Light Period, Temperature, and Kochia Flowering

Bell, Allyn R.; Nalewaja, John D.; Schooler, A. B.

doi:10.1017/s0043174500036146

Cited by 16 publications

(12 citation statements)

References 7 publications

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“…This prevented gene flow from R to S plants during the early flowering stage. However, kochia plants flower indeterminately, and S plants produced new flow- (2). The R biotype had a strong decreasing day-length requirement for flower initiation in the greenhouse, while the S biotype was less sensitive to day length (25).…”

Section: Resultsmentioning

confidence: 98%

Pollen-Mediated Gene Flow of Sulfonylurea-Resistant Kochia (Kochia scoparia)

et al. 1995

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The movement of sulfonylurea herbicide-resistant (R) kochia pollen was investigated in a spring barley field near Moscow, ID, using a Nelder plot design in 1991 and 1992. Each 61 m diameter plot had 16 rays spaced 22.5° apart and contained 211 kochia plants. There were 12 susceptible (S) plants and one R plant along each ray. The R and S plants were 1.5 m and 3.0 to 30.5 m from the center of the plot, respectively. Wind direction and speed in the 16 vectors, air and soil temperature, and rainfall were monitored continuously. Mature kochia seed was collected from individual plants, planted in the greenhouse, and sprayed with chlorsulfuron to test for resistant F1progeny. Results from the 2-yr study showed outcrossing of R pollen onto S plants at rates up to 13.1% per plant 1.5 m from the R plants and declining to 1.4% per plant or less 29 m from the R plants. At least 35% of the total R x S crosses occurred in the direction of prevailing southeastward winds. Predicted percentages of R x S crosses per plant ranged from 0.16 to 1.29 at 1.5 m, and 0.00 to 0.06% at 29 m. Thus, resistant kochia pollen can spread the sulfonylurea-resistant trait at least 30 m during each growing season.

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Section: Resultsmentioning

confidence: 98%

Pollen-Mediated Gene Flow of Sulfonylurea-Resistant Kochia (Kochia scoparia)

et al. 1995

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“…The slight delay in seed production at Huntley compared with Havre and Fort Benton is probably within the normal variation of flowering time for kochia. The kochia accessions studied by Bell et al (1972) showed substantial variability in the critical periods required for flowering: of two accessions from Groton, SD, one achieved 50% flowering under a 15 h 2 min daylength whereas the other required a 14 h 11 min daylength.…”

Section: Resultsmentioning

confidence: 99%

“…Kochia is a short day plant that initiates flowering when daylength falls below a critical period (Eberlein and Fore 1984). Bell et al (1972) determined the daylength at which several kochia accessions from northern latitudes of the United States (43ЊN to 48ЊN) achieved 50% flowering when planted at Fargo, ND (46Њ53ЈN). Critical periods required for flowering ranged from 13 h 12 min to 15 h 20 min, with most accessions flowering under 14.5-to 15-h daylength.…”

Section: Introductionmentioning

confidence: 99%

Postharvest Kochia (Kochia scoparia) Management with Herbicides in Small Grains

et al. 2004

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Uncontrolled kochia plants that regrow after small-grain harvest can produce substantial numbers of seeds. An average of 4,100 seeds per plant were produced between harvest (late July to mid August) and the first killing frost (late September) at three locations in Montana. Field experiments were conducted to determine the optimal timing of postharvest herbicide applications to prevent kochia from producing viable seeds. Herbicide treatments were applied at three timings from late August to mid September. The most effective treatments were glyphosate (631 g/ha) and paraquat (701 g/ha) applied at the second application timing (late August to early September). These treatments reduced kochia seed production by 92% or greater at each site. Kochia regrowth by this time had sufficient leaf area for herbicide absorption, but few viable seed had been produced. Herbicide treatments at the first and third application timings were generally less effective and more variable in reducing kochia seed production. Sulfentrazone (157 g/ha) and 2,4-D (561 g/ha) were not as effective at reducing seed production as other herbicide treatments.

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“…Kochia is a problem in late-harvested crops such as soybean, but has adapted to flower and produce seeds in early-harvested crops, such as small grains (Bell et al 1972). Kochia densities may exceed 2,100 seedlings/m 2 and reduce wheat yield more than 20% and soybean yield more than 30%.…”

Section: Introductionmentioning

confidence: 99%

Herbicide Strategies for Managing Kochia (Kochia scoparia) Resistant to ALS-Inhibiting Herbicides in Wheat (Triticum aestivum) and Soybean (Glycine max)¹

Wolf¹,

Clay

Wrage³

2000

Weed Technology

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Kochia (Kochia scoparia) control dropped from about 90% to less than 20% after three consecutive annual applications of acetolactate synthase (ALS)-inhibiting herbicides in several northeastern South Dakota fields. Field experiments were conducted to evaluate control of kochia resistant to ALS-inhibiting herbicides using combinations of herbicides applied postemergence (POST) in wheat (Triticum aestivum) and using herbicides applied preemergence (PRE), POST, and PRE plus POST in soybean (Glycine max). Thifensulfuron plus tribenuron did not control kochia in wheat (> 600 kochia plants/m2 at harvest) and wheat yield was similar to yield of the untreated control. Dicamba plus 2,4-D (in 1996) and bromoxynil plus MCPA (in 1996 and 1997) controlled kochia and increased yields by 15% or more. Kochia was sparse (less than 1 plant/m2) in soybean plots, but grass weeds were prevalent. PRE plus POST or POST herbicide combinations that included ALS-inhibiting herbicides controlled grasses, and soybean yields were as much as 20% greater than yields with combinations that did not contain ALS-inhibiting herbicides. Adding ALS-inhibiting herbicides to wheat herbicide combinations decreased profitability because treatment costs increased while yields did not. In contrast, adding ALS-inhibiting herbicides to soybean treatments increased profitability due to better grass control, resulting in increased yield and better return.

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Light Period, Temperature, and Kochia Flowering

Cited by 16 publications

References 7 publications

Pollen-Mediated Gene Flow of Sulfonylurea-Resistant Kochia (Kochia scoparia)

Pollen-Mediated Gene Flow of Sulfonylurea-Resistant Kochia (Kochia scoparia)

Postharvest Kochia (Kochia scoparia) Management with Herbicides in Small Grains

Herbicide Strategies for Managing Kochia (Kochia scoparia) Resistant to ALS-Inhibiting Herbicides in Wheat (Triticum aestivum) and Soybean (Glycine max)¹

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Light Period, Temperature, and Kochia Flowering

Cited by 16 publications

References 7 publications

Pollen-Mediated Gene Flow of Sulfonylurea-Resistant Kochia (Kochia scoparia)

Pollen-Mediated Gene Flow of Sulfonylurea-Resistant Kochia (Kochia scoparia)

Postharvest Kochia (Kochia scoparia) Management with Herbicides in Small Grains

Herbicide Strategies for Managing Kochia (Kochia scoparia) Resistant to ALS-Inhibiting Herbicides in Wheat (Triticum aestivum) and Soybean (Glycine max)1

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Herbicide Strategies for Managing Kochia (Kochia scoparia) Resistant to ALS-Inhibiting Herbicides in Wheat (Triticum aestivum) and Soybean (Glycine max)¹