354 STATE BOARD OF AGRICULTURE. 



repeat ten days to two weeks later. After fruiting if tlie bed is to be 

 fruited again, mow and burn over quickly (as on a day when there is a 

 wind, to avoid burning the crowns of the plants), If leaf rollers have 

 been present, spray with poison after the growth has started again, but 

 before the leaves curl. 



For strawberr\- root lice, see Michigan Bulletin No. 244, page 88. 



GENERAL TREATMENT FOR POTATOES. 



For the Potato Scar. Soak the uncut tubers for two hours in 30 

 gallons of water and one pint of formalin (can be secured of any drug- 

 gist). This solution can be used several times. Do not put treated 

 tubers back into crates or bags that held scabby potatoes. Make the 

 treatment only a few days before planting if possible. Do not plant 

 upon land that has recently grown crops of scabby potatoes or beets. 



FoK TiiK P>i.i(;irr and *']{r(;s." Pcgin sjji-aying with Pordcaux mix- 

 lure and poison when the ''bugs" first appear, or when the plants arc 

 about 8 inches high, and repeat about every 2 weeks as long as the 

 plants are growing. Spray often in warm, muggy weather; fewer spray- 

 ings are necessary in dry weather. 



Pse Pordcaux inixturc ((I pounds copiicr sulplialc and 4 or ."> i»ouii(ls 

 of lime to 50 gallons of water, and put in the poison, about I/2 pound 

 of Paris green or 2 pounds of arsenate of lead, or 1 quart of the stock 

 solution of Kedzie mixture). 



Dilute lime suljtlnir is not as good as the Pordoaux mixlin-o for i>o- 

 tatoes. 



Wart Disease of the Potato. This disease also is known as Black 

 Scab, Canker or Cauliflower Disease. It attacks the tubers mainly. In a 

 severe attack, big, dark warty excrescences sometime as large as the 

 tuber itself apj)ear at the sides or ends. In advanced stages' of the dis- 

 ease, the tubers are wholly covered by this growth and lose all resem- 

 blance to potatoes. In the final stages, the tubers turn to brownish 

 black soft masses, giving off a very unpleasant odor. In very mild at- 

 tacks, the tubers appear normal, but the eyes are found to have turned 

 gray, then brown and finally black. 



This disease is not known to be present in Michigan, but is likely to be 

 found at any time. No remedy is known. When once introduced into a 

 field, the whole crop should be burned and no tuber from the field used 

 for seed purposes. The field itself should not be used for potatoes for at 

 least six or seven years and the disease should be reported together with 

 specimens at the first outbreak or suspicion of outbreak to the Depart- 

 ment of Botany, Michigan Agricultural College. 



Send specimens in a tight mailing-case. 



