Irn-Bru maker AG Barr's share price fell sharply on Tuesday after the company issued a profit warning.
The Cumbernauld-based said it expected sales to drop by 10% and profits by up to 20% as they struggle against a strong year in 2018.
It cited poor weather and "challenges" facing some of its brands, particularly its Rockstar energy and Rubicon juice drinks.
Barr's share price was down by more than 28%, at 623p, by 16:30.
In a pre-close update, the company said trading so far this year had been below its expectations.
It added: "This has been exacerbated by some specific brand challenges, particularly in Rockstar energy and Rubicon juice drinks, as well as disappointing spring and early summer weather, most notably in Scotland and the north of England, and compounded further as we approach the half year when the prior year comparative weather was at its peak."
AG Barr's Rubicon division has faced challenges since the introduction of the sugar tax, with several drinks companies having to change their recipes to reduce sugar levels.
This has led to a backlash among some customers, who have complained about the new tastes.
The Rockstar energy division has also had to contend with a crackdown and awareness-raising by campaigners about teenagers drinking high-caffeine drinks. Several supermarkets have banned sales of the products to under-18s.
AG Barr chief executive Roger White said that although the cocktail mixer division Funkin was growing well, it had been a challenging start to the year for the rest of the company.
He added: "Weather comparatives and trading, particularly in the impulse on-the-go market, have been even tougher than expected which, along with some brand-specific challenges, have led to a short-term impact on our financial performance.
"We are focused on returning to growth and will continue to take the actions we believe necessary to succeed in the dynamic environment within which we operate."
These actions include launching three new Rockstar drinks by the end of the summer and "recipe improvement activity" for Rubicon juice drinks.
However, the company warned "the benefit of these actions will not be felt until later in the second half of the financial year".
Sales for the 26 weeks to 27 July are now expected to be about £123m - down 10% on last year - and further one-off costs can be expected to be announced later in the year, the company added.