In July 2020 many ideas were put forward as a partial answer to beating Cabbage stem flea beetle during the establishment phase of Oil Seed Rape.
Of these it would appear “water” at the right time was in fact the universal answer. Whether that be preserved moisture or rainfall, is open to debate but sure enough “water” did help.
Another was the use of companion cropping of which I will mention 4 types. Mustard, Buckwheat, Phacelia and Clover.
In the last 10 years I have seen different farms employ these crops to aid establishment of notably cereals and oil seed rape. In each case I cannot categorically say “it worked 100%” but I can say “it did seem to help.”
Clover where employed and managed correctly works not just for one crop but for the next and the next.
Mustard. That too works but you do need to watch the amount you sow.
Phacelia and Buckwheat I have seen establish well within the Oil Seed Rape crop which is also well established.
In all cases a “success” in establishment. Question still is “was that down to the companion crop or simply “water.”