Often known as the Queen of the Soft fruits, Raspberries are generally easy to grow and often present few if any problems. But, like all of every now and then they may go down with something; here's a handy guide to enable you to safeguard your delicious Raspberries.
A fungus borne disease which presents itself as brown patches near the base of the canes, causing the canes to split and go brittle. The problem can be spread by rain-water or air. Dig out infected canes helps by also increasing air flow through the bed. Avoid waterlogged soils.
Yellow orange pustules appear on the leaf surface from June onwards, usually progressing to the leaf underside. Copper based fungicides often help; some varieties are rust-resistant such as Julia or Malling Admiral.
Many mildews may affect Raspberries but this one is the worst, the powdery white coat can cover all the new growths & developing fruits in severe attacks. Sulphur based spray will help, pruning to ensure your raspberry bed does not get too congested and thinning canes also helps by improving air flow through the bed.
Purple spots appear around the buds, spreading further over autumn and winter. Overwinters on old canes so dig out all infected material to prevent spread; high nitrogen fertilizers make the problem worse so avoid feeding with those. May also affect Loganberries.
Good clean berries such as this rely on diligence against diseases.