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This study was done to assess the antifungal effect of some biocontrol agents effective microorganisms (EMs1), Pseudomonas fluorescences, and Bacillus pumilus, titanium dioxide (TiO2) nanoparticles, black cumin and wheat germ oils as well as the recommended fungicide (flutolanil) against root rot of tomato. Moreover, gas chromatography-mass spectrometry (GC-MS) examination was completed to identify the bioactive compounds in plant oils (dark cumin and wheat germ). Also the impact of these medicines on some biochemical and growth parameters of tomato was examined. Flutolanil was the best treatment followed by dark cumin, TiO2, EMs1, Pseudomonas fluorescens, Bacillus pumilus and wheat germ oil, individually in both test seasons. The outcomes demonstrated a marked increase in each biochemical character (chlorophyll substance, peroxidase and polyphenoloxidase) and plant development (height and fresh and dry weight) under all the tried treatments in comparison to the controls.
The experiment was carried out to determine the effects of different irrigation water levels on yield and some quality parameters of lettuce (Lactuca sativa L. Var. Longifolia cv.) under greenhouse conditions. Irrigation water was applied through drip irrigation method with 7 days interval during the total growing season. Irrigation treatments consisted of six different water levels (I1: non-irrigation, I2: 25 %, I3: 50 %, I4: 75 %, I5: 100 % and I6: 125 % of cumulative evaporation measured from Class A pan). The amount of irrigation water ranged between 0 and 106.3 mm among the treatments. Evapotranspiration (ET) values varied from 69.1 to 158.5 mm for the treatments. The highest yield was obtained from the I5 followed by I4. A significant polynomial relation (R2=0.77) was obtained between the yield and irrigation water, and linear relation (R2=0.99) was obtained between the yield and ET. This indicated that when irrigation water increased, yield also increased to a certain point. However, when the amount of irrigation water exceeded the plant water requirement, lettuce yield decreased. Yield response factor (Ky) was determined as 1.97. Since Ky ˃ 1, lettuce was very sensitive to water deficiency. In addition, the highest water use efficiency (WUE) and irrigation water use efficiency (IWUE) values were calculated in the I5 with 0.60 t ha.mm-1 and 0.96 t ha.mm-1 respectively. The best plant quality parameters which were plant weight (239.11 g), plant height (26.30 cm), plant diameter (44.82 cm), root weight (17.31 g), root length (9.02 cm), root diameter (10.04 cm) and leaf number (49) were also obtained in I5. As a result, it was suggested that I5 can be the most appropriate irrigation water level for lettuce with higher WUE, IWUE, yield and quality under greenhouse conditions.
Rhizomania is one of the most important diseases of sugar beet around the world – including in Iran. The disease causes a severe decrease in sugar yield and is a limiting factor in sugar beet cultivation. Control of the disease is very difficult due to the long-term survival of its fungal vector (Polymyxa betae) in the soil. In this study, we investigated the effects of antagonistic fungal isolates on the population of the resting structure (cystosorus) of P. betae, under greenhouse conditions. Antagonistic fungi, including Trichoderma harzianum and Talaromyces flavus, were isolated from soil samples collected from sugar beet infested fields in the Semnan Province of Iran. In the next step, their inocula were prepared through reproduction on rice bran. For evaluation of the efficacy of antagonists in greenhouse conditions, a split plot trial was conducted and performed. The main factor was three different methods of application of T. flavus as the soil treatment, seed treatment, and a combination of both methods. The sub-factor was the use of different fungal isolates. To determine the cystosorus population of the fungal vector, seedling roots in all treatments were stained with lactic acid and fuchsine (lactofushine), 60 days after sowing. The number of cystosorus in one gram of root was counted using a light microscope and hemocytometer. At the end of the study, average root weight in different treatments was also measured to select and introduce the best treatments in regard to their effects on root weight. According to the results, the number of cystosorus in 1 g of root was different in various treatments and those treatments containing TF-Su-M-1, TF-Su-M-2, TH-Su-M-1, and TH-Su-M-2 used as a soil application method were more effective in the reduction of the cystosorus population and root weight increase. Among the above-mentioned treatments, maximum reduction of cystosori population and the increase in root weight were observed in TH-Su-M-1 and TF-Su-M-2 through the soil application method.
