Vol. XVIII. No. 441. 



THE AGRICULTURAL NEWS. 



PRUNING CITRUS TREES. 



An item of great importance in citrus cultivation is the 

 pruning of tbe trees. When the young tree is removed from 

 (he nursery much of its root system, especially the fine 

 feeding roots, has been cut away, so that it is necessary to 

 reduce the top in order to give the root system a chance to 

 recuperate, and also to provide a strong frame work for the 

 future tree. The Queensland Agricultural /ourfial. 

 December 1918. gives some useful hints on this subject. 



Only a limited number of branches should be left — not 

 less than three, nor more than five — as these branches even- 

 tually become the main limbs of the trees. The mistake is 

 often made of leaving too many branches, with the result 

 that they are too crowded and weak, so that when ihey are 

 laden with fruits they are unable tp.bear I he weight, and 

 frequently break down. This is often the case with mandarin 

 orange trees, which are apt to produce a dense growth of 

 weak wood unless the main limbs are properly established, 

 and subsequent growths severely thinned. If the tree is not 

 pruned out properly, it will probably yield a great crop of 

 undersized fruits one year, and very little fruit the next. 



No citrus tree should be allowed to grow into a dense 

 bush. A typical citrus tree should have, one main trunk, from 

 2 to 3 feet high, with not more than three to five main 

 branches and these m»in branches should only be allowed to 

 carry sutfioient subsidiary branches to form the frame work of 

 the tree. All others should be removed. 



The inside of the tree should never be crowded; the limbs 

 should be properly spaced, and the outer branches on which 

 the fruit is produced should not only shade the inside of the 

 tree, but the ground under it. The ground requires shading 

 from the heat of the sun. 



Many citrus growers are afraid to prune hard enough, but 

 there is frequently much more harm done to trees by too little 

 pruning than by too much. Properly pruned trees produce 

 regular crops, as they make a good growth annually, but 

 underpruned trees are very apt to bear a large crop one year, 

 and consequently to make little new growth, so that the 

 following year they only produce a small crop, because they 

 have to make wood for the next season. 



The pruning of the lemon is different from thit of the 

 orange or mandarin, because the long straggling growth 

 which the lemon is prone to throw out must be kept well 

 shortened in order to encourage the production of fruit-pro- 

 ducing lateral branches. In pruning the lemon therefore, the 

 main object is to encourage the lateral growth on which the 

 fruit is produced, and to discourage the production of long 

 straggling branches. — 



The foregoing remarks apply to the pruning of young 

 and healthy trees, but it often happens that another class of 

 pruning is necessary, namely pruning old trees for renova- 

 tion. If such pruning is carefully carried out, many an 

 apparently worthless tree cin be made to produce a profitable 

 CTop. The bearing wood of many old trees frequently 

 becomes useless as the result of drought, neglect, starvation, 

 ■want of pruning, insect or fungus pests, etc. The roots of 

 such trees should be carefully examined, and if they are found 

 to be healthy the trees can be renovated by proper treatment. 

 This consists of removing the top of the trees, cutting back 

 all limbs to sound healthy bark and wood, and removing all 

 dead or superfluous branches. The trees should be then painted 

 or sprayed with a strong solution of lime sulphur. The ground 

 round the tree should be well worked up, and a good applica- 

 tion of manure given. This work should be done when the tree 

 is more or less dormant, and as soon as the rains come young 

 shoots will make their appearance aft'<>ver the tree, which 



should be carefully thinned out, only leaving enough to form 

 a well-shaped new top. If this work is carefully carried out, 

 an old tree which was practically useless will have a new 

 head of vigorous growth, and will continue to bear good 

 fruit, and if it is then preperly looked after, it will continue 

 to yield a profitable return for inany years. 



PROPER PACKING OP HEVEA SEEDS. 



Many complaints have been made in the past as to the 

 poor germination of oon-signments of Hevea seeds from one 

 country to another. In the India Jiubber Journal, December 

 28, 1918, an article by .J. G. A. Maas records the writer's 

 conclusions after a series of experiments conducted with a view 

 to finding out to what the speedy loss of germinative power was 

 due, and what measures should be adopted in preserving and 

 dispatching Hevea seeds to obviate rapid deterioration. 



The experiments have led to the following conclusions, 

 and given the following practical results: — 



All measures to be adopted in the preserving and dispatch 

 of seeds should be directed towards the prevention of drying up. 

 The seeds dry up quickly, and thus lose a large proportion of 

 their germinative power. For preference, collect the seeds 

 daily, otherwise every two or three days. 



Do not let the freshly collected seeds lie in the open, but 

 protect them from drying up. Note carefully not to let them 

 lie in the sun, and do not spread them out thinly, even on 

 sheltered floors, not even whgn the seeds h'lve to lie not more 

 than a few days. 



Do not preserve or dispatch seeds in air- tight or close 

 soldered tins. This is only admissible in a low temperature, 

 e.g. below 10° C. Many seeds die in closed receptacles, 

 probably as a result of si;ffocation and moulding. 



The dipping in was of each individual seed — with .or 

 without previous disinfecting — in the manner, for example, in 

 which cacao fruits are treated, is probably quite good under 

 certain conditions. It is, however, laborious. 



For the dispatch of seeds, use cases not larger than 30 

 by 40 by -50 centimetres, of strong timber, e.g. 1.5 millimetres 

 thick, with strengthening pieces on the corners. 



Line the cases on the inside with oil paper, .Japanese 

 paper, or rough packing paper, and divide up the contents, 

 when filling, with several folds of stift' paper in three or four 

 layers. The paper lining on the inside serves to oppose 

 drying up, and the dividing up in layers prevents the seeds 

 and packing materials from getting separated by the shaking 

 in transit. 



Use, as packing material, something which will retain 

 the damp, and dampen that material intentionally when filling 

 the cases. A gocd material for this purpose is powdered 

 coco-nut refuse mixed with soil or crushed charcoal. Freshly 

 crushed charcoal acts as a drier. The charcoal should be 

 dampened. A little damp clay mixed or not mixed widi 

 charcoal, is also a go.jd packing material. Do not use loo 

 little packing material. • ' '■ 



When stored in a temperature of .5^ to 10° C, the ger- 

 minative power of Hevea seeds rem lins well maintained. Not 

 very much packing material nci- i therefore be used, and 

 packing in bottles or tm^ can also i<t,- done without packing 

 materials. That is the temperature of the refrigerators of 

 large ocean steamers. In eventually importing limited quan- 

 tities of new material froro the place of origin of the Hevea 

 trees, this method would appear to be of great utility. In 

 this temperature th st^edt dc not germinate durinsi the 

 journey. 



