Soil physicochemical properties, virus loads, cultivation conditions, and precipitation after planting (22 variables total) were analyzed using a generalized linear mixed model to determine their effect on the incidence of lettuce big vein in lettuce fields of cropping type “harvest the next year” in the Seisan region, Kagawa Prefecture, Japan. Disease incidence tended to be higher in fields with higher calcium and high settled soil volume, virus load, and applied nitrogen. Disease incidence tended to be lower in fields with higher total carbon, higher number of consecutive dry days after planting, and had chemical pest control. Fertilizing appropriately based on a soil diagnosis, adding organic matter, improving field drainage and avoiding planting before long rains effectively reduce disease incidence. These techniques are easy to implement in commercial fields and should be combined with the use of resistant varieties and chemical control.

A leaf blight on golden chain trees (Laburnum anagyroides Medik.) was found in Tochigi, Japan, in 2019. First, small brown to reddish brown spots appeared and gradually increased in size and number. Most of the diseased leaves then fell off. The fungus isolated from diseased leaves was identified as Pleiochaeta setosa based on morphological and molecular analyses. The same symptoms developed after inoculation of the leaves, and the fungus was reisolated from the symptomatic leaves. We propose the name leaf blight (“hagare-byou” in Japanese) of golden chain tree for this new disease caused by Pleiochaeta setosa.