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Evaluation Of Imazaquin, Imazethapyr & Postemergence Herbicide Combinations For Control Of Johnsongrass (Sorghum Halepense) In Soybeans (Glycine Max), Terry Mashburn

Masters Theses & Specialist Projects

Johnsongrass (Sorghum halepense) competition in soybeans (Glycine max) has adverse effects on soybean yields. Profitable soybean production in Kentucky and the Southeastern United States has depended upon good, cost effective johnsongrass control. Several herbicides have been developed to control johnsongrass in soybeans. Four of these recently developed compounds were imazaquin (2-[4,5-dihydro-4-methy1-4- (1-methyl-ethyl)-5-oxo-1H-imidazo1-2-y1]-3-quino1inecarboxy1ic acid), imazethapyr (+/-)-2-C4,5-dihydro-4-methy1-4-(1-methy. lethyl)-5-oxo-IH-imidazol-2-y1)-5-ethy1-3-pyridinecarboxylic acid, quizalofop 2-[4-[(6-chloro-2-quinoxalinyl) oxylphenoxyjpropaonic acid,ethyl ester, and analog of quizalofop (DPX Y6202-31).

Field experiments were conducted in 1986 to evaluate (a) the effectiveness of imazaquin and imazethapyr preplant incorporated, postemergence, or in combination with pendimethalin [N-(1-ethylpropy1)-3,4-dimethy1-2.6-dinitrobenzenamine], and (b) herbicide antagonism with fluazifop[butyl(R)-2-(4-[(5- trifluoromethy 1 …

Evaluation Of Fomesafen For Broadleaf Weed Control, In Soybeans (Glycine Max), Ricardo A. Jimenez

Masters Theses & Specialist Projects

The lack of effective broadleaf weed control represents one of the major factors having detrimental effects on growth and yield of soybeans. Broadleaf weeds are a serious threat to soybean growers in the southeastern United States. A broad range of herbicides is being used in an effort to control broadleaf weeds in soybeans, and research is still being conducted to find new herbicides that can best work for this purpose. This study involved the use of one these herbicides. It was fomesafen, 5-[2-chloro-4-trifluromethyl) phenoxy]-N-(methyl-sulfonyl)-2-nitrobenzamide, which controls a broad spectrum of broadleaf weeds in soybeans.

The experiment was conducted in the …

Herbicide Effects On Cultivars Of Soybeans [Glycine Max (L.) Merr.], Mark Martin

Masters Theses & Specialist Projects

Breeding herbicide-tolerant cultivars is a means of extending herbicide utilization. In 1983 and 1984, 20 soybean [Glycine max (L. Merr] cultivars were screened for their reactions to the following herbicides: metribuzin 4-amino-6-(tert)-butyl-3-(methylthio)-astriazin-5-(4H)-one]; vernolate (S-propyl dipropylthiocarbamate); and fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl) aniline]. Each herbicide was applied at the recommended rate X, 2X, and 4X in 1983. An 8X rate was added in 1984. The recommended rates (X) for the herbicides were as follows: metribuzin 0.42, vernolate 2.80, and fluchloralin 1.12 kg/ha. The cultivars were Pella, Pixie, Cumberland, Williams, Essex, Union, Semmes, Tracy, Tracy M; North American Plant Breeders 350, 68225, 420, and …

Ultrastructural Effects Of Sethoxydim On The Intercalary Meristem Of Johnsongrass (Sorghum Halpense), Bobbie Dowden

Masters Theses & Specialist Projects

This investigation represents one of the first electron microscopic studies on determining the mode of action of the chemical herbicide sethoxydim, 2-[-1-(ethoxydimino)butyl] -5-.2-(ethiothio)propyl]-3- hydroxy-2-cyclohexen-1-one. Samples were excised from the intercalary meristem of johnsongrass (Sorghum halpense) at time intervals of 1,3, 6,12,24,36,48,60, and 72 hours and examined using electron microscopy. Transmission electron micrographs revealed that cellular activity shows alterations or abnormalities as early as six hours. Membranes show deterioration at this time and chloroplasts contain densely staining starch granules. As time intervals increase, cellular degradation becomes more evident. Nuclear membranes extend outward into the cytoplasm in various types of …

Evaluation Of Sethoxydim & Mbr 22359 For Control Of Rhizome Johnsongrass (Sorghum Halepense) In Soybeans (Glycine Max), E. Craig Musselman

Masters Theses & Specialist Projects

Johnsongrass (Sorghum halepense) is one of the most troublesome weeds in the southeastern United States. -everal herbicides have been developed to combat johnsongrass, and many new experimental herbicides with high johnsongrass control potential are presently being tested. Two of these new experimental herbicides for johnsongrass control in soybeans (Glycine max) are sethoxydim and MBR 22359.

Field experiments were conducted in 1981 and 1982 to evaluate the effectiveness of MBR 22359 preemergence and postemergence, sethoxydim in single and split applications, trifluralin in combination with mefluidide, or with glyphosate or sethoxydim in the wick, and alachior in combination …

Evaluation Of S-734 And Bas 9052 For Control Of Johnsongrass (Sorghum Halepense) In Soybeans (Glycine Max), Julio Beingolea Ochoa

Masters Theses & Specialist Projects

Johnsongrass is one of the more limiting factors in soybean production and is the most serious weed problem in the Southeastern United States. Actually, different herbicides are used in johnsongrass control, and still there are new herbicides which are being tested. Two experimental herbicides for johnsongrass control in soybeans are BAS 9052 and S-734.

