Arizona Agricultural Expe:riment Station 271 



ganisms or fungi, of which one was a species of fiisariiiin. This fungus 

 was present in practically every culture made from roots of plants that 

 had died from the disease known as root-rot, and it is believed to be 

 one of the organisms causing this disease. This is apparently the same 

 species of fusariiiin that Dr. ^McCallum studied several years ago at 

 this Station, in his work on root-rot. This fungus develops commonly 

 in great quantity as a white filamentous growth on roots of plants that 

 have recently died, when these are washed and placed in a moist, sterile 

 chamber. It is quite easily obtained as a pure culture and grows readily 

 in a large number of prepared media. With several trials Mr. Uphof 

 did not succeed in inoculating healthy seedling alfalfa plants with cul- 

 tiires of this fungus. This inoculation w^ork was done late in the season 

 when the fungus was quite inactive, which may explain the failures, 

 . Unfortunately, it was necessary to discontinue this work last June after 

 the departure of ]\Ir. Uphof. As is well known, root-rot disease is 

 widespread in our State and causes serious losses for the alfalfa grower, 

 orchardist and gardener. Accordingly, this study should be completed 

 at an early date so as to open the way for a possible economic control 

 of the disease. 



publications 



Bulletin Xo. 79, Cold Resistance in Spineless Cacti, was com- 

 pleted in July and is now in press. This work is an attempt to deter- 

 mine the factors which influence resistance to cold in spineless cacti and 

 completes an Adams' fund project that was outlined three years ago. 

 Spineless cacti have not proved very hardy in Arizona, which fact was 

 noted in Bulletin 67 of this Station. This statement led to consider- 

 able inquiry and correspondence and was partly responsible for the 

 present bulletin. For this work spineless cacti that were considered 

 hardy, were secured from several sources and, with others that were 

 known to be injured with a few degrees of frost, were planted in the 

 introduction garden at the University Farm in the spring of 1913. The 

 soil was loamy in character and the plants were given moderate care in 

 the way of irrigation and cultivation. 



The following varieties of platopuntias were among the more im- 

 portant of the ones planted: Opuntia Hens indica from Malta; 0. Hens 

 indica from Sicily; Opuntia sp. Burbank Special, regarded as very 

 hardy; O. fitsicaulis, a slender-jointed spineless pear; O. castillac, a 

 spineless Mexican cactus growing in Tucson gardens; and 0. EUisiana, 

 secured from Mr. B. R. Russell, San Saba, Texas. 



Careful notes were kept on these plants concerning their rates of 



