CUBA CRUDE SUGAR HARVEST FAR BEHIND SCHEDULE Cuban president Fidel Castro told a Congress of the Union of Young Communists here that the production of crude sugar during the harvest still in progress is 800,000 tonnes behind schedule. In a speech Sunday, published in today's official paper GRANMA, Castro said unseasonable rains since January seriously interrupted harvesting and milling operations especially in the central and western parts of the island. The Cuban leader said the mechanical cane harvesters scheduled to cut over 60 pct of the cane this year were particularly "vulnerable," as muddy fields prevent operations. Neither Castro nor the Cuban press have given out figures to estimate tonnes of crude production during the present harvest or the goals for the sugar campaign. However, a cuban sugar official told Reuters that the country will be lucky if crude output reaches last year's 7.2 mln tonnes. Output of crude for the previous 1984-85 harvest was 8.2 mln tonnes. The harvest was scheduled to end April 30 but due to the present shortfalls it will be extended into May and June, the official said.