The rainfall which has hampered Russian sowings of winter crops has hit the sugar beet harvest too, leaving a country which had come close to self-sufficiency in sugar likely to return to a steep production deficit.
Ikar, the Moscow-based analysis group, cautioned that it may cut below 3.5m tonnes, from 4.3m tonnes, its forecast for Russian production of beet sugar in the 2013-14 season, which began there last month.
The warning reflects concerns that a strong start to the harvest in southern areas- where farm ministry officials seeing record yields and sugar content in southern areas - contrasts sharply with output in the important production regions further north and east, thanks to excessive rains.
The rainfall in Russia's central region, besides in northern Ukraine, has already been cited by analysis group such as Agritel as slowing the corn harvest and sowings of winter grains.
As of Monday, beet producers had harvested 9.7m tonnes of beet, down 24% year on year, Ikar said.
"Heavy rainfall in August and September" has meant that "machines simply cannot enter the field", Ikar analyst Eugene Ivanov said.
And even when beets can be harvested, it is difficult to transport them to sugar mills which are being forced to operate at half capacity, or "go on downtime for several days" because of the lack of crop to process.
"Such a mode of operation is not very economical, and leads to additional losses in the production of sugar," Mr Ivanov said.
And the threat to output is growing "with each week", with the harvesting delays impinging on mills' operational cycle, and leaving beet more at risk of damage from the onset of winter.
The setbacks come at a time when output prospects have already been curtailed by a tumble in sowings, after two successive strong harvests undermined beet prices, prompting many growers to switch to other crops.
The International Sugar Organization forecasts Russian output falling to 4.35m tonnes this season, from 5.17m tonnes in 2012-13, and 5.51m tonnes in 2011-12.
The ISO pegs Russia's imports - the world's largest early in the century, hitting 5.65m tones in 2000-01 - at 1.58m tonnes in 2013-14, 760,000 tonnes in 2012-13, and 763,000 tonnes in 2011-12.