AND OTHER SMALL GRAINS

Bulletin No. 116 June, 1931 Montana State College, Extension Service, J. C. Taylor, Director, Cooperative Extension Work in Agriculture and Home Economics. Montana State College and Uni~ed States Department of Agriculture, co-operating. Distributed in furtherance of the Acts of Congress ~ay 8 and June 30, 1.914..~ CONTROL OF SMUT IN WHEAT AND OTHER SMALL GRAINS By H. E. Morris, Extension Plant Pathologist Waldo Kidder, Extension Agronomist Smuts cost the farmers of Montana many thousands of dollars each year. In 1930, stinking smut of wheat alone caused a loss of approximately $750;000, due to decreased yields and to a lower price per bushel. This loss and also that due to the smuts {..:Fig. 1. Smutted and normal heads of wheat. The head at the left,is a typi:cal head affected with covered or stinking smut, The next, head IS a he'althy head. The two heads on the right show two stages of the loose smut in wheat. (-Courtesy,D. S. Dept. of Agr.).,(

I 2 MONTANA EXTENSION SERVICE of oats, barley and rye may be largely prevented by adopting the methods of seed treatment described in this bulletin. What Is Smut Smut is produced by a small parasitic plant, mould-like in appearance, belonging to a group called fungi (Fig. 2). Smut lives most of its life within and at the expense of the wheat plant. The smut powder, so familiar to all, is composed of myriads of spores which correspond to seeds in the higher plants. In the process of harvesting and threshing, these spores are dis Fig'. 2. Comparison in size between: a, fine sand; b, very fine dust; c, spores of the fungus causing l'ose rust (Phragmidium); d, spores of the wheat-rust fungus (Puccinia); e, spores of the fungus. causing apple scab (Venturia); f, spores of oat smut (Ustilago); g, spores of blue mold of fruit (Penicillium) j h, spores of potato dry rot fungus (Fusarium). Mag. nified 110 times.

CONTROL OF SMUT IN WHEAT AND OTHER SMALL GRAINS 3 tributed, many of them adhering to the wheat. Conditions favoring the germination and growth of the wheat are favorable to the growth of the fungus. The spores germinate at the same time as the wheat. If the smut fungus comes into close contact with a young wheat seedling, it enters the tissues of the seedling and thereafter grows within the wheat plant. About the time when the wheat plant should normally form grain, the fungus produces spores, the familiar black smut powder (Fig. 3) which takes the place of the kernals of grain. Kinds of Smut Grain smuts may conveniently.be divided into three classes based upon their methods of attacking their hosts. First, smuts Fig. 3. Normal and smutted kernels of wheat. Smut balls shown at bottom when broken release the black powder which is composed of the spores (seeds) of the smut plant. Each smut ball contains thousands of these spores or seeds which may infect the wheat unless proper seed treatment is given. ('Courtesy, U. S. Dept. of Agr.)

4 MONTANA EXTENSION SERVICE including the stinking smut of wheat which cause infection only in the seedling stage are commonly called covered smuts. In this class the infection may develop from the spores (smut seeds) adhering to the grain kernel or from the spores in the soil. This class includes the stinking smut of wheat, the covered smut of barley and the oat smuts. Second, smuts, including the loose smut of wheat and the loose smut of barley, which infect only flowers. In this class the fungus is inside the seed.. Third, smuts such as corn smut which may affect any young growing part of the plant. Seed treatment is useless for controlling this class of smuts. - Different Smuts For Each Crop There are different kinds of smut, each peculiar to the plant in which it grows. Wheat smut will not grow in oats or barley, oat smut will not grow in wheat or barley, and barley smut will not grow in wheat or oats. Two Smuts of Wheat j. There are two -smuts of wheat, the stinking smut or bunt. which is the most serious, and the loose smut. Loose smut is sometimes mistakenfor stinking smut. Loose smut appears about the time the heads are emerging from the i boot and produces a black, loose, fluffy mass of spores (smut I l seeds) which are soon blown away by the wind leaving a bare stalk (Fig. 1).!I!his smut may be controlled only by treating seed with hot water. The characteristic symptoms of stinking smut are a bluishgreen color in contrast to a normal green color of the wheat heads in the dough stage; the stems of infected plants are often shorter,f. than normal ones; the presence of smut balls in the infected head (Fig. 1 and 3), and the stinking, smutty odor. Each smut ball contains numerous spores or "seeds" of the fungus: Each spore is capable of infecting a seedling wheat plant, and there are about as many spores in each smut ball as there are kernals in five or six bushels of wheat. In threshing, many of these smut balls are broken and the spores or "smut

