sssu Digitized by the Internet Archive in 2011 with funding from University of Illinois Urbana-Champaign http://www.archive.org/details/pestcontrolincom678powe / N PEST CONTROL In Commercial Fruit Plantings ^0* >©^w^ > AGRICULTURE LIBRARY Circular 678 University of Illinois College of Agriculture Extension Service in Agriculture and Home Economics In cooperation with Illinois State Natural History Survey CONTENTS I — INSECT AND DISEASE CONTROL 3-27 Control in Apple Orchards 3-15 Pears 17 Sanitation Is Important 3-5 Peaches and Apricots 18-22 Pruning Is Very Helpful 5-6 Plums 23 Don't Neglect to Thin Your Fruit . . 6 Cherries 24 Two Apple Borers Need Brambles 25 Watching 7 Currants, Gooseberries, and Grasshopper Control 7 Grapes 26 Spray Schedules 9-15 Strawberries 27 II — RODENT CONTROL (Mice and Rabbits) 28-31 III — NOTES ON SPRAY MATERIALS 32-37 Key for Identifying Newer Organic Materials 36 Compatibility Chart for Orchard Insecticides and Fungicides 37 N^ WHAT'S NEW in this circular . . . For late apples in central and southern Illinois, the DDT schedule (page 12) replaces the lead arsenate-nicotine sched- ule. For peaches, the lead arsenate schedules have been replaced by the chlordane spray schedule and BHC dust schedule. A petal-fall spray is recommended for peaches for the first time. This is to control curculio, catfacing insects, and brown rot. Schedules using parathion have been devised for both apples and peaches. On page 37 is a compatibility chart of orchard insecticides and fungicides. The efficiency of various mite sprays is given on page 14. Comments on new materials — including aldrin, dieldrin, "Aramite," "Dimite," etc. — are included in the notes on spray materials. Concentrate spraying is discussed on page 21. Brief directions for chemical fruit thinning sprays are also included (page 6). AUTHORS: D wight Powell, S. C. Chandler, and Victor W. Kelley of the Department of Horticulture, University of Illinois, and the Illinois State Natural History Survey. For helpful criticisms and suggestions the authors are indebted to C. J. Weinman, Illinois State Natural History Survey, and H. W. Anderson, A. S. Colby, and J. C. McDaniel, Department of Horticulture. (This circular is a revision of Circular 653 by the same title) Urbana, Illinois January, 1951 Cooperative Extension Work in Agriculture and Home Economics: University of Illinois, College of Agriculture, and the United States Department of Agriculture cooperating. H. P. Rusk, Director. Acts approved by Congress May 8 and June 30, 1914. cm ' PEST CONTROL In Commercial Fruit Plantings PART I INSECT AND DISEASE CONTROL EVERY ILLINOIS FRUIT GROWER who expects to make a success of his business must carry through a vigorous program of pest control every year. Each year the need for control measures becomes greater. In some kinds of orchards attention must be given this problem every season of the year. Fortunately better methods of pest control are being con- stantly worked out by various experimental agencies. This cir- cular brings together the latest recommendations from the Illinois, Kentucky, and Indiana Agricultural Experiment Sta- tions, the Illinois Natural History Survey, and the U. S. Depart- ment of Agriculture. Some growers may need to adjust these recommendations to suit their own special conditions; but they are urged not to experiment with untested materials and methods. To do so is likely to lead to disaster. CONTROL IN APPLE ORCHARDS Sanitation Is Important Sanitation has, in the past, aided greatly in reducing insects and diseases in Illinois apple orchards. With the general use of organic insecticides and fungicides and with the increased cost of hand labor, however, many growers are omitting such practices. Observations on codling-moth control have shown that there is less need for bark removal and banding when the spray schedule includes DDT. In orchards where DDT is not used codling moth still presents a problem and all of the following sanitation prac- tices are recommended. Remove all rough and loose bark from crotches, trunks, and branches. Do this "barking off" during the winter or by May 1. CIRCULAR NO. 678 Go high enough on the tree to get all bark that is so rough as to harbor codling moth larvae. Removing rough bark does two things : ( 1 ) destroys a large share of the overwintering larvae of the codling moth; and (2) prepares the trees for banding. Directing a straight stream of water under high pressure against rough bark is an excellent way to remove it from apple trees. With power spray equipment, the rough bark can be taken from mature apple trees in 2 to 4 minutes in this way. Standard spray guns fitted with a disk that has an %4-inch opening (No. 8 disk) should be operated at 500 to 600 pounds pressure at or near the full open position. Take care not to hold the gun in one position too long, as water at this pressure may tear through the solid bark. This method is excellent for removing punky wood and for cleaning out crotches and the area around the base of the tree near the ground line. Scraping bark off by hand takes so much work and time that that method is being largely replaced by the water spray. Band trees. Banding will reduce the summer broods of codling moth larvae 50 percent. Apply treated bands (Fig. 1) normally about June 10 to 30. The time for each section of the state will be an- nounced by radio. Thin out and destroy all dam- aged fruit as soon as discovered — fruit showing disease, insect injury, or rot. Break up fruit clusters. Collect and remove all dropped fruit at frequent intervals. Do not let culls accumulate around pack- ing shed. Avoid coarse mulching materi- als. Clip sweet clover or other cover crops to prevent rank stem