**3. The fatal yellowing (FY) disease**

#### **3.1 History in the world**

Several fatal syndromes of bud-rot severely affect plantations of oil palm in South and Central America [6, 38]. Bud-rot type disease was reported for the first time on oil palm plantations in Suriname in the 1920s, followed by another incidence in Panama reported by Reinking in 1927 [6]. In general, symptoms of bud-rot type diseases initiate with chlorosis of the youngest leaves and later necrosis that rapidly reach immature tissues of the meristem, causing a collapse of the spear leaf and plant death [9]. Bud rot diseases can take two forms: a lethal form found in Ecuador, Brazil, and in certain zones of Colombia and Suriname, and a non-lethal one, with a high recovery rate, found mainly in the Colombian Llanos [6]. The disease is synonym to a few other names such as "pudrición del cogollo" (PC) in most Spanish speaking countries, "PC típica" (PCt) or "PC diversa" (PCd) in the plantation Palmeras del Ecuador (PDE) in Eastern Ecuador, "amarelecimento fatal" (AF) in Brazil, "spear rot "in Suriname [1, 6, 7].

The first large-scale bud rot damage on oil palm plantations in Latin America was due to the PC disease in northern Colombia, where a field of 2,800 hectares located in the Turbo region was virtually devastated by PC in 1965 [9]. In Suriname, the spear rot was first registered in the Victoria region in 1976 on four-year-old oil palms in a plantation of 1,700 hectares. Despite the phytosanitary practices applied to control the disease, an exponential progression reduced the original area by 85% [39]. In Ecuador, the first PC cases happened in 1976 on four-year-old oil palms on the Pacific slopes of the Ecuadorian cordillera [1], and, like other regions, the plantation was decimated by the disease in a few years [6]. Recently Martinez et al. [7] carried out a study in Colombia to isolate microorganisms and reproduce PC in healthy oil palm plants and, in conclusion, they postulate that the oomycete *Phytophthora palmivora* is associated with the emergence of PC.

Fatal yellowing exhibits, by far, the most dramatic scenario among the bud-rot type diseases of oil palm in the Americas. The factors linked to the emergence of this disease in some countries remain unknown after experiencing more than 50 years of outbreaks in Brazil, Ecuador, Panama, Suriname, Costa Rica, Nicaragua, Honduras, Peru, and Venezuela [6, 9, 10].
