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Shading (92%) of `Redchief Delicious' apple (Malus domestics Borkh.) trees for 10-day periods from 10 to 20, 15 to 25, 20 to 30, and 25 to 35 days after full bloom (DAFB) caused greater fruit abscission than shading from 5 to 15, 30 to 40, 35 to 45, or 47 to 57 DAFB. Fruit 8 to 33 mm in diameter (10 to 30 DAFB) were very sensitive to 10 days of shade, even though fruit sizes of 6 to 12 mm are considered the most sensitive to chemical thinners. In a second test, shading for 3 days caused fruit thinning; 5 days of shade in the periods 18 to 23, 23 to 28, and 28 to 33 DAFB caused greater thinning than 11 to 16 or 33 to 38 DAFB. Shading reduced photosynthesis (Pn) to about one-third that of noncovered trees. Terbacil (50 mg·liter-1) + X-77 surfactant (1250 mg·liter-1) applied with a hand-pump sprayer 5, 10, or 15 DAFB greatly reduced fruit set and caused some leaf yellowing, particularly in the earliest treatments. Terbacil reduced Pn by more than 90% at 72 hours after application. Shoot growth of trees defruited by shade or terbacil was equivalent to defruited or deblossomed trees; ethephon (1500 mg·liter-1) inhibited tree growth and defruited trees. No terbacil residues were dectected in fruit at harvest from applications made 5, 15, 20, 25, or 30 DAFB. Eleven of 12 photosynthesis-inhibiting herbicides were also found to thin `Redchief Delicious' apple trees. Shading caused more thinning than terbacil at the later applications, which may reflect poorer absorption and/or lesser photosynthetic inhibition than when terbacil was applied to older leaves.

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An interlaboratory comparison was conducted in 1997 and 1998 to examine the feasibility of using C18 solid-phase extraction disks (Empore™) to simultaneously determine the herbicides atrazine, bromacil, and metolachlor and the insecticide chlorpyrifos in water samples. A common fortification source and sample processing procedure were used to minimize variation in initial concentrations and operator inconsistencies. The protocol consisted of paired laboratories in different locations coordinating their activities and shipping fortified water samples (deionized or local surface water) or Empore disks on which the pesticides had been retained and then quantitating the analytes by a variety of gas chromatographic methods. Average recoveries from all laboratories were >80% for atrazine, bromacil, and metolachlor, and >70% for chlorpyrifos. Detection of bromacil was unachievable at some locations because of chromatographic problems. Shipping samples between cooperating laboratories did not affect the recovery of atrazine, chlorpyrifos, or metolachlor in either matrix. Recoveries tended to be higher from disks shipped to cooperating laboratories compared with those from fortified water. Shipping disks eliminated many problems associated with the shipment of water samples, such as bottle breakage, higher shipping cost, and possible pesticide degradation. Recoveries of bromacil and metolachlor were lower from fortified surface water samples than from fortified deionized water samples. This collaborative research demonstrated that pesticides in water samples can be concentrated on solid-phase extraction disks at one location and quantitated under diverse analytical conditions at another location. The extraction efficiencies of the disks were comparable with or better than the recoveries obtained from the shipped water samples, and the problems associated with shipping water samples were eliminated by using the disks.

The fatty acid composition of the oils of five varieties of winged beans,Psophocarpus tetragonolobus (L.) DC, was determined and found to be similar to peanut oil. The total unsaturated fatty acids ranged from 53.8% to 68.5% (mean, 62.0%). Oleic acid and linoleic acids were the major unsaturated fatty acids. The major saturated fatty acids were behenic, palmitic and stearic acids. Parinaric acid, a toxic fatty acid, previously reported to occur in winged beans, was not present in the oil of the winged beans analyzed.

SUMMARY: DDT incorporated into chicken tissues during the growing period was reduced in concentration during cooking by either baking, frying, or steaming and during heating of tissues in closed containers for varying lengths of time. DDT was converted to DDD in each of the treatments, but the concentration of DDE was not altered significantly. Total losses of residue were greater when tissues were fried or steamed than when the samples were either baked or heated in closed containers. Losses of residue from chicken tissue occurred primarily through leaching of fat during the cooking process.

A simple teacher-scored method can be used to determine the proportion of correct usage in freshman ESL compositions. The method correlated highly with impressionistic rankings of overall writing quality and discriminated among four very narrow-range levels of proficiency: intensive English, minimally accepted freshman ESL, lower-level ESL, and a parallel lowerlevel freshman English class (remedial) for native speakers. Within this narrow range of skills, the scoring method provided reliable discrimination for purposes of class assignment and measurement of in-class progress. Six teachers of varying experience in ESL and freshman composition achieved high correlations both as a group and individually among numerical and impressionistic rankings of 20 selected essays, all on expository themes. All scoring was individually determined without group consultation or group grading practice. The two career freshman composition teachers showed slightly lower correlations among all data than the four career ESL teachers, indicating that discussions of criteria might have improved consistency between these two professional groups. Correctness scores are easy to compute and appear to be psychologically convincing to those teachers who prefer an exact numerical score to impressionistic rating as a measure of 1) the seriousness of a given usage error, 2) progress in usage improvement, and 3) readiness to pass into a higher level class. One year's trial and theoretical implications for composition research are discussed. A Practical ProblemThis study was the result of attempted solutions to problems encountered administering a university program in English as a Second Language. We needed a simple and quantitative measure of achievement level and progress in writing skill: a measure which would allow us to place students in classes along a continuum from Intensive English through two to three subsequent semesters of freshman English classes geared to both foreign and remedial American students. Intensive English is a full-time course of study five hours a day, five days a week, during which students are not permitted to enroll in any other university classes. Upon graduation from Intensive English, students attend a series of freshman composition classes each of which meets for 16 weeks (one semester) five hours a week, which carry university credit, and which permit simultaneous enrollment in other university classes. In general,