Show I PRACTICE OF BRIDGE GRAFTING OFTEN SAVES INJURED AND DISEASED TREES R R i ft F f How a Wound Is Repaired by Bridge Grafting Prepared b by the United States Department Department Depart Depart- ment of or Agriculture Bridge grafting the use e of scions or or small limbs to connect the cambium above e an and below a n large wound or girdled le strip may be practiced successfully successfully suc suc- ces on almost any kind of fruit tree that can cnn be propagated readily b by grafting Trees girdled leli by mice or rabbits suffering from mechanical In Injuries Injuries injuries In- In juries or from blight or 01 other disease dis ease case can be saved in many cases by hy bridge grafting The method metho also Is useful when large areas of bark have bc been n killed by hy sun scald and other In In- juries Effective Grafting To be effective bridge grafting should be done In the spring before growth starts though sometimes Itcan It Itcan itcan can be done after growth starts If It dorm dormant nt scions for tor the purpose can be secured Prepare the wound in the tree by cutting awa away nil all dead dea tissue and thoroughly thoroughly thoroughly thor thor- cleansing the Injured parts If possible sterilize by washing with a n solution of e of ot mercury coper coper cop- cop er or sulphate or some other antiseptic The Irregular edges of the bark above e tho the girdle tract or wound should be cut back Into an nn even edge far enough from the wound to make certain that healthy cambium is under the bark For the grafting select scions from wood of the previous seasons season's growth either cither branches which grew the preceding preceding preceding pre pre- ceding season or 01 water sprouts that are on only a 0 year old The scions should be a little longer than the space which Is to be bridged so the they will arch slightly over the central centra part of the woun wound Bevel the scions at nt each end on the same sl side e of ot the scion with a long sloping cut so that the wedge-shaped wedge ends thus formed forme will be relatively thin and anil permit their being thrust well under the bark without danger of of- separating It unduly from the cambium camm cam cam- hium at the points of Insertion The placing of the scions will be facilitated ed If the bark at nt the margins of the woun wound Is slit silt for a u short distance at atthe atthe atthe the points where the ends are to be Inserted Importance of Uniting Cambium In placing the scions It Is of the greatest importance that the cambium of the scions which is exposed In the sloping cuts nt at the ends be brought into intimate contact with the cambium cambium cam cam- blum that lies under the bark baric at the margins of the woun wounded e area The union of scion nn and tree can occur only where the cambium layers of the two come together The scions may be secure secured in their proper positions if It need be by driving a small nail through each end Into the trunk This will aid in drawing the cambium of scion and trunk closely together The operation is completed by thor thoI covering co the area occupied by byth bytha th tha ends of ot the scions an and the margins of the wound with grafting wax strips of waxed cloth or by some other means that adequately will prevent these parts from drying out Some operators cover o the entire wound scions and all nIl with melted war wax Where the bridged portion Is below or near the ground many operators conserve moisture by covering the grafts with earth Bridging From the Ground Where the wound Is so o large as to tomake tomake make or ordinary bridge grafting Impossible Impossible impossible sible another method of bridging may maybe maybe maybe be use used Two Two- year Two ear ol trees are planted about the base of the Injured tree and their tops grafted Into its trunk above the girdled space which has first been cleaned as in the other method As the tops of the small trees are too large to manipulate readily In the manner described for scions V-shaped V vertical grooves esten extending extending ex es- ex- ex ten tending through the cambium are cut Just above the wounded area In the bark of the tree to be treated The tops top of the small trees are shaped to correspond with these grooves The two are then accurately fitted together In such a manner as to bring the cambium cambium cambium cam cam- of ot one Into contact with that of ot the other Small nails may be driven through the tops of the trees Into the trunk to hoJ hold the parts firmly together er The woun wounds s Incident ent to Joining the tops of the small trees to the trunk of the large lare one should be well covered with wax to prevent pre drying out Sometimes cord Is tied around the trunk to aid in hoJ holding the tops of the young oun trees In proper position |