10 



The Florists^ Review 



July 25, 1912. 



bounded by the drying and storage 

 rooms, with the office in one corner. 

 A good idea of the arrangement may 

 be had from the general view shown 

 herewith. 



Mr. Gnatt appears to be well equipped 

 for success. He learned the business 

 thoroughly under the direction of his 

 father, who is the leading manufacturer 



of prepared foliage in Europe, and trav- 

 eled for over three years as his fa- 

 ther's representative. He has recently 

 been joined by his brother, who will aid 

 in the management of the Hammond 

 eetabliehmcnt. Mr. Gnatt' s pergonal rep- 

 r« sentative is Opcar Lfistner^ »a*eB atreDt, 

 Chicago 



DISEASES OF SWEET PEAS. 



[A paper by Prof. J. J. Taubenhans, of the Dela- 

 ware College Asrrlcultural Experiment Station. 

 Newark, Del. read at the annual convention of 

 the National Sweet Pea Society of Aniorlca. at 

 BcBton, July 12, 19l2, continued fioni Tho Review 

 of July 18.] 



Anthracnose of the Sweet Pea. 



Anthracnose is another new and 

 American disease of the sweet pea. It 

 was first described by Professor Shel- 

 don of the West Virginia Agricultural 

 Experiment Station. This disease, 

 though recently worked out, is appar- 

 ently an old disease, known under the 

 names of wilt or drop. In the little 

 booklet, "Sweet Peas Up to Date," 

 published by Burpee & Co., it is spoken 

 of as drop and is attributed to well 

 cultivated and heavily manured plants, 

 and also to wet seasons. A rich soil 

 and wet climates cannot produce the 

 drop. These are only factors which 

 help the disease in its destructive work. 

 The cause of the anthracnose disease 

 is a fungus, Glomerella rufomaculans, 

 which is the cause of the bitter rot 

 of the apple. Inoculations have been 

 carried on with these two organisms 

 and their identity definitely established. 

 This means that if your sweet peas 

 grow near some apple orchard and if 

 the latter suffers from the bitter rot, 

 it will be carried readily by the wind 

 or some insect to the sweet peas and 

 produce the anthracnose disease. We 

 have also proven that the organisms 

 which cause the anthracnose of the 

 pepper, the persimmon fruit and the 

 May apple fruit will also produce the 

 anthracnose disease of the sweet pea 

 and the bitter rot of the apple. It is 

 thus seen how serious a projjosition this 

 becomes, when we consider the many 

 hosts which can communicate this dis- 

 ease to the sweet pea. 



Symptoms of Anthracnose. 



The symptoms of the anthracnose of 

 the sweet poa are diverse. Sometimes 

 the disease is manifested as a wilting 

 and dying of the tips. These diseased 

 jiarts become whitish and brittle and 

 soon break oft'. Sometimes tlie dying 

 works downward and this involves the 

 entire branch. Often tlie leaves are 

 attacked and they soon tlie. On tlie 

 leaves tlie disease soon start-s as a white 

 spot, which enlarges and involves the 

 entire area. On the Idossoins the fun- 

 gus either attacks the junction between 

 the tlower buds and the i)eduncle. and 



in this case the bud drops off, leav- 

 ing the peduncle intact, or it attacks 

 both flower bud and peduncle, and this 

 time both dry up but do not fall off. 

 The seed pods are also attacked in 

 all their stages of development. In this 

 case the fungus works inward until it 

 reaches the seeds. The fungus is capa- 

 ble of living over winter on diseased 

 parts of the plants, in the soil or on 

 the seeds, as was definitely proved in 

 our experiments. 



There is another disease, known as 

 mildew. This disease is caused by a 

 fungus which lives on the surface of 

 the leaves and sends in suckers into 

 the interior tissue of the host. This 

 fungus attacks both indoor and outdoor 

 sweet peas. However, it need not be 

 feared, as it is easily controlled by 

 sulphur dusting. 



Control of Diseases. 



Little is done or known in the way 

 of controlling the diseases of the sweet 

 pea. There are, however, certain 

 measures of control which we can 

 adapt from methods of other plants 

 which suflFer from diseases of natures 

 similar to those of the sweet pea. 



