Crop prospects in the EU have taken on extra significance this year as Russia's invasion of Ukraine - a major wheat, corn and sunflower exporter - has disrupted Black Sea exports and raised uncertainty over Ukraine's harvest.

But sweltering temperatures and sparse rain hurt most of Europe's spring crops. In contrast, winter crops benefited due to better harvesting conditions.

MARS put its yield outlook for the EU's grain maize crop, which will be harvested in the autumn, at 6.63 tonnes per hectare (t/ha) down from 7.25 t/ha projected last month and now 16% below both the 2021 level and the five-year average.

For sugar beet, another spring crop also due to be harvested in the autumn, MARS projected the EU's yield at 75.3 t/ha, down from 77.4 t/ha forecast in July.

In oilseeds, MARS trimmed its EU sunflower seed yield forecast to 2.06 from 2.18 t/ha previously, while the soybean yield was expected at 2.46 t/ha, down from 2.72 t/ha in July.

Most of Europe was hit by the adverse weather, MARS said, with Spain, France, central and northern Italy, central Germany, Hungary, Romania, Slovenia and Croatia among the most affected regions.

"Water and heat stress periods partly coincided with the sensitive flowering stage and grain filling. This resulted in irreversibly lost yield potential," it said in its monthly report.

MARS slightly increased its winter crops yield projections as dry weather benefited harvesting in the bloc. That included a rise in its outlook for the EU's 2022 soft wheat yield to 5.76 t/ha from 5.74 t/ha last month.

The expected rapeseed yield this year was raised to 3.15 t/ha from 3.13 t/ha last month, while this year's total EU barley yield was expected at 4.85 t/ha from 4.83 t/ha last month.

To access MARS' August crop report: https://publications.jrc.ec.europa.eu/repository/bitstream/JRC127964/JRC127964_01.pdf

(Reporting by Sybille de La Hamaide, editing by Forrest Crellin and Susan Fenton)