CAUTION. 21 



while the plants are -till in the seed bed. The amount of spray n< 

 sary and the labor required in spraying varies with the growth of 

 the plant. It was found in June, when the plants were aboui 2 feel 

 high, that <S acres were sprayed in four hours by nine men and three 

 boys, using six spray pumps and applying 50 gallons of the diluted 

 emulsion per acre. This was at a cosl of about 55 rent- an acre for 

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

 pense will not exceed $20 an acre, even if found accessary to spray 

 twice weekly for the maximum period of ten weeks. 



Apparatus. — In applying the emulsion it is necessary, from the 

 nature of the crop, to use a knapsack sprayer. These sprayers can 

 be purchased for from $5 to $15. The writer would recommend the 

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

 satisfactory and in the end the cheapest. 



SUMMARY OF RECOMMENDATIONS. 



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

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



1. Practice clean cultivation of the field between crops. 



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



3. Locate the seed bed outside the tobacco field. 



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

 knapsack sprayer twice a week regularly, 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 1 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 be made up 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 

 i he oil globules, setting the oil free. 



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

 sun's rays will cause a burning of the leaves, following the spray. 

 Spraying may bo done on a cloudy day. but only when there IS no 

 danger of the clouds breaking away and allowing the sun to appear. 



Spraying should not follow an application of Paris green, and 

 when preceding it the plants should he allowed to dry before the 

 Paris green is applied, ('are should be taken not to spray into the 

 leaf bud. so far as that can be avoided. 



