Milk thistle in oilseed rape
Originally found only in the south of France, milk thistle (Silybum marianum) has been heading steadily north for some years now, particularly into the Central region where it has become a major problem.
Instantly recognisable with its broad, glossy, spiny leaves and white mottling on its upper surface, farmers are now finding milk thistle as far north as the department of Yonne. Capable of producing between 3000 and 5000 seeds per plant, milk thistle seeds can also survive in the soil for a very long time.
Due to its rapid growth and strong leaf development, milk thistle can choke OSR. It is all the more difficult to control in OSR, as pre-emergence products are ineffective against it. Whilst IELO/YAGO/BIWIX are fairly effective against young milk thistles they sometimes need to be supplemented with an application of LONTREL SG particularly as winter comes to a close around mid February.
On a lighter note, Silybum means edible thistle, and marianum is related to the Virgin Mary. Legend has it that when Mary was travelling from Judea to Egypt to escape King Herod, she hid Baby Jesus away in a grove of thistles. When she then breastfed him, a few drops of her milk fell onto the thistle leaves, giving them their white ribs. Milk thistle is also said to increase milk production, though this has never been proven, one way or another.