18 



The Florists' Review 



Ddcbmbib 28, 1916. 



DISEASES OF SWEET PEAS. 



Boot Bot and Other Troubles. 



' ' Ninety per cent of the failures with 

 greenhouse sweet peas are due to sick 

 soils; that is, to parasitic fungi present 

 there which make plant growth impos- 

 sible." (.Such, in substance, is one of 

 the introductory statements in an ar- 

 ticle by J. J. Taubenhaus, of College 

 Station, Tex., in a bulletin recently is- 

 sued by the Massachusetts Horticultural 

 Society. After thus emphasizing the 

 importance of his subject, the writer 

 proceeds to describe the principal sweet 

 pea diseases, especially those of a 

 fungoid nature, and to give suggestions 

 for their control. The part of the ar- 

 ticle which has reference to indoor cul- 

 ture may be summarized as follows: 



Root rot, or Corticum vagum, is a 

 source of considerable trouble to green- 

 housemen. The disease may destroy 

 the entire stand, or cause it to be un- 

 even, thus necessitating several resow- 

 ings. Severely infected plants have 

 practically no root system. In less in- 

 fected plants only one or two root- 

 lets may be destroyed. The fungus 

 produces a browning effect in the 

 root before total destruction sets in. 

 In early stages of infection the seed- 

 lings are seen to have a wilted ap- 

 pearance; as the disease progresses the 

 infected seedlings fall over and col- 

 lapse. The fungus is not confined to the 

 roots. It is frequently seen to work 

 its way up the stem and produce a 

 constricted area, marking it off from 

 the healthy part. The fungus, being a 

 soil organism, is usually introduced with 

 manure, infection taking place at any 

 part of the roots or stems. In the latter 

 case reddish sunken spots are observed 

 at the base. Root rot is primarily a 

 seedling disease, although older plants, 

 too, may be affected. Such plants lin- 

 ger for some time, but are valueless. 

 Overwatering and a sour condition of 

 the soil favors the disease. 



Fusarlum Wilt. 

 The ravages of fusarium wilt, or 

 Fusarium lathyri, are of much more se- 

 rious consequence to greenhousemen 

 than are those of root rot. The writer 

 has known of instances where the dis- 

 ease has ruined the entire crop of in- 

 door sweet peas. After several resow- 

 ings, the owners gave up in despair. 

 Florists should do everything to pre- 

 vent its introduction into the house. 

 In places where this disease has mad^ 

 its appearance the growing of green- 

 house sweet peas had to be abandoned 

 within less than two years. The dis- 

 ease produces a sudden flagging of the 

 leaves, which is accompanied by a wilt- 

 ing and collapse of the seedlings. 

 Usually, upon sowing the seed, a fair 

 percentage germinate and reach the 



height of eight to ten inches, when 

 they are attacked by the fungus. If 

 the collapsed seedlings are allowed to 

 remain on the ground, the dead stems 

 will soon be covered with the sickle- 

 shaped spores of the fusarium fungus. 

 Eventually the dead tissue rots, attract- 

 ing small fruit flies, which now begin to 

 distribute the spores to different places 

 in the same house. The trouble usually 

 manifests itself in widely separated 

 spots on the bench. These spots, how- 

 ever, quickly spread, involving the en- 

 tire bed, which may suddenly assume a 

 wilted appearance. Here and there, 

 however, and in the same bench, a few 

 plants remain alive and keep on grow- 

 ing in spite of the disease. 



Stem or Collar Bot. 



Stem or collar rot is usually a seed- 

 ling disease, although it may attack 

 plants of all ages. Like the rhizoctonia , 

 rot, it attacks many different kinds of 

 seedlings. The trouble is most severe 



in houses poorly ventilated and in beds 

 overwatered or lacking proper drainage, 

 and in damp places outdoors. The dis- 

 ease spreads quickly and is soon fatal. 

 Affected plants first show a wilting of 

 the tip and flagging of the leaves, and 

 then the seedlings fall over and col- 

 lapse. The cause of this disease is a 

 funguQ, Sclerotinia libertiana, which 

 also causes a drop disease of lettuce and 

 of other plants. The fungus does not 

 seem to attack the roots, but penetrates 

 the collar of the stem and completely 

 invades the vessels, thus clogging the 

 upward flow of the water from the roots 

 to the stem. Freshly collapsed plants 

 usually have a water-soaked appear- 

 ance, and are later overrun by a white 

 weft, which is merely the mycelium of 

 the fungus; this is followed by sclerotia 

 (resting bodies), which are found scat- 

 tered here and there on or within the 

 affected stems. The fungus is a soil or- 

 ganism which occasionally causes trou- 

 ble in clover flelds. It is introduced 

 with animal manure. 



Thlelavla Boot Bot. 



Plants severely infected with thie- 

 lavia have practically little or no root 

 system, since the latter is destroyed by 

 the fungus as rapidly as the roots ap- 

 pear. Whatever root system is present 

 is of a stubby nature, charred in ap- 

 pearance. The fungus sometimes works 

 up on the stem to a distance of two to 

 three inches above ground, but never 

 to the extent of invading the entire 

 stem. It is probably due to this black- 



(Continued on page 40.) 



College Station, Tex. — At the A. and 



M. College material is on the ground for 

 the new Lord & Burnham greenhouse to 

 be erected by the Department of Horti- 

 culture. 



Eustis, Fla. — The vanguard of the an- 

 nual army of wealtliy winter visitors 

 has put life in business, says Frank 

 Buneck, who caters to the elite from the 

 north. Carnation crops are good, but 

 all cut flowers ha . i. been scarce on ac- 

 count of the cold — for Florida — weather. 



Houston, Tex. — At the December 

 meeting of the Houston Florists' Club, 

 which was held at the Washington ave- 

 nue greenhouse, with Park Superintend- 

 ent C. L. Brock as host, the following 

 were elected officers for 1917: Presi- 

 dent, Henry Kuhlmann, Jr.; vice-presi- 

 dent, Paul M. Carroll; secretary, Clar- 

 ence L. Brock; treasurer, W. W. West- 

 gate. The club adopted a resolution rec- 

 ommending that an arboretum be estab- 

 lished on the new permanent exposition 

 grounds. The Texas florists believe that 

 this arboretum should contain specimens 

 of every plant that is and can be grown 

 in the southland. Another contest will 

 be held in 1917 for the prettiest yards 

 in Houston by the club. 



Boseland, Fla. — W. Huger Turner 

 states that the company of which he is 

 president has, during December; begun 

 the establishment of a floral garden, 

 growing not only fruit and vegetable 

 plants, but palms, decoratives, etc. 

 Preparations are being made to grow 

 large contract orders of various plants 

 that are particularly adaptable to Flor- 

 ida culture. The establishment, to be 

 known as Ercildoune Gardens, is located 

 at the confluence of the Sebastian and 

 Indian rivers, having a frontage of one- 

 and one-quarter miles. The Dixie high- 

 way traverses it for over half a mile. 

 It is particularly notable as having the 

 highest coastal elevation in all Florida 

 and on it is located the world-famous 

 frost-proof grove, the oldest citrus grove 

 in the state, furnishing millions of buds 

 for budding, being, therefore, largely 

 the parent, directly and indirectly, of 

 the major part of Florida groves. "We 

 have three flowing wells," says Mr. 

 Turner, "irrigating system, variety of 

 soils, barns, outbuildings, cottages, pack- 

 ing house, etc.; in fact, ideally situated 

 and arranged for plant growing. At 

 present we have thousands of palms and 

 various plants and bulbs in a state of 

 growth and will soon be ready for the 

 market." 



