as the bollworm on cotton) have shown promise as effective and specific controls for these two important agricultural pests. Methods are under development for the mass production of the host insects and the virus material. Results of laboratory and field tests have shown a degree of control comparable to the level obtained with insecticides. Polyhedral viruses of insects are highly specific and pose no known hazard to man, domestic animals, wildlife, and beneficial insects. These two insects attack a wide variety of crops and they have also developed resistance to certain insecticides. The development of effective and specific controls for these major pests are therefore in urgent need of development. 41. Cold weather complicates aphid control on winter vegetables and increases insecticide residue problem.-In field experiments on cabbage, lettuce, kale, turnips, collards, chard, and beets, parathion and other organic phosphate insecticides now recommended for the control of aphids on these crops did not give satisfactory control of the cabbage aphid and green peach aphid when temperatures remained below 70° F. At the same time there was a tendency for residues of such materials to persist much longer on the foliage than at higher temperatures. The increased persistence of residues at low temperatures was confirmed under laboratory conditions where other factors were controlled. In 21 days initial residues of 700-800 micrograms of parathion per bean leaf decreased to 7 micrograms at 70° F. but only to 100 micrograms at 50° F. Growers who in the winter follow normal insecticide programs developed for warm weather may not only fail to control aphids but may also cause their crops to be contaminated at harvesttime with excessive residues of insecticides. Special insecticides or special treatment programs with existing insecticides need to be developed for aphid control on winter vegetables during cold weather. 42. New information obtained on nature of insecticide resistance in insects and how to overcome it.-Recent research on the mode of action of organophosphorus insecticides and the enzyme systems involved in their metabolism and degradation in insects has provided a new insight into the mechanisms involved in insect resistance to this class of insecticides. Of special significance was the discovery that an enzyme or enzymes, commonly called ali-esterases (Ali-E), undergo a quantitative decline in strains of houseflies that have become resistant to organophosphorus insecticides. Furthermore, the Ali-E was changed to enzymes capable of degrading the insecticides. Many chemicals, generally trisubstituted derivates of phosphoric acid, were evaluated as inhibitors of the enzymes responsible for the degradation of malathion in efforts to find materials that would serve as synergists for malathion when used for controlling resistant strains. Certain of the chemicals tested acted as synergists to overcome resistance in both houseflies and mosquitoes to malathion. When the more effective synergists were added to malathion, resistant strains were equally as susceptible to malathion as nonresistant strains. The synergist did not increase the toxicity of malathion to nonresistant strains. This research confirmed the existing explanations of the mechanism of malathion resistance and the hypothesis that this resistance could be overcome by inhibiting a certain enzyme or enzymes. 43. Research findings aid screwworm control program in Southwest.--Research findings have played an important role in improving the efficiency of the sterile male screwworm release control program underway in the Southwest by Federal, State, and private agencies, and research workers have cooperated in developing more efficient control methods. Of special value was the discovery that sterilization could be achieved with a substantially shorter exposure to gamma rays by pretreating pupae in a 50-50 gas mixture of CO and air. Radiation damage to the flies was greatly reduced, thereby resulting in longer lived and more vigorous flies for release. During the spring of 1962 the sudden development of screwworm infestations 100 miles or more north of the known overwintering area of the insect in extreme south Texas and Mexico suggested that long-range migration of native flies might be responsible. To check on this theory, a series of traps were set up by research and control workers at 10-mile intervals over a distance of 180 miles along the Colorado and Concho Rivers and marked sterile flies released at intervals at the southernmost traps. Within 5 to 11 days marked flies were recovered at all distances up to 180 miles from the point of release. This finding shows that the flies can quickly migrate long distances, especially along waterways, which are the preferred adult habitat under dry, hot Texas conditions. Consequently, in the eradication program strategic releases of sterilized flies were initiated along all important streams. The demonstrated long migration also indicated that the sterile fly barrier should be at least 200 miles to prevent fly invasion from Mexico. 44. Attractant for honey bees found in pollen.