growth in which codling moth larvae might spin cocoons. Fig. 1. — Chemically treated bands 2 to 4 inches wide are effective in killing codling moth larvae on trees that have had bark removed from trunks, crotches, and branches. APPLES. INSECT AND DISEASE CONTROL 5 Store orchard crates and used baskets in a closed building. This will keep moths from escaping back to the orchard. Most of the moths can be collected and destroyed by darkening the build- ing and hanging a light over a pan of kerosene. If crates are not stored in a closed building, dip the corners in fuel oil or kerosene. Stack props as far as possible from the orchard. Screen the packing shed — if it is in the orchard and fruit was allowed to remain in the shed for any length of time during the harvest period. Collect and burn all prunings and other debris. Destroy broken crates and baskets, discarded sacks, weed stems, corn- stalks, cobs, etc. Pruning Is Very Helpful Good pruning is of utmost importance in good orcharding. For one thing, it acts as a sanitation measure to reduce certain diseases. Removal of twigs killed by blight or breakage will help to control frog-eye leaf spot and black rot infections. Pruning blighted twigs and cankers may reduce fire-blight infections. Good pruning serves other important purposes. If branches are thinned out and the height of tall trees is reduced (Fig. 2) it is easier to get good coverage of the trees with spray material. Fig. 2. — Tops of high trees should be low- ered for convenience in spraying and har- vesting. Fruit trees should not be allowed to grow more than about 20 feet high. If trees are already too tall, cut leaders back to horizontal lateral branches (se< arrows). Too-heavy cutting, ex- posing too much of the top to the sun, may cause branches to sun- scald. Light pruning, when the tree first be- gins to grow too high, is much better. 6 CIRCULAR NO. 678 Such pruning is especially worth-while in orchards where spray- ing is done by the non-stop system. It also appears to be of utmost importance in securing maximum efficiency of concen- trate sprays. Good pruning reduces the amount of spray required for thorough coverage of each tree; reduces fruit-thinning costs; and increases the quality of fruit. Don't Neglect to Thin Your Fruit Getting rid of surplus, defective, and low-quality fruit takes a big load off the tree. Limbs will rise, allowing better air circu- lation in tree. Sprays will dry faster, and spray injury will be reduced. Besides, fruit will be better color, size, and quality; picking costs will be lower; and there will be less low-quality fruit on the market. A number of growers have become interested in chemical thinning. This method of thinning apples cannot be generally recommended. Results will vary with variety, tree vigor, concen- tration of material used, time of application, and weather condi- tions. For those who want to try thinning sprays, however, the following suggestions are made for guidance: Hormones are more practical than dinitro materials because thinning may be done after bloom, when the set can be deter- mined and there is little danger of further thinning by late frosts. When heavy set is expected, use naphthaleneacetic acid hor- mones as follows : 1. Apply 1 or 2 weeks after bloom. Fruit cracking may result on Trans- parent and Duchess if sprays are made later than 2 weeks after bloom. 2. Use alone or in combination with the calyx or first cover spray. 3. Apply when weather conditions are favorable for drying. 4. For Golden Delicious, Transparent, Rome, and Wealthy use a concen- tration of 20 parts per million (double the strength recommended by the manufacturer for preharvest sprays). 5. For Grimes, Duchess, and York use 15 parts per million (l1/^ times the concentration for preharvest sprays). 6. For Jonathan, Delicious, and Winesap, use 10 parts per million (same concentration as for preharvest sprays). 7. Remember that it is very easy to over-thin trees low in vigor. 8. Spray thoroughly but do not over-spray, especially on the lower third of the tree, which is less vigorous than the upper part. A mist spray is better than a drenching spray. APPLES: INSECT AND DISEASE CONTROL 7 Two Apple Borers Need Watching There are two apple tree borers of importance in Illinois. Although neither is always present in apple orchards, both may cause very serious injury on trees up to about 12 years of age. The roundheaded apple tree borer is prevalent mostly in the northern two-thirds of Illinois. The burrows of this insect are usually made in the base of the trunk. They extend from 1 to 2 inches below the ground level to a foot or more above ground. Heavy DDT sprays with a suitable sticker are now being tested for the control of this borer. Sprays are applied by June, during the egg-laying period of the beetles. Xo recommendations can be made as yet, because effectiveness of the sprays has not been thoroughly determined. Anyone wanting to try this treat- ment on an experimental basis should write to the Illinois State Natural History Survey, Urbana. The flatheaded apple tree borer works higher up the trunk than the roundheaded borer and sometimes infests the branches. This borer nearly always locates on the sunny side of a tree, though infestations may extend completely around a tree. Weak- ened trees are especially susceptible. Shading the trunk will give some control. Either wrap it, or put two boards, nailed together in the form of a trough, near the south and west sides. The best in- surance against this insect is to keep trees in a good state of vigor. Grasshopper Control For several years grasshoppers have been troublesome in many orchards. Damage may occur on the foliage of young, nonbearing trees or on the fruit and foliage of bearing trees. To control this pest, use one of the following materials: Amount per acre for — Young hoppers Adult hoppers Residual toxicity Chlordane Vz lb. actual 1 lb. actual Excellent Toxaphene 1 Vz lb. actual 2 lb. actual Excellent Benzene hexachloride . . 