Effects of Vernalization on Flowering in Ripgut Brome (Bromus diandrus)

Ripgut brome has a quantitative response to vernalization in relation to flowering. In greenhouse studies, cold treatment (5 ± 2 C) of 2, 4, or 6 wk shortened the vegetative period, but longer exposure did not further decrease the time required to flower. Plants vernalized as imbibed seeds for 8 wk took 17 d to flower following transfer from cold treatment to the greenhouse. Unvernalized controls flowered 53 d after planting in the greenhouse. Greatest total seed dry weight and vegetative shoot dry weight were produced by unvernalized plants, whereas lengthening periods of vernalization from 2 to 8 wk decreased both parameters. The percent of total seed dry weight to total shoot dry weight was significantly greater for vernalized plants than unvernalized controls. In field studies, ripgut brome plants established in the fall flowered sooner after resumption of growth in the spring than those planted in the spring. Plants seeded after April failed to flower until the following spring.

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Vernalization Requirements for Flowering of Jointed Goatgrass (Aegilops cylindrica)

Weed Science ◽

10.1017/s0043174500059701 ◽

1984 ◽

Vol 32 (5) ◽

pp. 631-637 ◽

Cited By ~ 18

Author(s):

William W. Donald

Keyword(s):

Dry Matter ◽

Cold Treatment ◽

Dry Weight ◽

Field Studies ◽

Vegetative Shoot ◽

Aegilops Cylindrica ◽

Shoot Dry Weight ◽

Jointed Goatgrass ◽

Matter Production ◽

Growing Conditions

Jointed goatgrass (Aegilops cylindrica Host. ♯3 AEGCY) has a quantitative requirement for vernalization in order to flower. In greenhouse and field studies, increasing periods of vernalization progressively reduced the number of days needed for plants to mature following transfer from the cold treatment to favorable growing conditions. Plants that had been vernalized at 3 ± 2 C for 8 weeks as imbibed seed took 120 days to flower following transfer to the greenhouse. Unvernalized controls flowered 197 to 222 days after planting in the greenhouse. Lengthening periods of vernalization from 2 to 8 weeks increased the number of seedheads per plant and dry weight per seedhead. Vernalized plants partitioned more dry matter into seedheads than unvernalized controls. The ratio of seedhead dry weight to vegetative shoot dry weight increased with duration of vernalization, even though vernalization did not alter total shoot dry-matter production. In field studies, plants that were established in the fall flowered sooner and more synchronously after resumption of growth in the spring than those that were planted in the spring and flowered in the summer. Plants seeded after May failed to flower in the same summer.

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Spring Wheat (Triticum aestivum)Cultivar Responses to Trifluralin and Postemergence Herbicides

Weed Technology ◽

10.1017/s0890037x00023460 ◽

1995 ◽

Vol 9 (2) ◽

pp. 352-355 ◽

Cited By ~ 1

Author(s):

Sharon A. Clay ◽

Jim F. Gaffney ◽

Leon J. Wrage

Keyword(s):

Spring Wheat ◽

Plant Stress ◽

Dry Weight ◽

Field Studies ◽

Growth And Yield ◽

Hard Red Spring Wheat ◽

Wheat Field ◽

Shoot Dry Weight ◽

Cultivar Responses ◽

Postemergence Herbicides

Trifluralin is used for weed control in wheat but may reduce vegetative growth and yield. Postemergence (POST) herbicides may cause additional plant stress to trifluralin-stressed wheat. Field studies at Groton, SD in 1991 and 1992 and at Highmore, SD in 1992 evaluated the effects of 2,4-D-amine, difenzoquat, metsulfuron, and a combination of fenoxaprop-ethyl + 2,4-D-ester + MCPA-ester on hard red spring wheat cultivars ‘2375,’ ‘Prospect,’ and ‘Butte 86’ seeded in areas treated with preplant incorporated trifluralin either in the spring before seeding (0.56 kg ai/ha) or the previous year (1.12 or 2.24 kg ai/ha). Trifluralin applied alone in the spring, and followed by some POST herbicides, reduced shoot dry weight and grain yield. Trifluralin reduced the yield of Prospect the most and the yield of 2375 the least. Yields of trifluralin-treated wheat were reduced 23% by metsulfuron and 14% by fenoxaprop-ethyl + 2,4-D + MCPA compared to yields of wheat treated with only the respective POST herbicide. Yields were not reduced with any trifluralin-POST herbicide combination when trifluralin was applied a year prior to seeding wheat.

