Host Range Alteration of the Bioherbicidal FungusAlternaria crassawith Fruit Pectin and Bant Filtrates

Weed Science ◽  
1994 ◽  
Vol 42 (3) ◽  
pp. 487-491 ◽  
Author(s):  
C. Douglas Boyette ◽  
Hamed K. Abbas
Keyword(s):  
Host Range ◽  
Host Specificity ◽  
Water Soluble ◽  
Weed Species ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Hemp Sesbania ◽  
Greenhouse Tests

In greenhouse tests, the host specificity ofAlternaria crassa(Sacc.) Rands, a mycoherbicide for jimsonweed was altered by the addition of water-soluble filtrates of jimsonweed and hemp sesbania or fruit pectin to fungal conidia suspensions. Several crop and weed species that were resistant to the fungus alone exhibited various degrees of susceptibility following these amendments, with 100% mortality occurring to the weeds hemp sesbania, showy crotalaria, and eastern black nightshade when treated with the fungus/pectin mixture. Nonhost plants that were inoculated with conidial mixtures amended with sucrose or cellulose were not affected. Modification of host specificity of this pathogen could have an influence on its bioherbiddal potential

Growing Weeds in Nonaerated Nutrient Solution

1989 ◽  
Vol 3 (1) ◽  
pp. 143-145 ◽  
Author(s):  
Robert N. Andersen ◽  
Donald F. Ralston
Keyword(s):  
Nutrient Solution ◽  
Weed Species ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Wild Mustard ◽  
Green Foxtail

Velvetleaf, eastern black nightshade, wild mustard, common cocklebur, green foxtail, and yellow foxtail, grown for 4 weeks in nonaerated nutrient solution, developed satisfactorily compared to plants grown in soil. For experiments involving certain weed species grown in nutrient solution, aeration may be unnecessary.

Response of Selected Weed Species to Postemergence Imazethapyr and Bentazon

1995 ◽  
Vol 9 (2) ◽  
pp. 236-242 ◽  
Author(s):  
Troy A. Bauer ◽  
Karen A. Renner ◽  
Donald Penner
Keyword(s):  
Weed Control ◽  
Field Research ◽  
Dry Weight ◽  
Field Studies ◽  
Weed Species ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Redroot Pigweed ◽  
Treated Leaf ◽  
Petroleum Oil

Imazethapyr and bentazon were applied with petroleum oil adjuvant in a factorial arrangement to weed species in greenhouse and field research to determine if postemergence weed control by imazethapyr was antagonized when bentazon was tank-mixed. Tank-mixing 840 g/ha of bentazon with 13 or 27 g/ha of imazethapyr increased redroot pigweed and eastern black nightshade dry weight as compared to Colby's expected values in the greenhouse. However, weed control was not reduced in field studies. Subsequent greenhouse studies indicated that soil interception and resulting root uptake of imazethapyr increased redroot pigweed control. Bentazon decreased foliar absorption of14C-imazethapyr by 15% and translocation of14C from the treated leaf by more than 50% compared tol4C-imazethapyr applied alone.

Predicting weed emergence for eight annual species in the northeastern United States

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 913-919 ◽  
Author(s):  
Matthew W. Myers ◽  
William S. Curran ◽  
Mark J. VanGessel ◽  
Dennis D. Calvin ◽  
David A. Mortensen ◽  
...  
Keyword(s):  
Model Verification ◽  
Weed Species ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Giant Foxtail ◽  
Smooth Pigweed ◽  
Weed Emergence ◽  
Large Crabgrass

A 2-yr experiment assessed the potential for using soil degree days (DD) to predict cumulative weed emergence. Emerged weeds, by species, were monitored every 2 wk in undisturbed plots. Soil DD were calculated at each location using a base temperature of 9 C. Weed emergence was fit with logistic regression for common ragweed, common lambsquarters, velvetleaf, giant foxtail, yellow foxtail, large crabgrass, smooth pigweed, and eastern black nightshade. Coefficients of determination for the logistic models fit to the field data ranged between 0.90 and 0.95 for the eight weed species. Common ragweed and common lambsquarters were among the earliest species to emerge, reaching 10% emergence before 150 DD. Velvetleaf, giant foxtail, and yellow foxtail were next, completing 10% emergence by 180 DD. The last weeds to emerge were large crabgrass, smooth pigweed, and eastern black nightshade, which emerged after 280 DD. The developed models were verified by predicting cumulative weed emergence in adjacent plots. The coefficients of determination for the model verification plots ranged from 0.66 to 0.99 and averaged 0.90 across all eight weed species. These results suggest that soil DD are good predictors for weed emergence. Forecasting weed emergence will help growers make better crop and weed management decisions.

