Behavior and Fate of Metribuzin in Soybean and Hemp Sesbania

Weed Science ◽  
1974 ◽  
Vol 22 (3) ◽  
pp. 238-245 ◽  
Author(s):  
T. G. Hargroder ◽  
R. L. Rogers

The absorption, translocation, and metabolism of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H) one] by soybean (Glycine maxMerr. ‘Lee 68′) and hemp sesbania (Sesbania exaltataL.) grown in nutrient solution and in soil treated with14C-metribuzin were investigated. Absorption studies indicated there were no significant differences in the amount of14C-metribuzin absorbed from treated nutrient solution by soybean (tolerant) and hemp sesbania (susceptible). When these species were grown in14C-metribuzin treated soil, hemp sesbania absorbed appreciably more herbicide than did soybean.14C-metribuzin and (or) its14C-metabolites were translocated from the roots to the shoots of both species. Radioactivity was rapidly translocated and accumulated in all the leaves of hemp sesbania, but it tended to accumulate to the greatest extent in the roots and lower leaves of soybean. Translocation differences between the two species were apparent in plants grown either in soil or nutrient solution treated with14C-metribuzin. However, differences were greatest in plants grown in treated soil. Preliminary metabolic studies indicated that a higher rate of metribuzin degradation occurred in soybean than in hemp sesbania. The major14C-metabolite appeared to be the relatively nonphytotoxic deaminated diketo derivative [6-tert-butyl-1,2,4,-triazine-3-5(2H,4H)dione]. Thus, differences in the absorption, translocation, and metabolism of metribuzin all appeared to contribute to the differential susceptibility of soybean and hemp sesbania to metribuzin.

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 58-64 ◽  
Author(s):  
C. G. McWhorter ◽  
J. M. Anderson

The competitive effects of hemp sesbania [Sesbania exaltata(Raf.) Cory] on soybeans [Glycine max(L.) Merr. ‘Forrest’] were studied on Sharkey clay for 2 yr. In full-season competition, hemp sesbania populations of 1,600, 3,200, 3,900, and 5,500 plants/ha did not reduce adjusted soybean yields, but populations of 8,100 to 129,200 plants/ha reduced yields 10 to 80%. Competition by hemp sesbania at 68,000 plants/ha for 1 to 4 weeks after soybean emergence reduced soybean yields 8% or less, whereas competition by the same population for 6, 8, and 10 weeks after soybean emergence reduced adjusted yields 18, 27, and 43%, respectively. Hemp sesbania populations of 3,200 plants/ha or more reduced the grade of harvested soybeans and populations of 5,500 plants/ha increased the level of foreign material found in seed samples taken at harvest. Hemp sesbania populations above 10,700 plants/ha increased the levels of damaged kernels and moisture in harvested soybean seed. Early-season control was required for highest soybean yields and total returns. The most critical period for control was 4 to 10 weeks after emergence of soybeans.


Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 42-47 ◽  
Author(s):  
C. G. McWhorter ◽  
W. L. Barrentine

Mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]-amino] phenyl] acetamide} was applied postemergence in soybean [Glycine max (L.) Merr.] fields and its effectiveness in controlling johnsongrass [Sorghum halepense (L.) Pers.], hemp sesbania [Sesbania exaltata (Raf.) Cory], and common cocklebur (Xanthium pensylvanicum Wallr.) was evaluated. In plots treated preplanting with trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), mefluidide gave 95% johnsongrass control when it was applied postemergence (over-the-top without surfactant) once at 0.90 kg/ha or twice at 0.44 kg/ha. Directed sprays of mefluidide at 0.22 to 0.67 kg/ha without surfactant were more effective on johnsongrass than similar treatments applied over-the-top. When 0.5% (v/v) nonoxynol [α-(p-nonyl-phenyl)-ω-hydroxypoly (oxyethylene)] surfactant was added, mefluidide at 0.44 or 0.67 kg/ha applied as directed or over-the-top sprays provided 76 to 90% johnsongrass control. Mefluidide at 1.12 kg/ha plus nonoxynol surfactant, applied as a directed spray, was required to provide 81% control of hemp sesbania. Directed sprays containing mixtures of mefluidide at 0.28 kg/ha plus dinoseb (2-sec-butyl-4,6-dinitrophenol) at 2.2 kg/ha, or mefluidide at 0.28 kg/ha plus a 2:1 mixture of naptalam (N-1-naphthylphthalamic acid)/dinoseb at 4.7 L/ha, effectively controlled 40- to 60-cm-tall hemp sesbania. A single, directed spray of mefluidide at 0.56 kg/ha plus nonoxynol provided 92% common cocklebur control, and mixtures of mefluidide at 0.28 kg/ha plus dinoseb at 2.2 kg/ha or naptalam/dinoseb (a 2:1 mixture) at 4.7 L/ha increased control above that provided by either of the herbicides alone.


