杀雄嗪酸的合成及其生物活性的研究

研究以对氯苯胺为主要原料．经过五步工艺合成杀雄嗪酸的实验方法，总收率达到65%(以对氯苯胺计)。进行了该新型化学杂交剂诱导小麦雄性不育的药效试验研究。采用3～5kg／hm^2剂量时，诱导小麦雄性不育率大于95％。异交结实率大于95％。该化杀剂对雌蕊活性未造成有害影响。     

控释尿素对小麦增产效果与提高氮肥利用率的研究

采用控释尿素和普通尿素两种氮素肥料进行优质小麦郑麦366肥效试验研究。两地试验结果表明：100％控释尿素处理产量最高,为7980kg／hm^2和8290kg／hm^2,与同等氮素用量的普通尿素相比增产12．0％、14．0％;产量随氮肥用量的增加而增加;用量70％控释尿素处理与用量100％普通尿素处理之间相比,产量差异不大,没有达到显著性差异,说明施用控释尿素可以比普通尿素减少1／3的纯氮用量。     

两种新型小麦化学杀雄剂投放市场

苯哒嗪丙酯：为中国农业大学应用化学学院研制开发的、具有我国自主知识产权的一种新型低毒植物生长调节剂（小麦去雄剂），制剂为10％苯哒嗪丙酯乳油，商品名达优麦。该药能诱导自交作物雄性不育，培育杂交种子，主要用于小麦育种，具有优良的选择性小麦去雄效果。田间药效试验表明，该药施药适期为小麦幼穗发育的雌雄蕊原基分化期至药隔后期，1次喷药，用药量为每667平方米用有效成分50～66．6克（折成10％乳油商品量为500～666克／667m^2，一般加水30～40千克），喷施于小麦母木植株，具有诱导小麦雄性不育彻底，提高小麦去雄质量，达到杂种小麦制种纯度要求。对小麦的生长发育无不良影响，且施药适期较长。在施药剂量范围内，随着施药剂量的升高，小麦去雄效果越好，不育率可达95％以上，效果比较理想。可大大降低小麦育种过程中人工去雄的工作量，节省劳力。     

新型广谱杀菌剂10%苯醚菌酯SC(ZJ0712)应用技术

3年多的田间试验结果表明，10％苯醚菌酯SC对黄瓜白粉病和葡萄霜霉病具有非常优异的防效。在10—20ga.i.／hm^2的处理剂量下，对黄瓜白粉病的防效可达84％-95％以上；在50—100ga.i.／hm^2的处理剂量下，对葡萄霜霉病的防效可达69％-94％以上。该药剂也能有效控制小麦白粉病、苹果白粉病、黄瓜霜霉病、荔枝霜疫霉病、西瓜炭疽病和芒果炭疽病等多种植物病害的发生和为害。在使用剂量范围内对作物安全，并对作物的生长具有明显的促进作用。     

0.003%芸苔素内酯水剂在葡萄上的应用

两年的田间试验结果表明,0．003％芸苔素内酯水剂对巨峰葡萄具有明显的膨大作用,使用剂量为0．0261g a．i．／hm^2、0．0435g a．i．／hm^2和0．1305g a．i．／hm^2,分别于葡萄开花前12d和盛花后14d两次喷药,增产率可达21．24％～26．87％,且对葡萄品质无不良影响。     

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。     

控释尿素和控释BB肥对夏玉米的增产效果研究

采用控释尿素和普通尿素两种氮素肥料及含控释尿素的BB肥进行夏玉米肥效试验研究。试验结果表明：100％控释尿素处理产量最高,为8714kg／hm^2。和8838kg/hm^2,与同等氮素用量的普通尿素相比,分别增产658kg／hm^2和667kg／hm^2,提高8．2％和8．2％,增产效果显著;控释尿素用量在70％～100％时,产量随氮肥用量的增加而增加,普通尿素也呈同样趋势;70％控释尿素处理与100％普通尿素处理相比,产量差异不大,没有达到显著性差异,说明施用控释尿素可以比普通尿素用量减少约1／3的纯氮用量,夏玉米作物产量并不下降。     

