39 



night, so as to get the benefit of the low mean temperatures. The 

 other extreme of too low temperature should also be provided against. 

 During protracted cold spells the temperature inside the storage house 

 may get dangerously low. To guard against loss from freezing, oil 

 heaters are placed at suitable intervals in the walks and alleys to 

 maintain the temperature above the danger point. 



Storage troubles are more largely the result of careless handling and 

 bad ventilation than of diseases. Practically all of the rotting which 

 takes place during the storage period is the result of saprophytic 

 organisms attacking the badly handled or slighth^ diseased heads 

 under bad storage conditions. Poor cultivation, bad harvesting 

 methods, a long haul to storage, and rough handling in unloading and 

 storing are all to be avoided if cabbage is to be kept successfully 

 through the storage period. 



Insect Enemies and Diseases. 



The important enemies of the cabbage as a market-garden or farm 

 crop are the cabbage worms, which in some instances cause considerable 

 loss, the cabbage root maggot, and the cabbage "louse." 



Cabbage Worms. — The imported cabbage worm and some other 

 species of cabbage worms can be effectually controlled bj' the use of 

 (1) Paris green at the rate of 1 pound to 50 gallons of water, or (2) 

 arsenate of lead at the rate of 4 pounds to 50 gallons of water, sprayed 

 on the young plants before the heads are well formed. This treatment 

 should be repeated from time to time, as required, in order to protect 

 the plants. Where a few plants are to be treated insect powder or 

 pjrethrum is sometimes employed for the control of the insect by 

 dusting it upon the plants. 



Cabbage Root Maggots. — These insects sometimes cause considerable 

 damage and are difficult to combat. Tarred paper placed about the 

 bases of the stems prevents the flies from depositing their eggs. In- 

 jections of carbon bisulphid in the soil are effective in destroying 

 maggots, and another good remedy is found in carbolic acid emulson, 

 made by dissolving 1 pound of soap in a gallon of boiling water and 

 adding a pint of crude carbolic acid. This mixture is then diluted 

 with thirty times its bulk of water, and poured around the bases of 

 the plants. 



The Cabbage Aphis. — Cabbage aphides or "lice" are controlled by 

 the use of contact insecticides, such as kerosene emulsion or whale- 

 oil soap. 



Clubroot. — Among the field troubles to which the cabbage is subjece 

 none is of greater economic importance than clubroot. This diseast 

 is peculiar in its method of attack and in the way in which it per- 

 petuates itself. The chief danger with this disease arises from the fact 

 that either the seed bed or the field may be infected and thus con- 

 taminate the crop. There is danger, then, in purchasing plants. 



