Vol. X. No. 24G. 



THE AGRICULTURAL NEWS. 



309 



During the early years of growth other plants can be 

 cultivated between the young trees. In Java it is a common 

 practice to grow pepper in this way, but it should not be 

 planted before the kapok trees are three or four years old. 



The trees begin to bear in the third or fourth year, but 

 sometimes not till later. The crop is never very large until 

 the sixth year. A large tree brings 1,000 to 1,500 fruits to 

 maturity per annum, each of which contains about 07 to 1'2 

 grammes of dry fibre. Hence, on an average a well-developed 

 tree may be expected to give an annual yield of f to l\ 

 kilogrammes (or about H to 2| lb.) of clean fibre. 



The tree flowers in April or May, and the fruits mature 

 at the end of October or in November. As the fruit ripens 

 it becomes yellowish-brown and ihen begins to open. As 

 soon as this point is reached, the fruits are gathered by 

 means of long bamboo poles bearing small hooks at the 

 upper ends. They are then left on a clean floor, preferably 

 of cement, and exposed to the sun in order that they may 

 ripen completely .ind open fully. The fibre and seeds are 

 picked out of the capsules by women and children and dried 

 in the sun for some days. 



The seeds are usually removed from the fibre by beating 

 with sticks, or by means of a simple machine. A special 

 form of gin, resembling a cotton gin, has been recommended 

 for the purpose, but it must be remembered that in most cases 

 the kapok is only a subsidiary product, and produced in small 

 quantities, so that the provision of expensive machinery would 

 not be remunerative. 



The kapok is packed in bales by means of hydraulic or 

 hand presses, but must not be compressed too severely, or its 

 resilience will be impaired, and its value consequently dimin- 

 ished. Each bale weighs aliout 80 lb. The number of bales 

 exported from Java in recent years is as follows: 1907, 92,874; 

 1908, 109,8.52: 1909, 87,685. 



The value of the total imports of kapok into the United 

 Kingdom amounted to £23,752 in 1908, and to £27,645 in 

 1909. 



An account of the properties and u.ses of the fibre has 

 been given in this Jltilletin (1905, p. 221). 



A German firm has recently discovered a method by 

 means of which kapok can be spun either alone or in admix- 

 ture with cotton (see this Bulletin, 1911. p. 70). 



The market price of kapok has advanced during the last 

 few months from 'd. to about 9cif. per lb., and it is therefore 

 possible that the collection and preparation of this fibre for 

 export would prove a remunerative industry in certain British 

 Colonies and Dependencies. 



THE WATER REQUIREMENTS OF CROPS- 



Volume I, No. 10, of the Memoirs of tlw Depurtment of 

 Agriculture in India has been received. It concludes the 

 account of work that has been done by Mr. J. AV. Leather. 

 Ph.D., F.I C, Imperial Agricultural Chemist for India, in 

 regard to the water requirements of crops in that country. 

 The following facts are taken from the conclusions that are 

 expressed at the end of the account of the investigation. 



It was found that the water content of the soil that is 

 necessary for the proper growth of the plant varies largely 

 with the nature of the soil. Under field conditions, the effect 

 of the plant on the water content is to cause this to be lowered 

 throughout a number of feet of the soil in its vicinity. Thi.« 

 decrease, in the Pusa soils employed in the ejfperiment, was 

 found to be more or less uniform for about •'> or 6 feet; below 

 this the change is smaller. 



Observations were made for the purpose of finding the 

 lowering of the water content in a column of soil of given 

 dimensions. They showed that, allowing for evaporation 

 from the soil, the relation between this and the amount of 

 the crop produced is very nearly the same as that obtained 

 in experiments employing pot culture. It follows from this 

 that the observed decrease of water within the range of the 

 roots of a crop will give an indication of the quantity that is 

 required by it. 



After plants growing in soil have reached maturity, the 

 water content is Tower than it would have been if the land 

 had been allowed to remain fallow. When such plants no 

 longer occupy the ground, there is a tendency for water to 

 move from below toward the drier soil, but the process is 

 very slow. These and other considerations show that a crop 

 grown during the rainy season causes the amount of water ia 

 the upper parts of the soil occupied by the roots to be de- 

 creased, while that below this level contains an approximately 

 normal quantity. If a dry weather crop is grown in such soil, 

 the supply of water that is obtainable by the roots will be 

 defective, while it is not possible for the deficiency to be made 

 up by water from the soil below, even though it may be 

 present in very large quantities. The following interesting 

 general conclusion is also expressed: ' The whole of the facts 

 which have been brought out by the experiments detailed in 

 this memoir would be accounted for if the quantity of water 

 which can move through a soil per unit time were dependent 

 on the three factors, concentration, distance and physical 

 character of the .soil; temperature also, no doubt, has an im- 

 portant influence.' 



The author concludes by suggesting that if a laboratory 

 method could be devised for estimating the capacity of the 

 soil to conduct water, this method would prove of very great 

 value to agriculture. 



THE COAGULATION OF FIOUS ELASTIOA 

 LATEX. 



The Journal d' Agriniltnre Tropicale for April 1911 

 contains details concerning a new method of producing th« 

 somewhat ditticult coagulation of the latex of Ficus elastica. 

 This has been evolved in Java, where the tree is grown foi 

 rubber to a large extent, the latex being usually coagulated 

 mechanically, by beating with a wooden spatula. This 

 process requires a long time and a deal of labour, and in 

 consequence much has been done in the direction of finding 

 a way in which it may lie hastened. 



The principle of the new method is to ' encourage' coag- 

 ulation by the addition of a coagulum obtained in the follow- 

 ing way. On each day, about a pint of the thickest latex is 

 taken, and coagulation started by stirring (not beating) it 

 with a wooden spatula. When this has arrived at its proper 

 stage it is added to the ordinary, thinner latex, when the 

 rubber separates out in about a quarter of an hour, instead 

 of the hours that are required by the method in which beating 

 is employed. It is on account of this action that the added 

 coagulant is said to 'encourage' (amorcer) the coagulation. 



The writer of the article draws attention to the fact that 

 the advantage of such a method is that no foreign matter is 

 introduced into the latex, so that the maximum chance is 

 given for the production of rubber po.ssessing its natural 

 characteristics, and concludes with the suggestion that trials 

 of the method might well be made with the latex of C'astilloa 

 elastica. 



