Further studies on root symptoms in coconut palms affected by lethal yellowing disease in Jamaica

Roots were induced by banking moist coir dust around the boles of apparently healthy coconut palms growing in an area where lethal yellowing was spreading rapidly. Samples of roots were removed for inspection at 1–2 wk intervals after the detection of the first symptoms in palms. Frond symptoms were recorded weekly. Comparison of symptoms in roots and fronds of 28 of the 36 palms that developed lethal yellowing confirmed the earlier observations that the roots usually remained symptomless for a variable period of up to 4 months following detection of the first symptoms of the disease. When root symptoms appeared, most of the actively‐growing root tips became necrotic within a period of 2–4 wk and the collapse of the root system was closely correlated with the onset of progressive yellowing of fronds.