crazy top

noun

: any of several plant diseases in which the top growth undergoes characteristic alteration: as

a. : a disease of citrus that occurs on alkaline soils, that is marked by loss of mature leaves, stiff brushy terminal growth, and abnormal fruits, and that may be related to or a form of stubborn disease

b. : a disease of corn that is prob. due to a virus and that is characterized by the appearance of vegetative shoots often in bunches in place of floral organs

c. : a disease of almonds that is probably caused by a virus and is characterized by growth failure of many flower and leaf buds resulting in a sparse open tree with little fruit

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Plant Pathol.

a disease of cotton, corn, etc., characterized by abnormal branching and small, misshapen leaves in the upper part of the plant, caused by water shortage, organic deficiencies in the soil, or unknown causes.