DISEASES OF PLANTS, 747 



The roncet of the American grape in Sicily, E. Pantanelli {Bol. Min. Agr., 

 Inilus. e Com. [Rome], 9 (1!)10). Ser. V. No. 2, pp. 20-21; abs. in Riv. Patol. 

 Vcff., J, (1910), No. 9-10, pp. lf,9, 150).— In a summary of the results of three 

 years" study of this disease (E. S. K., 23, i)p. 4S, 550). the author discusses the 

 distinetiou between roncet aud other diseases which are often associiited with it. 

 the typical characteristics of the disease, its cause, aud remedies. 



The conclusion is reached that roucet is neither parasitic nor infective, but 

 is a symptom of progressive degeneracy produced by an insufficiency of tlie ab- 

 sorbent root system, associated with certain unfavorable physical properties of 

 the soil to which the grape is especially sensitive in the ;Mediterranean climate. 



Spring and summer remedies against parasites of the grape, L. Vivarei.li 

 (RiiLsia [Conegliuno], J,, scr., 16 {1919). Nos. 11, pp. 2-',9-2oS; 12, pp. 277-282; 

 hi. pp. 296-300). — The author gives about 40 formulas nnd methods of applica- 

 tion for the various liquid aud dry fungicides (in powder form) used in com- 

 bating six common diseases of the grape. 



The banana disease and other enemies of the plant in Costa Rica, H. Q. 

 Levy (Jour. Jamaica Agr. .s'oc, / '/ (1910). No. 7. pp. 2Ji1-247). — A rather elab- 

 orate description is given of the adverse conditions from which the banana 

 fields of Costa Rica are suffering, especially in regard to the so-called banana 

 disease, its ravages, field characteristics, and the various methods used in at- 

 tempting to control it. 



The adverse conditions, according to the author, are as follows: (1) Ex- 

 hausted fields, (2) lack of proper drainage, (3) roasted suckers, caused by 

 planting bananas in old river channels which have a few inches of rich soil 

 topping beds of sand, pebbles, aud bowlders, (4) grubs, (5) gophers, (6) bushy 

 fields which are not kept free from grass, weeds, etc., and (7) the banana 

 disease. 



It is stated that in the vicinity of Bocas del Toro thousands of acres of 

 bananas have been destroyed by the banana disease, and that in spite of all the 

 remedies tried, none have proved of practical value in stam])ing out or pre- 

 veutiug it. The disease, which is presumed to be of bacterial origin, attacks 

 plants in all stages of their growth, on new ground, on ground where diseased 

 plants once stood, and in either dry or wet localities. 



Young plants when first attacked split from the bulb upward for 1 to 2 feet, 

 exposing the lower layer of the sucker. Sometimes the split extends to the 

 heart, so that finally the heart, leaf, and branch turn black and rot. With older 

 lilants. a fringe of yellow appears on the lower leaves, and in a few days the 

 leaves turn yellow, followed shortly by a brown color. Finally all the leaves 

 hang quite limply down the side of the sucker, aud the whole tree rots to the 

 ground, giving off a very offensive odor. 



At all stages of growth, if the head or "yam" of an infected sucker be split 

 open the heart will be found quite rotten and composed of a putrid yellow mass, 

 while 1 inch from the outer surface a bright red streak Hanked by a briglit 

 yellow one will be found, which follows all the passages into and through the 

 roots to their extremities. In sick bunches the tips of the fingers present a 

 I>inched-in appearance. When closely confined, as in a railway car. they will 

 rii»en in 24 hours aud when lifted will shed every finger. 



The disease 2 years ago was contined to the Baltimore division in Costa 

 Rica. At the rate it was then spreading, in 10 years' time there will not be a 

 liealthy banana tree in Costa Rica. 



The following remedies were tried, none of which were wholly successful : 

 (1) Cutting down all diseased plauts level with the ground, thus exi)osiiig the 

 entire root to the action of the sun; (2) taking out the entire stool, allowing 

 the hole to remain open for some time l)efore replanting, and cutting into small 



