I've got so many numbers, it's really hard to keep track. Especially of the hop ones, where I've harvested ones in multiple different formats.
The Hop Control Board was established in 1917 after the government had forced hop growers to grub up half their hop bines nad grow food instead. The Board bought the whole of the crop and then sold it on to brewers. During the war the idea was to protect what was left of the hop industry. After it, to help it rebuild and get the acreage back to pre-war levels.
The Hop Controller also fixed the price of English hops. By keeping the price relatively high and not allowing any foreign hops to be purchased by brewers until the whole of the UK crop had been sold, they hoped to prevent a flood of cheap imported hops. The higher the price, the greater the acreage that would be planted, was the reasoning.
It worked to a certain extent, but not 100%. Interwar hope acreage peaked at 26,452 in 1922. It remained at 23,000-25,000 acres for the rest of the 1920's, but fell to around 18,000 acres for most of the 1930s. Or about half the pre-WW I level.*
What is it now? Far, far less. In 2010, just 2,644 acres, or about 10% of what it had been in 1921.**
|UK Hop acreage by region 1914 - 1921|
|Brewers' Almanack 1922, page 107.|
Note how uneven the fall in acreage was in different regions. Kent and Sussex fare better than average, everywhere else, worse. It looks to me like marginal hop-growing areas just couldn't be bothered to start up again.
* Brewers' Almanack 1955, page 63.
** Barth Hop Market Telegram June 2011