March 20, 1915 



HORTICULTURE 



373 



CARNATION DISEASES, 



Report of the Floricultural Patbologist, Uuiversily u£ Illinois Agricultural 

 Experiment Station, Urbana, Illinois, presented before tlie Illinois State Florists' 

 Association at Urbana, Illinois, March 2, 1915 by Geo. L. Peltier. 



Stem Rot of Carnations — Rhizoctonia 

 solani Kuhn. 



We now have in the process of pub- 

 lication, as a bulletin, the results of 

 the last three years' work on the fung- 

 us causing the stem rot of carnations. 

 This bulletin will be of a more or less 

 technical nature, but will be of value 

 to the florist. 



The fungus Rhizoctonia has been re- 

 ported in the United States as causing 

 more or less trouble to 164 species of 

 plants. About one half of this num- 

 ber Include floricultural and orna- 

 mental plants commonly grown by the 

 florists. The fungus is extremely ser- 

 ious in the cutting bench, not only to 

 carnations, but to practically all cut- 

 tings made from herbaceous plants. In 

 the seed beds it will attack seedlings 

 of a large number of plants, causing 

 the well known symptoms of "damping 

 off.' It is from the seed bed and cutting 

 bench that tfie fungus is carried, to a 

 large extent, into the fields and 

 benches, causing more or less loss 

 throughout the year. 



Cross inoculation experiments show 

 that one species of Rhizoctonia is the 

 cause of all the trouble. As I have 

 stated before, this fungus has been 

 found to attack a large number of 

 plants including field and vegetable 

 crops, floricultural and ornamental 

 plants, and many weeds. The fungus 

 has also been found growing in the 

 soil on dead plant material, so that 

 it is probably present, to a certain ex- 

 tent, in most fields. It is quite clear 

 then, that Rhizoctonia is present in 

 almost every carnation fleld, as well 

 as the soil that is put in the benches. 



You may inquire then — why are not 

 all carnation plants destroyed in the 

 field? Rhizoctonia is what we call a 

 facultative parasite; that is, under or- 

 dinary conditions it is a saprophyte — • 

 living on dead plant parts — but under 

 certain conditions it becomes an active 

 parasite and can attack and kill plants 

 of all ages readily. As I have men- 

 tioned in previous reports, the condi- 

 tions necessary for its parasitic devel- 

 opment, depend on a high temperature 

 and, to some extent, on moisture. 



It is hoped that by next fall an- 

 other bulletin taking up more specif- 

 ically the work on the carnation stem 

 rot will be ready for distribution. 



Branch Rot of Carnations, 

 Fusarlum sp. 



This disease has been under obser- 

 vation again this season. The fungus 

 is able to attack the cuttings very 

 easily and it is by the use of Infected 

 cuttings that the disease is spread 

 in the field and house. 



The completion of the work on stem 

 rot will allow us to take up the study 



of the fungus and methods of control 

 more fully in the greenhouse. 



Carnation "Yellows." 

 As I have suggested in past reports, 

 the only way this disease may be con- 

 trolled is by the selection of cuttings 

 from plants showing no signs of this 

 trouble. During the current year, a 

 from a number of varieties and the re- 

 sults have come out surprisingly well. 

 Cuttings taken from plants showing 

 "yellows" badly, produced plants oi 

 the same type. Cuttings taken from 

 slightly diseased plants, produced only 

 a few healthy, a number with "yel- 

 lows," while the majority of plants 

 showed only slight attacks of "yel- 

 lows". When cuttings were taken 

 from apparently healthy plants, they 

 developed, in the majority of cases, 

 into more vigorous plants showing no 

 "yellows." Occasionally cuttings taken 

 from an apparently healthy plant 

 would all produce plants with "yel- 

 lows" which tends to show that care 

 must be exercised in the selection of 

 cuttings from healthy plants. 



Another selection from the first 

 year's work has recently been made, 

 together with a further selection from 

 the stock now in the greenhouse. 



Antirrhinum Rust — Puccinia 



Antirrhini, Diet. 



& Holw. 



Due to the serious nature of the 

 snapdragon rust, Mr. Rees has devoted 

 his entire time, during the past year, 

 to this problem. It has been reported 

 in nearly all the middle western states, 

 in Massachusetts, and again in Oregon 

 and California. 



The rust appears on the plants in 

 the field about the last of July. The 

 uredo (summer) stage persists until 

 fall when the teleuto (winter) pus- 

 tules are found on the stems and 

 branches. The uredo, and to some ex- 

 tent the teleuto stage, is also found 

 in the greenhouse throughout the win- 

 ter, on cuttings, seedlings, and later 

 on the mature plants. During spring 

 the rust seems to die out in the house, 

 reappearing in the field during the 

 late summer. 



Mr. Rees published an account of 

 this trouble last fall in all the trade 

 papers, which no doubt most of you 

 have read. 



Stem Rot (Fusarlum sp.) and "Yel- 

 lows" of Asters. 



During the current year, a large 

 number of inquiries relating to vari- 

 ous plant diseases were answered. The 

 troubles most commonly reported last 

 summer were the "stem rot" and "yel- 

 lows" of asters. We are planning to 

 carry on some experimental work for 

 several seasons, on the aster troubles, 

 particularly the two mentioned above. 



Dry Rot of Gloxinias. 



We are also planning some work on 



a dry rot of Gloxinia bulbs, a disease 



which has recently been brought to 



our attention and which appears to 



be quite serious. 



British Horticulture 



Business as Usual. 



Despite the depressing influences ot 

 the war and the tendency to upset the 

 conditions which prevail in normal 

 times, the nursery and seed trade are 

 doing their utmost to maintain things 

 at the usual level. For instance, the 

 trade are rallying around the Royal 

 Horticultural Society in keeping the 

 shows going at the usual high stand- 

 ard. There was a meritorious display 

 at the Society's show in London on 

 Feb. IGth. Alpine plants were a special 

 feature, and in this department many 

 of the leading specialists showed some 

 notable specimens. There were saxi- 

 frages of the buseriana type, including 

 several new varieties. From China was 

 shown Primula sylviocola, in the ex- 

 hibits of Wallace & Co. Barr & Sons 

 obtained awards of merit for three new 

 crocuses — C. bilflorus Alsandri, C. b. 

 Lemon Queen, and C. Imperati albiflora. 

 Popularity of American Apples. 



The "apple habit" is now firmly 

 rooted in the British public. This is 

 indicated by the increased number of 

 grocers who now make a feature of 

 this fruit. Our national fruit bill each 

 year includes the sum of two million 

 pounds for Imported apples. With the 

 abundant supplies pouring into our 

 shores from America, Canada and Aus- 

 tralia, it is possible to have apples on 

 the dessert table all the year round. 

 British growers are gradually improv- 

 ing their methods— the examples of the 

 American and Colonial competitors 

 have not been Ignored. This season, 

 as usual, the markets have been well 

 furnished with apples from California, 

 chiefly Newtown Pippins, the Oregon 

 district, and from Nova Scotia. The 

 fruit usually arrives in excellent con- 

 dition, and meets with a ready sale at 

 remunerative prices. Besides apples 

 we are largely dependent upon America 

 for our pear supplies. From the fer- 

 tile Califomian ranches we receive 

 supplies of excellent samples of Winter 

 Nelis, Glou Morceau, and Easter Beurre. 

 For a cheaper trade the barreled Amer- 

 ican Keiffers find great favor. Al- 

 though in recent years increased atten- 

 tion has been paid to fruit culture in 

 Britain, we should come badly oft had 

 we to depend solely on the home sup- 

 plies of fruit. Although there have 

 been delays in obtaining some of the 

 over-seas supplies, so far the trade has 

 not been seriously hampered by the 

 war. 



Trenton, N. J. — The action of the 

 First Judicial District Court of Morris 

 has been affirmed by the Supreme 

 Court in giving judgment to Patrick 

 Connelly against Thuro Wollen. The 

 litigation involved the lease of six 

 greenhouses and a dwelling house in 

 Madison. It was contended by Con- 

 nelly that Wollen was in arrears for 

 rent, and the former sued to recover. 



