Vegetable and Field Crops 193 



Blue-mold {Penicillium sp.) is very similar to blue-mold on 

 apples. Damping-off {Pythium deharyanum) . — See p. 19. 

 Southern-blight (Sderotium) is common in the South; Cor- 

 ticium docs some injury to roots and causes occasional fruit 

 rot; Root-knot due to nematodes is common as is also Drop 

 {Sderotima libcrtiana) . 



GARLIC. See onion. 



GINSENG 2«-246 



Blight {AUernaria panax Whet.). — Brown cankers upon 

 the stem, and watery spots in the leaf, often involving the 

 entire top of the plant, mark this disease. Badly blighted 

 plants appear as if drenched with boiling water. It is a 

 serious menace to the ginseng industry of New York state. 

 The seed crop is sometimes completely lost. 



It can be controlled by thorough spraying with 3-3-50 

 Bordeaux mixture as soon as the plants come up, repeated 

 every other day during the first few weeks, less often later. 

 Diseased refuse should be destroyed. 



Wilt {Fusarium vasinfedwn Atk.). — ■ With the first symp- 

 tom of attack the leaflets droop, yellow, and die; then the 

 entire leaf dies to the base, dries up, and falls off. The 

 immature seeds shrivel and fail to mature. Secondary 

 decays, soft rots, may follow. 



Methods of control suggested for watermelon wilt apply 

 here also. 



Stem anthracnose {Vermiculaj-ia de^natium (Pers.) Fr.). — 

 Numerous black scars appear on the stems a few weeks 

 after the plants come above ground. These spread and 

 sometimes encircle the stems. The leaflets then brown. 

 Often the plants fall over, even before they wilt. The great- 

 est loss lies in the destruction of the seed crop. 



Bordeaux mixture applied about three weeks after the 

 plants appear in the spring and each three weeks thereafter, 

 until August, more often if the season is wet, will control 



