Norwich bulletin., 1918-07-10
LATE BLIGHT IN POTATOES.
Almost Sure to Occur Each year and Should Be Carefully Guarded Auainst.

70
 Late blight is without question the most destructive of all. potato dis eases and is found to a greater or less extent in all parts of the world where potatoes are grown. Under favorable conditions, it destroys the entire po- tato crops.
 At the present time we here in Connecticut cannot afford to take any chances. The value of food to the world in general and the impor- tant part that the potato is playing in our fight to outlast the forces of the Hun is well known. Farmers and gardeners have responded as true Americans should by planting pota- toss in large quantities, see to it that they reach. maturity and are not de- stYoyed by either insects or diseases.
 Late blight is practically sure to oc- GUY each year in New England and New York, and makes it's appear ance soon after the plants blossom, gradually increasing until by the end of the season the damage is severe. - The first signs of blight are pur- plish or brownish black spots found on the leaves. Later the stems are attacked and under conditions favor able to the blight it requires but a few days for the plant to be destroy ed. Whole fields may be killed in a short time. Where plants are de- stroyed by blight, the potato itself becomes infected. the spores washing down through the soil, thus causing loss.
 The disease does not occur in the soil but is carried over from one season to another in the potato it. self. Always avoid planting seed which shows signs of dry rot as there is no method known whereby seed potatoes may be treated to prevent late blight The disease spreads rapidly over large areas and may be carried many miles.
 Late blight probably causes severe loss to potato crops in Connecticut about one year in five, and a medium amount of damage in one or two of tde remaining years. It is sure to develop if a spell of warm muggy weather occurs The disease requires moisture and warmth for its develop rnent. Pay particular attention to po- tatees planted on low or clay soils. eIhere..is one and only one method for. controlling late blight and the most satisfactory feature of this meth od is that it is sure and if properly carried out will absolutely prevent all danger of loss from this disease.
 Spraying with Bordeaux mixture, Used as a preventative measure before hlight appears, will keep the vines free from attack throughout the sea : sen This holds true in every cal SC. Eeep the potato covered with Bor- desux and it is safe from blight even F plants in adjoining fields are de srToyed Spray as often as is neces- s7Fy to keep the plants well covered This means that vines must be spray <, July and August
 Bordeaily mixture is easily prepared sl home. and, if potato beetles or o-hey leaf eating insects occur; should have. arSenate of lead added, at the te of two pounds powdered arse nate Of lead (4 pounds pastel to 5t gallons of the Bordeaux,
 To prepare Bordeaux dissolve foul pounds copper sulphate in water, ther siake four pounds Of quicklime. PoW the two together and add enough water to bring the entire amount UT Q 5e gallons. Your Bordeaux is now ready to use. Smaller quantities car IS made in proportional is well tt sCr and strain both the dissolved copper sulphate and the slaked linn oefors they are mixed. The cope s1iphate should be dissolved in wooden or glass container as the cop Ter attacks tin or iron
 Mix only the quantity you can us z one time as it does not retain it full strength after having settled Ycu can, however. keep both the dis solved copper sulphate and teh slaket Hn1e ID separate containers for tn entire season. mixing them and add izr water as the spray is required fo usA
 ... For further information apply to tn IT. s. Department of Agriculture, you State Agricultural College or to YOU Iccunty Agent.-Ci M Codding. Spec ial Field Agent, L. s. Department o Africulture, Bureau of Entomology.