Methods of Collecting and Disposing of Prunings

New Zealand Journal of Agriculture, Volume 87, Issue 1, 15 July 1953, Page 19

Methods of Collecting and Disposing of Prunings

THE slow and arduous task of picking up • and burning orchard prunings by hand is gradually becoming outdated with the introduction of more modern methods. With the tendency toward an increase in mechanisation in orchards many fruit growers now use their tractors to do this job in a fraction, of the time of hand work and at greatly reduced cost. The various methods used by orchardists are outlined in this article by N. B. Congdon, Horticultural Instructor, Department of Agriculture, Hastings. A COMMON practice is to remove the heavier prunings and to disc in the remainder. It is claimed that this adds humus to the soil and saves time and labour. However, where a large quantity of wood remains on the ground most growers feel it necessary to remove and destroy as much of it as possible, leaving only the smaller and softer prunings to be worked into. the soil. Progressive Burning One method is to burn prunings progressively as the orchard is pruned. Prunings are collected by hand or with a fork and thrown into a portable furnace. This can be made of a halved 40-gallon drum or a larger tank which is attached to a chassis mounted on wheels. The furnace is usually made light enough to allow it to be pulled by hand from one part of the orchard to another. Once a good depth of embers is built up prunings burn easily, but holes should be made in the drum to create a draught. Larger limbs often require trimming to make them settle into the drum as they burn. Pruning Sheet The pruning sheet has been used fairly widely in the past, but nowa-

days has generally given way to more modern methods. Usually the sheet is composed of two pieces each measuring 20ft. x 10ft., but occasionally it is divided up the middle only as far as the centre. Sheets are placed beneath the tree before pruning and moved on to successive trees until the sheets are filled. Prunings are then emptied into heaps and from there forked either into portable burners, loaded on to trailers, or removed by hay sweep to a large stack for burning. - Sheets are usually hessian,' which is light and relatively durable. Modern Mechanical Methods The most modern methods require a tractor with various attachable implements. . A harrow may be used to advantage in collecting most of the prunings into windrows. A hay sweep attached to the front of the tractor may then be used to remove the rows of prunings to a common heap for burning. If two tractors are available, the sweep attached to the second tractor can take up the rows of prunings almost immediately. With this latter method it is possible to dispose of prunings from a 10-acre orchard within 2 to 3 days. Sometimes difficulty is experienced where ground is uneven and breakages of wooden prongs are unavoidable. The sweep method works more efficiently where the ground is level and where metal prongs bent slightly upward at their

extremities are used. When the height of the sweep above ground can be controlled hydraulically, working on uneven ground is no longer a problem. Use of Buckrake A hydraulically operated buckrake drawn by a tractor is used by some growers. With this equipment one man can remove prunings from a 5-acre pip fruit block in a day. On very uneven ground it may be necessary to use harrows for placing prunings in rows, but usually the buckrake is the only implement required, as the hydraulic control allows the rake to be set and regulated according to the ground level. The buckrake is solidly constructed of steel and as well as being capable of gathering the heaviest of limbs it can be used also for compacting prunings on the heap. The only disadvantage of this method is. that the operator is working backward and some physical inconvenience is thus incurred. Usually three or more fires are required to keep up with the rapid inflow of prunings by either the buckrake or hay sweep methods. Fires are placed at headlands or on waste ground well away from fruit trees. It has always been found difficult to burn prunings placed in . a heap by hand. The prunings are not consolidated sufficiently for a fire to consume the heap completely. When heaps are made with a sweep or buckrake they can be compressed by the tractor and once a fire is well started it will consume the whole heap rapidly. ■■ To create a good initial blaze old tyres, waste oil, or the contents of fire pots can be used.