Alfalfa in Kansas. 



343 



ALFALFA LEAF SPOT (Phyllosticta, sp.). Another leaf spot which was 

 very prevalent in the first and second crops throughout the state the 

 past season is one which is caused by an entirely different fungus from 

 the aforementioned. It is quite different in appearance, and proved to be 

 even more destructive. (See Fig. 286.) This leaf spot is caused by a 

 fungus which so infects the alfalfa foliage that it soon turns yellow, 



drops, and falls from the stem. In 

 many cases over 40 per cent of the 

 foliage was lost on the first and sec- 

 ond crops. It was also present, to a 

 lesser extent, however, on the third 

 and fourth crops. 



This particular leaf spot is most 

 easily recognized by the fact that it 

 does not produce definite spots on 

 the leaves, but scattered over their 

 entire upper surface are very minute, 

 pin-point-like dots. (See Fig. 286.) 

 These little fungus bodies contain 

 the spores of the fungus. Generally 

 the diseased leaves turn a sulphur- 

 yellow color, and curl more or less at 

 the margins during the later stages 

 of the disease. This same fungus 

 may attack the stems, where it 

 causes blackened spots, but generally 

 it does not kill them. (See Fig. 287.) 

 Although this disease may have 

 been present in the state before, it 

 has never been reported prior to this 

 season. Nothing can be done to pre- 

 vent this disease from attacking the 

 alfalfa crop. It is advisable to mow 

 the crop as soon as one discovers it 

 causing the foliage to drop. 



ALFALFA LEAF SPOT (Pleosphss- 

 rulina briosiana Pollacci). This is a 

 new alfalfa leaf spot in America, and 

 was discovered in this state by the 

 writer last year. It is different 

 in appearance from the other two 

 already described in that it forms 

 definite grayish spots with a dark- 

 brown margin. (See Figs. 288 and 



289.) The spots may occur on any part of the leaves, but most frequently 

 they appear along the margins of the leaflets. It is similar to the other 

 leaf spots mentioned in that it causes the foliage to drop previous to their 

 maturity. This disease does not attack the alfalfa stems. 



Fia. 288. Alfalfa leaf spot (Pleo- 

 sphcerulina briosiana Pollacci). 



