Mixture Of Thiram Research Articles

Synergetic effect of silver nanoparticles and thiram on lipid bilayers

The excessive concentration of nanomaterials and pesticides in industrial products, food, and in the environment can be a risk to human health. Exposure to these materials can occur through inhalation, dermal contact, or oral ingestion, which depends directly on the type of products we are exposed to. Extensive studies about the individual action of these compounds have been described. However, the effect of these mixtures (nanoparticles and pesticides, for instance) requires more investigation. Here, we evaluated by phase-contrast microscopy the individual and mixture effects of silver nanoparticles (AgNp) and thiram pesticide on mimetic systems of the lipid bilayer structure of the plasma membrane using DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) giant unilamellar vesicles (GUVs). Besides, the effect of thiram pesticide on DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) multilamellar vesicles containing AgNp (encapsulated) was also evaluated by surface-enhanced Raman scattering (SERS). The results showed a synergetic effect of the AgNp and thiram mixture, which lead to a loss of phase contrast intensity and rupture of the lipid bilayers. The synergetic effect was ascribed to the strong interaction AgNp-thiram through Ag-S bond formation.

In vitro inhibition of Sclerotinia sclerotiorum by mixtures of azoxystrobin, SHAM, and thiram

The necrotrophic fungal phytopathogen Sclerotinia sclerotiorum (Lib.) de Bary has a broad host range and frequently causes destructive diseases. The extensive use of common fungicides to control these diseases has selected for resistance in populations of S. sclerotiorum. In this study, 105 isolates of S. sclerotiorum from different geographical regions in Jiangsu Province of China were characterized for baseline sensitivity to azoxystrobin, and the average EC50 value was 0.2932μg/mL for mycelial growth. Of the mixtures of the fungicides thiram and azoxystrobin that were tested using an in vitro mycelial growth assay, the 1:4 ratio provided the greatest inhibition of S. sclerotiorum. When tested against nine isolates, the 1:4 mixture resulted in a mean synergy ratio of 2.31, indicating synergistic inhibition. Mycelial respiration was inhibited for about 2h by azoxystrobin alone but for 48h by the mixture of thiram and azoxystrobin. Salicylhydroxamic acid (SHAM, a known inhibitor of alternative respiration) also increased the inhibition of mycelial growth and respiration caused by azoxystrobin. These results suggest the need for further study of effects of combinations of azoxystrobin with thiram or SHAM in planta to evaluate their potential for management of diseases caused by S. sclerotiorum.

Chemical and biological treatments of castor bean seeds: effects on germination, emergence and associated microorganisms

The effect of chemical and biological treatments on castor bean emergence, seedling vigor, dry matter production, and also the control of microorganisms associated with seeds of the AL Guarany 2002 and Lyra cultivars, was evaluated. The products tested were carbendazim + thiram, carboxin + thiram and a product based on Trichoderma. Total seed and seedling emergence were evaluated at 27 days after sowing whereas dry matter production was verified for plants removed 45 days after sowing. The Guarany 2002 AL cultivar had a higher incidence of microorganisms than the Lyra cultivar. The chemical treatment was 100% effective in controlling fungi but the biological treatment did not reduce microorganism incidence on the seeds. Chemical treatment resulted in plants with more dry matter and the best results were for carbendazim + thiram and carboxin + thiram at doses of 60 g + 140 g and 50 g + 50 g/100 kg of seeds, respectively. The carbendazim + thiram mixture was the only treatment which was statistically higher for total emergence whereas the biological treatment increased emergence only for the Lyra cultivar, thus demonstrating its lower efficiency. The importance of fungicides to control pathogens associated with seeds was discussed.

Rice spikelet rot disease in China – 2. Pathogenicity tests, assessment of the importance of the disease, and preliminary evaluation of control options

In recent years, a rice panicle disease—rice spikelet rot, occurred seriously in large rice-growing area in China, causing the rice grains discolor, unfilled and deform. It does not only influence the rice yield, because of the colored pathogens and toxigenic, but also changes the appearance of the rice and reduces its quality. Spikelet rot disease influences on the rice production and market price, and causes harm to the safety and health of human and livestock. This paper makes effort to elucidate the occurrence, epidemic regularity of the disease, the pathogenicity of isolates. Fungicides to control the disease were preliminarily selected in lab and control efficiency test were conducted in field. The investigation results indicate that japonica varieties and their hybrid combination, tighten panicle varieties are easier to be infected by the disease than that of the indica rice varieties with loosen panicles. It was propitious to the disease occurrence and epidemic when rice late booting to flowering period met the overcast, rainy (high humidity) and warm (25–33 °C) climate. Indoor selection results showed that ketotriazole shows very good restraint effect on the pathogens. Seed treating with fungicide, spraying ketotriazole, carbendazim + thiram mixture or tricyclazole at later booting and/or flowering stage can reached over 70% control efficiency to the disease.

