Rhynchosporium

This disease shown in the photographs is Rhynchosporium, another described as polycyclic, quite capable of several infection cycles during one growing season.

According to the AHDB Recommended list varieties rated 4 or less are susceptible to infection. Currently 75% of those listed would be classed as susceptible or moderately susceptible to this disease.

Rhynchosporium is challenging to control due to its ability to spread in a number of ways.

Firstly it can be seed-borne, with infected seed allowing the disease to develop inside fresh shoots and roots before expressing itself more evenly during January or February.

It can start as an autumn infection caused by rain-splashed spores from infected trash, stubble and volunteers.

Visible symptoms are usually more significant and easy to spot during tillering. During wet weather infection splashes up the canopy eventually infecting the upper leaves and ears to finally infect the grain itself.

Wind also plays a significant role in the spread of this disease.

Since we no longer have Chlorothalonil for disease control in barley surely the alternative, Folpet will do something?

In reality, Folpet has limited activity on Rhynchosporium so no real help there. However there are a range of other modes of action to choose from to help combat this disease.

Rhynchosporium

polycyclic