248 EXPERIMENT STATION EECOED. 



diseases. Both diseases were frequently found associated with Phytophthora 

 infestans in the field and with Fusarium solani in storage. 



On the causes and methods of combating damping off of the sugar beet, 

 K. Stormer and A. Eichinger (Filhling's Landw. Ztg., 59 {1910), No. 12, pp. 

 393-413; (iM. in Bl. ZuclcerriibetiMu, 11 {1910), Nos. IJf, PP. 229-234; 15, pp. 

 245-247). — The results are given of a large number of experiments on the 

 causes (fungi and crusting of the soil) of the damping off of beet seedlings, on 

 the effect of turf meal, blanching and seed disinfection, condition (physical 

 and chemical) of the soil, and the value of commercial fertilizers in combating 

 the disease. 



It was found that three fungi. Phoma betce, Pythium debaryanuni, and 

 Aphanomyces Icevis, the first on the seeds and the other two in the soil, are the 

 main causative agents in producing the disease. P. hetw apparently dominates 

 during dry springs, while the other two seem more prevalent in wet seasons. 

 The crusting of the soil apparently has no influence on the outbreaks of the 

 disease. 



Blanching the seed and seed or soil disinfection had no practical influence 

 in checking the disease, but it was found that the use of lime, phosphoric acid, 

 and either table salt or potash in combination as fertilizers was of the greatest 

 value in controlling it. The addition of these fertilizers to the soil decreased 

 very materially the number of diseased plants, increased the germination, 

 produced a better stand, and resulted in a more vigorous development of the 

 plants left in the field. The table salt especially seemed to have a very 

 favorable effect on the germination of the seed. 



The cause of gummosis of tobacco and experiments on its control, J. A. 

 Honing {Meded. DelUProefstot. Medan, 5 {1910). No. 1, pp. 24, fig. /).— The 

 results are given of experiments on a disease of tobacco, known as slime disease 

 or gummosis, due, it is claimed, to bacteria which live in the soil and which 

 infect first the roots, then the stems and leaves, and finally kill the plant. 



It was found that the rotting stems of diseased tobacco plants, when mixed 

 in the soil around living plants, pi'oduced the disease. Also, various experi- 

 ments in infecting the holes for the plants and the roots of the plants, by 

 spraying with dilute culture solutions of the bacteria, and the roots, stems, 

 and leaves of plants by inoculation with bouillon cultures through punctures, 

 showed abundant evidence of infection by each method, although the soil 

 infection was slower in developing the disease than when the bacteria was 

 introduced directly into the plants through punctures. 



Experiments on the probable relationship of A-arious wild plants as propa- 

 gators of this disease are also reported, in which apparently a species of sting- 

 ing nettle and an Ageratum are capable of acting as carriers. 



Experiments in soil disinfection as a means of combating this disease were 

 tried with calcium chlorid. potassium permanganate, copper sulphate, and forma- 

 lin, from which it seems that either the chlorid of lime, from 2 to 2i gm. in from 

 1^ to 2 liters of water per plant, put in each hole just before the plants are 

 set out, or the same amount of potassium permanganate per plant, may prove 

 of value in reducing the number of diseased plants. 



Formalin also gave excellent results when used at the rate of 2 liters of 

 a 1 per cent solution to each hole, but its excessive cost prohibits its general 

 use as a field remedy against this disease. 



Control of certain greenhouse diseases, G. E. Stone {Massachusetts Sta. 

 Rpt. 1909, pt. 2, pp. 48-54). — It is claimed that experiments covering a period 

 of several years have demonstrated that by proper regulation of the moisture 

 in well-ventilated hothouses, anthracnose, downy mildew, Alternaria, and 

 powdery mildew of cucumbers and melons can be absolutely controlled. The 



