652 EXPERIMENT STATION RECORD. [Vol.36 



Work on the white pine blister rust in Minnesota, 1916, F, L. Washbubn 

 {[Minn. State Ent. Dept.] Circ. 40 (1916), pp. 19, pi. 1, figs. 6).— An account is 

 given of work carried on in the summer of 1916 for the eradication of tlie 

 white pine blister rust, the presence of which was definitely established in a 

 few counties in Minnesota adjacent to the Mississippi River. 



The white pine blister rust. Does the fungus winter on the currant? 

 W. A. McCuBBiN (Science, n. ser., 45 (1911), No. 1152, p. 87). — Data are pre- 

 sented that are considered to indicate that the white pine blister rust may 

 winter over on the currant under certain conditions. 



Keithia thujina, the cause of a serious leaf disease of the western red 

 cedar, J. R. Weie (Phytopathology, 6 (1916), No. 4, pp. 360-S63, figs. 2).— The 

 author reports observing a serious leaf disease on the western red cedar 

 (Thuja plicata), in the lake region of northern Idaho. 



An examination of the material showed that the disease was due to K. 

 thujina. This fungus is considered primarily one which attacks seedlings and 

 young trees, but the foliage of the upper crown of forest trees may also be 

 infected, although not to the same extent as the leaves on branches nearer 

 the ground. Evidence is presented which indicates that snow may be a factor 

 in promoting the growth of the organism, as it is particularly noticeable where 

 seedlings remain covered with snow until late spring. A preliminary experi- 

 ment indicates that the disease may be held in check by spraying seedlings in 

 nurseries with a rather strong soap-Bordeaux mixture. 



Note on " spike " disease in sandal, P. M. Lushington (Indian Forester, 

 42 (1916), No. 2, pp. 61-65). — Summarizing what is known of spike in sandal, 

 the author states that it was described, investigated, and reported on in 1902, 

 having at that time been prevalent in Coorg for four or five years. 



The disease appears to be very infectious and to spread rapidly. It is 

 thought that birds or insects may possibly be instrumental in spreading il, 

 and no tree once diseased in this way has been known to recover. Observa- 

 tions by a number of persons are given on the various phases of the disease 

 and on different plants showing a similar abnormality. It is stated that in 

 the KoUimalais sandal has been found to be considerably attacked by Viscum 

 verruculosum. 



A possible cause of " spike " in sandal, T. A. Whitehead (Indian Forester, 

 42 (1916), No. 5, pp. 243-247). — The view is advanced, with supporting observa- 

 tions, that the cause of spike in sandal is undue reduction in the supply of 

 water to the plant in proportion to its growing needs. The suckers produced 

 from the injured roots of an affected tree show the same trouble as do also 

 root suckers which spring up where a spiked tree has been dug up. The degree 

 of the trouble is the same throughout the tree at a given time. When death 

 sets in the ends of the shoots die before the branches. The so-called phyllode 

 in spiked trees is associated with excess starch in stems, twigs, and leaves. 

 It is stated that no spiked tree has been known to recover. 



No fungus has been found in connection with the spike disease and no trans- 

 mission of the disease has been accomplished experimentally. In spiked trees 

 the root ends die and the haustoria are found to be either absent or dead. 

 Both diseased and healthy trees may bear scars, evidencing pai'asitism. In one 

 case a living haustorium was found on a diseased tree. 



Spike has been observed in other trees noted. The rapid spread of the 

 disease, observed by Lushington as noted above, is thought to be due to the 

 overtaxing of a given area by sandal and the consequent relative exhaustion 

 of its means of obtaining water. Spike is thought to be not a disease, but a 

 symptom of increasing inadequacy iu the means of securing water. The remedy 



