Comparative study regarding in vitro infections with Erwinia amylovora and Pseudomonas syringae pv. syringae on pomaceae species

The knowledge about pome fruit trees bacterioses and their evolution in orchards is a major objective for plant protection. Erwinia amylovora and Pseudomonas syringae pv. syringae cause on attacked organs of Pomaceae species similar dieback symptoms in vegetative and flowering shoots of quince, pear and apple in spring. Both bacteria can produce disastrous diseases in orchards and are therefore of great economic importance. Biological materials represented by vegetative shoots, leaves and fruits of Pyrus spp., Malus spp., Cydonia spp. were used after isolation of different E. amylovora and Ps. syringae pv. syringae strains for in vitro infections. Results presented in this study established that for in vitro inoculation of Pomaceae species similar symptoms in case of leaves and, respectively different symptoms for vegetative shoots and fruits occurred. The occurrence time was the only difference, because Ps. syringae pv. syringae spread faster than E. amylovora. The vegetative shoots inoculated with E. amylovora, in comparison to Ps. syringae pv. syringae, were more damaged and for both bacteria the highest values for attack degree were recorded in case of pear species, followed by quince and apples, respectively

Acetochlor influence on soil microbial communities

The chloroacetanilide herbicide acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)-acetamide] was used to control the weeds on a maize (Zea mays L.) field experiment. Acetochlor was applied to soil at three different concentrations between 2.2 and 4.0 l/ha after sowing the crop. Before sowing a control soil sample was collected. At days 7, 14 and 21 after application soil sample were collected and analyzed to determine the herbicide effect on the microbial communities (Gram positive bacteria, Gram negative bacteria and micromycetes). The objective of this research was to determine the influence of acetochlor on the total number of microorganisms, on the relationship between the main groups (bacteria and fungi), and on the micromycetes spectrum determined in each variant of our experiment

Effects of chlorsulfuron on soil microbial population

The sulfonylurea herbicide chlorsulfuron [2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]- benzenesulfonamide] is effective used in wheat (Triticum aestivum L.) to control a wide spectrum of weeds and has low toxicity to humans and animals. Chlorsulfuron control weeds by inhibiting acetolactate synthase (ALS), an enzyme required for leucine, valine and isoleucine biosynthesis in plants and microorganisms. Tolerance of wheat to chlorsulfuron is based on its ability to metabolize this substance to herbicidally inactive conjugate. Different concentrations of chlorsulfuron ranged from 31.5 to 56.7 mg/l were used and his effect on the soil microflora was investigated. The influence of chlorsulfuron on the existing microbial population in soil (Gram positive bacteria, Gram negative bacteria and micromycetes) was measured every seven days for a month. The objective of this research was to determine the influence of chlorsulfuron on the total number of microorganisms, on the relationship between the main groups (bacteria and fungi), and on the micromycetes spectrum determined in each variant of our experiment

Influence of fertilization and different tillage systems on soil microflora

Researches were carried out on rapeseed (Brassica napus L.) field trials located in the south region of Moldavian plain (Ezareni Farm), studying the effects of fertilization (organic, mineral) and soil tillage systems on soil population. Soil tillage has been realized with plough (in classic system), with chisel, rotary harrow (in minimum soil tillage) and in notill system. The objectives of this investigation were to isolate and quantify the existing microbial population in soil (Gram positive bacteria, Gram negative bacteria, micromycetes) establishing their participation ratio, the main fungus genres which activate in soil and their activity level for each variant. The results illustrate the influence of the fertilization and soil tillage systems on the dinamic of microorganisms population, on the relationship between the main groups (bacteria and fungi), and on the micromycetes spectrum determined in each variant of our experiment

Study regarding effectiveness of some plant extracts and different pesticides against an Erwinia amylovora (Burrill.) Winslow et al., strain isolated from quince

The interest in management fire blight prevention and control increased considerably in last years due to pathogen spread almost throughout the country. The objective of this paper focuses on testing of some plant extracts such as Salvia officinalis, Thymus serpyllum, Pelargonium odoratissimum, Hedera helix, Ocimum basilicum, Levisticum officinale, Tagetes patula, Galium verum and different pesticides against an Erwinia amylovora strain isolated from quince dameged samples. In this study, the biological material was represented by quince shoots, harvested from pomological collection of "Vasile Adamachi" farm, which belongs to University of Agricultural Science and Veterinary Medicine Iaşi. The research were performed in the Phytopathology laboratory. Following the experiment performed note that among the eight plant extracts a good antibacterial activity has Pelargonium odoratissimum, Ocimum basilicum and Salvia officinalis and of the three pesticides, Alcupral 50 PU. Contrary to expectations worst results were obtained after testing Aliette 80 WG and Hedera helix products. The results were estimated statisticaly, by performing ANOVA test

In vitro susceptibility of Erwinia amylovora (Burrill) Winslow et al. strain isolated from pear to several plant extracts and different pesticides

In less than six months after infection, Erwinia amylovora may completely destroy a pome tree. This paper aims to increase awareness of the potential for developing plant protection strategies based on natural products. Since the damage caused by this bacterium are unrecoverable, we tested in vitro the effectiveness of a several plant extracts such as Salvia officinalis, Thymus serpyllum, Pelargonium odoratissimum, Hedera helix, Ocimum basilicum, Levisticum officinale, Tagetes patula, Galium verum and some pesticide products, on a strain of Erwinia amylovora isolated from the pomological collection of "Vasile Adamachi" farm, the University of Agricultural Sciences and Veterinary Medicine, Iaşi. The strain was isolated from damaged pear shoots, after performing patogenicity test on immature pear fruits. Following the experiment conducted, copper oxychloride (Alcupral 50 PU) and Pelargonium odoratissimum showed a very good antibacterial activity against EA - A.P. strain

Influence of aquasorb and different soil tillage systems on soil microbial populations in fields cultivated with Soybean (Glycine max merr.)

Aquasorb 3005 is a hydrophilic polymer (copolymer of acrylamide and potassium acrylate) that, when incorporated into a soil, improve water conservation through increasing of water retains capacity, reducing of infiltration rate and cumulative evaporation. This anionic polyacrylamide polymer works in absorbtion-release water cycles and has the property of absorbing up to 500 times their weight in distilled water. Researches were carried out on soybean (Glycine max Merr.) field trials located in the south region of Moldavian plain (Ezareni Farm), studying the effects of polymer quantity ha-1 , polymer administration moment and soil tillage systems on soil population. In this study we aimed to evaluate the influence of the hydrophilic polymer (Aquasorb) on existing microbial population in soil (Gram positive bacteria, Gram negative bacteria, micromycetes) establishing their participation ratio, the main fungus genres which activate in soil and their activity level for each variant. The results illustrate the influence of Aquasorb and soil tillage systems on the dinamic of microorganisms population, on the relationship between the main groups (bacteria and fungi), and on the micromycetes spectrum determined in each variant of our experiment