1979年2月,在印度卡利卡特地区农场,观察到2—7龄的厚皮种可可植株上发生的一种新病害。这些可可树是与椰子间种的,所有植株在相同的管理条件下培育。症状在该农场大约一公顷面积的密植区段观察了病害植株,在这块地差不多所有植株都感病。然而,病害的严重度有很大的不同。所有株龄群体的可可植株都可以看到这些病害症状。最初的症状是在新叶的叶脉之间出现小块褪绿,后来在叶 In February 1979, a new disease was observed on 2-7-year-old, thick-skinned cacao plants at the Calicut Regional Farm in India. These cacao trees are planted with coconut and all plants are grown under the same management conditions. Symptoms Diseased plants were observed in a densely populated area of ​​about one hectare on the farm, and almost all the plants in the area were susceptible. However, the severity of the disease is very different. All plant age groups of cacao plants can see these disease symptoms. The first symptom was the appearance of small patches of chlorotic green leaf veins, later on the leaves