182 



THE AGKICULTUEAL NEWS 



JuxE 16, 1906. 



CONFERENCE OF COTTON GROWERS AT BARBADOS. 



(CONTINUED.) 



Insect Pests of Cotton and Methods for their 

 Control. 

 Mr. F. A. Stockdale read the following paper on 

 behalf of Mr. H. A. Ballou, B.Sc, Entomologist on the 

 staff of the Imperial Department of Agriculture, at 

 present in the United States : — 



COTTON WOI!M. 



This important pest of cotton can be controlled only 

 by the exercise of sufficient care. A sharp lookout 

 must be kept for its first appearance and poison used 

 promptly. Paris green and lime have given good results both 

 in controlling the pest and as an economical poison. The 

 method in vogue is the use of Paris green and lime at the rate 

 of 1 ft. of Paris green to 6ft. of lime, or, when measured, 1 part 

 of Paris green to 12 parts of lime. Paris green may be used 

 without lime, and it should not require more when used this 

 •way than when used with lime, .\bout 1 ft. of Paris green 

 per acre for each application is sufficient to kill the worms. 

 The point to be observed is an equal application over the 

 plants. The cost of the Paris green and lime and of thelabout 

 for applying has beenplacedat about 2s. per acre for the entire 

 seasoQ ; but when carelessly applied with oat sacks and tin 

 shakers and things of that sort, the cost has been as high as 

 Ss. to 10s. per acre. This is far too much. The cost this 

 year will be a trifle more on account of the high price 

 of all arsenicals. The Acme Powder Bellows, which was 

 described in the Agricultural Neivs, Vol V, p. 154, is sold 

 in the United .States retail at 75c. each. This has been 

 used in the Sea Islands during the past season with very 

 satisfactory results. It is obtainable from ]\Iessrs. Gillespie 

 Bros. & Co., 4, Stone Street, New York, at about $3-00 per 

 dozen, not including piicking and freight. It is a simple 

 machine and should be economical and save time in 

 application. It will work better when the poison is used 

 without lime. 



Too much stress cannot be placed on careful supervision 

 as to the appearance of the worm and the use of poisons on 

 the plants. Green arsenoid will probably prove a good 

 substitute for Paris green, and it is expected will be slightly 

 cheaper. It is lighter than Paris green and will i)robably go 

 further in application. Arsenate of lead is expensive to apply, 

 because it must be spread, and it is slow in its action. It 

 adheres to the leaves very well and does not burn. 



Experiments with the different poisons will be carried 

 out during the coming season. 



CUT WOEJI. 



The cut worm has been a pest in some places 

 during the past j-ear. It attacks the young plants when 

 they first come up. It may be controlled by the use of 

 a poisoned bait made by adding 1 ft. Paris green to 50 ft. 

 bran, mixed to a mash with molasses and water. This 

 is applied at the time of planting the seed, a small quantity 

 being put in each hole or on the surface of the ground where 

 cotton is to be planted. Both methods have been tried with 

 satisfactory results. 



SCALE INSECTS. 



These pests have caused some loss to the cotton 

 growers during this past year, chiefly on estates where old and 

 scale-infested cotton from the previous season had been 

 allowed to stand over until after the new crop had started. 



This will not often happen if the old 2}l(ints are ttiheii out at 

 the end of the season ami before the new crop is j^lanted. The 

 same is true in a general way of the red maggot, which has 

 also been a pest on some estates this last .season. Great care 

 should be exercised not to injure the plants by hoeing, as every 

 wound in a plant offers an additional opening for attack by 

 this insect. If scale insects and the red maggot attack cotton 

 while it is still quite young, it will probably be best to cut out 

 or pull out the infested plants : but if the attack begins after 

 the plants are well grown, it may be desirable to get as much 

 cotton as possible from the plants before taking them out. 



The leaf-blister mite does not occur in Barbados at 

 present. The cotton stainer is very rare and is not a pest. 



Fungoid Diseases of Cotton and their 

 Treatment. 



The following paper, on the Fungoid Diseases of 

 Cotton and their Treatment, was i'ea<i by Mr. F. A. 

 Stockdale, B.A., Mycologist on the staff of the Imperial 

 Department of Agriculture : — 



Up to the present time the fungoid diseases of cotton 

 in Barbados have not proved to be serious, but, when the 

 area under cotton is increased, it is possible that they will 

 assume a greater importance unless constant watchfulness is 

 practised and remedial measures are promptly ajiplied. 



Many diseases of cotton are due to unfavourable con- 

 ditions, while many others siiread rapidlj- when the conditions 

 are such that the cotton plant is not in a vigorous state of 

 growth. Considerable care should, therefore, be given to the 

 situation, soil, cultivation, etc., so that the conditions are 

 made as favourable as possible to the growth of the cotton 

 plants, and consequently, unfavourable to the spread of 

 diseases. 



ANTHRACNOSE. 



In Barbados this disease has 'been noticed in almost 

 every field to a greater or less extent. 



Without doubt, it causes some damage to cotton in 

 certain parts of the island. It has been known to cause 

 a loss of 10 to 15 per cent, of the total crop in some 

 cotton districts of the United States, and therefore planters 

 should endeavour to keep it in check, so as not to incur the 

 losses experienced elsewhere. 



With reference to the remedial measures to prevent the 

 spread of the disease, all diseased bolls from the ground, and 

 all old cotton left standing with diseased bolls attached after 

 all the crop has been gathered should be collected and 

 Imrned. Old plants have been noticed that have been left 

 standing with numbers of diseased and worthless bolls 

 attached that should have been got rid of long before. 



It is also important that all seed used for planting 

 purposes should be disinfected. If this is not done spores 

 attached to the seed may cause disease on the 'seed-leaves' 

 or cotyledons, which may result in great loss in a crop. It 

 is estimated that ] gallon of solution of corrosive sublimate 

 (1 in 1,000) should be sufficient to disinfect 12 ft. of seed at 

 a co.st of a little more than Ic. 



MILDEW. 



This disease is fairly general in Barbados, and is 

 usually to be noticed as a white felt on the under surface 



