CANBERRA, April 19 (Reuters) - Chicago soybean futures fell on Friday to within a whisker of four-year lows and were set for their biggest weekly fall since August, as a strong dollar and plentiful supply of cheap beans from South America suppress U.S. exports.

Corn and wheat futures were flat, but also close to their lowest levels since 2020, with traders assessing whether dry weather in the U.S. wheat belt or a leafhopper insect infestation in Argentinian corn fields would tighten supply.


* The most-active soybean contract on the Chicago Board of Trade (CBOT) was down 0.2% at $11.32-1/2 a bushel by 0035 GMT and down 3.5% over the week, nearing February's four-year low of $11.29.

* CBOT wheat fell 0.1% to $5.52-1/2 a bushel and was down around 0.5% over the week, while corn rose 0.1% to $4.27-1/4 a bushel, but was headed for a 2% weekly loss.

* U.S. soybeans are being out-competed in export markets by beans from top producer Brazil, and a plunge in the value of the Brazilian real has triggered a rush of sales by farmers there.

* The U.S. dollar this week rose to its strongest against a basket of major currencies since November, making U.S. farm exports less competitive.

* For the first time in 17 years, top importer China has no U.S. soybean cargoes booked as of mid-April for the upcoming marketing year. Overall export sales for the upcoming season were also the lowest for mid-April since 2007.

* On the supply side, Paraguay, the world's no. 3 soybean exporter, is headed for a record harvest of around 10.4 million metric tons, although shippers are worried about low river levels slowing trade.

* Argentina's 2023/24 soybean production, meanwhile, is forecast at 49.7 million tons, the government said.

* Also weighing on soybeans is a plunge in the prices of palm oil in recent weeks. Palm oil is a competitor to soyoil.

* In other crops, the International Grains Council (IGC) cut its outlook for 2024/25 global corn production by 7 million tons to 1.226 billion tons and for wheat production by 1 million tons to 798 million tons, though both estimates are still increases from the previous season.

* A rare leafhopper insect plague in Argentina has knocked an estimated $1.3 billion off the expected 2023/24 corn crop, an official at the Rosario grains exchange said.

* Dry weather is stressing crops in portions of the U.S. Plains, with the U.S. Department of Agriculture (USDA) reporting that 24% of the U.S. winter wheat crop was located in a drought area, as of April 16.

* More broadly, Latin American nations must be on high alert as the weather phenomenon known as El Nino rapidly switches over to La Nina, experts said on Thursday, leaving populations and crops little time to recover.


* U.S. stocks vacillated on Thursday, swinging from red to green and back as investors contended with the push-pull of a strong economy and restrictive Federal Reserve policy.

(Reporting by Peter Hobson; Editing by Sherry Jacob-Phillips)