1992 ◽  
Vol 6 (2) ◽  
pp. 374-377 ◽  
Author(s):  
P. Roy Vidrine ◽  
Daniel B. Reynolds ◽  
James L. Griffin

Field studies were conducted at three locations in Louisiana over two years to evaluate mid-season, foliar-applied acifluorfen, fomesafen, and lactofen for hemp sesbania control in soybean. Acifluorfen and fomesafen were applied POST at 30, 40, 50, 60, 70, 140, and 280 g ai ha–1and lactofen was applied at 60, 80, 110, and 220 g ai ha–1. The data fit a quadratic model and log transformations were made to determine differences between treatments. Hemp sesbania control was highly correlated with herbicide rate for each herbicide. Averaged over rates of application, acifluorfen and fomesafen provided equivalent control of hemp sesbania, which was greater than that achieved with lactofen. The minimum effective rate of acifluorfen or fomesafen for 80 and 100% control of 50- to 60-cm hemp sesbania was 50 and 140 g ha–1, respectively. The minimum effective lactofen rate to provide at least 80% control was 220 g har–1.


Weed Science ◽  
1977 ◽  
Vol 25 (2) ◽  
pp. 135-141 ◽  
Author(s):  
C.G. McWhorter

Field experiments were conducted to study the feasibility of applying glyphosate [N-(phosphonomethyl)glycine] postemergence for the control of johnsongrass [Sorghum halepense(L.) Pers.], redroot pigweed (Amaranthus retroflexusL.), and hemp sesbania [Sesbania exaltata(Raf.) Cory] in soybeans [Glycine max(L.) Merr.]. Herbicide sprays were directed across the row to weeds growing taller than soybeans in June, July, and August. Herbicide not sprayed on weeds was trapped and reused. Glyphosate at 1.12 and 1.68 kg/ha effectively controlled johnsongrass with little soybean injury and with greatly increased soybean yields. The use of 0.1% surfactant frequently increased the toxicity of glyphosate at 1.12 and 1.68 kg/ha to soybeans, but this adverse effect was overcome by the use of 0.1% anti-drift polymer in sprays. Control of redroot pigweed with glyphosate at 1.12 kg/ha was improved by the use of 0.1% surfactant, but surfactant did not increase control with glyphosate at 1.68 kg/ha. Glyphosate at 1.68 kg/ha, with 0.1% surfactant, was required to provide more than 80% control of hemp sesbania. Glyphosate applied at 1.12 kg/ha in the recirculating sprayer provided equal johnsongrass control, increased soybean yields and caused less soybean injury than when glyphosate at 0.56 kg/ha was applied over-the-top in water or in foam.


1987 ◽  
Vol 1 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Khosro Khodayari ◽  
Roy J. Smith ◽  
Joel T. Walker ◽  
David O. Tebeest

A low-volume (21.5 L/ha) spinning disc (controlled droplet applicator) and a high-volume (187 L/ha) boom-nozzle applicator were compared in applying tank mixtures of the weed pathogenColletotrichum gloeosporioides(Penz.) Sacc. f. sp.]aeschynomene(henceforth designated C.G.A.) and acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} for control of northern jointvetch [Aeschynomene virginica(L.) B.S.P. # AESVI] and hemp sesbania [Sesbania exaltata(Raf.) Rydb. ex A.W. Hill # SEBEX] in soybean [Glycine max(L.) Merr. ‘Tracy M’]. Application with a spinning disc did not increase control of either weed species over the boom-nozzle applicator. C.G.A. controlled northern jointvetch in 2 of 3 yr. Northern jointvetch control with the spinning-disc was poorer at lower rates in years of unfavorable environment. Acifluorfen at 0.56 kg ai/ha and applied with either applicator controlled hemp sesbania satisfactorily.


