Seriously as a crop, I would think the 60s but probably in the late 50s? I would think as soon as the combine was sorted for efficient harvesting (they had been round years before the 50s - but not so common in the UK). Up to then smaller farms, extra capital outlay, and the UK climate with the available (strains of OSR) was an influence. Probably need to ask on a farming forum.
Historically rape oils were poor quality, containing high levels of eructic acid and the meal contained high levels of glucosinolates. After WW2 breeders reduced the level of eructic acid to very low levels so the oil became a quality oil for human consumption and in the 80's the glucosinolates were also bred out so the meal became an excellent protein source for animal feed. Glucosinolates break down into mustard oil which gives mustard and other brassicas (including leaf brassicas) their characteristic bitter/hot flavour. It is very toxic and is one reason why brassicas have very few specialised pests.
Oilseed rape (Brassica and related species, Brassicaceae) is now the second largest oilseed crop in the world providing 13% of the world’s supply. The world’s commerce is largely supplied by two species, Brassica napus L. and B. rapa L. Both species contain both spring and winter forms that are distinguished by vernalization requirement. Seeds of these species commonly contain 40% or more oil and produce meals with 35 to 40% protein.
The term “canola” is a registered trademark of the Canadian Canola Association and refers to cultivars of oilseed rape that produce seed oils with less than 2% erucic acid (22:1) and meals with less than 30 mmol of aliphatic glucosinolates per gram. The development and subsequent release of the first canola-quality cultivars by plant breeding programs in Canada during the 1970s created a new, high-value oil and protein crop that has gained tremendous acceptance worldwide.
Production of rape worldwide Rapeseed/Canola million ton
Came across a discussion on another list that OSR and Canola, are NOT the same crop which suprised me as I was always taught that "Canola" was the *polite* name for Oil Seed Rape.
The discussion was on price in USof A and rape seed and Canola achieved different prices. Canadian Canola being deemed the better of the two due to shelf life as the Americans do not consume creamed honey, for them it is a liquid product.
It looks like (from the web) there was not so much grown in the UK in the 60s (or even very little) so looks like I got the wrong decade. Seems it was the Common Market CAP that encouraged the crop with subsidies.
i remember in Bedfordshire trying to cut it with an old Massy combine harvester in 1968,.........the Massey threw all the OSR seed into the stone trap..They had to get a farmer with german Klaas to cut it
In Finland we had so called "butter mountain" and it was state policy not to use vegetable oils.
When it was convinced that butter eating is not good for heart and blood vessels, the state started to give penalty if cow had too high milk fat content.