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Vichan Vichukit - One of the best experts on this subject based on the ideXlab platform.
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Influence of Tillage, Fertilizer, and Weed Management on Weed Seed Bank at Various Soil Depth of Wheat Production Field In Ethiopia
2005Co-Authors: Kassahun Zewdie, Rungsit Suwanketnikom, Sombat Chinawong, Chairerk Suwannarat, Sunanta Juntakool, Vichan VichukitAbstract:Screen house experiments were conducted on two soil types at two locations of central highlands of Ethiopia during 2002 / 2003 to determine the combined effects of tillage, fertilizer, and weed management on weed seed bank at various soil depths in bread wheat (Triticum aestivum L.) field. Among the dominant weeds identified in the soil seed bank and in the field, 89 % of the majority of the weeds were annuals and 11% of them were perennials and biennials. From the total weed species, only few were the most dominant species including Polygonum nepalense, Galinsoga parviflora, Plantago lanceolata, Gnaplium unions, Sonchus arvensis, Spergula arvensis, Anagalis arvensis, Commelina benghlensis, Corrigiola capensis from broad leaf weed species and Setaria spp., Bromus pectinatus, Snowdenia polystachya and Phalaris paradoxa from grass weed species. The results revealed that tillage, fertilizer and weed management systems had significant effects on weed seed bank. The weed seed bank distribution and seed bank size differed among tillage treatments. The total amount of weed density tended to increase more in no tillage than conventional tillage or moldboard plow at both locations. The highest number of seed density in 0-30 cm depth of soil was found in the Kuyu black soil followed by Holetta red soil. In the NT system a large amount of weed seed was found in the depth of 0-10 cm followed by CvT and MP. The densities of broad leaf and grass weed seed were higher in NT than in CvT or MP at both locations. The highest percentages of weed seed reduction across locations were recorded 80 and 62% on MP and CvT or NT respectively. Tank mixture of fenoxaprop-P-ethyl and fluroxypyr +MCPA resulted in a significant reduction ranged from 70 to 80% of total weed number followed by hand weeding twice at all locations. The interactions between tillage and soil depth and between soil depth and weed management were species specific. Significant interactions were resulted from Spergula arvensis,, Corrigiola capensis, Polygonum nepalance and Galinsoga prviflora weed seed bank size. More than 60% of broad leaf and grass weeds were suppressed by tillage. Weed management was more important
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Weed Population Dynamics as Influenced by Tillage, Fertilizer and Weed Management in Wheat (Triticum aestivum L.) Cropping Systems of Central Ethiopia
2004Co-Authors: Kassahun Zewdie, Rungsit Suwanketnikom, Sombat Chinawong, Chairerk Suwannarat, Sunanta Juntakool, Vichan VichukitAbstract:Field experiments were conducted at Holetta, central highlands of Ethiopia during 2002 and 2003 to determine the combined effects of tillage, fertilizer and weed management on weed population dynamics in bread wheat (Triticum aestivum L.) field. The results indicated that tillage, fertilizer and weed management systems had a significant effect on weed population dynamics. The total amount of weed density tended to increase in no tillage than conventional tillage or moldboard plow in both years. The magnitude change ranged from two to four folds when comparing densities in no tillage with the others. Among the dominant weeds, Polygonum nepalense, Galinsoga parviflora, Plantago lanceolata, Ganaplium unions, Spergula arvensis, Setaria pumila, Bromus pectinatus, Echinocloa colona, Snowdenia polystachya and Phalaris paradoxa, were significantly reduced in density (P
Patricia F. Mason - One of the best experts on this subject based on the ideXlab platform.
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Isolation and Structural Identification of Sucrose Esters from Corn Spurrey (Spergula arvensis); Inhibition of Seed Germination
Journal of Chemical Ecology, 1998Co-Authors: Joseph K. Peterson, Maurice E. Snook, Howard F. Harrison, Patricia F. MasonAbstract:Polar as well as nonpolar extracts of Spergula arvensis (corn spurrey) were shown to cause inhibition of seed germination. The polar methylene chloride extracts were subjected to solvent partitioning and separations by a combination of silicic acid and Sephadex LH-20 column chromatography. All chromatographic fractions were monitored by a proso-millet seed germination assay, which resulted in the isolation of a group of sucrose esters (SE). The identity of the ester acids was determined by gas chromatography (GC) of their butyl esters. Further characterization of the SE by GC-mass spectrometry of their trimethylsilyl derivatives showed the presence of four different SE groups with two to seven acyl groups attached to sucrose. The SE isomers in greatest abundance contained either octanoic or dodecanoic acid along with two smaller branched-chain acids (butanoic and pentanoic acids). All four SE groups were inhibitory to seed germination. This is the first report of SE outside the family Solanaceae.
Joseph K. Peterson - One of the best experts on this subject based on the ideXlab platform.
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Isolation and Structural Identification of Sucrose Esters from Corn Spurrey (Spergula arvensis); Inhibition of Seed Germination
Journal of Chemical Ecology, 1998Co-Authors: Joseph K. Peterson, Maurice E. Snook, Howard F. Harrison, Patricia F. MasonAbstract:Polar as well as nonpolar extracts of Spergula arvensis (corn spurrey) were shown to cause inhibition of seed germination. The polar methylene chloride extracts were subjected to solvent partitioning and separations by a combination of silicic acid and Sephadex LH-20 column chromatography. All chromatographic fractions were monitored by a proso-millet seed germination assay, which resulted in the isolation of a group of sucrose esters (SE). The identity of the ester acids was determined by gas chromatography (GC) of their butyl esters. Further characterization of the SE by GC-mass spectrometry of their trimethylsilyl derivatives showed the presence of four different SE groups with two to seven acyl groups attached to sucrose. The SE isomers in greatest abundance contained either octanoic or dodecanoic acid along with two smaller branched-chain acids (butanoic and pentanoic acids). All four SE groups were inhibitory to seed germination. This is the first report of SE outside the family Solanaceae.