CONTROL OF SMUT IN WHEAT AND OTHER SMALL GRAINS 5 dust" coming like smoke from the combine or thresher are dusted over the good wheat or returned to the soil. The symptoms described for the two smuts of wheat are quite characteristic for the loose smuts and the covered smuts of other grain. Conditions Affecting Smut Infection The effectiveness of seed treatment may vary from year to year in the same locality. In explaining the occasional poor results of recommended treatments in controlling stinking smut, one must consider this disease in its relation to soil temperature and soil moisture. It is often stated that the date of planting is closely as,sociated with the amount of smut in the resulting crop. This is because soil temperature. greatly influences infection by stinking smut. The infection of smut takes place in the very young wheat plant before the first leaf emerges. Therefore, a quick emergence of the wheat plant after it is planted is advantageous because it lessens the chances of infection. With enough soil moisture, it takes from 12 to 22 days for the wheat plant to emerge when the soil temperature is between 41-50 F., while it takes only four to eight days when the soil temperature is from 59-68 F. Wheat should be planted about the time recommended for the locality, but under the most favorable conditions regarding soil moisture and soil temperature. Control of Grain Smuts Seed treatments which have proved very effective in reducing losses from various smuts are now being used by the most successful grain growers. Although information about seed treatment has been widely distributed, losses caused by smuts continue to increase. Losses in winter wheat can be greatly reduced and losses in spring wheat practically eliminated by strictly following these practices each year: First, by the use of only carefully re-cleaned seed grain.

6 MONTANA EXTENSION SERVICE Second, by proper use of the best seed treatment for the kind of grain. Third, by more careful tillage. Fourth, by more attention to planting grain when the soh is fairly warm and moisture conditions are favorable. All seed grain should be carefully re-cleaned over a good fanning mill before the seed is treated. :Such cleaning should remove all of the smut balls, all shriveled and broken seed, all weed seed, and other trash. The use of carefully cleaned and properly treated seed reduces smut losses and aids in producing cleaner and more profitable crops. Copper Carbonate Treatment For Stinking Smut of Wheat Winter Wheat: Use two to four ounces of 50 per cent copper carbonate to each bushel of re-cleaned seed. Mix until each kernel is thoroughly coated. Spring Wheat: Use two ounces of 50 per cent copper carbonate or two to three ounces of 20 per cent copper carbonate to each bushel of re-cleaned seed. Mix until each kernel is thoroughly coated. The results of many tests have proven conclusively that copper carbonate when properly applied is as effective in controlling stinking smut of wheat as either the blue-stone or formaldehyde methods of treatment formerly recommended. The wet treatments can no longer be. considered practical. Quality and Grades of ICopperCarbonate The copper carbonate powder recommended for the treatment of seed wheat should be light and fluffy and light green in color. It should be fine enough to permit 98 to 100 per cent of it to pass through a 200-mesh screen. Heavy, bluish and coarse powders should be rejected. A good dust should feel smooth when rubbed between the fingers. Copper carbonate is sold in two grades: pure or "50 %" copper carbonate contains from 50 to 54 per cent copper, while extended

CONTROL OF SMUT IN WHEAT AND OTHER SMALL GRAINS 7 or "20 %" copper carbonate contains from 18 to 20 per cent. copper. Since copper is the active agent, tbe pure copper carbonate is about two and one-half. times more concentrated than the extended product. Directions For Using Copper Carbonate "It is not the dust in the machine but the dust on the kernel that counts." Each kernel of wheat should be thoroughly coated with the dust. This can not be done by shoveling, by attempting to mix tbe grain and dust in the drill box, or by mixing the seed and dust on the floor with a rake. The best results have been secured when the treatment has been given with a power driven' continuous treating machine (Fig. 4), hence commercial power dusters are advocated for treating large quantities of grain. There are on the market some power machines of different types with a capacity of 30 to 150 bushels or even 300 bushels per hour. Fig. 4. IA commercial treating machine in operation. Note the drum. type, of,!ilacl;jine, the coppe,r carbonate container and the masks or respirators. to'.protect the operators from inhaling the dust.. ~ ok,>..1..~:{.';:<'-:.

