The chalara infection causes leaf loss and crown dieback, with repeated infection usually leading to tree death. It was first detected in Scotland in the summer of 2012, with 23 cases confirmed by November last year.
It has been found at 95 recently planted sites, three nurseries and 17 spots in the wider environment, according to Forestry Commission Scotland figures.
The infection is spread by the movement of young ash plants and airborne spores. It was initially found in the UK in planted stock at nurseries and it is thought that spores also reached the east of the country from Europe.
Conservationists say the apparent rise in Scottish cases in the past year could be partly due to increased survey coverage and under-reporting of the disease in the early stages because it can be difficult to spot.
Hugh Clayden, tree health policy adviser for Forestry Commission Scotland, said: "The best you can hope for is to try and buy some time by slowing down the spread, but there will be an inexorable movement of the disease through Scotland."
Despite the apparent rise in the number of cases, the pace of its spread is not as fast as was feared. The relatively dry summer may have helped delay the progress of the disease, experts say.
Forestry consultant Richard Worrell said: "My expectation for 2013 was we were going to find it much more widely, but we haven't. What we're pretty sure is going on is that it's not obvious enough for people out in the woods."
Efforts to reduce the impact of ash dieback are mainly concentrated on an area of north-west Scotland which has so far escaped the full impact of the disease.
Reports from some European countries also point to up to 25% of ash trees still remaining relatively healthy, despite a high incidence of the disease, although longer-term survival prospects may yet drop to 5% or less.
But experts warn chalara is just one of several diseases threatening Scotland's forests as a consequence of global trade and possibly climate change.