Leaf Spot Disease Development and Its Effect on Yield of Essential Oil-Producing Hemp Cultivars in Kentucky.

Leaf spot diseases are common on field hemp, causing defoliation, and blighting. The most prevalent leaf spot diseases of hemp in Kentucky are Bipolaris leaf spot (), Cercospora leaf spot (), and Septoria leaf spot (). In this study, disease progression, cultivar susceptibility, and yield loss were examined using cultivars from four relatedness groups at two locations and in two growing seasons.

Seeing double on : Haploids and heteroploids of on hemp and other dicots.

(= ) causes Bipolaris leaf spot (BLS), a devastating and widespread disease on industrial hemp (). An investigation of relationships of isolates from hemp and other plants indicated variation in ploidy that has not previously been reported for . Isolates were obtained from BLS lesions on hemp and nearby weeds in 11 Kentucky counties and were similar to each other in morphology and growth characteristics.

First report of black root rot (Berkeleyomyces rouxiae) on greenhouse hemp (Cannabis sativa) in Kentucky.

Hemp, Cannabis sativa, was reintroduced to the US in 2014 after 50 years of prohibition. Since then, growers have focused primarily on cannabinoid production using female plants. Thus, most modern hemp has been asexually propagated in greenhouses and transplanted into fields.

First Report of Fusarium graminearum Causing Flower Blight On Hemp (Cannabis sativa) in Kentucky.

In October of 2020, a grower in Boyle County, KY, reported mold and blight symptoms on flowers of field-grown hemp. Plants were approaching harvest, and the mold was affecting 100% of the cultivar 'White CBG' being grown for cannabinoid (CBD) extraction. Mycelium colonized the flower heads and any seeds within bracts.

Reemergence of Septoria Leaf Spot Caused by on Hemp in Kentucky.

Hemp reemerged in 2014 after being illegal for over 50 years and restricted for 90 years. Today, hemp is primarily grown for production of cannabidiol (CBD), with limited acreage dedicated to fiber. One of the most frequent and destructive leaf spot diseases of hemp cultivars grown for CBD is Septoria leaf spot.