8 MONTANA EXTENSION SERVICE A home made duster, satisfactory for treating small quantities of grain, may be made out of an old oi\ barrel for approximately five dollars (Fig. 5). -- ~ F'"o.. ~ 0,;,,-'(' ~ F';~-". 30 T(;'lNS pe'"lf",vre Fig. 5. A homemade treating machine. Advantages of the Copper Carbonate Treatment. The advantages of this dust treatment are: it controls smut, it causes no injury to germination, seed can be treated during spare time and stored until ready for use. Effect of,coppel' Carbonate on the Drill Copper carbonate may cause the parts of the drill to Uset" or to work hard. To avoid this trouble always rock the feed shaft gently with a wrench before starting the machine. The drill should be thoroughly cleaned and oiled before it is put away for the season.. Do Not Inhale Copper Carbonate If copper carbonate is inhaled it may cause nausea and

CONTROL OF SMUT IN WHEAT la'nd OTHER SMALL GRAINS 9 headache. Seed should be treated preferably out-of-doors or in a well ventilated room. The use of respirators (Fig. 4) are advocated where large quantities of grain are to be treated. Formaldehyde Method for All Grains The formula most commonly. used consists of 1 pint of formaldehyde (37-40 per cent strength) in 40 gallons of water. It may be used in the following ways:. First, as a dip. Immerse the grain in the solution in loosely filled sacks for ten minutes. Remove' the sacks, let the excess material drain back into the vat and allow them to stand without opening from two to six hours. Second, by using the solution in a smut treating machine according to the instructions furnished by the manufacturer. Third, as a spray. Sprinkle approximately one gallon of formaldehyde solution on each bushel of wheat or about one and a half gallons on each bushel of barley. Shovel thoroughly until each kernel is wet and cover the whole pile with sacks or canvas from two to Six hours. Formaldehyd.e Spray Method for Oats only Add one pint of formaldehyde to one pint of water. As the oats are shoveled over, the solution is slowly added by the use of a quart handsprayer or atomizer. After add~ng the solution the grain is covered with sacks or canvas for four hours. If sowing is delayed or if the oats are to be stored, the pile should be spread out and aired for one day. One pint of formaldehyde is sufficient to treat fifty bushels of oats. Modifications of this method are sometimes used. The solu-. tion may consist of one pint of formaldehyde in 10 pints of water or one pint of formaldehyde to 10 gallons of water. The treatment is carried out in the same manner except more solution is blsed. Hot Water Treatment For loose smut of wheat and loose smut of barley: I'Jlhese smuts may be controlled by the use of the hot water treatment.

10 MONTANA EXTENSION SERVI'CE This treatment is so difficult that it is better to buy clean seed wheat. In special cases where it is desired to disinfect a particular strain of seed, detaiied instructions will be given to the grower \ regarding this treatment. Organie Mercury Compounds Many patented fungicides are on the market. Some of them are effective but are rather expensive. In general, they do not control smut better than cappel' carbonate or formaldehyde. Dry Grain Best For Threshing Smut dockage and inoculation of wheat.often is reduced if the wheat is threshed when dry. Most of the smut is blown away from dry wheat while smut spores stick to damp wheat. Field Results of Seed Treatments in 1930. In cooperation with the Office of Cooperative Extension Work of the United States Department of Agriculture some field studies were made in Montana and other northwestern states during 1930 to determine the amounts of smut in the fields and to learn the methods of seed treatment used. Fig. 6 shows the results. The spring wheat studies were made in Montana; the 'winter wheat studies in Montana, the Dakotas and Minnesota. While these figures are for only one season they show conclusively that proper'treatment gives good control of smut and point out the lack of control by poor methods of treatment. The copper carbonate treatment was most effective. This study showed the value of fairly early planting (around September. 10th to 25th) of winter wheat, on summer fallow land. Spring wheat should be planted after the soil has become. warm. Good clean seed, good seed treatment and good tillage will reduce smut losses to a minimum, and Montana grain growers will profit greatly in securing better yields and higher prices.

