September, 1909,] 



209 



Fibres. 



expand, and it rests with the merchants 

 in India to decide whether they are to 

 have a share in it. This is the more 

 necessary should the product continue 

 to cut into the linseed and cotton seed 

 trades, as recent market reports state 

 that it is doing. Should it permanently 



affect the demand for Indian cotton 

 seed, the resultant drop in the internal 

 price will afford compensation in that 

 it will improve the projects of those 

 companies that engage in the manu- 

 facture of cotton seed oil and ghi 

 substitutes, 



FIBRES. 



DISINFECTION OF COTTON SEED. 



From the Agricultural Neivs, Vol. VIII., 

 No. 187, June 26, 1909.) 



Now that the time is at hand for plant- 

 ing cotton for the coming crop, it might 

 be well to consider again the advantages 

 to be derived from the disinfection of 

 cotton seed, and the methods to be 

 employed. 



Corrosive sublimate is a poisonous sub- 

 stance and a germicide. If eaten by 

 insects, animals or persons, it is a 

 poison in the ordinary sense, and a very 

 powerful poison at that. As a germicide 

 it kills bacteria, fungus spores, and 

 similar organisms by coming in contact 

 with them. It is used in a water solu- 

 tion, at a strength of 1 part of corrosive 

 sublimate to 1,000 parts of water. To 

 make this strength, use 1 oz. of corro- 

 sive sublimate and 7 gallons of water or 

 1 lb. to 100 gallons. The poison may be 

 dissolved in a small amount of hot 

 water, and then poured slowly into the 

 full amount of water. It is essential 

 that the poison should be thoroughly 

 dissolved in water before the solution is 

 used. 



There are two points that must be 

 borne in mind— one is, that the wooden 

 tub or cask in which the cotton seed is 

 usually soaked will probably absorb a 

 certain amount of the corrosive subli- 

 mate, thus weakening the solution ; and 

 the other is that the seed must be 

 thoroughly wetted, but must not stay 

 in the solution too long. In dealing with 

 the first of these points, the tub or 

 cask may be prepared some time 

 before it is proposed to disinfect the 

 seed. After it has been thoroughly 

 washed, the tub should be filled with 

 a solution of corrosive sublimate, 

 1-1,000, and left to stand a few hours. 

 By this time the reaction between the 

 wood and the solution will have been 

 completed. The solution may then be 

 thrown away, and the tub is ready for 

 use in disinfecting cotton seed. 



In order that the seed may be 

 thoroughly wetted it is only necessary to 

 stir it in the solution for a few minutes, 

 when it is first put in, so that the solution 

 may come in contact with all parts of 

 the surface. Ten to twenty minutes 

 should be quite long enough for thorough 

 disinfection. 



It is estimated that the cost of disin- 

 fection amounts to about one cent for 

 12 lb. of seed, 1 gallon of the solution 

 being sufficient satisfactorily to disinfect 

 12 lb., and the planter should always 

 bear this in mind. This solution is 

 weakened by the loss of corrosive subli- 

 mate, which is absorbed by the testa or 

 hard outer covering of the seed. 



When the seed has become thoroughly 

 wetted it should be taken out and, if it 

 is desired, may be planted at once, with- 

 out drying ; but if it is not to be planted 

 at once it should be thoroughly dried 

 before being put in bags for storing. 



There are no disadvantages to the dis- 

 infection of seed except the cost and the 

 labour required, each of which is only 

 a small item. The advantages to be 

 expected are several. Seed often germi- 

 nates better as a result of disinfection ; 

 it is reported that fields of cotton 

 planted with disinfected seed suffered 

 less from leaf-blister mite than the 

 adjoining fields, the seed for which was 

 not disinfected ; the spores of fungus 

 diseases are often transported with the 

 cotton seed, and disinfection is the best 

 means known of killing such spores and 

 thus warding off subsequent attacks. 



One of the most troublesome of the 

 fungus diseases liable to be transported 

 with the seed is anthracnose. This 

 fungus causes the damping off which 

 often kills the young cotton seedlings 

 when only a few days above ground, 



When this attack is serious, a large 

 proportion of the seedlings may be 

 killed. Later in the life of the cotton 

 this fungus causes the well-known 

 anthracnose of the boll. If the process 



