宝收与乙草胺或施田补混用防除玉米田杂草研究

试验结果表明，宝收与乙草胺或施田补混用可有效防除玉米田绝大多数杂草，且对玉米安全。播后苗前施用宝收15g加乙草胺1500g/hm^2，对玉米田杂草的总株防效和总鲜重防效分别为84．3％和86．4％。在玉米4叶期，杂草1－3叶期茎叶喷雾，用宝收10g加施田补700g/hm^2总株防效和总鲜重防效均在85％以上。     

除草剂对枣树砧木的安全性试验

在温室和田间试验了9种除草剂对枣树砧木的安全性，结果表明：在播后苗前使用，除草剂常规用量不影响酸枣出苗，但多数抑制植株和根系生长。在出苗后5叶期喷洒除草剂，曙草酮、仲丁灵都对酸枣幼苗有药害。96％S-异丙甲草胺EC 0．75～1．5kg／hm^2和48％氟乐灵EC 1．5～3．0kg／hm^2在出苗前和出苗后使用对酸枣幼苗安全。     

Uses of soybean oil in the application of herbicides

Field studies were conducted in 1982 and 1983 at Southern Illinois University to evaluate soybean oil as a carrier for preemergence and postemergence herbicides and as an enhancing agent for postemergence herbicides. Preemergence and postemergence herbicides applied with rotary nozzles in a soybean oil carrier volume as low as 5 L/ha afforded weed control equal to that achieved when the herbicides were applied in 187 L/ha water with flat fan nozzles. Soybean oil as an enhancing agent for four postemergence soybean herbicides was equal to petroleum crop oil concentrate with three of the herbicides but distinctly less effective with the fourth herbicide.     

大花萱草化学除草试验

大花萱草(Hemerocallis middendorfii)移栽定植后施用33％二甲戊乐灵乳油、72％异丙甲草胺乳油进行土壤处理防除杂草试验,结果表明：药后30d,33％二甲戊乐灵1500ml／hm^2(制剂含量,下同)除草效果在92％以上,72％异丙甲草胺1350～1800ml／hm^2除草效果则在90％以上。应用上述剂量除草剂定植后施用于大花萱草田,对大花萱草植株安全。     

33%二甲戊乐灵和48%氟乐灵土壤处理对唐菖蒲地双子叶杂草防效

选用33％二甲戊乐灵或48％氟乐灵除草剂进行土壤处理，对唐菖蒲地双子叶杂草防效进行了研究，结果表明：各处理对唐菖蒲安全，33％二甲戊乐灵和48％氟乐灵各1500ml／hm^2混合处理对双子叶杂草的防效最好，其株防效和鲜重防效分别为90.3％和90．6％，与其它几个处理间有显著差异或极显著差异。     

狼尾草对嗯草酮、二甲戊乐灵和异丙甲草胺的抗药性

（Pennisetum alopecuroides）是新型的园林观赏植物，在我国具有广阔的发展前景。利用化学除草剂防除狼尾草生产与应用中的杂草问题，对减少生产与管理费用意义很大。采用盆栽方法研究了狼尾草对常用的苗前型除草剂的抗药性，以期找出适宜控制狼尾草杂草的安全除草剂与安全用量。结果表明，狼尾草喷施异丙甲草胺后叶片变为紫红色，产生严重药害，晤草酮在2700mL／hm^2用量下或二甲戊乐灵在3500mL／hm^2用量下狼尾草的生长仍安全。     

狼尾草对噁草酮、二甲戊乐灵和异丙甲草胺的抗药性

狼尾草(Pennisetum alopecuroides)是新型的园林观赏植物,在我国具有广阔的发展前景。利用化学除草剂防除狼尾草生产与应用中的杂草问题,对减少生产与管理费用意义很大。采用盆栽方法研究了狼尾草对常用的苗前型除草剂的抗药性,以期找出适宜控制狼尾草杂草的安全除草剂与安全用量。结果表明,狼尾草喷施异丙甲草胺后叶片变为紫红色,产生严重药害,草酮在2700mL/hm2用量下或二甲戊乐灵在3500mL/hm2用量下狼尾草的生长仍安全。     

Protein influences on guayule and Hevea natural rubber sol and gel

Guayule (Parthenium argentatum) is under cultivation in the southwestern United States as an alternative source of natural rubber free from proteins that cause Type I latex allergies. However, since guayule lacks the protein‐polymer interactions present in Hevea latex, its physical and chemical properties may differ. The solvent‐soluble (Sol) and insoluble (Gel) fractions from guayule and Hevea natural rubbers were isolated through a solubilization/centrifugation deproteinization process. Protein could be reduced or removed by centrifugation, or concentrated in the gel fraction for both Hevea and guayule rubber. Separation of the sol fraction of Hevea rubber reduced the overall protein level, in some cases to below detection limits, without impacting rubber thermo‐oxidative stability. Notably, no detectable cross reactions took place between guayule protein antibodies and Hevea‐based materials, nor vice‐versa. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42051.     