-A substance extracted from certain pollens is attractive to pollen-collecting honey bees. When weak dilutions of the extract were added to ground cellulose, which by itself has no attraction for the bees and no nutritive value, the bees were readily stimulated to pack the treated particles in their pollen baskets for transport to the hive. The pollen from which the attractant substance was removed was no longer attractive to the bees. This discovery may lead to an explanation of why bees collect pollen from certain plants and not from others, and it may have value in finding ways to direct bees to pollinate a particular crop. The information may also eventually be of vital importance in the utilization of pollen substitutes to help maintain beehives during the winter. 45. Reduced volume of insecticide spray effective for grasshopper control.— Studies have shown that effective aerial coverage of rangeland for grasshopper control can be achieved with a quart of insecticide spray per acre instead of the usul gallon per acre. This low volume was made possible by modification of the boom and nozzle arrangements on the airplane, used in field control work. More precise application will result from the use of smaller amounts of spray, and reducing the volume per acre means that small planes instead of large ones can now be used in many areas. Suitable landing strips for small planes are generally available whereas large planes ordinarily ferry some distance to and from a landing field that will accommodate them. 46. Diptera catalog completed.-A comprehensive catalog of the Diptera or two-winged flies of America north of Mexico, 4 years in preparation, has been completed and sent to the printer. This monumental work lists more than 16,000 species giving their distribution, synonymy, and some references to the general biology of the different taxonomic groups. It will be an indispensable aid to taxonomists working on Diptera, many species of which are serious pests of man, agricultural crops, and livestock, while other species are of importance as parasites that aid in the control of harmful insects. Soil and water conservation research 47. Muscular dystrophy in livestock associated with low selenium in soilparent material.-A map developed by the U.S. Plant, Soil, and Nutrition Laboratory, Ithaca, N.Y., shows that muscular dystrophy is rare in regions where the soil-parent material contains seleniferous Cretaceous sediments of west central United States. The disease is common to the south and east of the Great Lakes and in areas in the Pacific Northwest where the soils are formed on young volcanic materials. The selenium content of forage crops from different areas has been measured and found to substantiate the pattern predicted on the basis of the geology of the soil-parent material. The selenium content of forages collected from areas where muscular dystrophy has occurred were uniformly low. Samples collected in western New York, central Oregon, and the Carson Valley of Nevada all contained less than 0.1 parts per million of selenium. Samples from western Iowa, Nebraska, western Minnesota, and Missouri, where the white muscle disease is rare, contained from 0.15 to 0.80 parts per million of selenium. These results suggest that the use of selenized fertilizers to increase the selenium content of forages may be a potential method for prevention of muscular dystrophy in the problem areas. An evaluation of two experimental selenized fertilizers is underway at the Laboratory. 48. Study of rainfall improves design of irrigation systems.-A simple procedure for estimating how much of the rainfall on irrigated lands is effective in reducing the needs for irrigation water for crop production has been developed by the USDA Hydrograph Laboratory at Beltsville, Md. Assuming that adequate evapotranspiration data are available, this procedure makes it possible, when irrigation projects are being designed, to more accurately balance the water requirements of the area against the available supplies from storage, diversion, or pumping. Rainfall data furnished by the U.S. Weather Bureau for all parts of the country were used in the analysis; thus the procedure is applicable to all of the conterminous United States. 49. Large leaf area important in cotton and tobacco production.—More efficient use of incoming solar radiation holds promise for conservation of moisture resources in Alabama, Georgia, North Carolina, South Carolina, and Virginia. Increased energy capture in the canopy of tobacco and cotton was made possible In by controlling leaf areas. This resulted in using more solar energy in photosynthesis and less in evaporating water. These investigations showed, however, that 4 to 6 acres of leaf area per acre of land area were desirable in cotton by July 1 and that if not attained until September 1, they adversely affected the crop-July and August being critical months in the growth of cotton. addition to plant spacing and fertility control to adjust leaf area of tobacco, genetic material capable of using the entire growing season was essential. The annual loss of water per acre by evaporation in part-season varieties was higher than in full-season ones. These studies further suggest that in addition to capture of energy from the sun, leaves can dissipate energy from rain and reduce erosion hazards in the area where climate offers the highest erosion potential of any area in the country. 50. Water retention by stratified soils.