BB—Lancaster Farming, Saturday, September 13,1980 How root rots cause unseen trouble in alfalfa LITITZ Disease affects every crop, and many far mers might argue which crop is most susceptible to disease attacks. Com growers have blights to contend with, gram sorghum farmers suffer from losses caused by an thracnose and wheat producers might run into rust or wheat streak. But, a little known fact is that alfalfa and the people who produce it, may face the biggest challenge. There are approximately 30 different diseases that quickly can slice into alfalfa yield potential. The battles that professional hay growers face during the growing season can sometimes rival the best of stories told by com growers following the devastating 1970 blight. The reasons not many people hear about alfalfa diseases are many. Few farmers raise alfalfa for their major income production. Thereto :e, there are a limited number of farmers to concern them selves and their peers with disease problems. Alfalfa isn’t produced as a commodity to be traded. So, if an alfalfa crop is wiped out, the news media as well as speculators and traders don’t pick up on it. Perhaps most im portantly, only recently have more and more producers concerned themselves with measuring yield. Like a hog being shown at a county fair, alfalfa either “looks good or it doesn’t.” Performance was rarely measured, and farmers had no means of knowing if a crop had a 10 or 20 percent yield reduction. Fortunately, this is changing. One of the most damaging diseases that preys upon the nation’s alfalfa crop is pbytopbthora root rot. Koot rot m alfalfa is not limited to particular regions of the country. Phytophthora root rot does exactly what the name implies. The fungus that causes root rot likes heavy precipitation and wet or poorly drained soils, where it gets its footrng and begins to rot tne roots ot plants. Stands of alfalfa are thinned and, of course, yield is reduced. Alfalfa growers face an I TRAILER LOAD SALE “SPECIAL DISCOUNTS” ON BUCK RUSTIC SIUGE COVERS SILO CAPS Pit, Bunker, Trench Silos MKSHW’S ANNUL HEALTH SUPPLY R4LITITZ, PA 17543 Phone 717-733-4466 extra challenge because phytophthora root rot cannot be controlled by any chemical means or cultural practice. There is some good news, however. Seed companies have bred resistance into some of the varieties they now market. As awareness of alfalfa yields and the effect diseases have on those yields increases, so do the sales of these recently in troduced resistant varieties. <*s