On http://www.scs.leeds.ac.uk/cgi-bin/p...opaeolum+majus I
read

"Research indicates that aphids flying over plants with orange or yellow
flowers do not stop, nor do they prey on plants growing next to or above
the flowers[201]. "

[201] Allardice.P. A - Z of Companion Planting. Cassell Publishers Ltd.
1993 ISBN 0-304-34324-2

So could one protect crops from aphids by putting out plastic flowers?
(which might be more convenient)

Steve Harris - Cheltenham - Real address steve AT netservs DOT com