The Influence of Environmental Factors on Oryzalin Activity

Weed Science ◽  
1983 ◽  
Vol 31 (5) ◽  
pp. 752-758 ◽  
Author(s):  
James E. Nelson ◽  
William F. Meggitt ◽  
Donald Penner ◽  
James S. Ladlie
Keyword(s):  
Environmental Factors ◽  
Foxtail Millet ◽  
Grain Sorghum ◽  
Amaranthus Retroflexus ◽  
Surface Irrigation ◽  
Setaria Verticillata ◽  
Effects Of Temperature ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Smooth Pigweed

Effects of temperature, sunlight, soil incorporation and surface irrigation on the phytotoxicity of oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) were studied. The activity of oryzalin applied 4 to 6 weeks prior to planting was enhanced by covering the soil with plastic as measured by the inhibition of grain sorghum [Sorghum bicolor(L.) Moench. 'Sexauer G-701′] root growth. Growth chamber studies demonstrated that oryzalin phytotoxicity to grain sorghum was greater at 20 and 25 C than at 30C. The control of foxtail millet[Setaria italica(L.) Beauv. #5SETIT] bristly foxtail[Setaria verticillata(L.) Beauv. # SETVE], redroot pigweed (Amaranthus retroflexusL. # AMARE), and smooth pigweed (Amarantbus hybridusL.), and injury to grain sorghum increased as the thoroughness of mechanical incorporation of oryzalin into soil increased. The phytotoxicity of surface-applied oryzalin increased with increasing amounts of irrigation water until it equaled the level of a preplant-incorporated treatment.

Stimulation of Common Cocklebur (Xanthium pensylvanicum) and Redroot Pigweed (Amaranthus retroflexus) Seed Germination by Injections of Ethylene into Soil

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 510-514 ◽  
Author(s):  
G. H. Egley
Keyword(s):  
Seed Germination ◽  
Laboratory Tests ◽  
Seedling Emergence ◽  
Amaranthus Retroflexus ◽  
Redroot Pigweed ◽  
Plastic Bags ◽  
Viable Seeds ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Stimulation Of

The effects of ethylene upon germination of common cocklebur (Xanthium pensylvanicumWallr.) and redroot pigweed (Amaranthus retroflexusL.) seeds were studied. In laboratory tests with seeds in sealed flasks in the dark, 10 μl/L ethylene increased germination of redroot pigweed seeds from 7% to 52% at 30 C, and increased germination of large and small common cocklebur seeds from 30% and 0% to 100% and 90% respectively, at 25 C. At least 12 h of exposure to ethylene was necessary for appreciable stimulation of germination. In growth chamber studies with known numbers of seeds in pots of soil, ethylene at 11 kg/ha was injected into the soil, and the pots were enclosed in plastic bags for 24 h. One such injection at 2 weeks after planting, and successive injections at 2, 3, and 4 weeks, significantly increased redroot pigweed seedling emergence, and significantly decreased the numbers of dormant, viable seeds remaining in the soil. When pots were not enclosed, injections did not significantly effect redroot pigweed seeds, but significantly increased common cocklebur seedling emergence and decreased the number of viable common cocklebur seeds remaining in the soil.

scholarly journals Inoculation Method, Temperature, and Relative Humidity Affect Leaf and Neck Anthracnose, a New Onion Disease in Michigan

2018 ◽  
Vol 19 (1) ◽  
pp. 64-68
Author(s):  
Lina M. Rodriguez-Salamanca ◽  
Rachel P. Naegele ◽  
Lina M. Quesada-Ocampo ◽  
Mary K. Hausbeck
Keyword(s):  
Relative Humidity ◽  
Disease Severity ◽  
Colletotrichum Coccodes ◽  
Conidial Suspension ◽  
New Disease ◽  
Inoculation Method ◽  
Millet Seed ◽  
Effects Of Temperature ◽  
Chamber Studies ◽  
Growth Chamber Studies