-Procedures for control of profile storage of soil moisture are being investigated in the Columbia River Basin. Investigations have shown that a layer of coarse material at the bottom of the root zone resulted in 2.3 times as much profile storage of available moisture as would be expected without such a layer. A coarse layer in the profile has such low flow characteristics, when unsaturated, that the profile behaves as if it had a perched water table on top of the coarse layer. For this reason, field capacity is reduced to a much lower tension. The drier limit of the available moisture range was not greatly affected. In areas where soil topography is altered to increase efficiency of application of water, these studies suggest that storage efficiency might also be increased. 51. Clay in streambanks influences their stability.-Fundamental studies of the soil materials of streambanks and the banks of ditches have shown that the amount and type of clay in the material is a key factor that determines how well the banks will withstand the erosive forces of the streamflow. The studies were carried out at the USDA Sedimentation Laboratory, Oxford, Miss., on more than 1,200 samples of streambank materials. The basic theories developed in the Laboratory will be checked against field observations of streams and channels in Florida, Arkansas, Georgia, Texas, Iowa, New York, and elsewhere to develop field procedures for assessing the erodibility of streambanks and developing criteria for control works for the many thousands of miles of eroding streambanks in the United States. 32. Efficiency of moisture use by corn increased by adjusting management.— Studies in western Minnesota and eastern South Dakota show that soil moisture can be utilized more effectively by corn if plant population, fertilizer, and other management levels are adjusted to the available soil moisture supply in the border area between arid and humid regions of the United States. While soils in the area have a moisture storage capacity of about 12 inches, soil moisture at planting time ranged from 1 to 14 inches. The probability of the soil moisture Corn yields reserves being recharged by rainfall after planting are remote. for 3. 7, and 11 inches of stored soil moisture were 43, 77, and 96 bushels per acre, respectively. With 11 inches of stored moisture, 20.000 plants per acre were required for maximum yields, while only 8,000 plants gave the highest yield with 3 inches of stored water. The extent to which fertilizer amounts should be lowered with extremely low soil moisture supplies or raised with high soil moisture are being clarified. 53. Movement of water and nutrients around bands of soluble chemicals in soil studied.-At Beltsville, Md., studies on the movement of nitrates and water around bands of sodium nitrate have shown that once the accumulating solution exceeded that which could be held by the soil, the excess soluble nutrient literally dropped out of the band under the force of gravity. When sodium nitrate was banded in a soil with moisture contents greater than field capacity, the soil water moved under the osmotic force generated to the band of sodium nitrate. The sodium nitrate then dissolved and was not able to diffuse away from the band because of the influx of water. As a result, the sodium nitrate accumulated in amounts which exceeded that which the soil could hold and the dropout occurred. This dropout continued until essentially all of the sodium nitrate had been dissolved. The movement of nitrogen below the root zone limited the plants' ability to utilize this nutrient. As a result, the efficiency of band application of nitrogen to crops like tobacco, cotton, corn, and sugarbeets could be very low. Subsequent studies showed that much of the downward movement of nitrate from a band could be eliminated by placing a simple U-shaped plastic shield under the band. These studies demonstrate the potential of controlling the leaching of soluble nutrients from bands by the use of inexpensive plastic shields. Tests are underway in the field to examine this phenomena. 54. Soil moisture found necessary for the uptake of phosphorus.-At Bozeman, Mont., studies show that the plant's ability to absorb phosphorus rapidly declines as the soil dries and that plants can get none from soils drier than the wilting point. Radioactive phosphate fertilizer was used in these experiments with wheat. After water was applied to the dry soil, the time required by the plant to take up a detectable amount of phosphorus varied with the size of the plant. At the tillering stage, 32 hours was required as compared to 5 days at the heading stage. These results suggest that the plant in dry periods must get its phosphate from moist subsoils or subsist on phosphorus previouly absorbed under moist conditions. The results also show that supplying the wheat plant with adequate phosphorus up to heading and none thereafter is sufficient for maximum yields. The absence of phosphorus for 2 weeks or longer in early growth severely reduced yields. These facts are extremely important to producers in dryland areas with phosphorus-deficient soils. In these areas, the surface soil, where the available native and fertilizer phosphorus is located, is dry a good portion of the time. This work also indicates that the reduced availability of phosphorus due to dry soils from heading time on may not be of much significance, provided that the plant has adequate phosphorus early in the growing season. Agricultural engineering research 55. Blacklight traps used for tobacco hornworm control.