Herbicides and Plant Physiology. Andrew H. Cobb. Читать онлайн. Newlib. NEWLIB.NET

Автор: Andrew H. Cobb
Издательство: John Wiley & Sons Limited
Серия:
Жанр произведения: Биология
Год издания: 0
isbn: 9781119157700
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Former Soviet Union 13.0 Oceania 9.6 Average 13.1

      Source: Lutman, P.J., Boatman, N.D, Brown V.K. and Marshall, E.J.P. (2003) Weeds: their impact and value in arable ecosystems. In: The Proceedings of the BCPC International Congress: Crop Science and Technology 2003 1, 219–226.

Weed species 5% yield loss (plants m−2) Weed species 5% yield loss (plants m−2)
Galium aparine 1.7 Poa annua 50.0
Anisantha sterilis 5.0 Epilobium spp. 50.0
Avena fatua 5.0 Polygonum aviculare 50.0
Lolium multiflorum 8.3 Sonchus spp. 50.0
Alopecurus myosuroides 12.5 Taraxacum officinale 50.0
Brassica napus 12.5 Fumaria officinalis 62.5
Sinapis arvensis 12.5 Geranium spp. 62.5
Tripleurospermum inodorum 12.5 Lamium purpureum 62.5
Cirsium spp. 16.7 Ranunculus spp. 62.5
Convolvulus arvensis 16.7 Veronica spp. 62.5
Fallopia convolvulus 16.7 Aethusa cynapium 83.3
Papaver spp. 16.7 Senecio vulgaris 83.3
Chenopodium album 25.0 Anagallis arvensis 100.0
Myosotis arvensis 25.0 Allium vineale 250.0
Persicaria maculosa 25.0 Aphanes arvensis 250.0
Silene vulgaris 25.0 Legousia hybrida 250.0
Stellaria media 25.0 Viola arvensis 250.0

      Yield loss may also occur in addition to direct competition for resources. Allelopathy is the production of allelopathic chemicals by one plant species that may inhibit (or, in the case of positive allelopathy, stimulate) the growth of other species. Anecdotal evidence of negative allelopathic effects has been reported for a number of weed species, although supporting research is often lacking. Recent findings have been reviewed by Olofdotter and Mallik (2001) and others (see Agronomy Journal vol. 93). Given the ample evidence of allelopathy exhibited by crop species, it is highly likely that many weed species will also display these effects, and that it is only a matter of time before research demonstrating this becomes readily available.

      Further examples of yield loss caused by weeds include the effects on non‐plant organisms. One example of this is the presence of dandelion (Taraxacum officinale) in fruit orchards. Dandelion flowers are preferentially visited by insect pollinators and so pollination of fruit blossom (and therefore fruit yield) is reduced.

       1.4.2 Interference with crop management and handling

       1.4.3 Reduction in crop quality

      Competition between crop and weed species can result in spindly leaf crops and deformed root crops which are less attractive to consumers and processors. A crop may have to be rejected if it contains weed seeds, especially when the crop is grown for seed, such as barley and wheat, and if the weed seeds are similar