几种除草剂对苹果砧木海棠幼苗的安全性评价

针对目前生产需要果树苗田化学除草,选用生产上常用的8种土壤处理除草剂进行温室盆栽安全性试验。结果表明,不同药剂对苹果砧木西府海棠（Malus micromalus)幼苗的安全性不同,其中60％丁草胺150ml,667m^2、72％异丙甲草胺200—250ml／667m^2、41％甲草胺200ml／667m^2在海棠播后苗前施药安全。33％二甲戊乐灵150ml／667m^2和48％氟乐灵100-150ml／667m^2在海棠5叶期施药比较安全。     

单嘧磺隆对谷子田杂草的防效

探讨了不同浓度单嘧磺隆对谷子田杂草的防除效果。田间试验结果表明,单嘧磺隆的播后苗前处理对马齿苋和反枝苋及其它杂草具有良好的封草和抑制作用,其中单嘧磺隆播后苗前675g／hm^2防除效果最好。     

当归田化学除草剂筛选试验

探讨了既对当归生长无明显影响又能有效防除当归田杂草的化学除草剂。2006年对120g/L草酮EC等10种除草剂进行了药剂筛选试验。结果表明,苗前除草剂120g/L草酮EC和苗后除草剂15%精吡氟禾草灵EC与25%氟磺胺草醚AS的复配剂对当归田杂草的防除效果最好,株防效分别达90.8%和92.3%。     

生姜田杂草防除试验

将33%二甲戊乐灵EC、24%乙氧氟草醚EC和20%二甲戊·乙氧氟草醚EC用作生姜田播后苗前土壤处理,结果表明,生姜田除草20%二甲戊·乙氧氟草醚EC2400～2850ml/hm2(制剂含量)防治效果最佳,优于33%二甲戊乐灵EC和24%乙氧氟草醚EC,在推荐剂量下,对生姜安全,且有显著增产效果。     

玉米田除草剂甲基磺草酮的生物活性及安全性

在温室条件下研究了甲基磺草酮的除草活性、对玉米的安全性以及表面活性剂、温度和降雨对甲基磺草酮除草活性的影响。结果表明，甲基磺草酮土壤处理150g／hm^2，茎叶处理100g/hm^2对杂草的防效可达到80％：在甲基磺草酮正常应用剂量下土壤处理或茎叶处理对玉米安全；表面活性剂快得7的加入可明显提高药效；温度高，有利于甲基磺草酮药效发挥；施药后1h降雨，对甲基磺草酮药效无影响。     

Molecular weights of natural rubbers from selected temperate zone plants

Molecular weights and molecular weight distributions are compared by gel permeation chromatography for rubbers from 33 north temperate zone plants, guayule, and Hevea. Rubbers isolated from all the northern plants had much lower weight-average molecular weight (M _w) values (9.72 × 10⁴–4.95 × 10⁵) than milled Hevea (1.31 × 10⁶) or guayule (1.28 × 10⁶) rubber. Pycnanthemum incanum, Lamiastrum galeobdolon, Monarda fistulosa, and Vernonia fasciculata produced potentially useful natural rubbers having M _w values above 4 × 10⁵ and polydispersity factors of 3.1–4.5.     

Oil content and fatty acid composition of seed oil from guayule plants with different chromosome numbers

Guayule, a perennial desert plant, is being developed for domestic production of natural rubber, a strategic commodity for which the United States presently depends totally on foreign sources. At present, rubber alone is not sufficient to make guayule a commercial crop, and additional revenues are being sought from by-products. Because guayule flowers profusely during several years of growth before it is harvested for rubber, seed may also contribute to the economics of guayule production. Seed from 120 plants, including 20 genotypes with 36, 37, 54 and 72 chromosomes, were analyzed for oil content and fatty acid composition. Oil content ranged from 17.1 to 30.5%. On average, seed from diploid and aneuploid plants (with 36 and 37 chromosomes) contained 40.4% more oil than the seed from polyploid plants. The oil consisted of four fatty acids—palmitic (8.7–11.5%), stearic (3.7–6.2%), oleic (6.5–13.9%) and linoleic (69.1–80.2%)—at all ploidy levels. Guayule seed oil was similar to the seed oil from high-linoleic safflower varieties. The use of genetic variation to increase seed yield and seed oil will depend on the absence of negative correlation between oil and rubber production.     