Weed Science ◽  
1979 ◽  
Vol 27 (3) ◽  
pp. 290-293 ◽  
Author(s):  
S. K. Johnston ◽  
R. H. Walker ◽  
D. S. Murray

Hemp sesbania [Sesbania exaltata(Raf.) Cory] was more tolerant to induced moisture stress than soybean [Glycine max(L.) Merr.] with osmotic potentials of −4 and −2 bars, respectively, required to reduce germination. Hemp sesbania germinated at temperatures of 15 to 40 C with optimum germination occurring at 30 to 40 40 C. Seed dormancy was caused by impermeable seed coats. Acid scarification of 45 and 60 min and mechanical scarification 20 and 30 s gave maximum germination. Scarification increased water absorption. Light had no effect on germination. As oxygen content increased from 0 to 21%, germination of unscarified seed increased from 5 to 39%, but germination did not increase as oxygen increased from 21 to 100%. Hemp sesbania and soybean emerged from depths up to 12 cm with maximum emergence occurring at the 1- and 3-cm depths. Hemp sesbania emerged faster and in greater numbers at all depths than soybean.


Weed Science ◽  
1985 ◽  
Vol 33 (5) ◽  
pp. 717-720 ◽  
Author(s):  
Phil J. Petersen ◽  
Lloyd C. Haderlie ◽  
Raymond H. Hoefer ◽  
Ray S. McAllister

Absorption and translocation of14C-dicamba (3,6-dichloro-o-anisic acid) in seven salt formulations were determined 60 h after application to leaves of soybean [Glycine max(L.) Merr. ‘Williams’] grown in nutrient solution. The dimethylamine (DMA) formulation was consistently absorbed and retained in the plant in amounts equal to or greater (46% of recovered14C) than other formulations (which averaged 19% of recovered14C) when applied without surfactant. Absorption and subsequent retention of the DMA formulation in the plant was least affected of all formulations by the addition of a surfactant. With a surfactant, absorption of the DMA, monoethanolamine (MEA), and inorganic salt formulations was similar (>75% of recovered14C). Addition of seven surfactants to the K-salt of dicamba increased both the amount of14C absorbed by 35 to 56% and the amount recovered in the plant. All surfactants except one enhanced absorption of the K-salt of dicamba to a similar degree. Dicamba exhibited predominantly symplastic translocation with the majority of14C being recovered in the new second trifoliolate leaves and nutrient solution. As much as 66% of the radioactivity absorbed through the leaves was exuded by roots into the nutrient solution 60 h after leaf treatment.


Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 91-97 ◽  
Author(s):  
C. Andy King ◽  
Larry C. Purcell

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.


1993 ◽  
Vol 7 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Chester G. McWhorter ◽  
James M. Anderson

The effect of delayed harvest was investigated with two soybean cultivars that were grown weed free or in competition with johnsongrass or hemp sesbania over a 3-yr period. Johnsongrass reduced the yield of early-maturing ‘Hill’ soybean 32, 35, and 36% when harvested at an average of 1, 2, or 3 wk after maturity, when compared to weed-free yields of 2490, 2430, and 2270 kg ha−1, respectively. Late-maturing ‘Lee 68’ yields were reduced 27, 29, and 39% on three harvest dates compared to weed-free yields of 2570, 2310, and 2200 kg ha−1, respectively. Seed grades of both cultivars improved with delayed harvest, but this was offset when johnsongrass was present. Hemp sesbania reduced yields of Hill 23% on the first harvest date and 26% on the second and third dates. Yields of Lee 68 were reduced 16, 22, and 28% by hemp sesbania on three successive harvest dates. The value of soybean yields adjusted for excessive foreign material, moisture, and damaged kernels was decreased by delayed harvest when hemp sesbania was present in Lee 68 and when johnsongrass was present in both cultivars.


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