scholarly journals So many weeds, so many weedings(23) Weed control system on V-furrow no-till direct seeded rice in Aichi prefecture, Japan

2012 ◽  
Vol 58 (2) ◽  
pp. 97-98
Author(s):  
Seok Weon Seo
HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 478E-479
Author(s):  
John Caldwell ◽  
Maurice Ogutu

Greater plant diversity is associated with reduced insect pest pressure, but field-scale vegetable production systems incorporating plant diversity have been lacking. Cucumber was grown in 1998 and 1999 at the Virginia Tech Kentland experimental farm, by direct seeding or transplanting into rye/vetch mixture rolled to make a no-till mulch alternating with strips of vetch left to flower as a habitat for beneficial insects between cucumber rows, or direct-seeded into black plastic mulch between habitat strips or with bare soil between rows. Rye and hairy vetch were seeded at 56 kg·ha–1 each the preceding fall; only rye was planted in plots without habitats. A rippled coulter, cutting shank, and daisy wheels mounted on a tractor-drawn toolbar enabled a belt-driven seeder to seed cucumbers without pulling the no-till mulch. One hand weeding in cucumber rows at 3 weeks after planting (WAP) provided weed control equivalent to pre-emergence herbicide. At 3 WAP, no-till transplanted cucumbers had higher above-ground plant dry weights than no-till direct seeded cucumbers in both years, but, at 6 WAP, cucumber above-ground plant dry weights were equal (1999) or higher (1998) in direct seeded no-till than in transplanted no-till or black plastic mulch on bare soil. In 1999, Pennsylvania leatherwings, Chauliognathus pennsylvanicus DeG. (Coleoptera: Cantharidae), a cucumber beetle predator, had higher densities and cucumber beetles lower densities in no-till plots than in black plastic mulch plots, and bacterial wilt incidence was reduced in plots with habitat strips and no insecticide application compared to plots without habitat strips and four insecticide applications. Cumulative marketable yields in no-till were 59% higher in 1998 and 23% higher in 1999 compared to yields on black plastic mulch.


Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 695-699 ◽  
Author(s):  
Steven M. Brown ◽  
James M. Chandler ◽  
John E. Morrison

A field experiment was conducted to evaluate weed control systems in a conservation tillage rotation of grain sorghum [Sorghum bicolor(L.) Moench.] – cotton (Gossypium hirsutumL.) – wheat (Triticum aestivumL.). Herbicide systems included fall and spring/summer inputs of high and low intensity. Tillage regimes were no-till (NT) and reduced-till (RT) systems; the latter included fall primary tillage followed by spring stale seedbed planting. Both tillage systems utilized controlled traffic lanes and wide, raised beds. Effective johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control required intense herbicide inputs at one or both application periods, i.e., in the fall and/or spring/summer. Grain sorghum and cotton yields for the most intense weed control system, which included high inputs in both the fall and spring/summer, were not superior to systems that included high inputs in only one of the two application periods. Seedling johnsongrass emergence occurred before spring planting in RT (but not in NT) in 2 of 3 yr, and control measures were ineffective. After 3 yr, the predominant weeds were johnsongrass and browntop panicum (Panicum fasciculatumSw. # PANFA).


1998 ◽  
Vol 12 (1) ◽  
pp. 32-36 ◽  
Author(s):  
William G. Johnson ◽  
Jeffrey S. Dilbeck ◽  
Michael S. Defelice ◽  
J. Andrew Kendig

Field studies were conducted at three locations in 1993 and 1994 to evaluate weed control and crop response to combinations of glyphosate, metolachlor, 0.5 X and 1 X label rates of chlorimuron plus metribuzin applied prior to planting (PP), and 0.5 X and 1 X label rates of imazethapyr applied early postemergence (EPOST) or postemergence (POST) in no-till narrow-row soybean production. Giant foxtail densities were reduced with sequential PP followed by (fb) EPOST or POST treatments. Large crabgrass was reduced equivalently with all herbicide combinations involving chlorimuron plus metribuzin PP fb imazethapyr. Common cocklebur control was variable but was usually greater with treatments that included imazethapyr. Ivyleaf morningglory densities were not reduced with any herbicide combinations. Sequential PP fb EPOST or POST treatments tended to provide slightly better weed suppression than PP-only treatments, but the difference was rarely significant. Soybean yields with treatments utilizing 0.5 X rates were usually equal to 1 X rates.


2012 ◽  
Vol 27 (1) ◽  
pp. 60-67 ◽  
Author(s):  
Steven J. Shirtliffe ◽  
Eric N. Johnson

AbstractOrganic farmers in western Canada rely on tillage to control weeds and incorporate crop residues that could plug mechanical weed-control implements. However, tillage significantly increases the risk of soil erosion. For farmers seeking to reduce or eliminate tillage, potential alternatives include mowing or using a roller crimper for terminating green manure crops (cover crops) or using a minimum tillage (min-till) rotary hoe for mechanically controlling weeds. Although many researchers have studied organic crop production in western Canada, few have studied no-till organic production practices. Two studies were recently conducted in Saskatchewan to determine the efficacy of the following alternatives to tillage: mowing and roller crimping for weed control, and min-till rotary hoeing weed control in field pea (Pisum sativum L.). The first study compared mowing and roller crimping with tillage when terminating faba bean (Vicia faba L.) and field pea green manure crops. Early termination of annual green manure crops with roller crimping or mowing resulted in less weed regrowth compared with tillage. When compared with faba bean, field pea produced greater crop biomass, suppressed weeds better and had less regrowth. Wheat yields following pea were not affected by the method of termination. Thus, this first study indicated that roller crimping and mowing are viable alternatives to tillage to terminate field pea green manure crops. The second study evaluated the tolerance and efficacy of a min-till rotary harrow in no-till field pea production. The min-till rotary hoe was able to operate in no-till cereal residues and multiple passes did not affect the level of residue cover. Field pea exhibited excellent tolerance to the min-till rotary hoe. Good weed control occurred with multiple rotary hoe passes, and pea seed yield was 87% of the yield obtained in the herbicide-treated check. Therefore, this second study demonstrated that min-till rotary hoeing effectively controls many small seeded annual weeds in the presence of crop residue and thus can reduce the need for tillage in organic-cropping systems.


