612 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



BEET DISEASES 



Beet Scab 



Thought to be the same organism as 

 produces the potato scab and affects the 

 roots in much the same way. 



Rotation of crops is suggested. 



See Scab under Potato. 



Crown Rot 



Phoma Betae 



Distributed pretty generally through- 

 out the beet growing sections. 



Cdrly Top. See Beet Leaf Hopper, this 

 section. 



Downy Mildew 



Peronospora schachtii 

 Causes a stunting of the inner leaves. 

 Occurs during the rainy season. 

 Destroy all affected plants. 



leaf Spot 



Cercospora heticola Sacc. 



Produces small dead spots in the leaves 

 followed at times by dying of the leaves. 



Bordeaux mixture applied at intervals 

 of three weeks. 



Root Knot 



Caused by the Nematode gall worm. 

 See under Potato. 



Root Rot 



Rhizoctonia sp. 



Appears in the young plant as a decay 

 of the root. Causes the root to fork and 

 become misshapen. 



Crop rotation, or, where practicable, soil 

 disinfection seem the best remedies. 



Rnst 



Vromyces betae 

 Appears as a red rust on beet leaves 

 when grown in the rainy season. Not 

 serious. 



BEET PESTS 

 Beet Aphis. Beet Root Aphis, Cali- 

 FOKKIA Beet Root Aphis. See Aphids. 

 See also Beet Louse, this section. 



The Beet Army Worm 



Laphygma exigua Hubn. 



Family Noctuidae 



Caradrina exigua Hubn. 



General .\ppearance 



The adult moth is mottled gray with 



distinct light markings on the fore wings. 



It is about one inch in length, with a 



■wing expanse of one and one-half Inches. 



The larvae are slender, dark green in 

 color and distinctly striped. 



life History 



The adult moths appear during the 

 months of April and June and deposit 

 eggs, the caterpillars hatching out in May 

 and the last of June and becoming most 

 abundant in August. There are probably 

 three generations a year — the first and 

 last doing the least amount of damage. 



Food Plants 



The favorite food of the caterpillars is 

 the sugar beet and it bids fair to become 

 quite a serious pest to that crop. Table 

 beets, corn, potatoes, peas, onions, sun- 

 flower, lambsquarters, pigweed, saltbush 

 and the leaves of the apple, mallow, wild 

 tobacco, plantain and wild grasses are 

 also attacked. 



Poison mash as for other cut worms. 

 E. O. EssiG 

 Beet leaf Hopper 

 Eutettix tenella Baker 



The adult is a small, pale yellowish- 

 green species. When fresh or when flying 

 this leaf hopper appears almost white, and 

 for this reason it has often been called 

 the "white fly." 



The eggs are white, elongate, slightly 

 curved and tapering at one end, and are 

 thrust into the leaf stem. 



The nymphs are very active, pale 

 creamy white or variously colored forms. 

 The commonest form is pale creamy In 

 color with a brown saddle on the middle 

 of the abJomen. 



The distribution seems to be general 

 over the West. 



The condition called "curly-leaf" or 

 "blight" accompanies the attack of these 

 insects and its severity is in proportion 

 to their numbers. 



Remedy 



Spray with kerosene emulsion stock 

 solution one to five parts water, using a 

 drag to turn the beet leaves up. 



Bureau Entomoloj)r.v Bulletin 66. 



Beet louse 



Pemphigus betae Doane 

 General Appearance 



The adult wingless lice are about one- 

 eighth of an inch long: somewhat round- 