—Promising preliminary results have been obtained in an experiment to help control tobacco hornworms conducted over a large area in the vicinity of Oxford, N.C., in 1962 and 1963. This experiment, which covered an area of 113 square miles, was the first large-scale attempt to control tobacco hornworms using newly developed procedures and a new trap design with blacklight lamps as an attractant. Data obtained during the two seasons showed a reduction in tobacco hornworn populations in the center of the area of slightly more than 50 percent in 1962 and 80 percent in 1963. 56. Minimum tillage tools and methods developed.—Special tillage tools and techniques to reduce field tractor operations and secure more reliable stands of weed-free cotton and white potatoes have been developed. At the delta branch of the Mississippi Experiment Station at Stoneville, Miss., a cotton tillage tool has been developed that is used in combination with the planting operations. It provides for mixing and leveling the prepared row bed and facilitate the placement of the seed at a predetermined depth. Also at Stoneville, a tool for placement of preemergence herbicides at a constant predetermined depth has been developed which will reduce the amount of chemical required and produce better weed control. In the Red River Valley of North Dakota and Minnesota, potatoes have been grown for 3 consecutive years on one of the principal potato-producing soil types that was plowed and cultivated in the previous late summer and fall. It was concluded that there was no advantage to disking and cultivation in the spring prior to planting. 57. Prototype single opener drill developed for separate placement of seed and fertilizer. Research over a number of years has shown that the best stand of many crops is obtained if the starter fertilizer is separated from the seed by a certain distance, usually below and to the side of the seed. To meet this requirement, the Department has developed a new design of drill opener which handles both the seed and fertilizer and effectively separates them over a wide range of operating speeds, placing the fertilizer below and to the side of the seed. This performance was achieved by means of relatively simple construction. The concept has already been adopted in experimental models by one major manufacturer. 58. Mechanized system for date harvesting reduces cost.-Experiments conducted in cooperation with the University of California have resulted in mechanized harvesting systems for dates that offer reduced labor requirements and less cost over hand harvesting. Utilizing movable towers to reach the fruit. mature bunches are cut and lowered to the ground where the dates are removed from the bunch by a vibrator directly into bulk bins as the tower progresses down the row. In another system, the harvested bunches are hauled in trailers to a central location for shaking to detach the fruit. It has been possible to remove 100 percent of the fruit with no apparent mechanical damage and with little sacrifice in quality from the once-over picking operation. 59. Lighter, lower cost, storage structures found suitable for heavily wilted silage. Studies at Beltsville, Md., and Athens, Ga., on conventional upright and horizontal structures for storing forage as silage show that loads on the storage structure are appreciably lighter and maintenance costs appreciably lower if the forage is heavily wilted before ensiling. Both man-hours and machinehours per ton for handling into and out of the storage are also reduced. Feeding tests with dairy cattle show they produce better on such silage. 60. Prototype electric silo unloader developed for horizontal silos.-A new prototype motor-driven silo unloader has been developed that will provide a major step toward automatic feeding from horizontal silos. An original feature of the new unit developed in cooperation with the Washington Agricultural Experiment Station is an efficient cutter that will facilitate removal of grass and peavine silage. The electrically operated and controlled machine when made automatic can be integrated into an automatic feeding system that will minimize labor in hauling and feeding silage. 61. Experimental farmhouses found comfortable and economical.-Studies of five experimental, small, low-cost, expansible farmhouses occupied by farmworkers at Beltsville, Md., showed that this type of house can be made livable and thermally comfortable at reasonably low cost by good engineering design and careful construction. Variations from conventional siding, roofing, and foundation practices produced satisfactory performance at lower cost. Findings are being applied to plans for rural dwellings developed for use by farmers and rural builders. STAFFING NEW LABORATORIES Dr. RODENHISER. The first item, Mr. Chairman, for which we are requesting an increase is for staffing and operating laboratories recently authorized by the Congress and for watershed research centers. I would like to refer to you the tabular material that has been prepared. Mr. Stephens, will you pass those out, please. (The material referred to follows:) Staffing and operating farm research laboratories and watershed research centers recently authorized by Congress |