MISC. PUBLICATION 4 4 0, U. S. DEPARTMENT OF AGRICULTURE 



Page 

 Parsley family— Continued. 



Carrot — Continued. 



Rhizoctonia crown rot 44 



Rhizopus soft rot 45 



Watery soft rot 45 



Celery 45 



Bacterial blight 46 



Bacterial soft rot 46 



Black-heart 48 



Brown stem — 49 



Cracked stem 49 



Early blight 50 



Freezing injury 51 



Gray mold rot 51 



Late blight 51 



Mosaics and other virus diseases 53 



Phoma root rot 54 



Pithiness (hollow stem) 56 



Page 

 Parsley family — Continued. 



Celery— Continued. 



Tarnished plant bug injury . 56 



Watery soft rot 56 



Finocchio 58 



Bacterial soft rot 59 



"Watery soft rot 59 



Parsley 59 



Bacterial soft rot 59 



Watery soft rot 59 



Parsnip 59 



Bacterial soft rot 59 



Gray mold rot 60 



Watery soft rot 60 



Literature cited 60 



Lily family 60 



Pulse family 63 



Parsley family 67 



For convenience in discussing the diseases common to a related 

 group of plants, the botanical family is made the basis of the separate 

 sections of this bulletin. Within the family the crops are listed 

 in alphabetical order. The diseases described are likewise arranged 

 in alphabetical order under each crop. 



LILY FAMILY 



The lily family (Liliaceae) is probably best known for its orna- 

 mental plants, although there are several important vegetables that 

 belong to this group. Listed in the order of their importance on 

 the market these food crops are onion, asparagus, garlic, leek, shallot, 

 Welsh onion, and chive. 



Asparagus 



The vegetable known as asparagus is the young unbranched shoot 

 of the asparagus plant (Asparagus officinalis L,). When cut just 

 as it emerges from the ground the shoot is chlorophyll- free. The 

 blanched asparagus shoots are used by canneries. If cutting is 

 delayed until the shoot has been exposed to light chlorophyll develops, 

 and the resultant stimulated growth leads to the production of green 

 tender shoots, which are preferred on the market. 



Among the factors that determine the marketability of asparagus 

 are firmness, tenderness, and freedom from decay. Tenderness is 

 primarily a matter of rate of growth and of age. Slow-growing 

 shoots and shoots developed late in the growing season have well- 

 developed vascular tissues and consequently are tough and woody. 

 Lack of firmness is due to excessive loss of water, which, although 

 it may take place before cutting, generally occurs afterward. 



Some field diseases of asparagus influence the production seriously 

 but seldom directly affect the marketable shoots. The most serious 

 one is rust (Pucdnia asparagi DC). It so weakens the plant that 

 the crown often becomes susceptible to attacks by soil fungi, and only 

 a few weak shoots are produced the next year. Cercospora leaf spot 

 (Cercospora sp.) causes only minor damage. 



The roots and shoots may be affected by bacterial soft rot, fusarium 

 rot (wilt), gray mold rot, phytophthora rot, and watery soft rot. 

 Bacterial soft rot and fusarium rot are the most common causes of 

 Loss of asparagus during transit and marketing. 



