Crop and livestock production prospects in southern Africa have been weakened by this year's strong El Nino, while the phenomenon also is impacting agricultural sectors in northern Australia, parts of Indonesia, and a wide area of Central America and Brazil, the U.N. Food and Agriculture Organization (FAO) said Tuesday. According to a special alert, the FAO previously warned in March that the current El Nino would be strong, and it now appears to be the strongest episode in 18 years. It is expected to peak in early 2016, before the usual harvest time for farmers in southern Africa. South Africa already has declared drought status for five provinces that comprise its main cereal producing regions, while Lesotho issued a drought mitigation plan, and Swaziland implemented water restrictions. Wholesale corn prices are up 50 percent from a year ago in South Africa, while retail corn prices have doubled in Malawi and Mozambique. "It's the sixth week of the cropping season now, and there's not enough moisture in the soil," Shukri Ahmed, an FAO deputy strategic program leader, said of the situation in southern Africa. The likelihood of another poor season is troublesome as it follows a poor one that depleted inventories, tightened supplies, and increased local prices, the FAO said. The impact of this year's El Nino is being felt elsewhere in Africa, with FAO field officers in Ethiopia reporting serious crop and livestock losses. The FAO also issued a warning on increased risk of Rift Valley fever (RVF), especially in East Africa. RVF outbreaks, which primarily affect livestock but can be lethal to humans, are closely associated with periods of El Nino-linked heavy rainfall, which support habitats for the mosquitoes that carry the disease.