Vol,. XVI r. No. il3. 



THE AGRICULTURAL XEVTS. 



The most interesting of tbf results obtained from the 

 experiments is the evidence they afford of strong negative 

 pressure^ in the water column during tlie afternoon, so that it is 

 entirely possible for the leaves to draw water back from the 

 young fruits. The actual dt crease of water in the fruit was 

 indicated to be as much as 15 to 20 percent., most of which 

 is believed to be caused in the manner above described. 

 The dropping of the fruit appears to be most severe when 

 the water relations are most abnormal, and there is consid- 

 erable probability that the shedding is a reaction to these 

 conditions. 



OPTIMUM MOISTURE CONDITIONS FOE YOUNG LEMON TEEES ON 



A LOAM SOIL, L. W. Fowler and C. B. Lipman 



{Ibid. Vol. 3, No. 2). 

 The conclusions reached are as follows: — 

 'In attempting to determine the optimum moisture 

 content of a rather heavy loam soil for young Lisbon lemon 

 trees grown in cylinders, at the Limoneira ranch, Santa 

 Paula, California, the following information wa.s obtained in 

 the course of the tirst two years of the experiment: — 



(1) A moisture percentage of 20 per cent, based on the 

 dry weight of the soil has produced the tallest trees. 



(2) Trees grown with 16 and 18 per cent, of moisture, 

 while not as tall as those grown with 20 per cent of soil 

 moisture, show better colour and more vigour. The differ 

 €nces are not very marked, however. 



(3) The foregoing facts seem to show that the range 

 of optimum or nearly optimum moisture percentages for the 

 soil and plant in question is a relatively wide one. 



(4) Much more visible damage results to the young 

 lemon trees from moisture percentages in excess of the 

 optimum than from those below the optimum. 



(j) Every successive increment of moisture beyond the 

 optimum is accompanied by a sharp depression in growth, 

 colour, and general vigour of the trees. 



(6) Every successive decrement of moisture from the 

 optimum shows only a relatively slight depression in growth.' 



W.N. 



SORGHUM TESTS IN QUEENSLAND. 



The London correspondent of the North Queinsland 

 Re'jiiler sands us the following interesting note on experi- 

 ments with varieties of Sorghum or Guinea corn in the 

 tropical districts of Queensland. It is evident that this 

 ^rain will prove to have as much value there as it has in 

 other tropical lands: — 



'Some interesting work has been done in Queensland 

 by the State Department of Agriculture in experimental 

 test growing of non-saccharine and saccharine varieties of 

 sorghums for seed and fodder purposes. Some of the returns 

 obtained exhibit features of interest in relation to their 

 important bearing on production. 



'The non-saccharine sorghum? are particularly valuable 

 to Queensland in many ways. The grain is usually bold in 

 character, and larger than the commonly known sorghums. 

 The white-seeded varieties form excellent food for human 

 beings or for stock, and the other more or less coloured kinds 

 are good alike for poultry and stock, particularly for fatten- 

 ing pig?. 



'This group of plants seems co be designed by Nature 

 to reproduce themselves in the face of adverse seasons. They 

 ■will ati'ird seed where maize would fail to produce a p yable 

 crop of grain, and thfy are undoubtedly prolific'. 



A NEW PALM WAX FROM COLOMBIA. 



A sample of crude wax obtained from the leaves of 

 Ceroxylon andicolu'i', Humb. l^ BonpL. the wax palm of the 

 Andes, was recently forwarded to the Imperial Institute for 

 examination and report. The palms, which oscur only in 

 western tropical South America, are stated to be exceedingly 

 abundant, but no was has yet been exported, although it is 

 used in Colombia for making candles. 



The sample in question con.sisted of tine powdered wax 

 of a pale straw colour, with a sm-ill admixture of vegetable 

 matter. After purification and removal of the vegeteble 

 matter, the wax was analysed with comparatively satisfac- 

 tory results. The puritied wax was completely soluble in 

 cold chloroform, carbon tetrachloride, benzine, or hot turpen- 

 tine oil, but it was not completely soluble in cold alcohol, 

 ether, or light petroleum. 



As prepared, the wax was submitted to firms of manu- 

 facturers and brokers, who reported ( 1 ) that the material 

 could replace Carnauba wax for many purposes. They 

 stated, however, that its value would be considerably 

 enhanced if it could be bleached, and that this process would 

 also widen its field of possible application in industry. 

 (2) A .second firm stated that the product could certainly 

 be employed industrially, and that its use was simply 

 a question of price. (3) A firm of brokers stated that it 

 was possible they might be able to place sapplies of tha 

 material on the market as a substitute for Carnauba wax:. 



This palm wax when purified, is said to be similar in 

 character to Carnauba wax, the product of another palm 

 {Copernicia <-irifera) which is collected chiefly in Brazil, and 

 to the Candelilla wax obtained from a species of Euphorbia 

 imported from Mexico, with the exception that its melting- 

 point is higher. It should be readily saleable at the same 

 prices as these waxes, which before ihe war were selling in 

 the United Kingdom at £b to £10 per cwt. 



As it would be necessary to purify the was before export, 

 experiments were mide at the Imperial Institute with the 

 object of devising a simple method of purification, especially 

 from vegetable debris. The following means were sug- 

 gested: — 



'The crude wax-dust, as collected, should be placed in 

 a canvas or calico bag. and immersed in boiling water, the 

 bag being weighted to keep it btlow the surface; most of 

 the melted wax will then gradually pass through the fabric 

 and rise to the surface of the water. A convenient device 

 would be a strong canvas bag, the mouth of which is sewn 

 or tied up after the bag has been filled with the wax dust. 

 Two sticks, each with a slit in one end, can bs fixed easily 

 along the top and bottom of the bag by means of screws. By 

 twisting the sticks pressure is exerted on the canvas bac and 

 causes the melted wax to pass through the canvas. Tha 

 water with the layer of wax on top can then be allowed to 

 cool. When ijuite cold the wax can be removed, powdered, 

 and dried in the sun or in a warm place. The dried pjwdered 

 wax should finally be melted in a deep vessel over a small 

 fire, or better, in an oven at about 110 C, care being taken 

 not to heat it longer than is necessary, or at .i higher 

 temperature than 1 10'C.,as otherwise it will darken in colour. 

 The remeltei wax on cooling will be found to have deposited 

 a dark layer at the bottom of the cake; this can be cut off 

 and either sold as a lower grade of wax or worked up with 

 the next batch of wax-dust. The cake thus freed from tha 

 dirty material will be ready for shipment. 



the Iih 



The above information is gleaned from the BulUun of 

 mperial Institute, Vol. -KV, No. 2. 



