Overview

One of the most economically important diseases affecting various vegetable crops, Beet Curly Top Virus (BCTV) has now been identified in hemp. ​Transmission of BCTV through beet leafhopper feeding poses a significant threat to hemp cultivation, but can be managed through cultural controls.

Beet leafhopper adult. Image credit: A.C. Magyarosy, Bugwood.org

Transmission

BCTV is exclusively transmitted by the beet leafhopper, Circulifer tenellus (Hemiptera: Cicadellidae).

Acquisition of the virus can occur through feeding on infected plant tissue in as little as 1 to 2 minutes¹. While hemp is not a good breeding host for beet leafhoppers, they are still able to transmit the virus while feeding on the plant. Once acquired, these insects can retain and spread the virus to healthy plants for days or even weeks past feeding on infected tissue².

Symptoms

Plants infected with BCTV often demonstrate stunting, leaf chlorosis, leaf curling, and twisting of the new growth. Other symptoms include leaf cupping and mosaic/mottling.
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Compared to healthy plants, infected plants have also been reported to have shortened internodes and increased lateral branching.

Identification

Plants suspected to be infected with BCTV can be tested using various molecular diagnostic techniques. (how much detail needed?)

-Resources available? (sending samples for testing, etc)

Management

The most effective prevention tool for beet leafhopper population and virus spread is cultural controls, such as removing weed hosts and BCTV-infected plants. Monitoring beet leafhopper populations with a sweep net or yellow sticky card is also recommended in order to give insight on leafhopper population density and migration pattern during the growing season³.

In other crops,  BCTV-resistant cultivars are heavily relied upon to manage the spread of the virus, however, there are currently no known hemp cultivars with resistance to BCTV³.