19161 DISEASES OF PLANTS. 151 



gives results of a study since 1912 of the sugar beet nematode (Heterodcra 

 scJinchtii). The results obtained by others are also freely used, as appearing 

 in the scattered but voluminous European literature covering a period of about 

 60 years. But little has as yet appeared in English on this subject. 



The present distrit)ution of the pest is very extensive, including a large por- 

 tion of Europe and the Azores. In the United States it has become estab- 

 lished in two of the oldest beet districts in California and Utah. It is dis- 

 tributed by tools, the feet, water, and numerous other agencies. 



The life history of the nematode is outlined, the brown cyst stage being 

 regarded as very important. Viable eggs and larvje have been found in these 

 cysts after four or five years, and their contents may withstand a considerable 

 degree of cold, heat, and desiccation. It is thought, however, that a tempera- 

 ture of 63° C. (145.4° F.) for one minute destroys all life in this stage. The 

 life cycle is said to occupy about four to five weeks, so that six or seven 

 generations may be produced in one season. Each female produces from 350 

 to 400 eggs. The parasite attacks the plants during its larval stage, producing 

 profound changes in their development and product. 



Lists are given of plants found to be susceptible or otherwise. Advantage 

 may be taken of this knowledge to starve out the pests by crop rotations 

 which are outlined. Small infested spots may be isolated by trenches filled 

 with lime. Chemical methods, as well as the metliod of trap plants, have been 

 found to be impracticable in Europe. Exposure of the beet seed to a tem- 

 perature of 65 to 70° for 5 to 10 minutes not only destroys all nematode 

 life, but apparently stimulates the germinability of the seed. This method is 

 claimed to be extremely simple, inexpensive, and practicable as applied to 

 seeds, and it is recommended that such treatment of imported seed be made 

 general. 



A bibliography is given. 



Spraying experiments at Ruakura, A. W. Green {Jour. Agr. [Ncxo Zeal.'], 

 It {1915), No. 2, p. ISJf).- — It is stated, in a report of orchard work at Ruakura 

 farm of instruction, that after this season's experiments there is little i*eason 

 to doubt the value of lime-sulphur solution in this connection. Unsatisfactory 

 results in previous experiments ai'e attributed to the strength of the spray 

 used. 



Cedar rust eradication in Berkeley County {Crop Pest Com. W. Va. Bien. 

 Rpt. 1 {1913-lJf), pp. 33-39, figs. 4).— Besides a discussion of the relations of 

 cedar trees to apple rust as regards control of the latter, an account is given 

 of the concentration of effort in Berkeley County, the practical difficulties 

 encountered in the removal of the cedars, and the results obtained thereby. 



The eye rot of the apple, E. S. Salmon and H. Wokmald {Oard, Chron., 3. 

 ser., 58 {1915), No. 150G, p. 289, figs. 2). — The authors report having received 

 from growers in Wye, Sussex, and Devonshire apples showing a blossom end 

 rot which may be causally connected with a fungus, apparently a Fusarium, 

 found in some diseased fruits. In one case the diseased apples were densely 

 infested with aphids. The authors recommend as tentative measures for pro- 

 tection the picking and burning of all affected fruit and the use of sprays for 

 the destruction of puncturing insects. 



The frog-eye leaf spot of apples, C. H. Crabill {Virginia Sta. Bui. 209 

 {1915), pp. 16, figs. 6). — According to the author the frog-eye leaf spot is one 

 of the most prevalent foliage diseases of the apple in Virginia, its attacks 

 often causing serious loss. Various fimgi have been attributed as causing this 

 disease, but investigations of the author show that the initial infection and 

 enlargement are caused by Sphccropsis malorum. Alternaria mali occurs as 