1983 ◽  
Vol 63 (1) ◽  
pp. 235-241 ◽  
Author(s):  
J. A. IVANY ◽  
J. R. ENMAN

Forage corn (Zea mays L.) was grown successfully in Prince Edward Island by no-till planting the corn into standing cereal stubble 15–20 cm tall using a Buffalo no-till seeder. Planting with the slot-type shoe in a preliminary experiment in 1978 gave better forage yields than planting with a slice-type shoe mainly because of better plant population achieved. Subsequent experiments in 1979–1981 using the slot-type shoe to no-till plant corn in cereal stubble gave good forage yields when adequate weed control was provided with herbicide treatment. Best control of quackgrass (Agropyron repens L. Beauv.) and dandelion (Taraxacum officinale Weber) and crop yields was achieved with glyphosate + atrazine (1.5 + 2.5 kg a.i./ha) or amitrole + atrazine (3.4 + 2.5 kg a.i./ha) applied preemergence after seeding corn and before corn emergence. Control of quack grass and dandelion with glyphosate or amitrole used alone ranged from 71–80%, but paraquat alone did not provide any weed control. Addition of atrazine to paraquat, glyphosate, or amitrole gave improved control of quackgrass and dandelion and higher forage corn yields. Addition of 2.5 kg a.i./ha atrazine gave better results than use of 1.0 kg a.i./ha of atrazine.Key words: Forage corn, no-till seeding, glyphosate, atrazine, aminotriazole, paraquat


2014 ◽  
Vol 32 (2) ◽  
pp. 409-416 ◽  
Author(s):  
G. Santos ◽  
R.S. Oliveira Jr. ◽  
J. Constantin ◽  
A. C. Francischini ◽  
J. B. Osipe

Weed resistance to herbicides has been a major issue in Brazil, mainly due to the inefficiency of the herbicides used in no-till areas and to the high cost of these herbicide treatments. Failures in controlling the weed Conyza have been reported in Western and Northern grain crop areas in Paraná (Brazil). This work aimed to evaluate the potential occurrence of C. sumatrensis biotypes resistant to the herbicides chlorimuron-ethyl and glyphosate. Experiments were carried out under greenhouse conditions with four biotypes (Cascavel-2, Toledo-4, Tupãssi-6, and Assis Chateaubriand-7) possibly resistant to, as well as a population considered susceptible to chlorimuron-ethyl and glyphosate. To obtain dose-response curves, eight herbicide doses of chlorimuron-ethyl (0, 2.5, 5, 10, 20, 40, 80 and 160 g ha-1) and glyphosate (0, 90, 180, 360, 720, 1,440, 2,880 and 5,760 g e.a. ha-1) were applied and weed control and shoot biomass evaluations were made. Results provided evidence that two biotypes (Cascavel-2 and Tupãssi-6) were resistant to glyphosate and four biotypes (Cascavel-2, Toledo-4, Tupãssi-6 and Assis Chateaubriand-7) were resistant to chlorimuronethyl. Multiple resistance to glyphosate and chlorimuron was confirmed for biotypes Cascavel2 and Tupãssi 6. This is the first report on multiple resistance in Conyza sumatrensis, worldwide.


Author(s):  
Sirinun Sirikunkitti ◽  
Kanokwan Chongcharoen ◽  
Prajuab Yoongsuntia ◽  
Amarin Ratanavis
Keyword(s):  

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 392-399 ◽  
Author(s):  
Douglas D. Buhler ◽  
Virginia L. Werling

In 1985, when weed densities were low (169 plants/m2in untreated control), imazaquin applied at 0.07 kg ai/ha early preplant controlled over 90% of all weeds before no-till planting of soybeans. In 1986 and 1987 when weed densities were higher (589 plants/m2in untreated control), addition of 1.1 kg ai/ha or more of metolachlor to imazaquin (0.07 kg/ha) before soybean planting controlled 95% or more of the grass weeds and 83% or more of the broadleaf weeds. Imazaquin plus metolachlor applied less than 1 day after soybean planting controlled less than 70% of the emerged weeds in 1986 and 1987; common lambsquarters was most tolerant. Early preplant treatments controlled more weeds throughout the growing season than treatments applied after planting. Splitting herbicide treatments among application times generally did not increase weed control compared to single applications. Early preplant applications resulted in higher soybean densities and taller soybeans 30 days after planting in 1986 and 1987 than treatments applied after planting. Soybean yields increased as weed control increased. Weed control and soybean yields were greater with early preplant treatments than paraquat plus alachlor plus metribuzin applied preemergence in 1986 and 1987. No carryover of imazaquin residue was detected through corn bioassay in the field.


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