How to Prune Short Branch Fuji Apple Trees
As an important member of the Fuji apple family, short branch Fuji is favored by fruit farmers due to its easy flowering and stable fruiting. However, it is this high-yield characteristic that makes scientific pruning a key step in ensuring fruit quality. Reasonable pruning can not only adjust the distribution of tree nutrition but also optimize the crown structure, achieving a dual improvement in yield and quality.
I. Core Techniques for Flower Bud Management
Accurate Thinning of Flowers to Save Nutrition
Each branch of short branch Fuji can form 6-8 flower buds, far exceeding normal requirements. Excessive retention of flowers can lead to nutrient dilution, increasing the rate of small fruits by 20-30%. It is recommended to use the 'Three Finger Rule': within 30 cm from the base of the branch, keep quality flower buds at intervals of 15-20 cm, and remove the rest. Special attention should be paid to removing malformed flower buds growing inward, as these buds can block sunlight after fruiting.
Breaking Bud Pruning to Promote New Branches
Considering the small leaf area of short branch Fuji, 'Breaking Bud Pruning' can be used. Make a diagonal cut on the top 1/3 of the flower bud with pruning shears, destroying the apical dominance while retaining the base bud eye. This operation can increase the germination rate of medium and short branches by 40%, effectively expanding the leaf area. Be sure to perform the operation on sunny days and apply healing agents to the cut surfaces to prevent diseases.
II. Branch System Management Plan
Dynamic Control of Branch Quantity
Retaining 60,000-70,000 branches per mu is considered the golden density. This can be judged by the 'Three Observation Principles': observing light transmission (30% crown light transmission), branch spacing (main branches spaced 80 cm apart), and the age of fruiting branches (timely renewal of branches over 3 years old). Pruning is divided into two sessions each year: in winter, remove diseased and crossed branches, and in summer, focus on thinning vertical, rapidly growing branches.
Strategy for Renewing Large Branches
Use the 'Alternating Backcut Method' to renew main branches, selecting 1-2 fruiting large branches over 5 years old each year, and making a backcut 30 cm from the main trunk to stimulate the growth of new branches from hidden buds. Combine this with 'Wound Healing Technology': treat the cut surface with a 5% copper sulfate solution, then wrap it with a breathable film, which can advance the germination time of new branches by 7-10 days.
Through systematic pruning management, short branch Fuji orchards can increase the rate of premium fruits to over 85%. It is recommended to complement this with nutritional diagnostics and promptly supplement calcium, boron, and other trace elements after pruning. Mastering the pruning principle of 'controlling flowers to promote leaves, and orderly replacement' can ensure both current yield and continuous healthy growth of the tree.