Leaf and neck anthracnose caused by Colletotrichum coccodes is a new disease of onion in Michigan. To test the effect of inoculation method, Prince onion seedlings were grown in the greenhouse and inoculated with either a conidial suspension of C. coccodes (alone or with an abrasive agent) or infested millet seed (dry or wet, 2 or 5 g). Foliar disease severity was greater when a conidial suspension (>39%) was used compared with infested millet seed (≤24.3%). Growth chamber studies were conducted using Infinity onion seedlings that were inoculated with a conidial suspension spray to determine the effects of temperature (15, 20, 25, or 30°C) and duration (0, 12, 24, 48, or 72 h) of high (95 ± 5%) relative humidity (RH) on disease severity (percentage of leaf area with C. coccodes lesions). Significant differences and interactions among temperature and RH were observed. The combination of high temperature (≥25°C) and extended (≥24 h) high RH resulted in >20% disease severity 28 days postinoculation. Results suggest that onion leaf and neck anthracnose symptoms are likely to be more severe when the environmental conditions are ≥25°C with ≥24 h of high RH.

Environmental Effects on MSMA Phytotoxicity to Wild-Type and Arsenical Herbicide-Resistant Common Cocklebur (Xanthium strumarium)

1996 ◽  
Vol 10 (4) ◽  
pp. 809-814 ◽  
Author(s):  
Chandrashekhar I. Nimbal ◽  
David R. Shaw ◽  
Gene D. Wills ◽  
Stephen O. Duke
Keyword(s):  
Relative Humidity ◽  
Xanthium Strumarium ◽  
Wild Type ◽  
Fresh Weight ◽  
Low Light ◽  
Herbicide Resistant ◽  
Effects Of Temperature ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Weed Resistance

Effects of temperature, relative humidity, and light on MSMA phytotoxicity to wild-type and arsenical herbicide-resistant biotypes of common cocklebur grown from seed collected in Mississippi were evaluated. In growth chamber studies, 20-d-old plants were sprayed with 0.5 kg ai/ha of MSMA, and after 7 d, fresh weight and chlorophyll content were measured to estimate phytotoxicity. All three environmental factors influenced the level of weed resistance. In studies with day/night temperatures of 30/25 C and 500 μmol/m2/s PPFD light with a 14-h photoperiod, phytotoxicity of MSMA at 40% relative humidity was minimal, but was significantly greater at 60 and 90% relative humidities. The resistant (R) biotype was affected less than the susceptible (S) biotype at the higher relative humidities. The level of resistance estimated by fresh weight reduction was greatest at 30/25 C, but was most pronounced at 35/30 C using chlorophyll measurements. Resistance was lowest at 25/20 C by either measurement. MSMA phytotoxicity occurred at light intensities of 75, 500, and 750 μmol/m2/s PPFD; however, biotypic response was greatest at 500, followed by 750 μmol/m2/s PPFD. Resistance of the (R) biotype to MSMA was not significant at 75 μmol/m2/s, suggesting that differentiation between the biotypes for MSMA sensitivity would be difficult under low light.

scholarly journals Grain sorghum transpiration efficiency at different growth stages  

2017 ◽  
Vol 63 (No. 2) ◽  
pp. 70-75 ◽  
Author(s):  
Thapa Sushil ◽  
Stewart Bob A ◽  
Xue Qingwu
Keyword(s):  
Flag Leaf ◽  
Grain Filling ◽  
Grain Sorghum ◽  
Yield Potential ◽  
Growth Chamber ◽  
Growth Stages ◽  
Transpiration Efficiency ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Different Growth Stages

Transpiration efficiency (TE) is an important physiological trait associated with drought tolerance of plants. Currently, little is known about the grain sorghum TE and its dynamics with the age of plants. To compare the sorghum TE at different growth stages, four studies (two in the greenhouse and two in the growth chamber) were conducted under controlled environmental conditions. Plants were grown in lid-covered boxes and harvested at six-leaf, flag leaf, grain filling and maturity stages. The mean shoot TE values were 4.47 and 4.10 kg/m<sup>3</sup> for two greenhouse studies, and 4.85 and 4.30 kg/m<sup>3</sup> for two growth chamber studies, respectively. The shoot TE was not different among four growth stages within each study, suggesting that sorghum plants used the same amount of water per unit of biomass production for different growing periods. Because crops grown under dryland environments often run out of water during reproductive periods, result supports the ideas that soil water availability at later growth stages is crucial to achieve the yield potential of dryland sorghum.  