Time of Emergence of Eight Weed Species

Weed Science ◽  
1984 ◽  
Vol 32 (3) ◽  
pp. 327-335 ◽  
Author(s):  
Alex G. Ogg ◽  
Jean H. Dawson
Keyword(s):  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Eastern Black Nightshade ◽  
Salsola Kali ◽  
Hairy Nightshade ◽  
Black Nightshade ◽  
Redroot Pigweed ◽  
Emergence Patterns

Under irrigated field conditions at Prosser, WA, Russian thistle [Salsola kali(L.) var.tenuifoliaTausch. ♯3SASKR] began to emerge by mid-March each year and usually had completed its emergence by May 1. Common lambsquarters (Chenopodium albumL. ♯ CHEAL) was the next to appear, usually during the third or fourth week of March. Barnyardgrass [Echinochloa crus-galli(L.) Beauv. ♯ ECHCG], redroot pigweed (Amaranthus retroflexusL. ♯ AMARE), hairy nightshade (Solarium sarrachoidesSendt. ♯ SOLSA), black nightshade (5.nigrumL. ♯ SOLNI), eastern black nightshade (S. ptycanthumDun.), and cutleaf nightshade (S. triflorumNutt. ♯ SOLTR) generally began to emerge during the first 2 weeks of April and emergence generally peaked mid-April to mid-May. Russian thistle and cutleaf nightshade had the most restricted emergence patterns, whereas seedlings of common lambsquarters, redroot pigweed, hairy nightshade, and black nightshade emerged each month from April through September. Shallow tillage at monthly intervals increased the overall emergence of common lambsquarters, redroot pigweed, black nightshade, and eastern black nightshade; decreased the emergence of barnyardgrass; and had no effect on the emergence of Russian thistle, cutleaf nightshade, or hairy nightshade.

Effect of weed growth stage and adjuvant on the efficacy of fomesafen and bentazon

Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 1016-1021 ◽  
Author(s):  
Robin R. Bellinder ◽  
Marija Arsenovic ◽  
Denis A. Shah ◽  
Bradley J. Rauch
Keyword(s):  
New York ◽  
Growth Stage ◽  
Field Experiments ◽  
New York State ◽  
Field Studies ◽  
Weed Species ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Weed Growth ◽  
Annual Weeds

The efficacies of bentazon and fomesafen in controlling annual weeds in dry and edible pod beans in New York State were investigated in greenhouse and field experiments. Dose responses to bentazon and fomesafen were studied for four weed species (ragweed, velvetleaf, eastern black nightshade, and hairy nightshade) under greenhouse conditions. Herbicides were applied at cotyledon to two-, two- to four-, and four- to six–true leaf stages, both with and without a crop oil concentrate (bentazon) or a nonionic surfactant (fomesafen). Field studies were conducted for 2 yr for all weed species except eastern black nightshade, for which no adequate field populations were found. Field studies confirmed greenhouse results, indicating that weed control could be improved by the use of an adjuvant, but there were exceptions. In general, adjuvant usage improved the efficacy of fomesafen more than it did with bentazon. The minimum rates of herbicide required for effective and consistent control was dependent on the particular combination of weed species, herbicide and its rate of application, growth stage at which the application was made, and adjuvant usage.

scholarly journals A Draft Genome Sequence of Pseudomonas syringae pv. tomato T1 Reveals a Type III Effector Repertoire Significantly Divergent from That of Pseudomonas syringae pv. tomato DC3000

2009 ◽  
Vol 22 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Nalvo F. Almeida ◽  
Shuangchun Yan ◽  
Magdalen Lindeberg ◽  
David J. Studholme ◽  
David J. Schneider ◽  
...  
Keyword(s):  
Host Range ◽  
Host Specificity ◽  
Pseudomonas Syringae ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Tomato Dc3000 ◽  
Type Iii ◽  
Host Range Determination ◽  
Range Determination