Cultural practices for lesquerella production

WhileLesquerella fendleri has good potential of becoming a domestic, water-efficient source of hydroxy fatty acids in the United States, little research has been done outside of Arizona to determine its environmental response and cultural requirements. This study examined the effects of planting date, irrigation rate and fertilizer on growth and yield in Oregon, and it also evaluated tolerance to existing herbicides as a first step in developing cost-effective weed control programs. An October planting failed, while a March planting generally out-yielded a May planting. Seed yield was maximized at irrigation plus precipitation in the range of 959 to 1111 mm. Fertilizer response was indefinite, although response to phosphorus sometimes occurred. Herbicides with excellent potential include trifluralin and benefin pre-plant incorporated, and fluazifop post-emergent. Potential herbicides also include pendimethalin preemergent, and oxyfluorfen, dicamba and clopyralid postemergent. In addition to further studies on herbicide, irrigation, fertilizer and planting date effects, studies to optimize other cultural practices (e.g., row width, plant density, seed source, varietal development) that increase oil yield and quality while reducing input cost are required if lesquerella production is to occur in Oregon.     

玉米田除草剂磺草酮的生物活性及安全性

在温室条件下研究了磺草酮的除草活性、对玉米的安全性以及温度和降雨对磺草酮除草活性的影响。结果表明,磺草酮在300～600g a．i．／hm^2剂量下于温室苗前及苗后茎叶处理对大多数阔叶杂草、禾本科杂草均具有较高的防除活性,温度高有利于磺草酮药效发挥,并且具有较强的抗雨水冲刷能力,且对不旧品种的玉米安全,是一种有广阔开发前景的玉米田除草剂品种。     

5种土壤处理除草剂对半夏田杂草防除效果

[目的]草害是制约贵州半夏产业发展的重要因素之一.生产上主要依靠人工除草方式,其除草成本高;化学除草是降低半夏田除草成本的有效措施,但生产上供选择的除草剂品种单一;试验旨在提供更多除草剂品种供半夏田选择应用.[方法]选用5种土壤处理除草剂,按照随机区组设计进行田间药效试验,在半夏播后苗前进行土壤喷雾处理.[结果]50％...     

The pH Dependence of the Spectral and Anion Binding Properties of Iron Containing Superoxide Dismutase from E. Coli B: An Explanation for the Azide Inhibition of Dismutase Activity

Examination of the optical and EPR properties of the ferric form of the iron containing superoxide dismutase from E. coli B, at pH values ranging from 4.5 to 10.9, has revealed two reversible structural transitions affecting the Fe³⁺ ion. The apparent pK_a. values of these transitions are 5.1±0.3 and 9.0±0.3. The binding of azide has been studied over the pH range 4.5 to 10.7; the affinity of the Fe³⁺ for N₃⁻ is independent of pH from 4.5 to ∼ 7.5, after which the dissociation constant decreased by a factor of 10 per unit increase in pH. The apparent pK_a. which affects N₃⁻ binding to the iron is 8.6±0.2. The association of N₃⁻ with the iron has been examined using the temperature-jump method at pH 7.4 and 9.3. The kinetics of ligand association were shown to conform to the minimal mechanism: K₁ was found to be essentially unaffected by pH whereas K₂ was much lower at pH 9.3 than at 7.4. The value of K₁ at pH 7.4 (100 M⁻¹) corresponds very closely to that obtained for the inhibition constant of azide, 10 mM.¹² A scheme is presented in which N₃⁻ inhibits the iron containing dismutase by competing with O₂⁻ for an anion binding site near, but not on the Fe³⁺.     

Fate of urea applied to winter spinach in New Zealand

Field trials were conducted during three years (1996–1998) to follow the fate of N fertiliser applied to spinach (Spinacea oleracea L.) grown over winter (May–September) in New Zealand. Urea labeled with ¹⁵N was applied to the spinach at different rates (0, 200 or 400 kg N/ha), times (as two or three split applications) and placement methods (broadcast or banded). The results showed that the typical fertiliser practice of applying 350 kg N/ha near planting time followed by 50 kg N/ha 4 weeks later, resulted in leaching losses of 119–292 kg N/ha depending on the rainfall. Plants recovered only a small proportion of the fertiliser N (3–18% of the ¹⁵N). Better utilization of the fertiliser and lower leaching losses occurred when the fertiliser was applied strategically in split applications with only a small amount (10%) applied near sowing and the majority applied to match crop demand. For example, in 1998 applying 200 kg N/ha (20 kg N/ha initially+100 kg N/ha after 4 weeks and 80 kg N/ha after 8 weeks) resulted in twice the spinach yield (25 t/ha compared with 13 t/ha) and less than half the leaching loss (108 kg N/ha leached compared with 246 kg N/ha) compared with the typical fertiliser practice.