Seed Germination and Seedling Emergence of Scotch Broom (Cytisus scoparius)

Weed Science ◽  
2009 ◽  
Vol 57 (6) ◽  
pp. 620-626 ◽  
Author(s):  
Timothy B. Harrington
Keyword(s):  
Seed Germination ◽  
Temperature Regime ◽  
Root Biomass ◽  
Seedling Emergence ◽  
Soil Drought ◽  
Dark Light ◽  
Scotch Broom ◽  
Effects Of Temperature ◽  
Chamber Studies ◽  
Growth Chamber Studies

Scotch broom is a large, leguminous shrub that has invaded 27 U.S. states. The species produces seeds with a hard coat that remain viable in the soil for years. Growth-chamber studies were conducted to determine effects of temperature regime and cold-stratification period on seed germination. Seedling emergence, mortality, and biomass also were studied in response to sulfometuron and metsulfuron herbicides and variation in soil texture and watering regime. Germination was greatest for a dark/light temperature regime of 15/20 C. Initial rates of germination increased as stratification period was varied from 0 to 60 d, but final germination after 90 d did not differ significantly among periods. Applied alone or in combination, sulfometuron and metsulfuron decreased biomass and increased mortality of seedlings. Mortality from simulated soil drought was greater in the presence versus absence of sulfometuron (20 and 6% mortality, respectively) probably because the herbicide reduced root biomass by 58 to 95%. Invasiveness of Scotch broom is facilitated by a prolonged period of germination across a broad temperature range. Increased control of Scotch broom seedlings with sulfometuron is likely if application is timed to expose recently emerged seedlings to developing conditions of soil drought.

scholarly journals Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea Mays)

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33741 ◽  
Author(s):  
Paul Szpak ◽  
Fred J. Longstaffe ◽  
Jean-François Millaire ◽  
Christine D. White
Keyword(s):  
Zea Mays ◽  
Stable Isotope ◽  
Growth Chamber ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Seabird Guano

Biocontrol of seed-borne Alternaria raphani and A. brassicicola

1987 ◽  
Vol 33 (10) ◽  
pp. 850-856 ◽  
Author(s):  
G. Vannacci ◽  
G. E. Harman
Keyword(s):  
Biological Control ◽  
Host Range ◽  
Trichoderma Harzianum ◽  
Pythium Species ◽  
Biological Control Agents ◽  
Fusarium Sp ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Radish Seedlings

Forty-two microorganisms were tested as biological control agents against Alternaria raphani and A. brassicicola. Tests were conducted for in vitro antagonistic ability, for ability to control the pathogens on naturally infected seeds germinated on moistened blotters, and in planting mix in growth chamber studies, and for their ability to reduce pod infection. The organisms tested were obtained from cruciferous seeds or were strains already identified as being effective against soil-borne Pythium species. The blotter test indicated that six organisms increased both the number of healthy seedlings and the number of seedlings produced from A. raphani infected radish seeds. An additional seven strains improved either germination or increased the number of healthy seedlings. Twenty-nine organisms increased the number of healthy cabbage seedlings from A. brassicicola infected seeds, but total germination was not modified by any treatment. Experiments in planting mix showed that five antagonists (Chaetomium globosum, two strains of Trichoderma harzianum, T. koningii, and Fusarium sp.) increased the number of healthy plants in both radish samples tested, while four additional antagonists provided a significant increase in only one of the samples tested. The five antagonists that consistently increased numbers of healthy radish seedlings also decreased pod infection by A. raphani. None were as effective as iprodrone, however. Several effective antagonists were found to be mycoparasitic against Alternaria spp. Some strains of Trichoderma previously found to be effective against Pythium spp. were also effective against Alternaria spp., indicating that these strains have a wide host range.

Effect of Corn-Induced Shading and Temperature on Rate of Leaf Appearance in Redroot Pigweed (Amaranthus retroflexus L.)