For the nematodes and all the other 

 root and soil diseases of the sweet pea 

 we would recommend the same treat- 

 ment as that recommended in Ohio by 

 Professor Selby for lettuce disease un- 

 der greenhouse conditions. The treat- 

 ments recommended are of two kinds; 

 namely, steaming the soil and formalin 

 treatment of the soil. The formalin 

 treatment of the soil consists, first, in 

 spading the soil and bringing it to a 

 good tilth condition as to moisture con- 

 tent. Then the soil is treated with a 

 solution of formalin made of two pints 

 of a forty j)er cent formalin in fifty 

 gallons of water, at the rate of one 

 gallon of the i)reparation to each 

 square foot of the surface. The appli- 

 cation may be given with an ordinary 

 watering can. After the heavy wet- 

 ting down, the soil should })e left free 

 for about two weeks, until all the 

 formalin evai)orates. This treatment 

 will rid the soil from all fungous j)ests, 

 but it will not be effective in con- 

 trolling the nematodes. Hence the heat- 

 ing method is the best. It is as fol- 

 lows: It is essential that the soil 

 should be sufficiently moist and at the 

 same time fairly loose. The steaming 

 consists in burying a series of pipes 



in the soil and letting live steam pass 

 through them. The pipes are perforated 

 with cross-head and boiler connection. 

 The surface soil is then covered with 

 canvas and the steam passed into the 

 pipes. The temperature for best re- 

 sults is 181 to 212 degrees, maintained 

 for a period of one hour. 



To Exterminate Cutworms. 



For cutworms, the following formula 

 is recommended: Bran, fifteen to 

 twenty pounds; middlings, ten pounds; 

 white arsenic, three pounds; molasses 

 or any cheap sirup, one gallon; freshly 

 chopped green clover, alfalfa, etc., 

 enough to make the moisture of a 

 greenish tint. Mix thorough; add 

 just enough water to allow of molding 

 into small balls. Put a pinch of this at 

 different intervals of the row. 



The biting insects could be controlled 

 by the same methods used to control 

 the cucumber striped beetle; namely, 

 a sprinkling of Paris green and flour. 

 Considering the important role that the 

 aphis plays in carrying the mosaic dis- 

 ease, it is important that the sweet 

 pea aphis should be kept in check. 

 There are two ways of accomplishing 

 this; the first is spraying with any 

 compound of nicotine, the other is to 

 have nature do it for us. In nature 

 the green aphis is parasitized by several 

 species of ladybird beetles. The latter 

 can be seen to feed voraciously on the 

 aphis; hence the lady beetle should not 

 be molested. Green aphis are also 

 parasitized by a small hymenopterous, 

 minute, blackish or brown, wasp-like 

 insect. 



Spraying for Anthracnose. 



We now have a series of experiments 

 under way on different spray mixtures 

 to control the anthracnose. Although 

 it is early yet to reach any conclusions, 

 it seems that potassium permanganese 

 is the most promising fungicide. A 

 one-half solution will control the an- 

 thracnose. The solution has a wine 

 color, but it is more or less colorless 

 when applied to the plant. It spots the 

 flower; therefore it should be applied 

 after picking the flowers. Spraying at 

 intervals of two weeks will be sufficient. 



This concludes my remarks on the 

 sweet pea diseases. It does not, how- 

 ever, exhaust the subject. There are 

 many more things that we should wish 

 to know about sweet pea diseases and 

 their control. 



We should like to know more about 

 the relation of lime, manure and ter' 

 tilizers to the diseases of the sweet pea: 

 the effect of excessive feeding; the 

 effect of drought and of watering i" 

 their relation to the diseases of the 

 sweet pea; the effect of deep and slial- 

 low planting, of thin or thick planting 

 and their relations to the diseases of 

 the sweet pea. More studies of the 

 mosaic disease are necessary before we 

 can conjecture any plans for control. 

 More studies and trials of insecticide? 

 and fungicides are necessary in order 

 to get the best results. We believe that 

 one more year of research will yi(dil 

 us the desired information. 



An Appeal to the Growers. 



For some reason or other the ex|H'ri- 

 ment stations have not as yet careil 

 for the interests of the seedsmen ^* 

 they do for the interests of the farmer. 

 Plant pathologists have not as y^^ 

 busied themselves with flower diseases 

 The Delaware Agricultural Experinio"* 

 Station is the first and only one in the 

 country to have taken up the diseases 