This is the first report of somatic embryogenesis from leaves of two strawberry cultivars (Selva and Comarosa) cultured on MS medium containing picloram. Maximum embryogenesis was induced using 2 mg/l picloram. Globular stage embryos developed into cotyledonary ones after transfer to hormone-free media containing 2%, 4%, 6%, 8% and 10% (w/v) sucrose. Increasing sucrose concentrations in culture media enhanced somatic embryo development. Cotyledonary somatic embryos were converted to plantlets after transfer on MS medium containing GA3, and maximum conversion was achieved with 1 mg/l and 2 mg/l GA3. Plantlets were capable of continuous growth under greenhouse conditions.
Effect of Bt maize MON 810 expressing Cry 1 Ab toxin on braconid Aphidius colemani in tritrophic plant - herbivore - parasitoid system was studied under greenhouse conditions by rearing the bird cherry-oat aphid (Rhopalosiphum padi) on genetically modified maize cultivar DKc 307 (MON 810) and its isogenic parent cultivar - Monumental of Monsanto Ltd. R. padi aphids reached higher population level when maintained on Bt-maize cultivar DKc 307 (MON 810) than on its isogenic parent cultivar - Monumental both in the winter and summer experiments. The braconid A. colemani developed higher population on R. padi aphid population feeding on Bt maize plants in the summer experiment and on non-Bt plants in the winter experiment. The observed effect of season on parasitation level by A. colemani on R. padi host feeding on Bt and non-Bt maize plants indicates that results obtained in a single greenhouse experiment may lead to questionable conclusions and should be confirmed by other experiments.
The biostimulant products are able to improve quality and quantity of medicinal plants. The comparative effects of biostimulants foliar spraying on peppermint (Mentha piperita L.) were investigated. These studies were done on the basis of randomized complete blocks design in 3 replicates during 2015. In field conditions, the highest leaves and stems dry weight by 400 mg/l chitosan (CH) + 400 mg/l citric acid (CA), essential oil content by 200 mg/l chitosan + 400 mg/l humic acid (HA) + 400 mg/l citric acid and menthol content in 200 mg/l chitosan + 800 mg/l humic acid + 400 mg/l citric acid were observed. In greenhouse conditions, the best results of those mentioned parameters were obtained by 400 mg/l chitosan + 800 mg/l humic acid + 400 mg/l citric acid, 800 mg/l humic acid and 400 mg/l chitosan + 400 mg/l humic acid + 400 mg/l citric acid, respectively.
The influence of an Uncaria tomentosa extract on the development of Capsicum plants grown in green-house conditions was examined. The effect of the treatment was investigated with microscopic techniques (light and electron microscope) in leaves from three levels of control plants and plants after treatment with the extract added to the soil in doses of 0.4 and 16 mg/ml (200 ml per pot/plant). In control leaves, changes typical of the subsequent phases of normal development were observed: nuclear chromatin became slightly condensed, plastoglobuli of chloroplasts increased in number and size, intragranal thylakoids were somewhat dilatated. In addition to such commonly occurring changes, some symptoms typical of pepper were observed in the ontogenesis of the examined plant: an increased number of spherical electron-dense deposits in vacuoles, an increased number of peroxisomes, the occurrence of numerous paracrystalline structures in chloroplasts of mature leaves, and, starting in mature leaves, expulsion of plastoglobuli from chloroplasts. After the treatment, most of those changes, leading to ageing, occurred much earlier and were more distinct. Chloroplasts, already in the youngest examined leaves, showed dilatation of intergranal thylakoids, which intensified with aging of the leaves and degradation of grana in the oldest leaves. Starch grains decreased in size and number and plastoglobuli became large. Vesiculation of ground cytoplasm in all leaves was stronger than in the control. No paracrystalline structures in chloroplasts or expulsion of plastoglobuli were observed. Another unusual phenomenon was the disappearance of spherical electron-dense deposits in the central vacuoles of cells. Those observations suggested that U. tomentosa extract enhanced the natural ontogenesis of Capsicum annuum leaves, by accelerating and enhancing the typical characteristics of ageing, and, additionally, it changed the structure and physiology of cells.
