Response of Eastern Black Nightshade (Solanum ptycanthum) to Low Rates of Imazethapyr and Metolachlor

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 897-902 ◽  
Author(s):  
Katherine I. Ward ◽  
Susan E. Weaver

Eastern black nightshade is a problem weed in soybeans primarily due to interference with harvesting operations and reductions in crop quality. Field and greenhouse studies were conducted in 1990 and 1991 at Harrow, Ontario, to determine whether sublethal rates of imazethapyr and metolachlor could suppress growth and berry production by eastern black nightshade. In the greenhouse, plants treated with metolachlor PRE at 0.8 kg ai ha−1or imazethapyr POST at 30 g ai ha−1(1/3 to 1/2 the labelled rates) produced significantly fewer berries in the first flower cluster, with fewer seeds per berry, than untreated plants. When a surfactant was added to the imazethapyr, almost all flower buds in the first cluster were aborted. Treated plants recovered from the damage, however, and did not differ significantly from control plants in dry weight or berry production 110 DAP. In the field, application of 50 g ai ha−1imazethapyr POST (2/3 of the lowest labelled rate), with or without a surfactant, resulted in delayed flowering, abortion of most of the flower buds in the first cluster, and greatly reduced growth and total berry production between soybean leaf abscision and harvest. Application of metolachlor + metribuzin PPI in the field at 2/3 of the labelled rate (1.6 + 0.25 kg ai ha−1) was not sufficient to reduce nightshade growth and berry production after soybean leaf abscision. Sublethal rates of imazethapyr and metolachlor did not reduce seed viability in either the greenhouse or the field.

2007 ◽  
Vol 21 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Adrienne M. Rich ◽  
Karen A. Renner

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.


Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 162-167 ◽  
Author(s):  
Larry H. Hageman ◽  
Richard Behrens

The basis for differences in response of eastern black nightshade (Solanum ptycanthumDun.), a tolerant species, and velvetleaf (Abutilon theophrastiMedic. ♯3ABUTH), a susceptible species, to foliar-applied chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide} was investigated by evaluating differences in spray retention and herbicide absorption, translocation, and metabolism. Based upon a foliar-applied rate causing a 50% reduction in dry weight, velvetleaf was greater than 20000 times more susceptible to chlorsulfuron than was eastern black nightshade. The differences detected in spray retention, absorption, and translocation were inadequate to account for the large response differences between the two species. The primary difference found was in the rate of chlorsulfuron degradation. In eastern black nightshade, 69.9% of the absorbed chlorsulfuron was metabolized within 24 h of application and 81.1% within 72 h of application. Only 7.1% of absorbed chlorsulfuron was metabolized in velvetleaf in a 72-h period.


1991 ◽  
Vol 71 (1) ◽  
pp. 167-174 ◽  
Author(s):  
L. A. Hermanutz ◽  
S. E. Weaver

The distribution and abundance of hairy nightshade (Solanum sarrachoides Sendt.) has been increasing relative to that of eastern black nightshade (Solanum ptycanthum Dun.) in cultivated fields in southern Ontario. The germination and early growth of the two species were compared under controlled environmental conditions. Individual seeds of hairy nightshade weigh almost twice as much as those of eastern black nightshade. Time to 50% germination of seeds of hairy nightshade was faster over a range of temperatures, and total germination in the dark and at low temperature was greater compared to seeds of eastern black nightshade. Seedlings of hairy nightshade also grew faster than those of eastern black nightshade, having greater height, leaf number, and aboveground dry weight at 10 and 21 d after emergence in growth chambers at 28/20 and 22/14 °C. Individuals of hairy nightshade began to reproduce earlier with a consequent decrease in vegetative growth. By 35 d after emergence, leaf area and aboveground dry weight of seedlings of eastern black nightshade equalled or exceeded those of hairy nightshade. Differences between species were consistent for populations from two separate locations in Ontario. Key words: Germination, eastern black nightshade, hairy nightshade


Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Susan E. Weaver ◽  
Nancy Smits ◽  
Chin S. Tan

Reductions in yields of processing tomatoes (Lycopersicon esculentumMill. ‘H2653’ and ‘Earlirouge′) caused by interference from eastern black nightshade (Solanum ptycanthumDun. # SOLPT) and hairy nighthsade (S. sarrachoidesSendt. # SOLSA) were estimated for transplanted and seeded tomatoes at two locations in southern Ontario. Tomato yield losses were significantly greater in seeded than in transplanted tomatoes. Stomatal conductance and transpiration rates of seeded tomatoes decreased more rapidly with increased nightshade density than did those of transplanted tomatoes. Percent yield losses also differed between sites. Seeded tomatoes grown at high density in twin rows (33 300 and 45 000 plants/ha) had higher yields and lower percent yield losses than did tomatoes grown at low density in single rows (12 500 to 22 500 plants/ha). Nightshade dry weight and seed production decreased per plant but increased per unit area with increasing nightshade density. Nightshade dry weights and seed production did not vary with site or method of tomato establishment. A hyperbolic model provided an excellent fit to data on both tomato yield losses and nightshade seed production as a function of nightshade density.


Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 408-412 ◽  
Author(s):  
Chang-Yeon Yu ◽  
John B. Masiunas

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.


1998 ◽  
Vol 12 (2) ◽  
pp. 293-299 ◽  
Author(s):  
Kelly A. Nelson ◽  
Karen A. Renner

Field and greenhouse experiments were conducted to evaluate postemergence (POST) soybean injury and weed control with CGA-277476 and cloransulam-methyl alone and in tank mixtures. In the field, visible soybean injury was 12 to 14% from CGA-277476 and 9 to 13% from cloransulam-methyl 7 d after treatment. Tank mixtures of either herbicide with acifluorfen or acifluorfen plus thifensulfuron were more injurious than CGA-277476 or cloransulam-methyl applied alone. Both CGA-277476 and cloransulam-methyl reduced velvetleaf dry weight 82%, and cloransulam-methyl reduced common ragweed dry weight 92%. Neither herbicide adequately controlled common lambsquarters, redroot pigweed, nor eastern black nightshade. The addition of acifluorfen to the spray solution improved common ragweed, common lambsquarters, redroot pigweed, and eastern black nightshade control with CGA-277476 and improved common lambsquarters, redroot pigweed, and eastern black nightshade control with cloransulam-methyl. Tank mixing thifensulfuron with CGA-277476 or cloransulam-methyl increased common lambsquarters and redroot pigweed control. In the greenhouse, CGA-277476 at 20 g ai/ha reduced velvetleaf dry weight 98%, and 79 g/ha was required to reduce common ragweed dry weight 93%. Cloransulam-methyl at 4.4 g ai/ha reduced velvetleaf dry weight 98% and common ragweed dry weight 94% at 8.8 g/ha. Chlorimuron reduced yellow nutsedge dry weight more than CGA-277476 or cloransulam-methyl. Antagonism of POST graminicide activity by CGA-277476 was grass species and graminicide related. CGA-277476 reduced giant foxtail control by clethodim but not by quizalofop. Cloransulam-methyl tank mixed with clethodim or quizalofop controlled giant foxtail.


Weed Science ◽  
2003 ◽  
Vol 51 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Leslie D. Milliman ◽  
Dean E. Riechers ◽  
Loyd M. Wax ◽  
F. William Simmons

Weed Science ◽  
2006 ◽  
Vol 54 (3) ◽  
pp. 490-495 ◽  
Author(s):  
Juliana K. Buckelew ◽  
David W. Monks ◽  
Katherine M. Jennings ◽  
Greg D. Hoyt ◽  
Robert F. Walls

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 577d-577
Author(s):  
Vamsgita Kolasani ◽  
John Masiunas

Eastern black nightshade is one of the problematic weeds in vegetables and soybeans in the Midwest. It is representative of a rapidly growing complex of broadleaf weeds where herbicide resistance would be expected to occur. Eastern black nightshade calli lines that are resistant and susceptible to acifluorfen were maintained on the medium without the herbicide. After two years, these lines were tested for tolerance to acifluorfen and paraquat. Tolerance to acifluorfen was maintained in the previously selected lines. The lines were also cross tolerant to paraquat. Plants were regenerated from these calli lines and grown in the greenhouse. 14C-acifluorfen and 14C-paraquat uptake, translocation, and metabolism were studied.


HortScience ◽  
1998 ◽  
Vol 33 (1) ◽  
pp. 88-91 ◽  
Author(s):  
Michael P. Croster ◽  
John B. Masiunas

Studies established the critical period for eastern black nightshade (nightshade) (Solanum ptycanthum Dun.) competition in pea (Pisum sativum L.) and determined the effect of N fertility on pea and nightshade growth. In 1992, pea yields were most affected when nightshade was established at planting and remained for 4 or 6 weeks, while in 1993, competition for 6 weeks caused the greatest reduction in pea yields. In a sand culture study, pea biomass and N content were not affected by three N levels (2.1, 21, and 210 mg·L-1). Nightshade plants were five to six times larger in the highest N treatment than at lower N levels. Nitrogen content of nightshade was 0.76% at 2.1 ppm N and 3.22% at 210 ppm N. Choosing soils with low N levels or reducing the N rates used in pea may decrease nightshade interference and berry contamination of pea.


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