0.3 lb. actual 0.3 lb. actual Poor gamma gamma Aldrin 2 oz. actual 2 oz. actual Excellent CIRCULAR NO. 678 j ■ :H,"issH : H ■*■ ,^*^w* I 1 - ■ .j 3 „ ■ * ■ ■■' E I* ■■■ ** ■ 1>V- • HSr*** ■^ A^ H^v ^■% ^ , ■M^ ^■^■i^ *** * 1 San Jose Oystershell Scurfy Fig. 3. — Some important scale insects in Illinois. San Jose scale is one of the most destructive pests in Illinois apple and peach orchards. Forbes scale, not shown here, has the same general appearance as San Jose scale and is also becoming a major pest on apples and peaches. Oystershell scale is of importance only in the northern half of the state. Scurfy scale causes little damage in well- sprayed orchards. Fig. 4. — Three types of apple scab on leaves. (1) Diffused irregular spots. (2) Spots diffused but especially prominent along leaf veins. The most severe spray injury results when caustic sprays are applied to leaves showing this type of scab. (3) Well-defined spots; note also lesions on leaf stem. Spray Schedules for Fall and Winter Apples STANDARD SCHEDULE Application and purpose Time to apply Materials in 100 gallons of water Dormant — for scale insects, aphids, European red mite for San Jose and Forbes scale, European red mite for green and rosy aphid for apple scab (in problem orchards) Before the buds are open. Early spring is safest and most ef- fective time Dormant oil, 3 gal. actual; DNC, 1 lb. actual (see page 33) — or — "DN 289" or "Elgetol 318," 2 qt. (sec pag( 33) Dormant oil, 3 gal. actual DNC, 1 lb. actual {si e page 33) — or — "Standard Aphid oil," 4 gal. "Elgetol" or "Krenite," ~Yz gal. (apply 500 gal. per acre to ground only) Prepink, for apple scab Before flower buds show pink (Fig. 5, Stages 3 through 6) Liquid lime sulfur. 2 gal. — or — Dry lime sulfur. 8 lb. — or — "Puratized Agric. Spra3r," 1 pt. (see page 34) Pink — for apple scab If red-banded leaf roller is serious If aphids are serious When most of buds in cluster have sepa- rated (Fig. 5, Stages 7 and 8) Same as prepink spray — or — Microfine sulfur, 8 lb." TDE, 1 lb. actual added to above spray 15% parathion, 1 lb. added to above spray (s< e page 34 for precautions) (Do not use lead arsenate or other poisons in this spray) Bloom — for apple scab, cedar and quince rust — for fire blight When 20% of the blossoms have opened Microfine sulfur, 3 lb. 70% ferbam, % lb. Copper sulfate, 2 lb. Hydrated lime. 4 lb. Calyx ■ — for codling moth, apple scab, curculio, red- banded leaf roller, rust — If red-banded leaf roller is serious — If curculio is serious of the petals have fallen (see Figs. 6 and 7) Lead arsenate, 3 lb. 70% ferbam, % lb. Microfine sulfur, 3 lb. TDE, 1 lb. actual added to above spray Chlordane, 1 lb. actual Calyx top-off, for same pests as calyx spray Apply immediately after calyx spray to top % of tree Same as for calyx spray a Microfine sulfur refers to the many wettable sulfurs on the market, including 70-percent sulfur paste. A notation sulfur paste, which contains only 40 percent sulfur, should be used at twice the recommended dosage. (FOR REMAINING SPRAYS SEE PAGES 12-14) 10 CIRCULAR NO. 678 Fig. 5. — Time apple sprays with development of fruit buds. Apply the strictly dormant sprays before Stage 1. Apply delayed dormant sprays during Stage 2. Apply prepink spray between Stages 3 and 6. Start the pink spray at Stage 7 (not later than 8). and complete by the time the first flowers open. APPLES: INSECT AND DISEASE CONTROL 11 Fig. 6. (abovi ). — Time to apply calyx spray for scab and codling moth. Petals have just fallen but calyx lobes are still open. Fig. 7 (right). — Too late for calyx spray. Calyx lobes have closed. HELPFUL HINTS Sulfur dust applied between the prebloom sprays is an excellent supplementary control measure. Lime-sulfur should not be applied to Jonathan, Ben Davis, and Golden Delicious varieties after the prepink spray. Ferbam is a coined name for the fungicide chemical, ferric dimethyldithiocarbamate. This compound is sold under various trade names, as "Fermate," "Ferradow," "Niagara Carbamate," "Nuleaf," etc. TDE is a coined name for the insecticide chemical, di- chlorodiphenyl-dichloroethane. This compound is sold under various trade names, as "Diatox," "Rhothane," etc. 12 CIRCULAR NO. 678 CENTRAL AND SOUTHERN ILLINOIS SPRAY SCHEDULE FOR FALL AND WINTER APPLES Application and purpose Time to apply Materials in 100 gallons of water 1st cover, for curculio, cod- ling moth, scab, blotch, rust, leaf roller — If curculio is serious 7 days after the calyx top-off spray Lead arsenate, 3 lb. 70% ferbam, 1 lb. Chlordane, 1 lb. actual added to above sprays 2d cover, for codling moth, red-banded leaf roller, leaf hopper, curculio, scab and blotch Approximately 7 days after 1st cover spray. (See spray service report ) Lead arsenate, 2 lb. DDT, i/, lb. actual 70% ferbam, % lb. 3d cover, for codling moth, scale, bitter rot, black rot If red-banded leaf roller is serious 10 days after 2d cover Lead arsenate, 2 lb. DDT, % lb. actual Copper sulfate, \'-> lb. Hydrated lime, 1 lb. Summer oil, 2 qt. TDE, 1 lb. actual added to above materials 4th cover, for codling moth. scale, bitter rot, black rot 10 days after 3d cover Same as for 3d cover 5th cover, for codling moth 14 days after 3d cover Same as for 3d cover except omit oil (For mite control .sec /'" lb. ■ — or — Copper sulfate, 8 lb. Hydrated lime, 8 lb. Summer oil, 1 gal. Prebloom, for anthracnose — If fruit worms or saw- fly larvae are present 7 davs before bloom