Vol. VIII. No. 192. 



THE AGRICULTdRAL NEWS. 



281 



The Action of Heat and Antiseptics on Soils. 

 Experiments that have been conducted by the 

 Imperial Department of Agriculture have indicated 

 that the treatment of soils with carbon disulphide has 

 a tendency to cause an increase in the growth of plants 

 that are subsequently raised in them^au increase that 

 cannot, of course, be accounted for on the supposition 

 that the carbon disulphide directl}' adds plant food 

 to the soil. Light appears to be thrown on the subject 

 by some experiments that have been undertaken at the 

 Rothamsted Experiment Station, the purpose of which 

 was to compare the effect of moist heat, and of various 

 antiseptics, such as carbon disulphide, chloroform, 

 benzene, ether and kerosene on the productiveness of 

 soils. It was found that when soils are treated with 

 such antiseptics, chemical changes take place and 

 the amount of soluble organic matter in them is 

 increased, just as is the case when they are heated. 

 Like heated soils, too, they have the effect of prevent- 

 ing germination of seeds in them, to a certain extent. 

 This effect is due to the presence of some definite sub- 

 stance which is probably the same in all cases, and also 

 the same as that formed by heat. The amount of 

 change caused by antiseptics is equivalent to that 

 obtained by heating the soil to about 60 C. or 75 C, 

 and this may be sutScient to account for the increased 

 growth of plants in soils which have been treated with 

 them. When such soils are kept for a few weeks at 

 a summer temperature, some of the organic matter 

 that has been rendered soluble becomes insoluble, and 

 their action in preventing germination is reduced. 

 Heated soils showed a similar decrease in the amount 

 of soluble organic matter, especially when they were 

 repeatedly watered ; on the other hand, in ordinary 

 soils its amount is increased. 



Agricultural Conditions in Bermuda. 



It is stated that the importance of Bermuda as 

 a producer of early vegetables, etc., is decreasing and 

 that it is rapidly attaining increased impoi-tance as 

 a tiiurist resort. The chief reasons for the decline are 

 said to be connected with the depletion of the soil, the 

 increase of fungus diseases, and the changed conditions 

 of competition in the United States. In regard to the 

 last, the area on which crops such as the potato and 

 onion are raised in the latter country is so large, and 

 the transport of the produce so quick, that the small 

 area of arable land in the former cannot hope to 

 continue to compete. An additional disturbing factor 

 is that the system of reporting shipments from Hamil- 

 ton a week in advance causes the produce to arrive on 

 a falling market instead of on a rising one, as was 

 formerly the case. 



On the other hand, the increasing recognition of 

 Bermuda as a resort for the winter months has led to 

 a corresponding increase in the number of tourists 

 arriving there ; so much so, that this was nearly four 

 times as great in 1908 as in 1907. This is leading to 

 the erection of new hotels, as well as to the enlarge- 

 ment of those which exist already, and the chief effect 

 on agriculture will be that crops will bo raised for 

 home consumption rather than for export. 



Washes for Cacao Thrips. 



The annual report on the Experiment Plots, St. 

 Lucia, for 190.S-9, describes experiments with different 

 washes for the purpose of determining their efficiency 

 in controlling thrips on cacao trees. The trials were 

 conducted with those described in the Went Indian 

 Bulletin, Vol. IX, pp. 191-2, which are (1) resin wash, 

 (2) kerosene emulsion, (.3) emulsion with whale-oil soap, 

 (4) resin and whale-oil soap compound. It is stated 

 that each of these was more or less effective in 

 destroying thrips, but that the resin wash appeared to 

 do the best work, on account of its property of sticking 

 firmly to any surface with which it may come into 

 contact. ' More of this mixture adhered to the leaves 

 than in the case of the other washes, and dead thrips 

 were observed in greater numbers on trees treated 

 with it.' 



Some care is necessary, however, in applying this 

 wash, as the trees treated with it dropped their leaves 

 within a few weeks of being sprayed. This circumstance 

 was probably due to the fact that it contains caustic 

 soda. 



The Best Conditions for Growing Alfalfa. 



The New York State Agricultural Experiment 

 Station has recently carried out more than 100 experi- 

 ments, in co-operation with farmers, for the purpose 

 of finding out what effect the operations of liming and 

 inoculating land on which alfelfa is to be grown has on 

 the chances of raising a successful crop. The results 

 show that the chances of raising a good crop are as 

 follows : one in five, where neither liming nor inocu- 

 lation is employed : two in five where lime is applied 

 at the rate of 13i cwt. to the acre ; three in five, 

 where naturally inoculated soil is added at the rate of 

 about 2 cwt. to the acre : four in five, where both 

 liming and inoculation are employed. The trials 

 were made on land poor in nodule-forming organisms, 

 and which was in the receipt of the usual cultural 

 operations. 



Germination of Ceara Rubber Seeds. 



A rapid method of germinating Ceara rubber seeds 

 is in use at La Zucualpa Botanical Station, Mexico. It 

 consists in placing a layer of fresh horse manure in 

 a box, to the thickness of about 6 inches, spreading 

 the seeds on the surface, and covering with about 1 inch 

 of the same material mixed with a small quantity of 

 sand. The soil should be slightly packed, and the box 

 covered with glass. If put in a warm place or in the 

 sun, germination will take place very quickly. The 

 seedlings should be planted as soon as they are an inch 

 or tw^o high, and some manure added to the soil. 

 After such treatment the seedlings will grow very 

 rapidly. In planting at stakes the holes should be 

 made as large as possible, or at least 4 feet square. The 

 soil should be well watered, and if too sour, some 

 lime should be added before planting. 



