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Show FUSARIUM OF POTATO Too Much Water and Heat Cause of Disease. Exaet Condltlona Hava Been Dlacov-red Dlacov-red by Expert of Colorado College Preventive to Be Pieced Within Reach of Raiaer. The exact rouditioua which cauae fuHarlum." the dlaeuBe which caiiBed a loaa of more than $20,000,000 to the potato rrop In the aouthcrnmoat po-tato-ralalng atatea from Colorado to Ohio and I'etuwylvaula last year, have been discovered by Prof. C. U Htch. jKrtato expert at the Colorado Agricultural Agricul-tural college. Kxperlmente to determine deter-mine what these conditions are have been under way In a greenhouse at the college here for the aat 100 daya and are Jmit coming to a clone The renulta Botinht-Juat what combination combina-tion of noli temperature and water aupply ratlin the dlaeaae have recently re-cently been made manifest. The result la that Trof. Fitch bni obtained data by which ho will be ablo to ad viae the potato raiaer ai to what meaBiirea to adopt to make the dlaeuse leaa likely to affect bli crop. A cure, however, has not yet h'" discovered; for, after the disease appears ap-pears there la no meani of itopplng It. Hut the result U that means of prevention the disease, to a very great extent, will bo placed within the reach of the potato ralHer. 'TuHarlum" Is not a new disease. It la an uiectlni? of the potato plant which makes Itself manifest in very hot. dry Hennons. like last season. To secure the data mentioned Prof. Fitch created In one of the green-! green-! houses at the college the very same ! rondltlons that exlut In the potato field I In the auninief. The temperature In the four cabinets where the experiment experi-ment wns carried on was kept at DO, 05, HO nnd 95 degrees, and the moisture mois-ture was regulated nt 10, 20, 30 and 40 per cent. When the plants reached the proper stage of development samples sam-ples from each cabinet were placed In the 95 degree cabinet and encloned In glans nnd. by means of electric lights, the temperature wns raised to between 00 and 100 decrees such temperatures us are found in a potato field on a moderately hot summer day This glass cabinet was so arranged as to supply proper circulation of air ns nearly ns possible Imitating the average summer breeze. The niols ture was raised on half the hills tc .10 and 40 per cent, and the final tesi was on. The plants were put In the glapi cabinet on a Monday morning. Wed nesday morning fusarlum developed The plants were decidedly "sick," am before night It was evident that the; were dying. The experiment had beei successful and Professor Fitch ha( cause to rejoice. Tho plants which had been supplied with 30 and 40 per cent of molslun showed the effects of the disease soon er and died more rapidly, while thosi which had been supplied with 20 pet cent withstood the test longer, but fl nally nhowed signs of the dlseafe Those which had 10 per cent are itil healthy. From these experiments Professo: Fitch had determined that, to lrrl gate pota'o fie'1' Past 20 Per c''nt 0 moisture when the temperature of thi soil la nhove SO degrees, will certain ly produce "fusarlum" and also pre ly produce "fusarlum" to take hold Tie also found during the experl ment that a soil temperature of abou 70 degrees, with an application of 2 per cent, of moisture, supplies altnos Ideal condition! for potato raising. Of course, th results of the experl metits do not mean that the problen has been solved, for there are yet t bo devised methods of putting the lr formation to practical use and of dr Ing what mhy be done to cool the sol! A special thermometer for tli farm er's use In testing the aolls Is one o the needs. With this he can ascertnli Just at what time It will be safe to Ii rlgat his fleldit. All these new fart I approvo the practice of careful ol farmers who think that during th hottest period of the summer It I wis" to Irrigate at night. Professor Fitch believes that, unde the most adverse conditions, the 'ten 'perature will be so lowered by m!: night that. It will be safe to apply th water at that time, and that before th hent of the next day Is cast upon th n-lda thla water will have done It work In supplying the plants and wl have soaked away Into the aoll ao tha thn heat will not cauao the disease. Another feature which will prov valuable la the method of preparln tbe aeed bed and puahlng the plant t early growth. It la believed that b applying aufflclent moisture to th - tlM.( t,ed to dampen It deeply wit hoi soaking and puahlng the growth c the planta aa rapidly possible earl p In the season, before the hot weathf romea. the plants themaelves will fu " nlsh shade to the aoll which will b the chief aid In the battle against th - disease. f The Importance of thla work ma be Judged by tbe loaa to Colorad alone, estimated to have been not let than 1.000,000 on last aeaaon'i cro baaed on average price! |