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Effects of Barnyardgrass (Echinochloa crus-galli) on Growth, Yield, and Nutrient Status of Transplanted Tomato (Lycopersicon esculentum)

Weed Science ◽

10.1017/s0043174500075810 ◽

1988 ◽

Vol 36 (6) ◽

pp. 775-778 ◽

Cited By ~ 14

Author(s):

Prasanta C. Bhowmik ◽

Krishna N. Reddy

Keyword(s):

Unit Area ◽

Tomato Fruit ◽

Growth Yield ◽

Dry Weight ◽

Nutrient Status ◽

Field Studies ◽

Fruit Weight ◽

Fresh Weight ◽

Shoot Dry Weight ◽

Marketable Fruit

Field studies were conducted to determine the effects of various barnyardgrass populations on growth, yield, and nutrient concentration of transplanted “Jetstar’ tomato. Barnyardgrass densities at 16, 32, and 64 plants/m tomato row were tested in 1982 and 1983. Barnyardgrass shoot fresh weights/unit area increased as density increased. Fresh weight of barnyardgrass shoots ranged from 17 100 kg/ha at 16 plants/m of row to 35 500 kg/ha at 64 plants/m of row. At the vegetative stage, tomato shoot dry weight was unaffected by barnyardgrass. As crop growth progressed, tomato shoot dry weight decreased at all barnyardgrass densities. Season-long interference of barnyardgrass reduced marketable tomato fruit number and fruit weight at all densities compared to weed-free plots. Reductions in marketable fruit weight ranged from 26% to 16 plants/m row to 84% at 64 plants/m row. In 1982, concentrations of N, P, K, Ca, and Mg in tomato shoots were unaffected by season-long interference of barnyardgrass at all densities. However, in 1983, concentrations of N and K decreased and concentration of P increased in tomato leaves as the density of barnyardgrass increased. Concentrations of Ca and Mg in tomato leaves were unaltered by barnyardgrass density.

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Dog mustard (Erucastrum gallicum) response to crop competition

Weed Science ◽

10.1017/s0043174500093048 ◽

1997 ◽

Vol 45 (3) ◽

pp. 397-403

Author(s):

David A. Wall

Keyword(s):

Interspecific Competition ◽

Leaf Area ◽

Seed Production ◽

Growth And Development ◽

Dry Weight ◽

Field Studies ◽

Limiting Factor ◽

Shoot Dry Weight ◽

Summer Fallow ◽

Crop Competition

Greenhouse studies suggested that dog mustard was less competitive than wheat, but of similar competitiveness to flax. In field studies, dog mustard growth and development were markedly affected by crop competition. Competition from flax and wheat reduced dog mustard leaf area, shoot dry weight, plant height, and seed production compared with the weed grown on summer-fallow. Dog mustard was a prolific seed producer when grown in the absence of interspecific competition. On summer-fallow, dog mustard produced as many as 79,100 seeds plant−1when moisture was not a limiting factor. However, average seed production was 19,400 and 8000 seeds plant−1in 1994 and 1995, respectively.

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Tolerance Evaluation of Vegetatively Established Miscanthus × giganteus to Herbicides

Weed Technology ◽

10.1614/wt-d-13-00050.1 ◽

2013 ◽

Vol 27 (4) ◽

pp. 735-740 ◽

Cited By ~ 6

Author(s):

Xiao Li ◽

Timothy L. Grey ◽

Brian H. Blanchett ◽

R. Dewey Lee ◽

Theodore M. Webster ◽

...

Keyword(s):

Weed Management ◽

Dry Weight ◽

Field Studies ◽

The United States ◽

Invasive Potential ◽

Shoot Height ◽

Shoot Dry Weight ◽

Miscanthus Giganteus ◽

Reduced Height ◽

Giant Miscanthus

Giant miscanthus is under consideration as a biofuel crop in the United States; however, there is little information on weed management for the establishment and survival of this crop. Therefore, greenhouse and field studies using ornamental pots were conducted in summer 2011 at Tifton, GA, with the objective of screening potential PPI, PRE, and POST herbicides and herbicide combinations for giant miscanthus when establishing from vegetative rhizomes. For the POST treatments, giant miscanthus was established from rhizomes in 7.6-L containers in the field and treated with 27 POST herbicides to evaluate efficacy. Thifensulfuron, metsulfuron, tribenuron, chlorimuron, halosulfuron, rimsulfuron, cloransulam, pinoxaden, bentazon, and metribuzin did not significantly lower shoot height, reduce shoot dry weight, or increase injury compared with nontreated control (NTC) when evaluated at 4 wk after treatment. Nicosulfuron, trifloxysulfuron, sulfometuron, clodinafop, fluazifop, and pyrithiobac caused the greatest injury, reduced plant height, and reduced dry weights compared with the NTC. Sethoxydim, diclofop, flumioxazin, imazamox, imazapic, and imazethapyr decreased plant heights or resulted in increased injury. PPI and PRE treatments included 21 herbicides and herbicide combinations applied at two rates. Results indicated that most treatments containing atrazine, metribuzin, pendimethalin, acetochlor, metolachlor, and mesotrione did not injure or stunt growth; however, EPTC at 4.5 kg ai ha−1 significantly reduced height and dry weight and oxadiazon resulted in greater injury compared with NTC at both rates. These results indicate that PPI, PRE, and POST herbicides can be utilized for establishment of giant miscanthus from vegetative rhizomes. Considering the invasive potential of giant miscanthus, several POST herbicides evaluated in this study such as fluazifop, pyrithiobac, and sulfometuron may be viable options to control this species if it becomes invasive.

