Dead wood has long been challenging for fresh citrus fruit production. Spores in twigs can form which causes blemishing diseases that downgrade fruit for lower profits. More recently, it has come to light that there are horticultural and entomological reasons to remove this wood as well.
Many growers are familiar with melanose, the disease most widely associated with dead wood. The fungal spores formed in the fine dead twigs (less than 1/8-inch) blemish the leaves, twigs, and young fruit. These spores are most damaging to grapefruit, but if there is significant dead wood from any cause, oranges and tangerines can be damaged, too.
Other diseases can also take advantage of these twigs. Citrus black spot (CBS) is another disease that has spores formed in the dead wood in the canopy, causing lesions on fruit. These spores are less abundant than those from melanose, but since CBS is a quarantine disease, removing as much inoculum as possible is wise to improve disease management. CBS is most problematic on late hanging sweet oranges but is known to infect nearly all citrus types. Although unconfirmed, it appears that some of the inoculum for diplodia stem-end rot comes from dead wood. These diseases are three good reasons to consider removing some of that wood.
Damaged or dead wood can provide a habitat for unwanted insect pests. In recent years, there have been …..
Read more of your UF/IFAS Tip of the Week By Megan Dewdney, Tripti Vashisth, and Lauren Diepenbrock, Time to Cut the Dead Wood on the Citrus Industry website.
Megan Dewdney is an associate professor and Tripti Vashisth and Lauren Diepenbrock are assistant professors — all at the University of Florida Institute of Food and Agricultural Sciences Citrus Research and Education Center in Lake Alfred.