1060 DISEASES AND INSECTS 



DISPORUM 



1334. A traction power sprayer, for street and park trees. 



The essentials of a good pump are (1) durability: 

 secured by having working parts made of material least 

 susceptible to the action of the various spray solutions, 

 friction considered; (2) strength: obtained by a good- 

 sized cylinder, substantial valves, wall and piston; 

 (3) easily operated : found in a pump with a long handle, 

 large air-chamber and smoothly finished working 

 parts. A pump should be strong enough to feed two 

 leads of hose and throw a good spray from four nozzles. 

 Nearly all spray mixtures require constant stirrings to 

 prevent settling and insure uniformity, and an agitator 

 is a necessary part of the equipment. 



Nozzles. Much of the efficiency of a spraying 

 machine depends upon the nozzle. It should be chosen 

 for the particular work to be done, rather than for any 

 special design. The development of nozzle construction 

 has been rapid, new features being embodied as neces- 

 sity demanded, until today there are four main types, 

 each of which is intended for specific work: (1) The 

 Bordeaux nozzle is the oldest of the modern types. It 

 came into general use about 1890 and was at first 

 universally adopted for all spray work. It throws a 

 stream which may be regulated from a solid jet to a 

 coarse fan-shaped spray, both of which are too coarse 

 for general use. The Bordeaux has, however, one 

 place in the list of modern spray nozzles and that is for 

 the codlin-moth spray. For this application it is desir- 

 able to force the material into the calyx cups of the 

 developing fruit and no nozzle does this quite so effic- 

 ciently as the Bordeaux. (2) The Vermorel was the next 

 step in development after the Bordeaux. It was 

 .very much superior to the latter, breaking the 

 material up into finer particles, and was generally 

 used until about 1906. This nozzle, however, does 

 not possess any desirable features not found in the 

 disc types and therefore has no special uses in 

 modern spraying. (3) The disc nozzles are stand- 

 ard for general spraying work. They are repre- 

 sented by a large number of sorts, each made 

 by different manufacturers, but all working on 

 the same principle. The material is whirled 

 inside of the nozzle before it reaches the final 

 outlet, thus breaking it up into finely divided 

 parts and producing the desired mist. The 

 material is lastly passed through a disc, which 

 may have either a large or small opening. 

 For orchard and small crop spraying, the 

 small opening is used, in which case the nozzle 

 should be 3 to 7 feet from the object to be 

 sprayed. For taller orchard trees and for 

 small ornamental trees, the large opening is 

 used. This produces a solid jet which breaks 

 into finer particles at a distance from the 



nozzles, depending upon the pressure used. 

 (4) Shade tree nozzles, to be used only for 

 spraying very tall ornamental trees, and in 

 connection with at least 300 pounds pressure. 

 They throw a solid stream 30 or more feet in 

 the air, at which point the material is broken 

 into a coarse mist. This type came into use at 

 the time of the introduction of the brown-tail 

 and gypsy moths in the New England states, and 

 has since been widely used for parks, estates and 

 forest spraying. Q. g. WILSON. 



DISEMMA: Passiflora. 



DISOCACTUS (two-shaped Cactus). Cactdcese. 

 Bushy cactus, 2-3 ft. high, sometimes seen as a 

 pot-plant in collections. 



Stems terete, usually erect: branches flattened 

 as in Epiphyllum: fls. regular, with very short 

 tube; petals few, elongated, spreading; ovary 

 nearly naked, small. 



biformis, Lindl. (Phyllocdctus bifdrmis, Lab.). 

 Soon pendulous, the branches cylindrical: short 

 branches If.-like, the lower egg-shaped, the upper more 

 lengthened: fls. small, purple-red, less than 2 in. expan- 

 sion; ovary without angles and with minute scales. 

 Honduras. B.M. 6156. V. 2:159. J. N. ROSE. 



DISPORUM (Greek, double one-seeded). Syn. Pro- 

 sdrtes. Liliacese. FAIRY BELLS. Small perennial rhizo- 

 matous herbs, sometimes planted in the wild garden. 



Allied to Smilacina and Streptopus, being leafy- 

 stemmed, but fls. in umbels (or solitary): perianth 6- 

 parted, with narrow deciduous segms.; stamens 6, the 

 filaments filiform or slightly flattened and longer than 

 the extrorse anthers; ovary 3-celled, the ovules 2 or 

 more in each cell, the stigma 3-cleft or entire: fr. a 

 red or reddish few-seeded berry. About 20 species, in 

 N. Amer. and in the Himalayan region, Java to China 

 and Japan. Little known to horticulturists; probably 

 require no particular skill in cult. 



A. Lvs. rarely cordate at base. 



B. Style 3-cleft. 



Menziesii, Nichols. (Prosdrtes Menziesii, Don). 

 More or less soft-pubescent: st. 2-3 ft. long, forking, 

 arching above: Ivs. ovate to ovate-lanceolate, narrowly 

 acuminate or the lowest acute, sessile, 2-3 in. long, 

 often resin-dotted: fls. 1-3, greenish, cup-shaped, from 

 the topmost axils, nodding, 9-12 lines long; pedicels 

 puberulous; perianth-segms. nearly erect, acute, 6-11 

 lines long; stamens a third shorter; anthers included, 

 times shorter than the filaments: fr. oblong- 



1335. Spraying park trees with the machine shown in Fig. 1334. 



