DISEASES OF PLANTS. ()1 



or weeds growing in or near coffee plantations proved that the fungus would grow in 

 wounds on J'Jrj/lhrina litltospermn, Alhizzia inolnklcdiut, and Cedrela serrata, but only 

 when the experiments were conducted in moist air. Open air cultures were unsuc- 

 cessful. The fungvis will not grow on sugar cane {Saccharuin offirinarum). 



For treatment of the disease the author recommends burning all disease<l trees; 

 or, if this is not (l{!siral)le, cutting out the infected parts and coating the wounds with 

 tar. Tree trunks shoul<l be coated with Bordeaux mixture or lime to prevent inst'ct 

 injurie-i. All wounds due to j^runing should be coated with tar. If diseased trees 

 are allowed to remain in the ]>lantation, the trunks should ])ecoate<l with tar to ))re- 

 vent the dissemination of spores. — ii. m. pietkks. 



Mulberry-dwarf troubles, U. Suzuki (BuI. Col. Aijr. Imj). Univ. Tul-t/o, ■} (JfXiO), 

 No. 3, pp. 167-J2('>, ph. -2J). — For 10 years or more there has I)een known in Japan a 

 widespread disease of the mulberry which attacks the leaves and branches, checking 

 the growth and finally causing the death of the plant. This disease has spread, caus- 

 ing great losses to silkworm raisers l)y almost entirely destroying the croji of mul- 

 berry leaves. 



In 1897 the Japanese Government appointed a commission to investigate the subject, 

 and the present Ijulletin is in the nature of a report. The first recognition of the 

 disease is supposed to have been 20 or 80 years ago. Different varieties of mulberries 

 are unequally affected. (Generally speaking, those varieties which are most highly 

 esteemed for leaf production are most subject to the disease, while those which are 

 characterized by hard leaves and slow growth are comparatively free from it. 



The different methods of cutting mulberries are descril)ed, and the belief expressed 

 that the primary cause of the disease is attributable to the pra<'tice of subjecting the 

 mulberry to repeated cuttings. This treatment results in a deficiency of reserve 

 material in the twigs antl tends to abnormal development. 



Chemical analyses of healthy and diseased plants at various stages of growth are 

 reported upon in considerable detail. Investigations were made on the reserve mate- 

 rials of the mulberry tree and their relation to the disease. It was found that the 

 diseased leaves were remarkably poor in nitrogen and in the development of woody 

 liber. The deficiency in nitrogen in the diseased plants was not due to an insufficient 

 supply of nitrogen in the soil, but is attributed to a diminution of the absorptive 

 l)Ower of the roots and the chemical activity of the plant cells. The repeated cutting 

 of twigs (jr plucking of leaves residts in the exhaustion of the new shoots before they 

 have attained a height and development sutticient to enal)le them to perform the 

 function of assimilation. This statement, it is claimed, is supported by the fact that 

 tiie disease always appears in new shoots after cutting in. the growing season and is 

 never observed in plants which have not been cut. Diseased plants may recover 

 when kept from cutting for a number of years. 



Differences in the susceptibility of varieties and the effect of different soils are 

 menti(jneil. It ai)pears that a plant becomes more liable to disease by accelerating 

 its growth with abundant soluble manures. Young plants are rarely diseased. This 

 is thought to be ilue to the rapid develoi)mentof the roots and the large capacity for 

 the al)Sori)tion of mitrients by the young i>lants. ( )lil plants have less power of devel- 

 oping new roots, and conseiiuently there is a tleficiencj' of reserve material which 

 ••an not l)e supplied by the alisorption of material from the soil and air. 



Careful investigations were made, but no fungi or other micro-organisms were 

 found constantly a.ssociated with thedisease, the decay of the roots being considered 

 secondary. Aside from the correction of methods of pruning which suggest them- 

 selves, no other means f)f jirevention are described. 



The black rot and mildew of grapes and their treatment, Schloesinc (Rev. 

 Vil., 1900, \<). .li:o, Siiji.). 



Guignardia reniformis in the Caucasus, A. I.ebeoekk '('oithl. BaLi. n. Par., 2. 

 AfiL, I! {JUOO) , X(}. JO, J). iio.i, Jiij. 1). — A rejjort is given of studies of grapes received 



