72 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Disease of Cabbage. — M. P. RB^Bmif^oi^ (Phytopathology, 1918, 8, 

 379-431, 10 figs.) has made a thorough study of a disease of the leaves, 

 stems, and roots of cabbage due to the fungus Phoma lingam. The 

 plants are most susceptible in the seedling stage, but may be attacked at 

 any time. Lesions are produced at the infected areas, and the small 

 black pycnidia appear on the sunken tissues. Various Cruciferte are also 

 liable to infection. Advice is given as to treatment both of the plants 

 and of the infected soil. A. L. S. 



Rubber Disease. — A. Sharples {Ann. App. Biol., 1918, 4, 153-78, 

 6 pis.) publishes an account of disease due to Ustulina zonata, which was 

 first known as a disease of tea and other plants, but which also attacks 

 Hevea hrnsiUensis, and in Malaya is responsible for the death of many 

 trees. The roots are chiefly attacked, and fructifications of the fungus 

 are found at the collar. Holes made by boring insects are entered by 

 the fungus, which spreads thence through the tissues. The writer 

 recommends strict sanitation methods, clearing the ground of rotting 

 timber, and the removal of old trees. A. L. S. 



Potato Leaf-roll.— E. J.Woin!hiiY'(Fhytopaiholof/y, 1918, 8, 507-29, 

 16 figs.) has made a study of the occurrence and history of this disease 

 in Bermuda. After describing the effects produced on the potato plant 

 he states that if the plants are carefully dug up the roots and stolons 

 show darkened patches bearing on the surface the characteristic mycelium 

 of Rhizoctonta. A long account is given of experiments in planting 

 different kinds of potatoes. A. L. S. 



Diseases of Parsnip. — After describing a cracking disease of 

 parsnip due to weather changes, A. D. Cotton (Keio Bull., 1918, 8-21, 

 2 pis., 2 figs.) has added a summary of diseases due to fungi : — Erysiplta 

 Polyoni, Phyllachora Pastinacse, Ramularia Pastinacse, Cercosporella 

 Pastmacse and Plasmopora nivea, all of which occur on the leaves and 

 petioles of Pastinaca sativa. A. L. S. 



Rose-blotch Fungus. — N. L. Alcock {Kew Bull., 1918, 193-7, 

 1 pL, 2 figs.) gives an account of this fungus, which produces black 

 blotches on the leaves in summer and autumn. The ascigerous stage 

 has never been found in this country, but some years ago such a stage 

 was discovered in America, and described under a new genus, Diplocarpon 

 Wolff (Microthyriacese). The writer found conidial pustules on young 

 twigs ; she suggests remedial measures, either spraying or removing all 

 leaves and twigs that have been attacked. A. L. S. 



'f •- 



Treatment of Scab in Potato Tubers. — G. II. Goo^fi {Phytopathology, 

 1918, 8, 457-68) records satisfactory results in the treatment of seed 

 potatoes by sprinkling them with formaldehyde or by immersion in 

 solutions of mercuric chloride. Without such treatment the crops 

 raised from scattered tubers were poor and weak. Coons prefers the 

 treatment with corrosive sublimate, 1 in 1000, for one half-hour. 



A. L. S. 