The effects of caraway and peppermint extracts was evaluated at concentrations of 2, 4, 6, 8 and 10%, respectively on the radial mycelial growth of Sclerotium rolfsii. High significant inhibitory effect on radial fungal growth was observed with different concentrations of each of plant extracts. Concentration of 6% and more of the two extracts in combination were able to cause complete growth inhibition of the tested fungus. In greenhouse, the efficacy of plant extracts in addition to the fungicide Rizolex-T as seed dressing on pea root rot incidence was evaluated in pot experiment using soil artificially infested with the disease agent. All treatments showed a significant reduction in disease incidence compared with the control treatment. Rizolex-T followed by combination of caraway and peppermint extracts as a mixture showed superior reduction effect on root rot disease incidence at pre-, and post-emergence growth stages than individual treatment with each of extracts. The usage of caraway and peppermint extracts for seed dressing before sowing might be applied as control measure for controlling root rot diseases.
The leaves of succulent Crassula multicava growing in greenhouse conditions showed disease symptoms, yellow and gradually browning spots, and the disease was caused by Pestalotia sp. In the excised healthy leaves of Crassula multicava kept in natural or inverted position in natural light conditions the accumulation of red-violet anthocyanins were formed but in the excised leaves with disease symptoms caused by Pestalotia sp. kept in the same light conditions anthocyanins did not form at a distance of about 4-8 mm from infected spots. The possible mechanism of anthocyanins accumulation in the excised healthy leaves of Crassula multicava in light and the lack of anthocyanins accumulation around the infected spots caused by Pestalotia sp. is discussed.
The effect of the application of salicylic acid (SA) and hydrogen peroxide (H2 O2 ) was evaluated on sensory quality traits of two commercial sweet bell pepper varieties, Fascinato and Orangela, by descriptive sensory evaluation, principal component analysis (PCA), and Multivariate Analysis of Variance (MANOVA). A sensory descriptive lexicon was established for the sweet pepper and an intensity score was assigned for 25 sensory attributes in all the samples. Such intensity score was performed by twelve trained panelists. Among the results it was shown that foliar application of elicitors to pepper crop produced signifi cant differences in sensory traits of the harvested fruits. MANOVA allowed detecting differences in aroma profi le among treatments and varieties, showing important changes depending on the combination of elicitors applied on each variety. The principal component analysis (PCA), showed that the PC1 explained 81.02%, while PC2 explained 9.24% of the variance in the results. A strong correlation between varieties and treatments 2 (36 mM H2 O2 ) and 4 (0.1 mM SA and 36 mM H2 O2 ) with PC1 was observed. Treatments 2 and 4 were related to changes in aroma and flavor traits. Fascinato was more susceptible to the effect of elicitor than Orangela. Therefore, elicitor combinations used in this experiment were capable to improve sensory quality of peppers, and not only promote an increase in shelf life as previous studies have shown.
As opposed to direct sowing, production of seedlings of vegetable crops for .ting is commonly practiced by vegetable growers. This study was undertaken to determine the effects of humic acid on the growth and the macro and micro contents in tomato (Lycopersicon esculentum) and eggplant (Solanum melongena var. esculentum) seedlings under greenhouse conditions. Different levels of :humanic acid (50, 100, 150, 200 ml 1-1) were applied to growing media (peat) after transplanting of examined seedlings of the species every ten days by the time of planting.The highest growth rate for leaf stem and root growth were obtained at 50 and l00 ml-1 HA and 50, 100, 150 ml 1-1 HA for tomato and eggplant seedlings, :Y as compared to the control.. The highest content of macro and micronutrient contens were obtained at 100 ml 1-1 HA and 200 ml l-1 HA for tomato and eggplantseedlings, respectively as compared to the control.
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