The effect of a mixture of seed-borne Microdochium nivale var. majus and Microdochium nivale var. nivale infection on Fusarium seedling blight severity and subsequent stem colonisation and growth of winter wheat in pot experiments

Greenhouse experiments were conducted in order to determine the impact of seed-borne Microdochium nivale var. nivale and var. majus inoculum, and seed treatment with a carboxin+thiram mixture, on the development of seedling blight, and on subsequent stem colonisation and growth of winter wheat (cv. Cadenza). Experiments were conducted at temperatures favourable (3°C) and unfavourable (22°C) to M. nivale. Seed-borne inoculum resulted in seedling blight symptom development when plants were grown at 3°C, but not when plants were grown at 22°C. For seedlings grown at 3°C, plants arising from heavily blighted seedlings developed more severe symptoms of stem colonisation, when compared with those arising from seedlings from carboxin+thiram treated seeds. In addition, the vigour of such plants (assessed by determining the number of tillers and ears per plant, stem length, green leaf area, dry weight and yield) was also significantly lower than for plants arising from carboxin+thiram treated seeds. Microdochium nivale var. majus and var. nivale appeared to have little effect on plant vigour from seedlings grown at 22°C. This is the first recorded incidence of seedling blight affecting subsequent plant growth. Microdochium nivale var. majus and var. nivale stem colonisation increased from growth stage (GS) 40–49 to harvest in plants raised from seedlings grown at both temperatures. Microdochium nivale var. majus and var. nivale were isolated from the second node at GS 40–49 and the third node at harvest of plants from seedlings grown at 3°C. For plants from seedlings raised at 22°C, M. nivale var. majus and var. nivale were isolated from the first node at GS 40–49 and the second node at harvest. Carboxin+thiram seed treatment decreased the extent and severity of stem colonisation on plants from seedlings grown at 22°C.

Associação de Alternaria dauci e A. alternata com sementes de coentro e eficiência do tratamento químico

Association of Alternaria dauci and A. alternata with coriander seeds and efficiency of chemical treatments Twelve lots of coriander seeds were evaluated for the presence of Alternaria spp., using 600 seeds per lot in the blotter test. Two Alternaria species were detected, A. dauci (AD) in eight lots and A. alternata (AA) in six lots. A sample of 400 seeds was sown in styrofoam trays and the incidence of spots on cotyledons was evaluated 21 days after sowing. Only lesions caused by AD were observed on leaves. The seed lot with higher incidence of AA and AD was treated with fungicides (thiram, benomyl, captam and iprodione) and 400 seeds in each treatment were placed in four gerbox boxes with sterilized wet filter paper. Seeds were observed under stereoscopic microscope for presence of AD and AA. The best treatment was the mixture of thiram + iprodione resulting in 0.5% and 0% incidence of AA and AD, respectively. Treated seed samples were sown in styrofoam trays to verify transmission of Alternaria spp. from seeds to seedlings. Plants resulting from non treated seeds presented 13% of infection with AD. Plants from seeds treated with the mixture thiram + iprodione were not infected by AD. The results demonstrated the efficacy of thiram + iprodione mixture for treatment of coriander seeds against A. dauci and A. alternata.

A repellent to reduce mouse damage to longleaf pine seed

Direct seeding is a potential method for reforestation of pines on many southern sites. The success of direct seeding, however, depends, at least in part, in reducing seed predation by birds and rodents. We conducted a series of tests to assess the efficacy of capsicum and thiram in reducing mouse damage to longleaf pine ( Pinus palustris) seeds. House mice ( Mus musculus) predation was reduced ( P<0.05) by treating seeds with either capsicum or thiram or a mixture of the two ingredients. Deer mice ( Peromyscus maniculatus) avoided seeds treated with a mixture of capsicum and thiram. We conclude that the capsicum and thiram mixture should be pursued as a potential repellent to protect longleaf pine seeds from animal predation when these seeds are used in direct seeding efforts to establish southern pine forests.

Studies on the biology of black mould (Aspergillus niger) on temperate and tropical onions. 2. The effect of treatments on the control of seedborne A. niger

Treatment of A. niger‐inoculated onion seed with benomyl dust (1 g a.i./kg), or a foliar spray of thiram (0·4% a.i./ha) applied to plants grown from inoculated seed under temperate (UK) conditions reduced the incidence of A. niger in harvested crops. Treatment of naturally contaminated Sudanese onion seed with a benomyl + thiram mixture at a rate of 2·5 + 2·5 g a.i./kg or soaking the seed in hot water (15 min at 60°C) reduced the incidence of black mould on bulbs grown in the Sudan in field soil that had not previously been used for onion production. The seed treatments were less effective in crops produced in fields regularly used for onion production. However, incubation of harvested bulbs in moist chambers showed that damage to the internal storage tissue of onion bulbs caused by A. niger was reduced by seed treatment.