How do I save a tree or shrub with Cytospora canker? Individual upper branches may show symptoms as well. Canker in plum trees comes from an invasive fungus, which can eventually eat away at and kill your plum trees if left untreated. Decontaminating tools will help prevent movement of Cytospora kunzei from branch to branch and from tree to tree during pruning. 4 0 obj stream Cytospora canker usually first appears on lower branches and progresses up the tree. These structures release yellow tendrils of spores in wet weather. a� �VI�I�Ƒ?GN\1X�\��(� [�� It appears most frequently on Colorado spruces and Norway spruces. Over several years, symptoms of cytospora canker spread and upper branches brown and die. Also minimize environmental stresses to any tree susceptible to Cytospora canker. Immediately remove and destroy any diseased branches by pruning them using the three-point method of pruning (see University of Wisconsin Garden Facts XHT1014, “How to Properly Prune Deciduous Trees”, for details). Optimally, when trees are full sized, they should be far enough apart so that branches do not overlap. We had our plant pathologist look at your photos and he does not think this is a disease. What does Cytospora canker look like? is the one that does the vast majority of the killing It is the number one killer of the Colorado blue spruces and only occurs on spruces when the trees are not grown in their native range. endobj p�W �X�h��}Q��(�q]k����_Tx{ ܵdֈ����R^4�R�$ A smaller tree will have a canopy where air will more easily penetrate into the interior, thus drying branches and needles more rapidly. "��t ���#E2�&�1N�sbO4�ɵ y~ ��/Ɛ˽y_�X���|�xv���yv6�I������ۃ+�Dy��M��b���P9,Y5��7S�u���������/`e�䢂K+h��3��.�� What does citrus canker look like? What does Cytospora canker look like? endobj <>/Metadata 145 0 R/ViewerPreferences 146 0 R>> This disease can also affect Engelmann, Norway and white spruce, as well as balsam fir, Douglas-fir, European larch, tamarack, and white pine. <> Spray disinfectants that contain at least 70% alcohol also can be used. Cytospora canker usually first appears on lower branches and progresses up the tree. 1 0 obj Plant Disease Diagnostic Clinic Dead areas of bark appear, known as cankers. In our experience, pruning crews are often loath to make the extensive cuts required to remove Cytospora cankers. DO NOT pile mulch against the trunk of the tree; keep mulch approximately four inches from the trunk. Proper spacing will provide good air flow and again promote drier conditions that are less favorable for disease. To help maintain proper soil moisture, mulch out to at least the drip line of the tree. Therefore, growers, managers and/or PCAs should monitor pruning cuts or downed wood to make sure pruners are making clean cuts – not leaving Cytospora in the trees – as they move across the block. The species P. syringae exists as a large number of pathovars, (abbreviated to pv. Prevent water stress by avoiding soil compaction and by ensuring adequate soil drainage. x��=ko�8���?���E���� �m:�t�3�l������(���XN���sI=,1�ҸR۔����y��~�������}x���ٛ�g��?��>>����Ȋ���Be��̔qk3�'�L�pc������R��M���ȾA��O�_��|>+5~Hò�?>�X��숱"��,�+���X�0���#�]�Me&���,��t��_����~��,��8�Lp�K�qk�Rd\��NGg���|zn�7�@�;��9�y~��#�p��5�{��"���?`¿'o���z:��l:c�d3����t&����|��j;U��޲���|����U= �?O�C������Vj���b�������!��E��&-����.��������g���$QiX�5v�g��a�6���&5`-\�Q����:���au_e4���� F��h �L���x/�1�����0������!F��aCX�w:���i1�nk�v3�y��c.T�s���������wJ�(A#Z���3����se3c�3d� (c8��O���)�U*�B��}Ƣ�mu7�s�{ K���? Dead areas of bark appear, known as cankers. If you choose to plant a full-sized tree, leave adequate space between the tree and other trees in your landscape. These trees are susceptible to boring beetles and white pine weevils, especially in … The University of Wisconsin Soil and Forage Laboratory ( can assist with soil and plant tissue fertility testing, as well as provide fertilization recommendations. Spores are spread to new branches by wind or rain. They may be present for several years, extending along the branch, before they kill it. Of the three, Cytospora spp. A complete inventory of University of Wisconsin Garden/Farm Facts/Pest Alerts is available at the University of Wisconsin-Madison Division of Extension Plant Disease Diagnostics Clinic website: Individual upper branches may show symptoms as well. Cankers can develop on the large branches or even the trunk and enlarge to the point where they'll choke off and kill the part of the tree above them. 1630 Linden Dr. Room 183 Cytospora canker is a fungal infection that affect a variety of stone fruit trees, including peach trees. Dark, raised, pimple-like, spore-producing structures form on infected branches. The fungus survives in infected branches and spores are spread by wind, rain splash, insects, birds, and mammals. How to Control Cankers. Over several years, symptoms of cytospora canker spread and upper branches brown and die. For more information on Cytospora canker:  See UW-Extension Bulletin A2639, “Colorado Blue Spruce and Other Spruce Disorder:  Cytospora Canker” (available at, or contact your county Extension agent. Needles on infected branches turn purple, then brown and die. Cytospora canker rarely kills spruce trees, but it can severely deform them. Prune only in dry weather. The disease often makes trees look so unsightly that owners will have the trees removed. One of the first symptoms of cytospora canker disease on spruce is the browning of needles on the tree’s lower limbs. Cankers on stems and branches are often elongate, slightly sunken, discolored areas in the bark. Symptoms are seen on a variety of fruit and shade trees throughout the United States. Needles on infected branches turn purple The fungus grows so fast on stressed trees that there is no evidence of a sunken canker. In general, a drier environment is less favorable for disease development. Diseased needles eventually fall off and infected branches die. Occasionally, it attacks Koster's blue spruce and Douglas fir. Cytospora canker is one of the most common fungal diseases of Colorado blue spruce.