Show A new alfalfa disease I 1 ani r m I 1 amr artalie up to the present time the alfalfa plant in colondo colon Color rdo do has bien ben practically ff free ca from dis diseases pases it is true that leaf spot is always present an and in damp situations a mildew often makes its appearance the former disease causes a considerable amount of damage in the aggregate but after all its presence is not usually considered recently ft a bacterial blight lias has appeared and in some localities it has been quite dis truc tive complaints have come from one locality for the past three seasons of the dying out of alfalfa plants in the spring the growers could scarcely believe that the trouble was due to winter injury since it had not occurred oc cured before under similar conditions and since dead plants were found alike on high and on low land and on wet and on dry situations the presence of numbers of small maggots in the decaying crowns was the most popular theory advanced to account for the dead plants on visiting the fields early in the spring it was evident that winter injury could not have caused the damage and that the maggots were only present because of the decay and not as a cause of it in juno june we had the first opportunity of inspecting the fields during the growing season the cause of thein the injury was as the numerous blackened stems from which a thick juice was waa oozing plainly indicated a bacterial blight and subsequent examination has haa shown this to be the probable causo cause of the trouble the first evidence of disease to be noticed by the casual observer is a short weak and light colored growth of the first crop and the stems even over a large field may not average over a foot in height at the th time the first cutting is usually made aclise A close examination shows that a majority of these a terns stems are discolored in fact nearly black for a portion of their length leneth and drops of dried juice will be found on many of them such stems are also very brittle and easily broken the disease apparently does not kill many plants the first year but in time so many of the plants die that the fields ar are e useless the disease evidently runs its course for the season with the first crop and those plants which have sufficient vigor make satisfactory growth for the second and third cuttings and little or no trace of blight is seen during the remainder of the season but the follo following spring a renewal of the outbreak may be expected the plants begin to die after the blight has haa been abundant for more than one season as the decay appears in the crowns of the plants and may involve the tap root the crown buds are thus destroyed or the nutrition may be so interfered with that the plants die almost nothing is kno known n of this blight as yet consequently remedial measures cannot be discussed except that it seems to be advantageous to cut the first crop earls earl and to delay the date of the first irrigation until after this time if possible |