Vol. XVIII No. 455. 



THE AGRICULTURAL NETWS. 



316 



(5) 'After onion, cabbage, and related crops are harvest- 

 ed, clean up the field and keep it clean, because thrips 

 continue to breed on any living portion of thefe plants, and 

 on almost any kind of weeds that remain in the field. 



(6) 'After harvest, plough as deeply as possible, and 

 harrow and repeat before planting the following season if 

 onions are to be planted anywhere in the vicinity 



(7) 'Plant as early as possible and use quick-acting 

 fertilizers where possible after the onions are well set or the 

 bulbs have begun to form, particularly so where the fertilizer 

 has not been applied before planting. 



(8) 'Watch your onion fields constantly and keep the 

 plants growing thriftily, since once the plants become 

 checked in their growth from any cause, the thrips will 

 multiply with unusual rapidity and it will be a hard 

 fight to save the crop. 



SPRAYING WITH NICOTINE SULPHATE. 



'Onion growers should be able to control the thrips with 

 the aid of the instructions here presented, provided they 

 «mploy the proper sprayers for the purpose. Experts of the 

 Bureau of Entomology who have feeen working on the 

 onion thrips for several years past have been most successful 

 with nicotine sulphate solutions. 



'Where nicotine sulphate is mentioned in the formula, a 

 solution containing -tO per cent, nicotine is understood. 



'The following nico-ine spray formula has been found 

 the be;l for the control of the onion thrips: — 



Nicotine sulphate (40 per cent) jj pint 



SoMD (dissolved) 4 or more Bb. 



Water 50 gallons 



'Tliis formula gives 1 part nicotine sulphate to 1,000 

 parts water. 



'The quantity of soap required will vary with the quality 

 of water, more soap being required in 'ha-d' «ater;but on 

 the average, the proportion specified in the formula will give 

 satisfaction An examination of a freshly sprayed leaf will 

 show whether there is sufficient siap in the mixture. If 

 the spray draws together in drops, and leaves a part of the 

 foliage dry, more soap should be added. Where possible, 

 fish oil soap should be used, but if it cannot be procured, 

 cheap laundry soaps will do. The composition of the cheap 

 soaps is variable, and if too nmch soap is used, some 

 injury may result to tender foliage, especially if applied in 

 the hot sunshine. 



'In the use of nicotine sulphate the etfeclive application 

 of the spray is of tie utmost importance, since it is 

 pr marily upon ibis that the success or failure of the treat- 

 men' dei ends If the liquid has stood for any length of time 

 it should be agitatid thoroughly before use. The insects 

 Ihemse'ves must receive a thorough coat of the spray or they 

 will not be killed, and immediate inspection after spraying 

 should show ihe foliage occupied by the insects to he 

 completely wet. 



'Spraying should be done always on the first appearance 

 of tbe insect, not only because it is good practice to keep 

 the plants free from pests, but because more thorough work 

 can be done on small plants. 



'When spraying is once begun it should be continued 

 at frequent intervals, as often as from seven to ten days, if 

 necessary, provided there is no btavy rainfall during this 

 period, and no surrounding breeding host for the insect. 

 The spraying should, as a general rule, be continued up to 

 within three or four weeks of harvest time ' 



HA.B, 



Rats Troublesome in Trinidad.— At a recent 

 meeting of the Trinidad Board of Agricultuie, says the 

 Port-oj- Spain Gazette, Mr. Urich reported that the cicap 

 beetle campaign was going on, but the beetles themselves 

 were in abeyance owing to the rains. Thrips had not made 

 any appearance yet in numbers. Sangre Grande district 

 was pretty free, and in Toco district there were just slight 

 indications of inciea.se, but not enough to warrant sprayiqg. 

 Tbe pests giving trouble now in Tobago and on the Nomi 

 Coast were rats In spite of the presence of the mongoosi^ 

 on the North Coast, rat damage went on. Small plots of 

 canes were being cultivated at Woodbrook near the Electric 

 Light plant, and the rat damage was very extensive to the 

 canes, although there were, he felt, a good many mongoose 

 about the field there. The rats on tlie northern range took 

 care of themselves by climbing up trees. In connexion 

 with the rat depredations, phosphorus poison had been 

 successfully used. As that, however, was appuently no 

 longer available, barium carbonate mixed with arsenic was 

 suggested. 



Trinidad Exports.— The following figures show the 

 exports from Trinidad for the period .January 1 to August 31, 

 1919. Tliese are official returns piiblished in a recent issue 

 of the Port-of-Spain Gazette (Trinidad):- 



In dealing with bi'esand stings produced by insec s and 

 their allies, Mr. G. K. Bodkin, in the Jour iiat of the Board of 

 Agriculture cf British Cruiana, s^yj that the crimson colour 

 of bete rouge is not due to ingested blood, for this creature 

 does not suck blood, but merely enters a sweat pore of the skin 

 and induces intense irritaion. 'I'hick grease or soap etfrctive'y 

 prevents the bete rouge from crawling on or penetrating iho 

 skin. 



The different varieties of sugar cane under cultivation in 

 British Guiana during 1918 is dealt with in ihe /ourna/ oj 

 the Board of Agriculture of British Giiia/iiioT .April 19 la. 

 Under D.625 there were 22,538 acres; under B.208 theie 



were 3,453 acres; and under Bourbon 3,185 acres. 

 were the three principal varieties in regard to acreage. 



These 