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Studies on the Allelopathic Effect of Corn Spurry (Spergula arvensis L.) on Cole Crops and English Pea
HortScience, 1997Co-Authors: Howard F. Harrison, Joseph K. Peterson, Maurice E. SnookAbstract:These studies were initiated to investigate severe growth inhibition observed when some vegetable crops were infested with corn spurry (Spergula arvensis L.). Interference by a natural population of the weed reduced the shoot weights of English pea (Pisum sativum L.) and collard (Brassica oleracea L.) by 93% and 72%, respectively. In a greenhouse experiment where light competition by corn spurry was prevented, broccoli (Brassica oleracea L.) shoot weights were reduced by corn spurry, but pea weights were not different from the controls. Homogenized corn spurry shoot tissue incorporated into a greenhouse potting medium inhibited the growth of both species, and a concentration effect was observed. Sequential hexane, dichloromethane, methanol, and 50% aqueous methanol extracts of corn spurry root and shoot tissue were tested for inhibitory activity using millet seed germination and broccoli seedling growth bioassays. Dichloromethane, methanol, and aqueous methanol shoot extracts were inhibitory to broccoli; whereas all shoot extracts inhibited millet germination. Shoot extracts were more inhibitory than root extracts. Further fractionation of the inhibitors using a combination of reversed-phase sephadex LH-20 and silicic acid column chromatographic procedures showed that a major portion of the millet germination inhibition was due to sucrose esters (SE). Preliminary characterization of the esters showed that there were four different SE groups. The major groups contained either octanoic or dodecanoic acid along with butanoic and petanoic acids. All groups inhibited seed germination at concentrations as low as 20 ppm. This is the first report of the SE class of defense chemicals in plant species outside of the solanaceae family.
Claudio M. Ghersa - One of the best experts on this subject based on the ideXlab platform.
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Ozone Exposure of a Weed Community Produces Adaptive Changes in Seed Populations of Spergula arvensis
2016Co-Authors: Jennifer B. L, Pedro E. Gundel, M. Alej, Ra Martínez-ghersa, Claudio M. GhersaAbstract:Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergula arvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75 % RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5 % RH and 25 ºC/75 % followed by 5 % R
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Ozone exposure of a weed community produces adaptive changes in seed populations of Spergula arvensis.
PloS one, 2013Co-Authors: Jennifer B. Landesmann, Pedro E. Gundel, M. Alejandra Martínez-ghersa, Claudio M. GhersaAbstract:Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergulaarvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 oC/5% RH and 25 oC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production.
Maurice E. Snook - One of the best experts on this subject based on the ideXlab platform.
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Isolation and Structural Identification of Sucrose Esters from Corn Spurrey (Spergula arvensis); Inhibition of Seed Germination
Journal of Chemical Ecology, 1998Co-Authors: Joseph K. Peterson, Maurice E. Snook, Howard F. Harrison, Patricia F. MasonAbstract:Polar as well as nonpolar extracts of Spergula arvensis (corn spurrey) were shown to cause inhibition of seed germination. The polar methylene chloride extracts were subjected to solvent partitioning and separations by a combination of silicic acid and Sephadex LH-20 column chromatography. All chromatographic fractions were monitored by a proso-millet seed germination assay, which resulted in the isolation of a group of sucrose esters (SE). The identity of the ester acids was determined by gas chromatography (GC) of their butyl esters. Further characterization of the SE by GC-mass spectrometry of their trimethylsilyl derivatives showed the presence of four different SE groups with two to seven acyl groups attached to sucrose. The SE isomers in greatest abundance contained either octanoic or dodecanoic acid along with two smaller branched-chain acids (butanoic and pentanoic acids). All four SE groups were inhibitory to seed germination. This is the first report of SE outside the family Solanaceae.
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Studies on the Allelopathic Effect of Corn Spurry (Spergula arvensis L.) on Cole Crops and English Pea
HortScience, 1997Co-Authors: Howard F. Harrison, Joseph K. Peterson, Maurice E. SnookAbstract:These studies were initiated to investigate severe growth inhibition observed when some vegetable crops were infested with corn spurry (Spergula arvensis L.). Interference by a natural population of the weed reduced the shoot weights of English pea (Pisum sativum L.) and collard (Brassica oleracea L.) by 93% and 72%, respectively. In a greenhouse experiment where light competition by corn spurry was prevented, broccoli (Brassica oleracea L.) shoot weights were reduced by corn spurry, but pea weights were not different from the controls. Homogenized corn spurry shoot tissue incorporated into a greenhouse potting medium inhibited the growth of both species, and a concentration effect was observed. Sequential hexane, dichloromethane, methanol, and 50% aqueous methanol extracts of corn spurry root and shoot tissue were tested for inhibitory activity using millet seed germination and broccoli seedling growth bioassays. Dichloromethane, methanol, and aqueous methanol shoot extracts were inhibitory to broccoli; whereas all shoot extracts inhibited millet germination. Shoot extracts were more inhibitory than root extracts. Further fractionation of the inhibitors using a combination of reversed-phase sephadex LH-20 and silicic acid column chromatographic procedures showed that a major portion of the millet germination inhibition was due to sucrose esters (SE). Preliminary characterization of the esters showed that there were four different SE groups. The major groups contained either octanoic or dodecanoic acid along with butanoic and petanoic acids. All groups inhibited seed germination at concentrations as low as 20 ppm. This is the first report of the SE class of defense chemicals in plant species outside of the solanaceae family.