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Elucidating the Potential of Native Rhizobial Isolates to Improve Biological Nitrogen Fixation and Growth of Common Bean and Soybean in Smallholder Farming Systems of Kenya

International Journal of Agronomy ◽

10.1155/2016/4569241 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 13

Author(s):

Ernest Wandera Ouma ◽

Anne Mercy Asango ◽

John Maingi ◽

Ezekiel Mugendi Njeru

Keyword(s):

Nitrogen Fixation ◽

Common Bean ◽

Farming Systems ◽

Dry Weight ◽

Field Studies ◽

Smallholder Farming ◽

Shoot Dry Weight ◽

Smallholder Farming Systems ◽

Commercial Inoculant ◽

Biological Nitrogen

Identification of effective indigenous rhizobia isolates would lead to development of efficient and affordable rhizobia inoculants. These can promote nitrogen fixation in smallholder farming systems of Kenya. To realize this purpose, two experiments were conducted under greenhouse conditions using two common bean cultivars; Mwezi moja (bush type) and Mwitemania (climbing type) along with soybean cultivar SB 8. In the first experiment, the common bean cultivars were treated with rhizobia inoculants including a consortium of native isolates, commercial isolate (CIAT 899), a mixture of native isolates and CIAT 899, and a control with no inoculation. After 30 days, the crop was assessed for nodulation, shoot and root dry weights, and morphological features. In the second experiment, soybean was inoculated with a consortium of native isolates, commercial inoculant (USDA 110), and a mixture of commercial and native isolates. Remarkably, the native isolates significantly (p<0.001) increased nodulation and shoot dry weight across the two common bean varieties compared to the commercial inoculant, CIAT 899. Mixing of the native rhizobia species and commercial inoculant did not show any further increase in nodulation and shoot performance in both crops. Further field studies will ascertain the effectiveness and efficiency of the tested indigenous isolates.

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Yellow Nutsedge(Cyperus esculentus)Control in Kentucky Bluegrass(Poa pratensis)with Bentazon, Cyperquat, and Perfluidone

Weed Science ◽

10.1017/s0043174500049900 ◽

1978 ◽

Vol 26 (3) ◽

pp. 280-283 ◽

Cited By ~ 2

Author(s):

A. D. Kern ◽

W. F. Meggitt ◽

Donald Penner

Keyword(s):

Poa Pratensis ◽

Dry Weight ◽

Field Studies ◽

Kentucky Bluegrass ◽

Cyperus Esculentus ◽

Yellow Nutsedge ◽

Shoot Dry Weight ◽

Two Factors ◽

Postemergence Herbicides ◽

Sod Production

Bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4) 3H-one 2,2-dioxide], cyperquat (1-methyl-4-phenylpyridinium), and perfluidone {1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide} were evaluated for their potential use as postemergence herbicides for selective yellow nutsedge(Cyperus esculentusL.) control in Kentucky bluegrass(Poa pratensisL.) in field studies. High rates of these herbicides as single or split applications were effective and only slightly reduced verdure of Kentucky bluegrass, indicating excellent selectivity. In greenhouse studies perfluidone exhibited growth retardant properties. Shoot dry weight production was inhibited and root dry weight of treated plants was markedly reduced. These two factors are undesirable features for commercial sod production.

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Water Relations in Quackgrass (Agropyron repens) Following Postemergence Herbicides

Weed Science ◽

10.1017/s0043174500074853 ◽

1988 ◽

Vol 36 (3) ◽

pp. 273-278 ◽

Cited By ~ 4

Author(s):

Mark C. Trimmer ◽

Dean L. Linscott

Keyword(s):

