The ancients believed that diseases in plants were induced by evil spirits. For instance, the rust of wheat was thought by the Romans to be caused by the evil spirit Rubigo. The remedy then employed was to frighten away the spirit by beating with drums of various kinds. Today , some insist that all plant diseases are brought about by conditions of environment such as excessive sunshine, drought, rain or dew. We may perhaps justify these views when we consider that plants in their mute way are unable to tell of their ailments. The keen eye and the close observer, how-2 CULTURE OF THE SWEET PEA ever, have singled out on plants parasitic organisms whose work brings about deviations from the normal. Today Plant Pathology has become recognized as a definite science. There is hence no reason why we should tolerate certain plant diseases when we realize the vast store of scientific knowledge available. Indeed it is highly imperative that any man who is engaged in the growing of crops should be able to recognize a diseased condition in plants. Like every science, Plant Pathology has made slow progress in its beginning. Scholars who considered it from a purely speculative or philosophical point of view only were interested in it at first. It was really during the first half of the nineteenth century that Plant Pathology built for itself a solid foundation, and gained a place among the leading sciences. It 4 CULTURE OF THE SWEET PEA trained Pathologists at that time to cope with the situation. A similar epidemic was that of downy mildew of grapes in France, in 1882. France, however, met the crisis through one of her noble sons, Professor M. Millardet, then of the Academy of Science at Bordeaux. His keen observations and studies have evolved a remedy for the grape mildew. Millardet was in fact the first to show the value of copper as a fungicide; and incidentally also laid the foundation to modern methods of spraying and of disease prevention in general. Today Plant Pathologists are everywhere investigating plant diseases which cause serious epidemics. And they are going farther, for the diseases of every weed is important and will aid in the solution of many problems regarding disease in vegetables, fruits and crops. Although nearly every Agricultural Col-* By Professor A. C. Beal of Cornell University. 9 12 CULTURE OF THE SWEET PEA tinued until the larger part of the world's supply now comes from California. Meanwhile the variety Blanche Ferry was discovered growing in a garden in New York State and was put on the market in 1889. From this was developed the varieties Early Blanche Ferry, Earliest of All, Earliest White, and the whole race of winter-flowering sweet peas. The American originators have given us many good striped varieties, such as America, Aurora, etc., and also such blues as Navy Blue and Flora Norton. Other notable varieties are

In 1923, specimens of a peculiar and, until recently, puzzling cotton root trouble were received. The specimens were of cotton plants with welldeveloped tops but with extremely shallow and very greatly reduced root systems ( fig. 1 a)

No abstract

In the course of my investigations on the diseases of the sweet potato (25) the name Java black rot was applied to a disease caused by the fungus Lastodiplodia tubericola E. & E. The investigation plainly showed that the above fungus behaved very much like a Diplodia. Experiments were undertaken to prove the pathogenicity of the fungus, its relationship to the genera Diplodia, Chaetodiplodia, Botryodiplodia, and Diplodiella.The genus Diplodia founded by Fries (9) in 1849 shows the following characteristics: Pycnidia scattered, subcutaneous to erumpent, black, characteristically papillate at the mouth, spores one-septate, brown to dark. The genus Botryodiplodia founded by Saccardo (20) in 1880 is described as follows: Pycnidia caespitose (clustered) erumpent, and in a stroma; hairy or hairless, spores one-septate, dark. The genus Diplodiella founded by Karsten (14) in 1884 resembles Diplodia in every way except that the pycnidia are superficial instead of erumpent. The genus Chaetodiplodia was also founded by Karsten (15) in the same year; it resembles Diplodia in that the pycnidia are scattered. In this genus however they possess bristles, or hair; spores one-septate, dark. The genus Lasiodiplodia was created by Ellis and Everhart (6) in 1896 and described as follows: Pycnidia and subicle are enclosed in a hemispherical stroma. In addition there are paraphyses intermingled with the basidia of the sporules in the pycnidia; otherwise as in Diplodia.From the above descriptions it is evident that the classification is without proper basis. To separate Diplodiella from Diplodia because the pycnidia are erumpent in the latter, while they are superficial in the former is not justified from a generic standpoint. The same is true for the other genera here mentioned. From what follows, it is evident that with the exception of the genus Diplodia, which was first described, the others are not valid.

Newark, Delaware fertilizers should be used very judiciously. The aim should be to apply a food that is well balanced, i. e., it should contain the proper amount of nitrogen, phosphorus, potash and lime. Too much of one of these elements and too little of the other will produce disturbances in the metabolism of the plant as will be seen later under the discussion of physiological diseases. For an ordinary garden land, the following is a well balanced fertilizer devised by Prof. T. F. Manns of the Del. Expt. Station. Before plowing a surface application of well rotted manure at the rate of 6 tons per acre is first applied to the soil. After plowing and harrowing the soil, it is furrowed and 5 tons of rotted manure per acre is applied in the furrows. The manure is worked in deep with a spade and the following fertilizer is applied in the furrows *Sodium nitrate 200 lbs. per acre Dried blood 250 lbs. " " Acid phosphate 1200 lbs. " Potassium sulphate 240 lbs. " " Rock phosphate 400 lbs. " " Hydrated lime 200 lbs. " " Carbonate of lime 600 lbs. " " The fertilizer is well mixed up with the soil and the seeds are planted on top and covered to a depth of about two to three inches. Care of the Seeds and Depth of Sowing. Most of the whiteseeded varieties are subject to decay in the soil. Most of the blackseeded varieties are more resistant to soil decay but they do not germinate evenly. In order, therefore, to hasten germination, it is advisable to place the seed in tepid water over night. With this treatment the seeds swell and are ready to be sown the next day. The Rev. W. T. Hutchins, a well-known sweet peas specialist in America, advises the placing of the seed in moist earth for seven or eight days. They are then taken out and examined. The swollen seeds are planted and the hard seeds cut with a knife to hasten germination. Whatever method is used the aim should be to hasten germination in order to prevent the seed from laying too long in the ground and thereby causing decay. The depth of sowing the seeds varies from two to three inches according to the nature of the soil. As to distance, five feet *This mixture was recommended for a very heavy acid soil deficient in organic matter.