Same as for 1st cover Lead arsenate, 2 lb., added to above spray Special sprays, for mites June and early July (See page 14) Post-harvest spray, for an- thracnose and Septoria leaf spots and mites Immediately after harvest 70% ferbam, 1% lb. Summer oil, 1 gal. — or — Copper sulfate, 4 lb. Hydrated lime, 4 lb. Summer oil, 1 gal. 26 CIRCULAR NO. 678 CURRANTS, GOOSEBERRIES SPRAY SCHEDULE FOR CURRANTS AND , GRAPES GOOSEBERRIES Application and purpose Time to apply /Vlaterials in 100 gallons of water Dormant, for scale insects Before growth starts Dormant oil, 2 gal. 1st cover, for currant aphids and leaf spot When leaves start to unfold Copper sulfate, 4 lb. Hydrated lime, 6 lb. Nicotine sulfate (40%), 1 pt. 2d cover, for currant worm and leaf spot When in full foliage; do not wait for worms to appear Copper sulfate, 4 lb. Hydrated lime, 6 lb. Lead arsenate, 2 lb. Additional covers — for leaf spot . for worms feeding on plants in fruit 2 sprays 2 weeks apart, following 2d cover As needed Same as for 2d cover except omit lead arsenate Rotenone garden dust or spray (comparatively non-poisonous to man) SPRAY SCHEDULE FOR GRAPESa Application and purpose Time to apply Materials in 100 gallons of water Dormant, for scale and anthracnose Before buds open (seldom needed) Commercial liquid lime sulfur, 7 gal. When new growth is 2 to 4 inches long 1 st cover, for black rot and grape flea beetle DDT, 1 lb. actual 70% ferbam, 1% lb. Soybean flour, % lb. 2d cover, for grape berry moth, rose chafer, black rot, and anthracnose Just before the bloom DDT, iy2 lb. actual 70% ferbam, 1% lb. Soybean flour, ^4 lb. 3d cover, for grape leaf- hopper, grape leaf folder, grape root worm, rose chafer, black rot, anthrac- nose, and downy mildew After bloom, when berries are set Same as for 2d cover 4th cover,b for leafhopper, black rot, anthracnose, ripe rot, mildews 3 weeks after 3d cover Same as for 2d cover ' This schedule is based on the supposition that each application will use approxi- mately 250 gallons of spray per acre. b Later applications of DDT and ferbam may be advisable, depending on the season. These sprays have not been recommended because of lack of knowledge concerning the residual problems which might arise. STRAWBERRIES 27 STRAWBERRIES Sanitation Diseases and insects of strawberries can usually be controlled by cultural and sanitary methods. The following practices are recommended : ( 1 ) To avoid white grubs, do not plant strawberries on sod- land until it has been under cultivation for at least two years. (2) To reduce crown borer injury, separate new beds at least 350 yards from old beds and plow up the patch after two picking seasons. (3) Choose varieties resistant to disease in so far as pos- sible. For example, in areas where red stele root rot is common, plant varieties resistant to this disease. (4) Renovate beds im- mediately after each harvest. (For a full discussion of cultural and sanitation methods for strawberries, see Illinois Circular 1^53, Strawberry Culture in Illinois.) SPRAY SCHEDULE FOR STRAWBERRIES Application and purpose Time to apply Materials in 100 gallons of water 1st cover, for leaf spot and First appearance of leaf roller blossoms Copper sulfate, 4 lb. Hydrated lime, 6 lb. Lead arsenate, 3 lb. 2d cover, for leaf spot and leaf roller Immediately after blossoming Same as for 1st cover Additional covers, for leaf roller on plants with fruit As needed Rotenone garden dust or spray {comparatively non-poisonous to man) A dust containing 5 percent DDT and 5 percent chlordane is recommended for control of strawberry weevil and of insects causing buttoning of strawberries. Apply 30 pounds per acre when blooms first appear and again in one week. Tests in Ken- tucky indicate that if an additional application is made in the first part of March good control of the crown borer may be expected. PART II: RODENT CONTROL1 Rodents take a heavy toll in killed and damaged trees each year. Definite programs should be adopted for control of these pests as for insects and diseases. MICE Mice do most of their damage to orchards in the dormant season. Meadow mice, pine mice, and lemming mice (Fig. 9) are found in Illinois. The meadow mouse is the most common. It has coarse, shaggy fur and can be distinguished by its tail, which is about twice as long as its hind foot measured from the hock to the tip of the toes. It feeds and lives largely above ground and has surface runways beneath the ground cover. In contrast, the pine mouse has compact, silky-fine, reddish-brown fur and lives and feeds largely below the surface of the ground. Its tail is barely longer than its hind foot. The lemming mouse looks some- what like the meadow mouse but its tail is no longer than its hind foot. Its habits are practically the same as those of the meadow mouse. k\[ w\w i !i l,ih.i\!,;\\\\\)lft if Meadow mouse Pine mouse Lemming mouse Fig. 9. — These are the mice that damage Illinois orchards. They are easy to distinguish by length of tail and other differences (see text above). 1 These recommendations are adapted for the most part from material furnished by G. C. Oderkirk, Division of Predator and Rodent Control, U. S. Department of the Interior, West Lafayette, Indiana. For further information on controlling mice, write U. S. Fish and Wildlife Service, U. S. Department of Interior, Wash- ington, D.C., for Conservation Bulletin 36, "Control of Destructive Mice." 28 RODENT CONTROL 29 A survey should be made each fall to determine whether mice are present. This can be done by walking up and down the tree rows, watching for mouse runways underneath the grass or mulch on top of the ground, and noting whether there are any small openings extending to runways underneath the soil surface. If there is evidence of mice, prepare for baiting. Zinc phosphide is a very effective poison against all three mice just mentioned. Preparation. Select small ripe apples about iy2 to 2 inches in diameter. Cut each apple in half and then slice each half into four equal pieces. If the pieces are cut smaller, mice may carry them away to store instead of eating them, thus making the bait ineffective. Do not peel or core. Place 3 to 5 quarts of the cut bait in a clean, dry metal pail or can. Measure one level tea- spoonful of the zinc phosphide for each quart of cut bait. Dust this over the sliced apples and stir or shake until the bait is uni- formly coated with the poison. It is then ready to use. One quart of bait will treat % to 1 acre of orchard, depending on the degree of infestation. Prepare fresh bait daily. Application. Distribute bait systematically and thoroughly row by row. Use an ice pick or pointed stiff wire to place the bait. Mice require protective cover and seldom leave their trails under matted grass or other cover. For this reason bait contain- ers of tile, glass, metal, or wood are no longer recommended. Baits should be placed only in surface runways, mole burrows, and holes. Examine the cover crop for runways at about 12-foot intervals. Circle each tree and find the runways beneath the drip area. Where runways are found, 3 to 4 placements within the area should suffice. One apple slice at each baiting spot is enough. Place grass lightly over the bait. Mice commonly inhabit mole burrows. To avoid collapsing these burrows, put bait through a hole in the side rather than through the top. If trees are mulched, raise the mulch, place the bait in the runways beneath, and let the mulch down again. Fencerows, low unplanted areas, spots where trees are missing, as well as adjoin- ing fields of clover or alfalfa, should be baited. Timing. The best time to bait an orchard is after harvest, when cool weather has caused mice to complete their migration. 30 CIRCULAR NO. 678 This will vary from mid-October through mid-November. Mice are most active from the late forenoon until midafternoon; hence baiting is best done in the forenoon. Avoid very windy days, rainy days, or very cold days. Precautions. Entrust preparation of bait only to reliable per- sons. Wash your hands and all utensils after mixing the bait, and at the end of the day wash all utensils in which bait was handled in the orchard. DO NOT HANDLE POISONED BAIT WITH BARE HANDS. Use only zinc phosphide taken from airtight containers, as this material loses its potency when exposed to air. It is impor- tant to follow directions carefully. Strychnine-treated grain bait is not so effective against the pine mouse (page 28) but will take care of the other two. It may be purchased already mixed from reliable dealers. Place a heaping teaspoon ful of it at each bait location in surface run- ways, holes, or mole runways. It is worth the added trouble to put out both grain and apple bait so that the mice will have a choice. RABBITS During the winter, especially when snow is on the ground and food is scarce, rabbits feed on the tender bark of many kinds of young fruit trees. Protection may be secured by using a me- chanical barrier or a chemical repellent. Mechanical barriers. Mesh wire will keep rabbits from the trunks of young trees as long as necessary, or the trees may be wrapped each fall with paper of various kinds (Fig. 10). Veneer bands will also protect the trunks. During deep snows the bases of the framework branches will need protection, since rabbits travel on top of the snow. Cotton- tail rabbits can reach about 2 feet. Chemical repellent. The use of a chemical repellent is the least effective method for rabbit control. However, growers who wish to use a repellent can purchase one ready-mixed from the RODENT CONTROL 31 Fig. 10. — Protection of young trees against damage by rodents and insects is very important. Failure to do this, even for one season, may result in the com- plete loss of many trees. Galvanized gravel screen, 4 meshes per inch, placed around the trunk (A) gives protection against rodents. Wrapping paper tied around the trunk with twine (B) protects against both rodents and wood-boring insects. District Agent, Division of Predator and Rodent Control. U. S. Department of Interior, West Lafayette, Indiana. This material can be applied either as a paint or as a spray. When used as a paint it can be put on with a cheap paintbrush, without dilution but after it is thoroughly stirred. When using it as a spray, dilute each quart of the paint mixture with 2 quarts of ethylene dichloride. Since cottontail rabbits can reach about 2 feet above the sur- face of the snow, the trunks and the scaffold branches of low- headed trees should be painted 2 feet higher than the snow is expected to drift. The amount of repellent required will, of course, depend upon the height of treatment and size of tree. One gallon will treat 150 to 200 two-year-old trees. PART III NOTES ON SPRAY MATERIALS Aldrin. In two years' tests aldrin at the rate of % to y2 pound to 100 gallons has given results equal to or better than chlordane at 1 pound. The cost is about the same. The use of aldrin has not yet been approved except for grasshoppers and certain cotton insects. "Aramite." Sold most commonly as a 15-percent vvettable powder, "Ara- mite" is compatible with most fungicides and insecticides except those of an alkaline nature. Two years' tests have shown this material to be very effec- tive against mites. It has an excellent residual toxicity. Benzene hexachloride. Mainly of interest for control of plum curculio and catfacing on peach. It is effective for only a short time, but has given good control when used as outlined in spray and dust schedules in this circu- lar. When used as a spray it may give a musty flavor to fruit if too much is used or it is applied too late in season. Used as a dust, it has not tainted fruit. Will probably be used most commonly as a dust because frequent applications are needed and dust is cheaper. No injury to fruit or foliage from this chem- ical has been observed. Bordeaux mixture. Made of copper sulfate (blue vitriol or bluestone), hydrated lime, and water. Copper sulfate can be bought as crystals, granules, or powder. All forms have same composition. Indicate desired form when ordering. Because of its convenience, growers like powder form. Crystals require several hours to dissolve. When possible, get hydrated lime from firms making a special spray lime. Do not keep lime from one season to another. Formulas are indicated by numbers: %-l-100 means mixture contains % pound copper sulfate, 1 pound hydrated lime, and 100 gallons water. Most growers use instant method of mixing bordeaux, thus: Slowly sift copper sulfate into tank as it is being filled with water and the agitators are running. After adding 2/3 of water and all the copper sulfate, sift in lime while adding rest of water. Always add copper sulfate before lime. If bordeaux mixture is to be used with oil, add the oil just before the tank is completely filled. Always add the oil last. Chlordane. One of the most promising new insecticides. Marketed as an emulsifiable concentrate, a wettable powder, and a dust under various trade names. Has wide variety of uses but is of most interest to fruit growers for grasshoppers, plum curculio, and catfacing insects. Four seasons' tests in Illinois and other states show that when chlordane is used as a spray it is much superior to lead arsenate for plum curculio on peaches. No objectionable features have yet been observed in chlordane. "Crag 341." This material has proven very effective for apple-scab control and may have other places in the apple schedule. It has also shown promise for brown-rot control on peaches. Growers would be wise to use this material experimentally to become acquainted with it. Follow manufacturer's directions. DDT. Now commonly included in spray schedules for late apples in central and southern Illinois. One of the most effective materials ever found 32 NOTES ON SPRAY MATERIALS 33 for codling moth and leafhoppers. Drawbacks are an increase in mites, red- banded leaf roller, and scale. Other hazards may develop. Some growers feel they get better apples without DDT. General use is not recommended in northern Illinois, where codling moth is not usually a serious problem. For same reason it is not suggested for summer apples. In spray schedule for grapes DDT has replaced lead arsenate and nico- tine. Tests show it to be as good, frequently better, for control of berry moth. Excellent for leafhoppers. No drawback except a possible increase in mealy bug infestation. Included in Illinois peach schedules, spray and dust. Apply early in season for catfacing insects and later (when twigs have hardened) for oriental fruit moth. Dieldrin. In two years' tests % pound to 100 gallons of water has given better control than any other material used on plum curculio. Because of its unusually long toxicity, dieldrin is especially good for use in the petal-fall stage. It will give protection if unfavorable weather should delay the regular sprays in the standard schedule. This material has not been released except for experimental purposes. "Dimite." A water-miscible, amber-colored solution consisting of 25- percent active ingredient. It is compatible with most materials except those of an acid nature. Acts as a contact spray against mites and exhibits unusu- ally long residual toxicity. "DN 111." A wettable powder, very effective for mites on apples; some- what more toxic to two-spotted mite than European red mite. In 100 gallons of water % pound gives satisfactory control and is not so likely to injure fruit or foliage as 1^4 pounds recommended by manufacturer. If used when temper- ature is above 90° F. may injure fruit or foliage. Also causes injury when used with oil sprays. For control of mites spray inside of tree thoroughly. "DN 289." A non-oil dormant liquid used at 2 quarts per 100 gallons of water in strictly dormant stage on apples. This material was very effective in 1949 tests. Do not use on peaches. DNC (Dinitro-o-cresol). Marketed under many trade names as wettable powders and solutions. "Elgetol" and "Krenite" are 23-percent solutions of sodium dinitro-o-cresylate. "DN Dry Mix" is a wettable powder containing 50-percent dinitro-o-cresol. The solutions are used in dormant sprays on apples, as ground sprays for apple scab and cherry leaf spot, and also for blossom thinning. Do not use these compounds except in strictly dormant period, and do not use on peaches at any time. "Elgetol 318." Another formulation of the same chemical used in "DN 289." Ferbam. A common name for the fungicide chemical, ferric dimethyldithi- ocarbamate. Is marketed under several trade names such as "Fermate," "Niagara Carbamate," "Ferradow," etc. May be used in apple sched- ule for scab, blotch, and cedar rust. May be substituted for or used with sulfur. May be substituted for bordeaux mixture or hydrated lime but must NOT be used in combination with either. Do not use before or after a bor- deaux spray — may injure fruit and foliage. 34 CIRCULAR NO. 678 Nicotine. Sold mostly as nicotine sulfate and "fixed" nicotine. Nicotine sulfate is primarily a contact insecticide. May be combined with many other sprays. Fixed nicotines are combinations of nicotine and other materials such as bentonite, oil, and DDT. Designed mostly for stomach poisons, as nicotine stays in spray residue for comparatively long time. Oil sprays. Summer oils are made from highly refined white oils and an emulsifying agent. Mineral oils used on foliage should be paraffin type from a straight distillation run, not blended to meet sulfonation or viscosity speci- fications. Unsulfonated residue should be 85 percent or above, with a viscosity of 55 to 83 seconds, 100° F., Saybolt test. Miscible oils are concentrated emul- sions, contain little or no water, and do not freeze. Organic mercury. Formulations containing organic mercury include "Puratized Agricultural Spray," "Tag 331," and "Puratized Apple Spray." These materials have given excellent apple-scab control in experiments over the past several years and are thus included in the Illinois recommendations. Since they contain mercury, these materials should be used only in the early sprays. Do not use with hydrated lime or oil sprays. Organic mercury causes serious damage to fruit and foliage of peaches. Also, spray operators should avoid contact with the concentrated material. Parathion. Parathion is a deadly poison and in view of the known hazards to those handling or applying it, its use is NOT RECOMMENDED. Although parathion is a highly effective insecticide for many purposes it should not be used where a safer material will give reasonably satisfactory control. Where situations demand it and operator is in a position to enforce proper precautions its use may be justified. Information on parathion is there- fore given in this circular for guidance of those who will assume full responsi- bility for its hazards. For the use of parathion on apples, see page 14; for its use on peaches, see pages 21 and 22. It is essential that these precautions be followed: 1. Use only 15-percent wettable powder or 1-percent dust. 2. Do not use with oil. 3. Do not spray from the inside of the tree. 4. Use mask to protect lips, nose, and mouth from accumulating residue, especially while emptying parathion sacks into the spray tanks. 5. Stand out of the drift when putting the powder into the tank or emptying the sacks of dust into the hopper for dusting. 6. Do not wash the material through the screen into the tank. Sift it in quickly with the screen removed. 7. Do not breathe dust or powder. 8. Dust with the wind and be careful of the turns at the ends of the rows. A duster or sprayer operated by one man with controls at the tractor is safer than the more common, manually operated, two-man outfit. 9. Wash hands thoroughly after each contact with the material and before touching the lips, eyes, etc., and before eating any food. 10. Do not smoke while spraying or dusting. 11. Change clothes and bathe at least daily. Accidentally soaked clothes should be replaced at once. NOTES ON SPRAY MATERIALS 35 Atropine is the emergency antidote for parathion poisoning. Keep on hand a supply of atropine tablets (1/120 grain or 0.5 mg.). You will need a doctor's prescription to get them. Never take atropine or similar drugs until AFTER warning symptoms appear. Symptoms of parathion poisoning include headache, blurred vision, weakness, nausea, cramps, diarrhea, and discomfort in the chest. If you feel any symptoms while spraying with parathion, quit spraying, take two atropine tablets at once, and go to a doctor. If you cannot rigidly follow ALL precautions, do not use parathion. "Phygon XL." This material is very effective against peach brown rot blossom blight (page 20). It also has been used successfully for apple-scab control. Because of its toxicity to plants it should be used at the rate of % pound plus sulfur, 3 or 4 pounds, to 100 gallons of water. "Phygon XL" has proved to be a skin irritant to some people. To avoid this difficulty, follow the precautions recommended by the manufacturer. Sulfurs. Can be bought as liquid or dry lime sulfur, 70-percent sulfur pastes, microfine wettable sulfurs, ground wettable sulfurs, and fused and ground sulfur and bentonite. Dry lime sulfur is more expensive than liquid but more convenient. Both forms are very efficient but more likely to cause injury than other sulfur fungicides. Next to lime sulfur, sulfur pastes are the most efficient sulfur fungicides. Have particle size of 1/25000 to 1/2500 inch. Not convenient to handle, but their mildness and efficiency offset their bulkiness. Microfine wettable sulfurs are highly efficient. Have average particle size of 1/2500 inch. (Microfine commonly means dry sulfurs that have been espe- cially treated to break them into small particles and make them wettable in water.) Select brands with care — fineness of particle is very important. TDE. A common name of the insecticide chemical dichloro-diphenyl- dichloroethane. Has shown excellent results against the red-banded leaf roller. Will be marketed under various trade names such as "Rhothane," "Diatox 25," etc. Recommended rate is 1 pound of actual TDE to 100 gallons of water. Tetraethyl pyrophosphate (TEPP). Because of its extremelv poisonous nature, THIS COMPOUND IS NOT RECOMMENDED. It' is poison- ous whether taken in through mouth or absorbed through skin. Very dan- gerous to eyes, causing contraction of the pupil and temporary blindness. Following suggestions for mite control on apples are made only for those growers who want to risk the hazards involved: In 100 gallons of water use ^2 pint of 20-percent concentrate (x/4 pint of 40-percent) two or three times 7 to 10 days apart starting when mites first appear. May be added to regular codling moth sprays except when bordeaux or hydrated lime is used. For protection of operator, these precautions are imperative: Do not use with oil. Use goggles to protect eyes. Do not spray from inside the tree. Do