Controlling disease in our newest plant-based sector
02 May 2021
The disease, caused by Hop Latent Viroid (HLVd), has been found in established cannabis-growing regions worldwide and can cause significant loss of yield. The first instance found in New Zealand was recently reported by Helius Therapeutics.
Plant & Food Research has worked with Helius to establish in New Zealand a laboratory test to identify the presence of HLVd in medicinal cannabis plant material, based on overseas knowledge. A research programme is under way to investigate how the viroid spreads within and between plants so robust testing procedures can be developed for cultivators to identify infected plants and take action. Plans are in development to identify real time, in-field test methods for the viroid and to identify potential methods for treating plant material to remove any viroid prior to cultivation.
“Early detection of a disease is a major factor in minimising its effects on a sector,” says Dr Richard Newcomb, Chief Scientist of Plant & Food Research. “Hop latent viroid was first identified in cannabis in California in 2017, and has caused major issues for the local sector. By identifying the disease early in New Zealand we can work with the industry, and the associated hemp industry, to develop diagnostic and management techniques that work for the New Zealand sector.”
HLVd is a disease originally discovered in hops and has been present in New Zealand since the 1980s. The disease affects some other plants of the Cannabaceae family, such as cannabis and hemp. The viroid causes curling or yellowing of leaves, and can reduce the quality and quantity of flowers produced by the plant. The viroid can affect different parts of the plant in different ways, and be present without the plant displaying symptoms. It is spread primarily by mechanical means, such as on pruning shears or other tools.