CAUTION. 21 



Avliile the i)Iiuits iuv still in tlie seed bed. The amount of spray neces- 

 sary and the labor required in sprayinfr varies with the <j;rowth of 

 the plant. It was found in June, when the plants were about 2 feet 

 high, that 8 acres were sprayed in four houi's by nine men and three 

 boys, using- six spray pumps and api)lying HO gallons of the diluted 

 (inulsion })er acre. 'I'his was at a cost of about 55 cents an acre for 

 hibor and 50 cents for spray. It is roughly estimated that the ex- 

 pense Avill not exceed $20 an acre, even if found necessary to spray 

 twice weekl}^ for the maxinuun period of ten weeks. 



A pixiratus. — In applying the emulsion it is necessary, fi'om the 

 nature of the crop, to nse a knapsack spi-ayer. These sprayers can 

 be |:)nrchased for from $5 to $15. The wi-iter would reconnnend the 

 the purchase of the better grades, as they will be found the most 

 satisfactory and in the end the cheapest. 



siirsi^rAHv OF recommendations. 



The folloAving recommendations are made as a result of the ex- 

 periments carried on in 1905, and the success following their practice: 



1. Practice clean cnltivation of the field between crops. 



2. Plant fields bordering the shade to other than cereal crops. 

 8. Locate the seed bed outside the tobacco field. 



4. Apply kerosene emulsion (1 part to 10 parts of water) with a 

 knai)sack sprayer twice a week I'egularly, commencing while the 

 plants are in the seed bed. 



It is very important that the spray be regularly and carefully ap- 

 plied during the first few weeks after transplanting, in order that the 

 adult thrips which have passed the winter in the tobacco field be 

 killed before depositing their eggs on the tobacco or weeds in the field. 



CAUTION. 



The kerosene emulsion must be churned until thoroughly emulsi- 

 fied, else burning will follow the application. 



The emulsion should not l)e made uj) to the 1 to 10 strength until 

 shortly before using, as when left standing for longer than two days 

 the excess of water has a tendency to dissolve the soap surrounding 

 the oil globules, setting the oil free. 



Spraying must be done in the evening (aftei' 5 o'clock), else the 

 sun's rays will canse a burning of the leave?;, following the spray. 

 Spi-aying may be done on a cloudy day, but only when there is no 

 danger of the clouds bivaking aAvay and allowing the sun to appear. 



Spraying should not follow an a implication of Paris gi'een, and 

 when preceding it the jilants shoidd be allowed to dry before the 

 Paris green is applied. Caie should be taken not to spray into the 

 leaf bud, so far as that can be avoided. 



