116
0. R. POTTS AND 0. P. VICKERMAN
TABLE I11
Dominant weeds in a random sampk of 103 cereal field. in west ~ u a s e x
etudy area, mid June 1972
Number of fields in
which weed was common
Chickweed (Stellaria media (L.) Vill.)
63
Speedwells (Veronica spp.)
60
Meadow grasses (Poa trivialis L. and P. a n n w L.)
66 (monocots.)
Other grasses (Loliwm, Agroatk, Abpecurua and Avena)
30 (monocots.)
Mayweed (Anthemia arvensis L.)
24
12
11
9
9
Yellow Charlock (Sinapis arvensis L.)
8
Hemp Nettle (Qaleopeia tetrahit L.)
6
Cleavers (Qalium apm‘ne L.)
6
Parsley Piert ( A p h m a r v e k L.)
6
4
4
4
3
Polygonurn spp.
34
Pansy (Viola arvensia Murr.)
12
Forget-me-not (Myosotia memk (L.) Hill)
Red Poppy (Papaver rhoear, L.)
Red Dead Nettle (Larnium p u p r e w m L.)
Shepherd’s Purse (Capsella bursa-paet& (L.) Medik.)
Sun Spurge (Ewphorbia helioscopia L.)
Scarlet Pimpernel (Anaqallie arvenaia L.)
White Campion (Sikne alba (Mill.))
Corn Sowthistle (Sonchua m e & L.)
Fumitory (Pumaria omi7aalk L.)
3
Crane’s-bill (Geranium spp.)
3
Madder (Sheradia m e n a b L.)
3
Thistles (Cirsiwm spp.)
3
Nipplewort (Lalpsana mmunie L.)
2
Fat Hen (Chenopodium album L.)
Groundsel (Senecio Pnclgaria L.)
2
Silver Weed (Potentilla amerina L.)
Venus’ Looking Glass (Legow& hyh& (L.) Del.)
Sorrel (Rumex wetosa L.)
1
Corn Buttercup (Ranunculua arvensie L.)
Nettle (Urtica dioica L.)
1
Fluellen (Kickzia elatine (L.) Dum.)
2
1
1
1
1
and Ranunculus arvenais L., many of the more MCPA-tolerant
annual weeds are as frequent or have even increased in importance
(Evans, 1966; Fryer and Chancellor, 1971). Examples of the latter are
chickweed (Stellaria media (L.) Vill.), common knotgrass (Polygonum
aviculare L.), redshank ( P . pereicaria L.), black bindweed (P. convolvulus L.) and speedwells (Veronica spp.). In many areas, however, the
recent introduction of broad-spectrum herbicides is affecting even these
species (Potts, 1 9 7 0 ~ ) .
0. R. POTTS AND 0. P. VICKERMAN
TABLE I11
Dominant weeds in a random sampk of 103 cereal field. in west ~ u a s e x
etudy area, mid June 1972
Number of fields in
which weed was common
Chickweed (Stellaria media (L.) Vill.)
63
Speedwells (Veronica spp.)
60
Meadow grasses (Poa trivialis L. and P. a n n w L.)
66 (monocots.)
Other grasses (Loliwm, Agroatk, Abpecurua and Avena)
30 (monocots.)
Mayweed (Anthemia arvensis L.)
24
12
11
9
9
Yellow Charlock (Sinapis arvensis L.)
8
Hemp Nettle (Qaleopeia tetrahit L.)
6
Cleavers (Qalium apm‘ne L.)
6
Parsley Piert ( A p h m a r v e k L.)
6
4
4
4
3
Polygonurn spp.
34
Pansy (Viola arvensia Murr.)
12
Forget-me-not (Myosotia memk (L.) Hill)
Red Poppy (Papaver rhoear, L.)
Red Dead Nettle (Larnium p u p r e w m L.)
Shepherd’s Purse (Capsella bursa-paet& (L.) Medik.)
Sun Spurge (Ewphorbia helioscopia L.)
Scarlet Pimpernel (Anaqallie arvenaia L.)
White Campion (Sikne alba (Mill.))
Corn Sowthistle (Sonchua m e & L.)
Fumitory (Pumaria omi7aalk L.)
3
Crane’s-bill (Geranium spp.)
3
Madder (Sheradia m e n a b L.)
3
Thistles (Cirsiwm spp.)
3
Nipplewort (Lalpsana mmunie L.)
2
Fat Hen (Chenopodium album L.)
Groundsel (Senecio Pnclgaria L.)
2
Silver Weed (Potentilla amerina L.)
Venus’ Looking Glass (Legow& hyh& (L.) Del.)
Sorrel (Rumex wetosa L.)
1
Corn Buttercup (Ranunculua arvensie L.)
Nettle (Urtica dioica L.)
1
Fluellen (Kickzia elatine (L.) Dum.)
2
1
1
1
1
and Ranunculus arvenais L., many of the more MCPA-tolerant
annual weeds are as frequent or have even increased in importance
(Evans, 1966; Fryer and Chancellor, 1971). Examples of the latter are
chickweed (Stellaria media (L.) Vill.), common knotgrass (Polygonum
aviculare L.), redshank ( P . pereicaria L.), black bindweed (P. convolvulus L.) and speedwells (Veronica spp.). In many areas, however, the
recent introduction of broad-spectrum herbicides is affecting even these
species (Potts, 1 9 7 0 ~ ) .