Knotweed disease ?

Knotweed disease ?

Observation - Knotweed disease ?. Description: Are these marks on the leaves of Japanese Knotweed a disease ? There were many leaves on different plants over a large area showing the same pattern of marks.Leaves which were less heavily marked had spots on the tip and outer edges of the leaf.The area a

Are these marks on the leaves of Japanese Knotweed a disease ? There were many leaves on different plants over a large area showing the same pattern of marks.Leaves which were less heavily marked had spots on the tip and outer edges of the leaf.The area along the midrib of the leaf is the last to show spots.