Standard descriptions of growth stages of annual dicotyledonous weeds

Lutman, P. J. W.; Tucker, G. G.; Broad, H. R.

doi:10.1111/j.1744-7348.1987.tb04188.x

Cited by 9 publications

(3 citation statements)

References 3 publications

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“…Grass growth stage is recorded using a modified combination of Zadoks' scale for cereals (10) and Robson's scale for perennial ryegrass (9). Broadleaf growth stage is recorded using a modified version of that given by Lutinan and Tucker (6). The growth stages are described in on-line help screens included with the program.…”

Section: Data Entry Procedures Specifying Sites Weeds and Herbicidesmentioning

confidence: 99%

Format of a Weed Control Database

Mueller‐Warrant

1991

Weed technol.

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Access to detailed descriptions of the effects of applying specific rates of herbicides to crops and weeds in various growth stages is hampered by the format in which the relevant information is stored. Compared to traditional formats of journal articles and herbicide registration labels, computer database systems could easily cross-reference data from large numbers of experiments and answer specific questions concerning herbicide performance under particular conditions. Availability of this type of information could have far-reaching consequences for herbicide users, consultants, researchers, and regulators. A preliminary format for storing weed control information in IBM-PC compatible computers was developed, including procedures to enter data and retrieve information. Weed control efficacy or crop injury data for all rates of a herbicide or tank-mixture applied at a specific growth stage in a single test are used to generate dose/response equations by means of regression analysis routines. The best fitting of these equations is then used to estimate herbicide rates that would provide ten categories of control, ranging from a “no observable effect level” (NOEL) up to complete control. Rates are estimated only for those categories either within or bordering the range of the observed data, the remaining categories are empty. The estimated rates are stored in the database, along with the original data and other qualifying information. Access to information is organized around searches for a single herbicide, plant species, or pair of species. Search output is presented in a tabular format listing species, growth stage, herbicide name, and herbicide rates for the ten categories: NOEL, 10, 30, 50, 70, 83, 90, 95, 98, and 100% control or injury.

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Section: Data Entry Procedures Specifying Sites Weeds and Herbicidesmentioning

confidence: 99%

Format of a Weed Control Database

Mueller‐Warrant

1991

Weed technol.

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“…Groups of plants sown on 29 May 1985 (Exp. I) were inoculated with BMYV on 19 June, 25 June or 1 July when they were in the early cotyledon stage, late cotyledon stage and the 2-leaf-stage, respectively (growth stages according to Lutman and Tucker, 1987). The plants of these three groups showed symptoms simultaneously around 31 July when leaf 3 and 4 attained their final size.…”

Section: Development Of Symptoms During the Season Leaves Inoculatedmentioning

confidence: 99%

The incubation period of beet yellowing viruses in sugar-beet under field conditions

Werf

Kempenaar

Peters

1989

Netherlands Journal of Plant Pathology

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In three years field trials, the incubation period, i.e. the time between infection and the appearance of symptoms, of beet yellows virus (BYV) and beet mild yellowing virus (BMYV) increased with later infection during the growing season. The incubation period of BYV, a closterovirus, increased from 3 weeks in young plants infected before canopy closure, to 9 weeks in old plants infected in August. The incubation period of BMYV, a luteovirus, increased from 4 to 5 weeks in young plants to 9 weeks in old plants. Symptoms were observed c. one week earlier on the inoculated leaves than on those infected systemically, except on young BYV-infectecl plants. On these plants, symptoms developed in 3 weeks on both leaf types.The incubation period decreased at increasing temperature, a fixed temperature sum being required for the development of symptoms on plants of a certain age. This temperature sum increased with plant age. Symptom development was related to leaf growth; the systemic symptoms appeared after the infected leaves attained their final size. Young, expanding leaves did not show symptoms. Thus the development of symptoms seems to be related to physiological conditions occurring only in full-grown leaves. A low rate of leaf expansion may constitute the underlying reason for the long incubation period of virus symptoms in old plants and at low temperatures.The incubation period was not substantially affected by: (I) the number of Myzus persicae used to inoculate the plants, (2) the number of leaves inoculated, (3) the development stage of the inoculated leaf and (4) the source plant of BMYV, beet or shepherd's-purse, Capse/la bursapastoris. The incubation period can be used to obtain rough estimates of the infection-elate of individual plants, given the date on which symptoms appear.

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“…In the United Kingdom, keys produced under the aegis of The British Crop Protection Council and published by the Association of Applied Biologists have been introduced for cereals (Tottman, 1987, following Zadoks et al, 1974, oilseed rape (Sylvester-Bradley & Makepeace, 1984), peas and beans (Knott, 1987(Knott, , 1990 and potato (Jefferies & Lawson, 1991). Weeds have received less attention, but the key for annual broad-leaved weeds produced by Lutman & Tucker (1987) has proved particularly useful as an aid to standardisation of the description of weed growth stages on herbicide labels. This has led to a demand for a suitable key for annual grass weeds, particularly for use in the field by farmers, advisers and those involved in the development of herbicide recommendations.…”

Section: Introductionmentioning

confidence: 99%

The description of the growth stages of annual grass weeds

Lawson¹,

Read²

1992

Annals of Applied Biology

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The decimal code for the growth stages of cereal crops, devised by Zadoks, Chang & Konzak (1974) and expanded by Tottman & Makepeace (1979) and Tottman (1987) was found to be generally applicable to annual graminaceous species encountered as arable weeds in the United Kingdom. For the great majority of growth stages no difficulties were found in using the Zadoks code, but agronomists, crop protection advisers and farmers identified practical problems in assessing the transition from tillering to stem elongation to node development in certain species. It is recommended that these problems could be minimised if label and advisory statements avoided the use of GS30-pseudostem (leaf sheath) erectionas a growth stage description for annual grass weeds. The benefits of being able to use one key for graminaceous crops and weeds in the United Kingdom considerably outweigh any inconvenience caused by the need to amend herbicide labels to achieve this objective.

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Standard descriptions of growth stages of annual dicotyledonous weeds

Cited by 9 publications

References 3 publications

Format of a Weed Control Database

Format of a Weed Control Database

The incubation period of beet yellowing viruses in sugar-beet under field conditions

The description of the growth stages of annual grass weeds

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