CONCERN OVER "EL NINO" IN PERU - USDA REPORT There are heightened fears that "El Nino" may be returning to Peru with an intensity approaching the 1983 disaster, which affected the weather on several continents and caused widespread damage through floods and drought, the U.S. Agriculture Department's officer in Lima said in a field report. Continued heavy rains in the northern coastal area, flooding of several major rivers and mud slides have led to increased concern, the report, dated March 17, said. However, it said official sources still believe that this year's El Nino will have only weak to moderate intensity. EL Nino is a phenomenon involving a shift in winds and waters in the pacific. The USDA report said that so far the El Nino now being experienced has not had an overall negative impact on agricultural production. Excessive rains in the Piura Pima cotton area may reduce yields by about 20 pct due to excessive growth too early in the crop cycle. Also insect damage to crops could be more extensive where excessive moisture exists, it said. However, the El Nino has resulted in a much improved supply of irrigation water in the major dams which will improve prospects for many crucial crops such as rice and corn, and slow the decline in sugar production, it said. If El Nino picks up momentum, Peru's fishing industry could receive a setback. But trade sources still believe the fish catch for industrial processing will reach 5.5 mln tonnes in 1987, almost 20 pct above last year, the report said. Water temperatures in the northern fishing areas are three to four degrees centigrade above normal but still not high enough to drive the fish to cooler southern waters, it said. It said there is still the outside chance that El Nino will intensify and carry on through late March, April and May causing problems as crops approach harvest. "There appears to be no way to project the course of El Nino -- only time will tell," the report said.