UPDATE 2-EU crop monitor trims wheat, barley, rapeseed yield outlook on dryness

(Adds details and links to table, report)

PARIS, May 23 (Reuters) - The European Union’s crop monitoring service, MARS, on Monday trimmed its yield forecasts for this year’s EU wheat, barley and rapeseed harvests due to dryness and said significant rain was needed to avoid further yield losses.

Developing drought in parts of Europe, including in top EU grain producer France, has unsettled an international market already grappling with loss of Ukrainian supplies due to Russia’s invasion.

In a monthly report, MARS lowered its forecast of the EU’s 2022 yield for soft wheat - the bloc’s biggest cereal crop - to 5.89 tonnes per hectare (t/ha) from 5.95 t/ha projected last month.

That is now 2.5% below the 2021 level although 0.9% higher than the average of the past five years, it said.

“Our yield forecasts for winter crops were revised slightly downwards at EU level, but remain above the five-year average. Substantial rainfall in the coming weeks will be necessary to sustain the yield potential,” MARS said.

However, it warned that weather forecasts for the week to May 28 showed fewer than three days with precipitation above 5 mm (0.2 inch) across Europe and the longer-range outlook for June-August suggested warmer- and drier-than-usual conditions were likely in most of the region, “potentially exacerbating the negative climatic water balance.”

For barley, MARS cut the overall projected yield to 4.89 t/ha from 4.97 t/ha last month, reflecting a drop in the forecast spring barley yield to 4.18 t/ha from 4.31 t/ha and a slight reduction to the winter barley projection, to 5.78 t/ha from 5.79 t/ha.

For rapeseed, the EU’s main oilseed crop, MARS revised down its outlook for this year’s yield to 3.17 t/ha from 3.19 t/ha forecast in April.

Forecast yields for spring crops were mostly increased slightly, with grain maize pegged at 7.92 t/ha against 7.91 t/ha last month, sugar beet nudged up to 78.0 t/ha from 77.8 t/ha and sunflower seed raised to 2.39 t/ha from 2.38 t/ha.

Reporting by Gus Trompiz and Forrest Crellin in Paris Editing by Mark Potter and Matthew Lewis