Water Uptake ◽

Butyl Ester ◽

Acid Methyl Ester ◽

Dry Weight ◽

Field Studies ◽

Propanoic Acid ◽

Water Usage ◽

Time Required ◽

Postemergence Herbicides ◽

Agropyron Repens

In laboratory and field studies, quackgrass (Agropyron repens(L.) Beauv. # AGRRE) was subjected to postemergence applications of the butyl ester of fluazifop-P {(R)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid}, methyl ester of haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid}, or ethyl ester of quizalofop {2-[4-[[6-(chloro-2-quinoxalinyl)oxy] phenoxy] propanoic acid}. Haloxyfop, fluazifop-P, and quizalofop each required a minimum of 1 week to reduce quackgrass transpiration or water uptake in the laboratory. At rates lower than 0.56 kg ae/ha, fluazifop-P reduced quackgrass transpiration and water usage less quickly and to a lesser extent than equivalent rates of haloxyfop and quizalofop. The time required for significant transpiration and water uptake reduction by herbicide-treated quackgrass was several days longer in the field than in the laboratory, but the reaction patterns among the herbicides were similar. Little if any benefit was obtained from sequential applications of the herbicides compared with single applications of the same total dosage. All three herbicides significantly reduced quackgrass dry weight.

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Response of Dry Bean to Sulfentrazone Plus Imazethapyr

International Journal of Agronomy ◽

10.1155/2014/287908 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Nader Soltani ◽

Christy Shropshire ◽

Peter H. Sikkema

Keyword(s):

Dry Weight ◽

Field Studies ◽

Research Station ◽

Seed Moisture Content ◽

Visible Injury ◽

Dry Bean ◽

Black And White ◽

Shoot Dry Weight ◽

Seed Moisture ◽

White Bean

Field studies were conducted in 2010 and 2011 at the Huron Research Station, Exeter, Ontario and from 2009 to 2011 at the University of Guelph Ridgetown Campus, Ridgetown, Ontario to evaluate the sensitivity of four market classes of dry bean to sulfentrazone applied preemergence at 105, 140, and 280 g ai/ha alone and in combination with imazethapyr at 37.5 g ai/ha. At 1 week after emergence (WAE), sulfentrazone alone or in combination with imazethapyr at all doses evaluated caused no significant visible injury in dry bean. At 2 WAE, sulfentrazone alone caused 1–11, 1–11, 1–5, and 3–19% visible injury, and sulfentrazone + imazethapyr caused 3–11, 2–10, 2–5, and 4–20% visible injury in black, cranberry, kidney, and white bean, respectively. At 4 WAE, sulfentrazone alone caused 1–7, 1–7, 0–4, and 1–16% visible injury and sulfentrazone + imazethapyr caused 1–8, 1–5, 1–3, and 2–14% visible injury in black, cranberry, kidney, and white bean, respectively. Sulfentrazone PRE caused slightly greater injury in black and white bean compared to cranberry and kidney bean. Generally, crop injury with sulfentrazone at rates up to 140 g ai/ha alone and in combination with imazethapyr at 37.5 g ai/ha was minimal with no adverse effect on plant height, shoot dry weight, seed moisture content, and yield. Based on these results, there is potential for preemergence application of sulfentrazone at rates up to 140 g ai/ha alone or in combination with imazethapyr at 37.5 g ai/ha in black, cranberry, kidney and white bean.

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Influence of purple nutsedge(Cyperus rotundus)density and nitrogen rate on radish(Raphanus sativus)yield

Weed Science ◽

10.1017/s0043174500089682 ◽

1998 ◽

Vol 46 (6) ◽

pp. 661-664 ◽

Cited By ~ 18

Author(s):

Bielinski M. Santos ◽

Jose P. Morales-Payan ◽

William M. Stall ◽

Thomas A. Bewick

Keyword(s):

Field Experiments ◽

Dry Weight ◽

Field Studies ◽

Cyperus Rotundus ◽

Shoot Biomass ◽

Purple Nutsedge ◽

Shoot Dry Weight ◽

Radish Root ◽

Negative Effect ◽

Nitrogen Rates

Greenhouse and field experiments were conducted to determine the effects of nitrogen (N) supply and purple nutsedge population densities on the yield of radish. In the greenhouse studies, additive series with purple nutsedge densities of 0, 50, 100, 200 or 350 plants m−2were established. Nitrogen rates of 0, 110, 220, or 330 kg ha−1were provided to the potting medium. A significant density by N interaction was found for radish fresh weight. Within a given nutsedge density, radish yield decreased as N rate increased. In field studies, additive series of 0, 50, 100, 150, or 200 nutsedge plants m−2were established the same day radish was sown. Nitrogen rates were 100 or 200 kg ha−1. Marketable radish yield losses and nutsedge shoot dry weight and height were determined 30 d after seeding the crop. Nutsedge densities and N rates interactively influenced radish root yield. Radish yield loss reached 100% at nutsedge densities of 75 and 125 plants m−2at 200 and 100 kg N ha−1, respectively. Purple nutsedge produced larger shoot biomass as N increased from 100 to 200 kg ha−1. Results of both greenhouse and field studies showed that as N increased, the negative effect of the weed on the crop was enhanced.

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