Studies on the epidemiology of spear rot in oil palm (Elaeis guineensis Jacq.) in Suriname.

The epidemiology of spear rot, an infectious disease of unknown etiology, was studied over 10 years at three government-owned oil palm plantations in Suriname. As with other and similar diseases, amarelecimento fatal in Brazil and pudrición del cogollo in Latin America, which too show rot and yellowing, fatal to the young leaves, the affected trees die. Remission of symptoms may occur more than once during the life of a diseased palm, but is not permanent. A combination of classical and modern methods, used to analyze the temporal and spatial patterns of disease spread in the plantations, led to the conclusion that (i) there were two different patterns of dispersal, (ii) initial inoculum sources were outside the plantation, (iii) the disease was vector-transmitted (iv) disease increased logistically, and (v) dispersal was influenced by the wind. A situation where diseased trees were maintained to harvest the last bunches, led to the conclusion that blocks be abandoned at about 40% disease incidence. At that point yield was down to 50% and marginal profits from extra bunches turned to losses. Recommendations for plantation-managers and policy-makers dealt with problems of replanting, opening up new oil palm areas and prioritizing research on spear rot