UPDATE 1-Extreme weather to hit German grain harvest for third year-DBV

* DBV puts German 2020 grain harvest at 42.4 mln tonnes

* This is almost 5% below long-term average

* Calls for state to subsidise insurance (Adds details)

BERLIN, Aug 18 (Reuters) - Germany’s 2020 grain harvest will fall below average for the third year in a row as farmers grapple with extreme weather conditions, the DBV farmer’s association said on Tuesday.

The grain harvest this year is expected to amount to 42.4 million tonnes, down from 44.3 million tonnes a year earlier, and almost 5% below the average for the years 2015 to 2019, the association said in its final harvest estimates.

DBV president Joachim Rukwied said: “2020 was the third year in many places marked by extreme weather conditions, which threatens the existence of some farms.”

Depending on the region, farmers are facing significant harvest losses due to extreme drought, night frosts in May or mice appearing en masse, Rukwied said.

The DBV called for the state to subsidise multi-peril insurance for farmers to insure against weather-related yield losses and to introduce a tax revenue reserve.

Germany is the European Union’s second largest wheat producer after France and in most years the EU’s largest producer of rapeseed, Europe’s main oilseed for edible oil and biodiesel production.

Germany will harvest about 21.1 million tonnes of winter wheat in 2020, down from 22.8 million tonnes last year due to a decline in the area under cultivation, the DBV said.

Germany’s 2020 winter rapeseed harvest improved on the previous year, rising to 3.3 million tonnes from 2.8 million tonnes in 2019.

In France, the EU’s largest wheat producer, the crop has fallen by about 25% on 2019 to around 29-30 million tonnes, with yields damaged by spring drought and sowings reduced by torrential autumn rain. (Reporting by Caroline Copley Editing by Michelle Martin)