NOTES AND ABSTRACTS. 



419 



Spinach, Physiological Studies of Normal and Blighted. By R. H. Ince 

 O. F. Black, J. W. Kelly, H. H. Bunzell, L. A. Hawkins, S. L. Jodidi, and 

 . E. H. Kellogg {Jour. Agr. Res. xv. pp. 369-408; Nov. 1918). — Carbohydrates 

 accumulate in leaves affected by spinach blight more than in normal leaves. 

 This is not due to inability to make proteins. It is thought that denitrification 

 occurs in blighted tissues, so that part of the nitrogen absorbed is lost as nitrogen 

 or ammonia. — F. J. C. 



Strawberry Diseases. By N. E. Stevens and R. B. Wilcox (U.S.A. Bur. 

 PI. Industry, Bull. No. 686, pp. 1-16). — Rhizopus nigricans is the most im- 

 portant strawberry-rot after picking the fruit. Berries picked in early morning 

 are less liable to this disease. Cooling the fruit in transit is suggested. 



Botrytis is a field-rot of strawberries, especially in damp fields. The diseased 

 berries are easily recognized and should not be included in fruit intended for 

 market. Botrytis is able to grow at low temperatures and produces abundant 

 spores. It is, however, of minor importance as a cause of loss in transit due to 

 decay. — A. B. 



Taxodium and Glyptostrobus. By Sir E. G. Loder (Gard. Chron. Nov. 22, 

 1919 ; p. 259, with 7 rigs.). — Deals with the synonymy of the American Taxodium 

 distichum var. imbricarium Sargent(var. pendulum of common use) ,and the Chinese 

 Glyptostrobus sinensis Henry, better known as G. heterophyllus. Certain 

 differences and likenesses are described. The Chinese plant is but little grown 

 in Britain, the American one being oftener planted for it. — E. A . B. 



Thrips, The Pear. By A. E. Cameron and R. C. Treherne [Agr. Dep. 

 Canada, Bull. 15, May 8, 1918 ; pp. 7-51, 22 figs.). — A full description 

 of the life-history of the Pear Thrips (Toeniothrips inconsequens Uzel) and 

 remedies for combating this serious pest in British Columbia. Prunes, plums, 

 and cherries are more seriously attacked than apples and pears, and the most 

 serious damage is effected on the buds just after bursting and before flowering. 



The insect measures inch, and is seen from the end of March in large 

 numbers on the opening buds after migrating from the soil. 



The eggs hatch in five to seventeen days. 



The larvas remain about three weeks on the trees, and when mature fall 

 to the ground and enter any crevice. 



They often penetrate quite deeply, usually 6-10 inches, and remain in the 

 soil three to four months before changing to prepupae in their earthen cells. 



This prepupal condition only lasts seven to ten days, and they then turn to 

 true pupae, remaining as such for six to eight weeks. 



During November the pupae become imagos and remain in the soil for about 

 five months, and the following late March they emerge from the soil to the trees. 



There is only one generation a year. 



Spraying against the adult Thrips is more important than against the larvas, 

 and two sprays should be put on before the blossoming, and should be done 

 when the Thrips are seen to be running on the outside of the buds. The first 

 spray should consist of miscible oil No. 2, 2 gallons ; nicotine sulphate, 1 pint ; 

 water, 200 gallons ; and the second spraying should consist of whale-oil soap, 

 10 lb. ; nicotine sulphate, i\ pint ; water, 200 gallons, and both washes should 

 be put on at 170-200 lb. pressure to ensure success. — G. F. W. 



Tobacco, Angular Leaf-spot. By F. D. Fromme and T. J. Murray (U.S.A. 

 Jour. Agr. Res. xvi. No. 8, Feb. 1919, pp. 219-228; 3 plates). — A leaf- 

 spot disease of tobacco which was prevalent in Virginia in 191 7 has been de- 

 scribed as " Angular Leaf-spot." The disease is caused by a bacterium, B. angu- 

 latum, which is a new species. It is a short rod with rounded ends, '5 ll x 2 to 

 2* 5 fx, motile by tuft of flagella at one pole, stains readily in ordinary dyes, is 

 Gram negative and not acid-fast, forms round, smooth, white colonies on agar, 

 liquefied gelatine, and is aerobic. 



Rainfall is an important aid to infection, and the development of the organism 

 within the tobacco leaf is dependent on those predisposing factors which promote 

 the rapid vigorous growth of the host. The disease produces much loss in both 

 yield and grade, in some cases 20 per cent, reduction in yield, and 40 per cent, 

 reduction in grade of the crop. 



A short bibliography is appended. — A. B. 



Tobacco Strains resistant to Root Rot. By James Johnson and R. H. 

 Milton (U.S.A. Bur. PI. Ind., Bull. 765, April 1919, PP- 1-12).— The Root Rot 

 disease is caused by Thielavia basicola, and this attacks the roots of numerous 

 varieties of tobacco, causing much damage to the crop. It is commonly spread 