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 590-593 ◽  
Author(s):  
Stephane M. Mclachlan ◽  
Clarence J. Swanton ◽  
Stephan F. Weise ◽  
Matthijs Tollenaar
Keyword(s):  
Field Experiments ◽  
Linear Increase ◽  
Amaranthus Retroflexus ◽  
Planting Date ◽  
Weed Interference ◽  
Redroot Pigweed ◽  
Field Temperature ◽  
Effects Of Temperature ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Leaf development and expansion are important factors in determining the outcome of crop-weed interference. The comparative effects of temperature and corn canopy-induced shading on the rate of leaf appearance (RLA) of redroot pigweed were quantified in this study. Growth cabinet results indicated a linear increase in RLA with increased temperature. Weed RLA was predicted utilizing both this function and field temperature data. The ratio of observed to predicted RLA of redroot pigweed grown in field experiments decreased in 1990 and 1991 as shading increased with increased corn density and delayed weed planting date. Results indicated that RLA is substantially affected by canopy-induced shading in addition to temperature.

Interference between hemp sesbania (Sesbania exaltata) and soybean (Glycine max) in response to irrigation and nitrogen

Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 91-97 ◽  
Author(s):  
C. Andy King ◽  
Larry C. Purcell
Keyword(s):  
Field Experiments ◽  
Yield Loss ◽  
Individual Species ◽  
Weed Species ◽  
Soybean Yield ◽  
Sesbania Exaltata ◽  
Competition For Light ◽  
Hemp Sesbania ◽  
Chamber Studies ◽  
Growth Chamber Studies

Soybean yield loss from weed interference depends upon weed density and competitiveness of crop and weed species in response to environment. Soil water availability and nitrogen fertility were evaluated for their effect on competitiveness of individual species in field experiments. Early-season temperatures in 1995, which were cool compared to 1994, slowed hemp sesbania growth without affecting soybean growth. This resulted in negligible competition with soybean by hemp sesbania at densities of 3 or 6 plants m−2. In 1994, hemp sesbania grew above the soybean canopy, decreasing soybean light interception 29 to 68%, and reducing soybean yield 30 to 48%. Fertilizer nitrogen increased soybean competitiveness, as indicated by biomass production, only in irrigated plots with hemp sesbania at 3 m−2, but did not affect soybean yield. Apparently, competition for light is a primary cause of soybean yield loss from hemp sesbania infestations. In growth chamber studies, simulating temperatures from the field, hemp sesbania growth was stimulated more by warm temperatures than was soybean. Hemp sesbania and soybean dry weights increased 4.4- and 2.7-fold, respectively, at 30/20 C day/night temperatures compared to 25/15 C.

Factors Involved in Alachlor Injury to the Potato (Solanum tuberosum)

Weed Science ◽  
1977 ◽  
Vol 25 (6) ◽  
pp. 482-486 ◽  
Author(s):  
J.N. Belote ◽  
T.J. Monaco
Keyword(s):  
Solanum Tuberosum ◽  
Soil Surface ◽  
Growth Chamber ◽  
Herbicide Application ◽  
Time Of Application ◽  
Plant Emergence ◽  
Chamber Studies ◽  
Growth Chamber Studies

Results from greenhouse and growth chamber studies indicated that alachlor [2-chloro-2′,6-diethyl-N-(methoxymethyl) acetanilide] injury to ‘Superior’ potatoes (Solanum tuberosumL.) was related to time of herbicide application and temperature. Injury to the ‘Superior’ cultivar was observed when alachlor was applied just before potato emergence. Necrosis of shoots near the soil surface, shoot dieback, stem swelling, leaf crinkle, and plant stunting were characteristic symptoms of alachlor injury. Cool temperatures appeared to intensify the injury. ‘Superior’ potatoes outgrew injury within 41 days after treatment. Herbicide placement studies in the growth chamber suggested that alachlor or its metabolites were absorbed by the shoots of emerging ‘Superior’ potatoes. Under growth chamber conditions the ‘Katahdin’ cultivar was injured by preemergence applications of alachlor when the herbicide was applied just before plant emergence. Injury symptoms were similar to those observed on the ‘Superior’ cultivar. ‘Pungo’ and ‘Norchip’ potatoes were tolerant to preemergence applications of the herbicide regardless of time of application.

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