~:!,. C0NTROL OF SMU'f IN WHEATA:ND OTHER SMALL GRAINS 1J: :EFfECTIVENESS OF' SMUT CDNTRDL METHDOS TR.EA'TMENT 50 % Copper Carbonate Home made mixer 50% Copper Car~nate Commercial machines Ceresari Home made mixer formaldehyde Commercial machine Avera'i,e PerCent Smut in Wheai () R 8 10 12 I.e. 16 18 RIJ el 24- I~ I~ r j I Blue ViI riol soa~ I I 50% Copper Carbonate i shoveled I Wln~er Wheil.\ formaldehhde - ~rn~ed and 5 ovele 20% Copper Carbonaie Commercial Machines No treatment I ~ T.i:U:ATME:N..,.. I. i% 2r. 31-4-:t Sf. BY. 7:< 8;< 97: loa.' 50 %COl!I!er Ca.rIJonate,. l1ac77il7e~m/xed 20% COjJjJer CtJroonate. flachine':"mix.ed \- rormaldel,de t1achtne- /xed I~I Sprin9 Wneat. 20% COlfer Carbonate Home-made mixer!~ Ceresan 'Machine -mixed I~ rormaldehyde 3prtnlrle I :20% CONer C8rbontl.te- Shovel-mixed.._--..-..... - ~.. ~-... N~ treatment. ~ Fig. 6.

;'._-"-..&::~~~ Cereal Smut Ch~mical Wheat Oats Stinking smut Loose smut Loose smut Loose and covered smut all varieties Barley Covered and (six-row) loose smut Barley Covered smut (two-row) loose smut Copper carbonate 52% Copper carbonate 20% Hot water Hot water Formaldehyde Formaldehyde "'Formalin dust compound (**Certain organic mercury salts) Formaldehyde (**Certain organic mercury salts) Same as barley 6-rowed Hot water SEED TREATMENTS FOR SMUTS How Used 2 to 4 oz. per bu. 2 to 3 oz. per bu. 129 0 F. 120 0 F 1 pt, in 1 pt. water, for 50 bu. oats 1 pt. in 30 gal. water for 50 bu. oats 8 oz. per bu. 1 pt in 40 gal. water 1 oz. in 3 gal. water 126 0 F Treatment On winter wheat-mix until each kernel is coated On spring wheat-mix until each kernel is coated Modified method-1st, soak 4-6 hrs. at 68-85 0 F. 2nd, soak 1 minute at 120 0 F. 3rd, soak 10 minutes at 129 0 F. 4th, dip in cold water; spread thin to dry. Single bath method-soak 1 hr. and 35 minutes; spread thin to dry. Spray with atomizer-cover 5 hrs. Soak 30 minutes or sprinkle thoroughly and cover 2-8 hrs. Mix until each kernel is coated. Sack and stand 3 hrs. Follow directions on package. Soak 30 min. and cover 5 hrs. or soak for 2 hrs. Follow instructions on package. Soak 4-6" hrs. at 68-85 0 F.; 1 minute at 120 0 F.; and 13 minutes, at 126 0 F. Dip in cold water, spread thin to dry. Corn Smut No seed treatment No seed treatment Destroy affected parts and crop refuse; crop rotation. Sorghum Covered kerand Millet nel smut Copper corbanote 52% 2 oz. per bu. Mix until each gemel is coated. *This "compound was developed by the Ohio Experiment station and is sold under the trade name of "Smuttox." "*There are several products of this kind on the market, under such trade names as Ceresan, Chlorophol, Uspulun, etc.