Diverse gene products including phytotoxins, pathogen-associated molecular patterns, and type III secreted effectors influence interactions between Pseudomonas syringae strains and plants, with additional yet uncharacterized factors likely contributing as well. Of particular interest are those interactions governing pathogen-host specificity. Comparative genomics of closely related pathogens with different host specificity represents an excellent approach for identification of genes contributing to host-range determination. A draft genome sequence of Pseudomonas syringae pv. tomato T1, which is pathogenic on tomato but nonpathogenic on Arabidopsis thaliana, was obtained for this purpose and compared with the genome of the closely related A. thaliana and tomato model pathogen P. syringae pv. tomato DC3000. Although the overall genetic content of each of the two genomes appears to be highly similar, the repertoire of effectors was found to diverge significantly. Several P. syringae pv. tomato T1 effectors absent from strain DC3000 were confirmed to be translocated into plants, with the well-studied effector AvrRpt2 representing a likely candidate for host-range determination. However, the presence of avrRpt2 was not found sufficient to explain A. thaliana resistance to P. syringae pv. tomato T1, suggesting that other effectors and possibly type III secretion system–independent factors also play a role in this interaction.

Row Spacing and Seeding Rate Effects on Eastern Black Nightshade (Solanum Ptycanthum) and Soybean

2007 ◽  
Vol 21 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Adrienne M. Rich ◽  
Karen A. Renner
Keyword(s):  
Dry Weight ◽  
Field Studies ◽  
Production Costs ◽  
Row Spacing ◽  
Seeding Rate ◽  
Soybean Yield ◽  
Eastern Black Nightshade ◽  
Solanum Ptycanthum ◽  
Black Nightshade ◽  
Rate Effects

Reducing seeding rates in 19- or 76-cm row soybean below the optimum rate may reduce soybean competitiveness with weeds, and indirectly increase production costs to the grower. Field studies in 2001 and 2002 evaluated the effect of soybean seeding rate and row spacing on the emergence, growth, and competitiveness of eastern black nightshade (EBN) in soybean. EBN emergence ceased within 45 d after planting (DAP), and was similar across soybean seeding rates and row spacing. EBN control by glyphosate was not affected by soybean population or row spacing. Soybean planted in 19-cm rows was more competitive with EBN, regardless of seeding rate. Increasing the soybean seeding rate in 76-cm rows from 185,000 seeds/ha to 432,000 seeds/ha reduced EBN dry weight threefold at East Lansing and nearly twofold at Clarksville in 2002. There was no increase in EBN density or dry weight in 19-cm row soybean planted at 308,000 seeds/ha compared with 556,000 seeds/ha, whereas a seeding rate of 432,000 seeds/ha in 76-cm row soybean did not suppress EBN dry weight or increase soybean yield in the presence of EBN compared with a seeding rate of 308,000 seeds/ha.

Characterization of Acifluorfen Tolerance in Selected Somaclones of Eastern Black Nightshade (Solanum ptycanthum)

Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 408-412 ◽  
Author(s):  
Chang-Yeon Yu ◽  
John B. Masiunas
Keyword(s):  
Eastern Black Nightshade ◽  
Solanum Ptycanthum ◽  
Black Nightshade

Acifluorfen tolerance in eastern black nightshade somaclones was characterized in two experiments. One experiment determined the involvement of absorption, translocation, and metabolism in acifluorfen tolerance. Less than 6% of the applied14C-acifluorfen was absorbed. There were no differences in acifluorfen absorption between susceptible and tolerant somaclones. More14C-acifluorfen was translocated in the susceptible than the tolerant somaclones. The susceptible somaclone did not metabolize acifluorfen while some somaclones (i.e., EBN-3A) metabolized14C-acifluorfen. A second experiment determined the tolerance of the somaclones to oxyfluorfen, diquat, and paraquat Most acifluorfen-tolerant somaclones were tolerant to oxyfluorfen but were susceptible to diquat and paraquat One somaclone, EBN-3A, was extremely tolerant to acifluorfen, paraquat, and diquat.

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.

Sign in / Sign up

Export Citation Format

Share Document