional fermented dairy foods. -
Weed control with herbicide incorporation in sunflower
73-76Views:151During the last decade certificate registration of 13 active ingedients were removed by European Union from sunflower herbicide market, including the basis for the incorporating technology, the trifluralin active ingredient as well. Its relative, the benfluralin active ingredient, which include the Balan 600 WDG herbicide product in sunflower, will be sold again from 2015 spring in Hungarian pesticide market. It has a broad-spectrum and lond residue besides it has very high level selectivity on sunflower. It has very good effect against annual monocotweeds such as common barnyadgrass, foxtail species, large crabgrass and wild proso millet, dicotyledonous weeds such as common lambsquarters,and redroot pigweed. It has significant side-effect against common ragweed, black nightshade, wild buckweed and prostrate knotweed. The long effect residue provide the weed-free til harvest. Benfluralin is totally selective on sunflower, as no colouring, any deformation or growth inhibition was not observed during the entire growing season. It should be sprayed 3-4 days before sowing within 1 hour and to be incorporated into the soil in 4-6 cm depth with tillage equipment. It can be used in tank mix with fluorochloridon in incorporated technology against annual dicotyledonous weeds. After the Balan incorporation can be used postemergence timing imazamox and tribenuron-metil active substances against hard kill and deeply germinating weeds. The products can not be used in tank mix with bacterial products.
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Testing a biological active plant extract’s antifungal effect against soil fungi
247-252Views:95In Hungary today is about 5 million hectares of agricultural land contaminated with ragweed. The ragweed problem a year is about 60 billion HUF to be paid, of which 30 billion are used to reduce the agricultural damage. Experiments with ragweed pollen has mainly been carried out in connection with terms of allergy. The other biochemical experiments and studies with this plant, have so far been the scientific horizons of public life, boosted the edge. We wanted to demonstrate that the ragweed, which is a weed, containsbiological active (for example: antifungal) compounds. For our experiments in the previous cycle of flowering, plants were collected manually, with its roots and with each plant part. The extraction of the substance from dry plant – meal was carried out using appropriate solvents. The biological activity of ragweed-extracts were tested against fungi isolated from soils and meadow with different mode of cultivation. Our results suggest that ragweed contains biologically active substances, which inhibit the growth of fungi, depending on the concentration of active ingredients of the plant.
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Usability of vegetable extracts in the protection against Alternaria alternata
113-116Views:132In our country, wormwood ragweed (Ambrosia artemisiifolia) may cause serious problems. Nearly 5 million hectares of agricultural area was infected with ragweed (Ambrosia artemisiifolia), which is believed useless weed. Allergological point of view, most problematic weeds adventive. However, many physiologically very beneficial compound also included, those with the effects have been known also by the Indians. On this basis, herbs can be thought of as ragweed. Our goal was to present that the ragweed contains antifungal active substances as well. In this paper we tested the biological activity of the extracts against Alternaria alternata F.00750 in vitro. We related based on our examination that ragweed contains biologically active agents, by which it is hampered the reproduction of the Alternaria alternata. The minimum effective concentration was 300 mg extract in a Petri dish, which was three days inhibited the growth of fungus. Full fungicidal effect was observed over dose 525 mg.