How to Manage Pests
UC Pest Management Guidelines
(Reviewed 12/09, updated 12/09)
In this Guideline:
Crumbly fruit are caneberry fruit that do not stay together very easily and crumble or fall apart when picked or handled. Crumbly fruit is usually a result of incomplete drupelet set or drupelets on the fruit that have not filled (drupelets are the individual fruit of which in aggregate compose a raspberry or blackberry fruit). Unfilled and missing drupelets leave spaces in the fruit, causing a collapse of the surrounding drupelets into this space.
There are several causes of crumbly fruit in caneberries, which include:
The pattern of crumbly fruit development in individual caneberry plants as well as in the field is very useful in indicating the probable cause. Viruses infest the whole plant, and infested plants have crumbly fruit up and down the cane. Extremities in weather most often occur over a few days, so only those flowers and subsequent fruit exposed to these conditions will express crumbliness. Crumbly fruit then would be found through the whole field only at a certain height of cane or length of fruiting lateral in the case of exposure to extremes in weather. In the case of improperly done plant propagation, problems can be transmitted from an initially low number of plants to large numbers of nursery stock. In the field this will manifest itself as entire blocks that express the problem evenly throughout.
UC IPM Pest Management Guidelines: