COOPERATIVE EXTENSION SERVICE L40Rev. MAX C. FLEISCHMAN COLLEGE OF AGRICULTURE M A Y '7 8 U.S. DEPARTMENT OF AGRJCULTURE AND UNIVERSITY OF NEVADA COOPERATING MOV 1 7 2000 LIFE so do not leave skips in the field. These are areas where damage will con-tinue to the maximum, and will also provide sources for reinfestation of the treated areas. For aerial applications, use flagmen and apply materials at a volume rate of 5 (18.9 1) to 10 gallons (37.8 1) per acre (.405 ha). Ground applications should be applied at 40-60 psi (281 - 421 kg/sq cm) pressure using 15 (56.7 1) to 20 gallons (75.6 1) per acre (.405 ha) of water. Avoid drift by treating in early morning or late evening when there is little air movement. BEE POISONING Pesticides are hazardous to bees. Do not apply insecticides to fields being worked by bees. Note that bees will be attracted to eeds an 1 alfalfa bloo "a s and to fields in which aphids are producing honeydew. Do not apply Furadan ', Cygon or Supracide to fields within 14 days or methyl parathion F.M. within 5 days (particularly if weather turns cool) before bees become active or are moved into a field. Cool nights in Nevada extend the time the pesticides will affect bees. ALFALFA WEEVIL The alfalfa weevil is the most damaging insect pest of alfalfa hay production in Nevada. Parasites and predators, though present in fields, seldom exert sufficient control. Newly estab-lished fields may escape serious injury for the first year or two. Experience is important in determining when to treat. One with experience can examine a field and determine when at least 95O/0 of the eggs have hatched and 40-50°/o of the tips show feeding damage and larvae are still small. The presence of unhatched eggs is determined by examining the stems for eggs or observing the field until small first instar larvae are no longer found in the tips. Without experience, it is best to use a 15-inch (38.1 cm) sweep net with a 26-inch (66 cm) handle. Make 180 degree sweeps at several places through the field. Treat when there are 25 or more larvae per sweep 10 to 20 days prior to cutting or 35 or more 7 to 10 days before harvest. Material Amount Actual Days to Per Acre (0.405 ha) Harvest Remarks Alfa-tox 8 2 Qts. Mlxed E.C. 7 carbofuran* 4 oz. (113.4 g) 7 Use 8 oz. if aphids are present. Make only one e application per season. Apply only to pure (Furadan) 8 oz. (226.8 g) 14 stands of alfalfa. dlazinon 16 oz. (453.6 g) 10 malathion 16 02. (453.6 g) 0 Not recommended when there are more than 100 larvae per sweep. Temperature must be at least 65'~. when material Is used. met hg1 parathion*E.C. 6 02. (170.1 g) 15 methyl parathion F.M. 6 oz. (170.1 g) 15 . Do not use when weeds or alfalfa is in bloom. methidathion*e 8 02. (226.8 g) 10 Use only once per cutting. (Supracide) e lhnethyl F.M. (Flowable Microcapsules) - A new type of formulation (trade name Penncap-M) methyl parathion is encapsulated in 30 to 50 mlcron polymetric microcapsules dispersed in water, making a flowable-type material. It may be applied by: conventional ground or air spray equipment with 50 mesh or larger screens. When applied, the water evaporates and the methyl parathion is slowly released resulting in extended control. Compared with methyl parathion E.C., the F.M. formulation Is much safer to use. Do not mix with organic solvents or other emulsifiable concentrates, Read the label for more detalls. APHIDS Three aphids may be pests of alfalfa in Nevada. The pea aphid adult is a large green aphid with lmg legs and occurs on the growing tips, stems and leaves. The blue alfalfa aphid adult is a little smaller than the pea aphid and usually has a blue green color. The spotted alfalfa aphid, the smallest of the three, is pale yellow with dark spots and occurs on the lower portion of the plant. Treat pea and blue alfalfa aphids when there are 50 per sweep or when honeydew is present and there are few parasites or predators in the field. Damage may occur with lower counts of blue alfalfa aphids. Treat spotted alfalfa aphids when there is an average of one per plant on seedlings. Treat established stands infested with spot-ted alfalfa aphids when there are 20 aphids per stem. Spotted aphids, unless numerous, are difficult to pick up in a sweep net. Materials suggested below are in addition to those recommended above under alfalfa weevil. Material Amount Actual Days to Remarks Per Acre (0.405 ha) Harvest d lmethoate 4 oz. (113.4 g) 10 Use only once per season, Do not apply when to (cygonO) 8 02. (226.8 g) there are bees working in the field. mevinphos* ' 4 oz. (113,4 g) 1 For quick control just prior to cutting. (phosdrine) demeton See addendum (~ystoxB) 2 CUTWORMS & ARMY WORMS (Includes alfalfa looper and zebra caterpillar) Several species are injurious. They are usually dull gray, brown, may be spotted or with stripes. They will usually curl up when disturbed. Fields that do not "green up" in the spring or after cutting should be checked. It is important to watch fields and to treat when larvae are small. Control is difficult on mature larvae. Irri-gate if possible, before treating, to bring cutworms to soil surface. Apply treatment in the evening. Material methomyl* Amount Actual Days to Per Acre (0.405 ha) Harvest 8 oz. (226.8 g) 7 Remarks to (~annate') 16 oz. (453.6 g) trlchlorfo (spray) ?I 16 oz. (453.6 g) 0 May make up to three applications per cutting. (Dylox 1 carbaryl bait (~evln') 1.5 Ib. (680.4 g) 0 Follow label directions. trlchlorfon bait (~ylox') 1.0 Ib. (453.6 g) 14 Not more than one application per cutting. Alfalfa looper, western yellowstriped armyworm and zebra caterpillars are on the plants at all times. For these pests apply Dylox or Lannate spray as suggested above. Apply either morning or evening. GRASSHOPPERS Several species, both nymphs and adults, are injurious. Treat when damage is evident or when grasshoppers are moving into fields. Material Amount Actual Days to Per Acre (0.405 ha) Harvest Remarks dlazlnon malathion 8 oz. (226.8 g) 7 0 days for grazing. 16 oz. (453.6 g) 0 SPIDER MITES Very small, usually dark in color. Plants will yellow and appear to dry. Webbing may be present. Problem occurs on hay usually in early spring. Irrigation will often decrease mite num-bers. Treatment then is generally unnecessary. Material Amount Actual Days to Per Acre (0.405 ha) Harvest Remarks malathion 12 02. (340.2 g) 0 Has Federal Registration. to 16 02. (453.6 g) Not tested in Nevada. methyl parathlon*E.C. 8 02. (226.8 g) 15 *Should be applied only by trained applicators, 8 Trade Names carbaryl (Sevin) 0 and lmidan 0 These materials have Federal registration for alfalfa weevil control but are not recommended to be used alone because of their relative ineffectiveness against aphids. The use of these materials alone in-creases the possibility of additional pesticide treatments for aphid control, Our policy to protect the environment is to not recommend materials that may make it necessary to apply additional pesticide applications. CHEMICAL PESTlClDE RESIDUES: These suggestions for pest control are based on the best Information currently available to the University of Nevada Reno for each pesticide listed. The application should result in satisfaqtory control and, from the best of our knowledge, unless otherwise stated, should not leave resldues that would exceed the established tolerances fqr any particular chemical. To avoid excessive residues, follow suggestions carefully. Particular emphasis should be placed on dosage levels, number of applications, and mini-mum interval between application and marketing. THE PRODUCER OF THE CROP IS RESPONSIBLE FOR the correct use of pesticides in conjunction with his business. The presence of any Illegal chemical residues on his products or any damage proven to be caused by drift of pesticides from his property are also his direct responsibility. Post fields as required to prevent persons from enterlng. Dispose of containers as label directs. TRADE NAMES: To avoid complicated descriptions or chemical definitions, it is sometimes necessary to use trade names of products or equipment. (Trade names when used are marked 0.) Trade names may be used when no common name exists. In doing so, it is sometimes unavoidable that similar products on the market under other trade names may not be cited. No endorsement of the name product is intended nor is criticism implied of similar products which are not mentloned. *Should be applied only by trained applicators. B Trade Names g gram ha hectare kg/sq cm kilogram per square centimeter I liter Addendum: The Nevada State Department of Agriculture has recently accepted supplementary labeling for SYSTOX 6, EPA Reg. No. 3125-221, on a special local need basis for use on alfalfa grown for forage for control of aphids. A summary of the accepted labellng follows: FOR DISTRIBUTION AND USE ONLY WITHIN NEVADA EPA SLN NO, NV 77-0007 RECOMMENDATION FOR USE ON ALFALFA CROP Alfalfa l NSECT Aphlds Ounces SYSTOX 6 REMARKS 2-2/3 Apply specified dosage per acre. Makeonly oneap-plication per cutting, however, DO NOT apply to FIRST grazing or cutting in the spring. For subsequent cuttings do not apply withln 14 days of cutting or pasturing. Do not use treated alfalfa for direct human consumption. It is a violation of Federal law to use this product in a manner inconsistent with Its labellng. Cooperative Extension work In agriculture and home economics. State of Nevada. The Unlverslty of Nevada Reno and the U.S. Department of Agriculture cooperating. Distributed in furtherance of purposes provided for by Acts of Congress of May 8 and June 30, 1914. DALE W. BOHMONT, Director The programs of the Nevada Extension Service are open to all wlthout regard to race, color or national origin.