838 PopULAK Editions or Station Bulletins of the 



In general, commence spraying when the 

 Directions plants are six to eight inches high^ and repeat 



the treatment at intervals of 10 to 14 davs 

 spraying. . -, ■, ^ -, ■,-, i -"i 



m order to keep the plants well covered with 



bordeaux throughout the season. During epidemics of blight it 

 may be advisable to spray as often as once a week.^ Usually, six 

 applications will be required. The bordeaux should contain four 

 pounds of copper sulphate to each fifty gallons in the first two 

 sprayings and six pounds to fifty gallons in subsequent sprayings.^ 

 Whenever bugs or flea beetles are plentiful add one or two pounds 

 of paris green, two quarts of arsenite of soda stock solution or three 

 to five pounds of arsenate of lead to the quantity of bordeaux re- 

 quired to spray an acre. 



Thoroughness of application is to be desired at all times, but 

 is especially important when flea beetles are numerous or the 

 weather favorable to blight. The more frequently and thoroughly 

 the plants are sprayed the better. There is no danger of injuring 

 the foliage by too much spraying. Using the same quantity of 

 bordeaux, frequent light applications are likely to be more effect- 

 ive than heavier applications at long intervals ; e. g., when a horse 



1 On Long Island an earlier spraying is sometimes necessary to protect the 

 young plants from flea beetles which attack them severely while they are 

 coming up. For the best success in the control of bugs it is necessary to 

 spray with bordeaux and poison just as soon as a majority of the first brood 

 are hatched. Usually, this occurs when the plants are six to eight inches 

 high. Spray applied three days or more before the bugs hatch will fail to 

 kill many of them, because, in the interval the plants make considerable new 

 growth upon which the bugs can feed with impunity and cause considerable 

 damage before it is time to make the next regular spraying. 



2 On the south shore of Long Island between Southampton and Amagansett 

 this is frequently necessary. 



3 It can not be definitely stated what formula is the best one to use._ Much 

 depends upon the quantity used per acre and the manner of its application. 

 Weak bordeaux applied in the form of fine spray which covers the plants 

 thoroughly may give better results than stronger bordeaux carelessly applied 

 in the form of coarse spray. Both the cost of chemicals and the expense of 

 application must be taken into consideration. It is plain, however, that the 

 mixture should be strengthened as the season advances and the danger from 

 blight increases. None of the ready-made bordeaux mixtures on the market 

 are as good as the home-made bordeaux. Neither can the lime-sulphur solu- 

 tion be profitablv substituted for bordeaux in spraying potatoes (See Bui. 

 347 of this Station). In the preparation of bordeaux the writers prefer to 

 use stone lime rather than any of the "prepared" limes. 