not expose hands, arms, or any other part of the body to either the con- centrated or diluted mixture. KEY FOR IDENTIFYING NEWER ORGANIC MATERIALS FOR CONTROL OF INSECTS, DISEASES, AND WEEDS Common name, brand name _. . . . .. , Chemical or abbreviation3 Use Aldrin Hexachloro-hexahydro- dimethanonaphthalene Grasshoppers; curculio (experimental) "Ammate" Ammonium sulfamate Weed killer "Aramite" Beta-chloroethyl-beta- (paratertiary butylphenoxy ) -alpha-met hylethylsulfite Mites BHC Benzene hexachloride Curculio, grasshoppers Chlordane Octachloro-met hano- tet rahydroindane Curculio, catfacing insects, grasshoppers "Crag 341" Heptadecyl glyoxalidine Apple scab, cherry leaf spot, brown rot 2, 4-D 2, 4-dichlorophenoxyacetic acid Weed killer DD 1, 2-dichloropropane and 1 , 3-dichloropropylene Soil fumigant DDT Dichloro-diphenyl- trichloroethane Codling moth, leaf hoppers, oriental fruit moth, catfacing insects Dieldrin Hexachloro-epoxy-octahydro- dimethanonaphthalenc Curculio (experimental) "Dimite" Di(parachlorophenyl ) methvlcarbinol Mites "DN 111" Dicyclohexylamine salt of 2, 4-dinitro-o-cyclohexy phenol Mites; sooty blotch (experimental) "DN 289" Dinitro-o-sec-butylphenol Dormant spray for mites, scale, and aphids DNC Dinitro-o-cresol Scale, aphids on apple "Elgetol" Sodium dinitro-o-cresylate Scale, aphids on apple Apple scab ground spray "Elgetol 318" (See "DN 289") Ferbam Ferric dimethyldithio- carbamate Apple scab, blotch, cedar rust "Krenite" (See "Elgetol") Lindane Gamma isomer of benzene hexachloride Curculio, grasshoppers Parathion o-diethyl-p-nitrophenyl t hionophosphate Mites, codling moth, scale curculio, etc. PDB Paradichlorobenzene Peach tree borer "Phygon XL" 2,3-dichloro-l,4- naphthoquinone Peach blossom blight, apple scab "Puratized Agricul- tural Spray" Phenylmercuric triethanol ammonium lactate Apple scab "Puratized Apple Spray" Phenylmercuric monoethanol ammonium acetate Apple scab "Tag 331" Phenyl mercury acetate Apple scab TDE Dichloro-diphenyl- dichloroethane Red-banded leaf roller TEPP Tet raethyl pyrophosphate Mites, cicadas Toxaphene Chlorinated camphene Grasshoppers a Brand names (in quotation marks) have been used only when necessary to clarify the existing confusion concerning the identity of these chemicals. ORCHARD INSECTICIDES AND FUNGICIDES 37 Compatibility Chart for Orchard Insecticides and Fungicides 1 Karathane emulsifiable concentrates should not be used with sulfurs. 2 Organic mercuries may be physically incompatible with some emulsifiable formulations. Key to symbols X Materials can be used together. — Materials cannot be used together. • Materials are physically compatible and their combination does not increase their damage to plant tissue. However, they are incompatible in that the residual effectiveness of either or both would be reduced. 0 There is no need to use materials together, or they should not be used together because of increased toxicity to the operator. How to use this chart This chart is made on the same principle as a mileage chart. For instance, if you want to know whether bordeaux mixture and DN 111 should be used together, you read down the column headed by "Bordeaux mixture" until you get to the row labeled "DN 111." The minus sign where the two meet indicates that the materials are not compatible and should not be used together. (Orchardists will find this kind of spray record very useful.) RECORD OF MY APPLE SPRAY SCHEDULE 195 SPRAY Started (date) Finished (date) Total gals, or tanks Materials used or other remarks Dormant Prepink Pink Bloom Calyx Calyx top-off COVER First Second Third Fourth Fifth Sixth Sixth top-off SECOND BROOD First Second Third Fourth 38 RECORD OF MY PEACH SPRAY OR DUST SCHEDULE 195_ SPRAY or DUST Started (date) Finished (date) Wind direc- tion Amount of material used Materials used or other remarks Dormant Prebloom Bloom 1 Shuck-split COVER First Second Third Fourth Fifth Sixth Seventh ! Eighth Ninth Tenth • Eleventh 3 9 Weekly Report on Orchard Insects and Diseases Radio programs. Each Monday noon the ILLINOIS FARM HOUR gives latest information on controlling orchard pests. This program originates at W-I-L-L, the University of Illinois Radio Station, 580 on your dial. Many other stations give similar service. Consult your local station, your farm adviser, or the Illinois Agricultural Experi- ment Station, Urbana, for details. Reports by mail. Mimeographed copies of The Spray Serv- ice Report, carrying the same information as the radio programs, will be sent to Illinois orchardists under free mailing privilege at no cost to them. Anyone wishing to receive these weekly re- leases by faster mail may send 75 cents to pay for third-class mailing, or $1.00 for first-class mailing. (Either stamps or checks payable to the University of Illinois are acceptable.) Out-of-state growers will be furnished this information under postage at the above rates if the total number of requests is not too large. These weekly reports are prepared by the agricultural experiment stations of Indiana, Kentucky, and Illinois, the Kentucky State Horticultural Society, the Federal Deciduous Fruit Insect Laboratory at Vincennes, Indiana, and the Illinois State Natural History Survey. It is probable that the federal government will establish spray-residue tolerances for DDT, TDE, parathion, and chlor- dane, as well as all other poisonous agricultural chemicals, by harvest-time, 1951. If these materials are used in the concentrations and at the times suggested in this circular, there should not be excessive spray-residue on the fruit at harvest. Do not use such materials at greater rates than recommended, for there is no evidence as yet that heavy residues can be removed by washing. 10M 1-51 46174