Minnesota Plant Diseases. 



421 



Poplars, 



powdery mildew of, 121, 125, 272 

 red knot on, 134 



Pore fungi (Fig. 85), 



175, 176, 177, 1/8 



birch fungus (Fig. 126), 254, 255 

 creeping wood rot of, 258 



currant rot, 320 



dry rot fungus, 245, 247 to 250 

 earth-dwelling habit, 39 



false tinder fungus, 250 



flattened, rot (Fig. 123), 



251,252 



fruiting bodies, 23 



hairy pore fungus, 259 



oak Dredalea, 257 



zoned pore fungus, 258 



on ground (Fig. 85), 176 



on stems, 64 



parchment, on larch (Fig. 



.36), 81, 258 



pitch-stemmed, 259 



ring-scale of pine, --' 



root-rot of currant (Fig. 



163), 32i 



scaly (Fig. 125), 254 



sulphur fungus (Fig. 124) 



252, 253 

 timber rots and wound 



parasites, 235 



tinder fungus, 251 



trametes radiciperda, 256 



undetermined (Fig. 127), 257 

 wound parasites, 47 



Portulaca, white rust of, 112 



Potash of lime, in resin 

 bordeaux, 218 



Potassium permanganate, 221 



Potassium sulphide, 220, 221, 357 

 for brown rot of plums, 358 

 for carnation rust, 373 



for downy mildew of onion, 



334 



for mildew of chrysanthe- 

 mum, 380 



for powdery mildew of 



gooseberry, 325 



for powdery mildew of 



rose, 379 



for powdery mildew of 



vines, 366 



Potato disease, losses by, 202 



Potato blight (Fig. 39), 



80, 99, no, in, 112 

 destroyer of leaves, 80 



destructive effect, 78 



distribution of spores, 27 



epidemics, 100 



spores of (Fig 44), 109 



Potato, damping-off of seed- 

 lings, 382 

 downy mildew of (Figs. 166, 



167), 331- 332, 333 



early blight of, 329 



fungus stimulation of 



tubers, 50 



scab (Fig. 164), 326 



scab, corrosive sublimate 



treatment, 226 



scab formalin treatment, 223 



starch, converted to sugar, 114 



sterile-fungus rot of, 329 



wet rot of (Fig. 172) 340 



Powder guns (Fig. 115), 231,232 



Powders, dry bordeaux, 227 



for dusting plants, 227 



sulphur, 227 



sulphur and lime, 227 



Powdery mildew (Figs. 50, 51, 



52), 80. 124, 125 



degree of parasitism, 58 



fruiting bodies, 23 



kinds of spores, 25 



of apple, 361 



of chrysanthemums, 379, 380 



of composites (Fig. 210), 



396, 397 



of cucumbers. 324, 325 



of elms (Fig. 135), 274 



of gooseberry. 325 



of grasses (Fig. 152), 304 



of hazel, 395 



of hops, 325 



of lilac, 377 



of mints, 397 



of plums and cherries (Fig. 



192), 360, 361 



of rose (Figs. 203, 204), 378, 379 

 of strawberry, 324 



of vines, 366. 367 



of vetch and crowfoot, 395, 396 

 of willow (Fig. 134), 272, 273 

 on limited areas, 79 



spores of, 118 