The experiments were conducted in 1980 and 1981 with the objective to evaluate the effectiveness of S-734 alone and in combination with mefluidide and BAS 9052, BAS 9052 applied early or late postemergence, trifluralin, alachlor, and fluchloralin for seedling and rhizome johnsongrass control.

In both areas …

Evaluation Of Seedbed Preparation & Alachlor Combinations For Weed Control In Soybeans, Ralph Young

Masters Theses & Specialist Projects

Alachlor [2'-chloro-2',6'-diethyl-N-(methoxymethyl) acetanilide] in combination with linuron [3-(3,4-dichlorphenyl)-1 methoxy-1-methylurea (n'-(3,4-dichlorophenyl)-N-methoxy-Nmehtylures)] and metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one 4-amino-6-(1,1-dimethy-ethyl)-3-(methylthio)-1,2,3-triazin-5(4 H)-one] was evaluated for its control of broadleaf and annual grasses in Mitchell soybeans (Glycine max L.) under four different tillage conditions.

The experiment was conducted in the summers of 1978 and 1979. The tillage treatments evaluated were conventional tillage, double disking, single disking, and no-tillage. Alachlor at 2.2, 2.8, and 3.4 kg/ha was used alone and in combination with metribuzin at 0.4, 0.6, and 0.8 kg/ha and linuron at 0.6, 0.8, and 1.2 kg/ha. All treatments were compared with a check which received no …

Evaluation Of Bas 9052 & Bas 9021 For Control Of Johnsongrass (Sorghum Halpense) In Soybeans (Glycine Max), Sheryl Rogers

Masters Theses & Specialist Projects

The lack of adequate weed control is one of the major problems encountered in soybean production. Johnsongrass presents one of the most serious weed control problems in the Southeastern United States. numerous herbicides are used in an effort to control johnsongrass, and research is still being conducted to find new herbicides for this purpose. Two of these herbicides are BAS 9021 [6,6-dimethyl-2,4-dioxo- 3[1-[2-(propenyloxy)amino]butylidene]-cyclohexane] and BAS 9052 [2-(n-ethoxybutyrimidoyl)-5-(2-ethylthiopropy1)-3- hydroxy-2-cyclohexen-1-one].

In 1978, johnsongrass control with BAS 9021 at 1.1 and 1.7 kg/ha in sim-le early postemergence or late postemergence applications, or in each of two split applications, was evaluated using the herbicide …

Evaluation Of Herbicides For Suppression Of Rhizome Growth From Johnsongrass (Sorghum Halepense L.) In Corn And Soybeans, John Oakes

Masters Theses & Specialist Projects

Johnsongrass (Sorghum halepense L.) presents a serious problem in the production of corn and soybeans in Kentucky.

Various rates of the thiocarbamates, dinitroanilines, carbamates, amides, ureas, and triazines were used in association with the crops corn (Zea mays L.) and soybeans (Glycine max L.) to determine the degree of suppression on rhizomatous johnsongrass infesting the previously named crops.

Suppression was determined by selecting areas within each treated plot, counting the number of culms, then harvesting johnsongrass rhizomes. Dry weights of rhizomes were then determined as a measure of rhizome suppression.

Results show that of …

Effects Of Time Of Application Of Glyphosate In The Control Of Johnsongrass, Marlin Moody

Masters Theses & Specialist Projects

Investigations were conducted to determine the effects of the herbicide glyphosate and its time of application on the control of johnsongrass.

Johnsongrass plots were divided into areas designated undisturbed, spring plowed, and clipped. These areas were compared to determine differences in control of johnsongrass when using glyphosate with different management procedures. Glyphosate was applied at weekly intervals and treatment effects were statistically analyzed. There were three replications of each treatment.

It appears from the results that:

1. Glyphosate kills approximately 100% of the johnsongrass topgrowth regardless of the application date.

2. Height of the johnsongrass plant at the time of glyphosate application …

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Evaluation Of Glyphosate In No-Till Double Crop Soybeans Using Varying Volumes & Pressures, Charles Rogers

Masters Theses & Specialist Projects

No-tillage production of crops has developed and become widespread since the late 1950/s. No-till is dependent upon the use of broad spectrum herbicides to kill weeds already growing at planting time. Until recently, this has almost exclusively been paraquat (1,1'-dimethy1-4,4'-bipyridinium ion). Glyphosate [N-(phosphonomethyl)glycine] is a new herbicide which has great potential for use in no -tillage production.

Soybeans (Glycine max L.) were planted in the stubble after wheat (Triticum aestivum L.) was harvested. All plots received applications of the residual herbicides alachlor [2-chioro-2',6'-diethyl-N-(methoxymethyl)acetanilide] and linuron [3-(3,4-dichlorophenv1)-1-methoxy-1-methylurea]. Each plot also received either paraquat or glyphosate or was designated as …

Distribution & Life Cycle Of Nodding Thistle (Carduus Nutans L.) In Kentucky, Garry Lacefield

Masters Theses & Specialist Projects

Carduus nutans L., commonly called nodding thistle or musk thistle, has been in the United States for over 50 years; however, it was not until the early 1940's that it was identified in Kentucky. It was first identified in Kentucky in Warren County, and by 1970 had spread to 88 of the 120 counties in Kentucky. The thistle is present in all regions of the state, but most of the counties not having the thistle are located in the mountainous region of Eastern Kentucky.

The thistle plant has a fleshy tap-root which is characteristically hollow near the soil surface. Flowering …