1546 



ROOT - GALLS 



nd apricot in the Southwest, but as yet it remains to 



- on the roots of the mulberry are said to be 

 due to the hypertrophy of the lenticels. Some inves- 

 tigators have attributed gall-like root-growths in some 

 instances to the hypertrophy of adventitious buds. 



The root-galls caused by the nematode (Heterodera 

 radicicola) may usually be readily recognized from 

 other forms of hypertrophied tissue by the numerous 

 knotty enlargements on the smaller roots infested by 

 the worms. By careful search, m 

 most instances, the distended female 

 worms may be found in the infested 

 tissue, where they appear as small, 

 nearly spherical, pearl-like bodies, 

 readily seen with the unaided eye. 

 This minute worm, commonly called 

 eel-worm, feeds upon the roots of a 

 great variety of cultivated plants and 

 is particularly destructive in the 

 South. It is only injurious in the 

 northern states to plants growing 

 under glass. The most effective 

 remedy in the case of field crops is 

 -the removal of all rubbish that would 

 harbor the worms during the winter. 

 In greenhouses steam can be forced 

 through the infested soil. When 

 potted plants are badly affected they 

 may be severely root-pruned and re- 

 potted in soil free from worms. They 

 are not troublesome in soil that has 

 been frozen since an infested 

 crop was grown in it. 



The root-swellings caused by 

 the grape-vine gall-louse (Phyl- 

 loxera vastatrix) may be read- 

 ily recognized from other root- 

 galls by the presence of the 

 insects. The young insects, by 

 puncturing the epidermis of the 



'^-<J > ^ly* 3 """" roots and sucking the sap, cause 



i^J _\\'m the galls to develop. The in- 



L-^^T"^ 'ill sect is found on the diseased 



roots in all stages of develop- 

 ment during the summer. 



The most effective method 

 of holding the insect in check 

 appears to be in the use of re- 

 sistant roots, i. e., the grafting 

 of the more tender -varieties 

 on roots of those that are 

 stronger and better able to re- 

 sist the attack of the insect. 

 Bisulfide of carbon in some in- 

 stances has proved effective in 

 killing the lice. 



The crown -gall appears to 

 be the most harmful of root 

 diseases affecting cultivated 



plants in this country. These galls have been reported 

 upon the roots of the peach, apricot, almond, prune, 

 plum, apple, pear, walnut, grape, raspberry, blackberry, 

 cherry, poplar and chestnut, and without doubt further 

 investigation will find it upon other plants as well. 



As yet it is not known whether the crown-gall as at 

 present known always arises from the same cause, as 

 the galls vary considerably on different plants and the 

 cause has been definitely ascertained only in a few 

 instances. The fleshy outgrowths so abundant in the 

 Southwest on the roots of the peach, apricot and allied 

 plants, known under the name of crown-gall, are caused 

 by a slime-fungus (Dendrophagus globosus), which is 

 parasitic in the infested roots. 



Seedlings from one to six months old appear to be 

 most susceptible to this disease, hence it is particularly 

 destructive to nursery stock. When the galls appear on 

 young trees they almost always occur on the side of the 

 main root a few inches below the surface of the soil, or 

 in the region of the crown. With more mature trees 

 they are likely to occur at greater depth on lateral roots. 

 At first the gall has a uniform outer appearance, but 

 later it becomes warty from unequal growth. The 



2145. A Root-gall. 



ROSA 



tissue of the developing gall is soft and succulent, with 

 nodules of woody tissue scattered through it. The galls 

 vary much in size and may reach a diameter of ten 

 inches. 



But little is known as to remedies for crown-gall. As 

 the disease is primarily a nursery disease, the most 

 effective remedy is in securing stock for planting from 

 a non-infested nursery. The disease can be held in 

 check to some extent in infested orchards by cutting off 

 the galls that appear on the tree boles at the surface of 

 the soil and applying to the wounds a paste made from 

 bluestone and lime. j_ ^y_ TOUMEY. 



ROQUETTE or ROCKET-SALAD (Et-hca satlva, 

 Mill.), a low-growing hardy annual from southern Eu- 

 rope, whose leaves resemble those of radish and turnip, 

 is much used by the French as a spring and autumn 

 salad and pot-herb. The flavor of the young, tender 

 leaves, which are the parts used, bears a strong resem- 

 blance to that of horse-radish. In America it is but 

 little grown. 



The first sowing may be made in early spring, the 

 seed being dropped thinly in shallow drills a foot apart, 

 with successional plantings each second or third week 

 through the season. The soil must be rich and well 

 supplied with moisture, else the leaves will probably be 

 tough and acrid. Inter-culture is the same as for spin- 

 ach, lettuce and similar crops. Frequent watering and 

 tillage in hot, dry weather to insure rapid, vigorous 

 growth should result in succulent, mild-flavored leaves. 

 In summer the plants run rapidly to seed; in spring 

 and autumn they will produce abundantly after being 

 cut. The pale citron-yellow flowers emit a perfume re- 

 sembling that of orange blossoms. j_ 



ROS A (ancient Latin name). Rosacen. ROSE. Orna- 

 mental deciduous shrubs, upright or climbing or creep- 

 ing, usually with prickly stems, alternate, stipulate, 

 odd-pinnate, rarely simple leaves, showy purplish, car- 

 mine, pink or white flowers, and conspicuous, often or- 

 namental, usually scarlet fruits. There is probably no 

 flower more popular and better known than the Rose. 

 From time immemorial poets have sung its praise, and 

 the love of it can be traced through the most ancient 

 documents in the literature of the Aryan race. It is re- 

 markable to note, however, that the Rose has played a 

 far inferior part in the horticulture of the Chinese and 

 Japanese. It is probably the first flower known and 

 cultivated in a double state, and it is the double-flowered 

 Garden form whose image the word "Rose" almost in- 

 variably brings to our mind, while to the wild single- 

 flowered Roses much less attention has been given. The 

 ornamental value of single Roses is rarely fully appre- 

 ciated. The Wild Roses have a simple charm and 

 graceful beauty of their own. No doubt the bold and 

 dominating beauty of the double Roses has eclipsed the 

 more modest attractions of the single Roses. The longer 

 blooming season of the Garden Roses is also a factor in 

 their favor. Though the Wild Roses cannot, perhaps, 

 be compared with their more noble sisters of the gar- 

 den, they are nevertheless fully able to rival other 

 ornamental shrubs for the adornment of park and plot. 

 According to the habit peculiar to each species, they 

 can be used for a variety of purposes. Most of the spe- 

 cies are shrubby, rarely exceeding G or 8 ft., and may 

 be used for borders of shrubberies or for covering 

 slopes and rocky ridges, especially .K. rngosa, K. liu- 

 milis and various American species. Some kinds, like 

 Jf. ruyosa and R. lucida, make handsome ornamental 

 hedges. The climbing species are used for covering 

 walls, trelliswork, arbors, porches or pillars, but per- 

 haps display their beauty to the most advantage when 

 allowed to ramble over shrubs or rocks. The half-ever- 

 green R. Wichuraiana makes a beautiful ground-cover 

 and may also be used for edging groups and flower 

 beds. 



The fruits of most species are decorative and often 

 remain on the branches all winter. The red stems of 

 most of the species of the Carolina? and Cinnamomeae 

 groups are effective in winter also. The foliage of most 

 of the American species turns purple-orange or yellow 

 in autumn, and so does that of -B, rugosa, which is in 