河南省三大土壤类型区的平衡施肥研究

河南省三大土壤类型区氮磷钾平衡施肥对优质小麦郑麦366的增产作用不同。从试验结果看,氮磷钾平衡施肥在三大土壤类型区（褐土、潮土、砂姜黑土）均能提高小麦产量;限制小麦产量的主要因素：第1位是氮素,第2住是磷素,第3位是钾素。在平衡施肥处理时,潮土区小麦产量最高为8749kg／hm^2,其次褐土区产量为8385kg/hm^2,砂姜黑土区产量最低为7616kg／hm^2和8029kg／hm^2。     

18％百菌清·霜脲氰悬浮剂防治黄瓜霜霉病田间药效试验

对18％百菌清·霜脲氰悬浮剂防治黄瓜霜霉病（Pseudoperonospora cubensis）田间效果进行了试验,结果表明．18％百菌清·霜脲氰悬浮剂用量为405g a．i．／hm^2、472．5g a．i．／hm^2、540g a．i．／hm^2时,其对黄瓜霜霉病的防效分别为61．00％、68．82％、74．05％,小区折合产量分别为33946．2kg／hm^2、36709．0kg／hm^2、37595．7kg／hm^2,与空白对照相比分别增产7．38％、16．08％、18．88％。     

氟磺胺草醚对作物的药害及解决措施

氟磺胺草醚在施药不均匀，剂量倍加的情况下可对大豆和后茬敏感作物产生药害。盆栽试验表明，氟磺胺草醚剂量为750g／hm^2时对大豆株高有显著影响，剂量为1500g／hm^2时大豆株重显著下降。间隔90d播种作物，剂量为495g／hm^2时玉米和小麦株重显著下降；剂量为562．5g／hm^2时，对油菜株重显著下降；而在推荐剂量375g／hm^2时，玉米、小麦和油菜的侏重没有显著影响。氟磺胺草醚与灭草松混用可以降低前者的使用剂量，是降低药害风险良好的措施，     

化学杂交剂BAU-9403的高效液相色谱分析

采用高效液相色谱法,使用正相硅胶柱,乙腈-乙醇为流动相,用外标法对化学杂交剂BAU-9403原药及乳油进行定量分析,方法的变异系数分别为0．534％和0．638％。线性相关系数分别为0．9999和0．9998。回收率分别在98．19％～100．88％和98．02％～101．26％之间。     

Response of direct-seeded guayule to preemergence herbicides

Direct-seeding guayule (Parthenium argentatum Gray) in west Texas has been successful; however, seedlings grow slowly and are extremely susceptible to weed competition. An effective preplant or preemergence herbicide is necessary for establishment. The objective of this study was to examine the effects of preemergence herbicides on guayule stand establishment by direct seeding. Experiments were initiated on a Dalby clay in 1991 and 1992 at the Texas Agricultural Experiment Station Guayule Research Site near Fort Stockton, Texas. Conditioned guayule seed (Mexican Bulk) was planted 10 mm deep on raised beds with a Gaspardo SV255 pneumatic planter at 100 seeds/m. The following herbicides were applied immediately after planting: dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate (DCPA) [4.5, 9.0, 11.0 kg ai/ha (hectare)], pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] (0.3, 0.6, 1.1 kg/ha) and prodiamine [N³,N³-Di-n-propyl-2,4-dinitro-6-(trifluoromethyl)-m-phenylenediamine] (0.3, 0.6, 1.1 kg/ha). Herbicides were applied in a 0.5-m band on each bed by using a CO₂-powered backpack sprayer with a single-nozzle boom delivering 300 L/ha at 172 kPa pressure. The lowest rates of all herbicides did not significantly reduce guayule stand density in 1991 when compared to the control. DCPA at 9.0 kg/ha was adequately selective in both studies. Guayule stand reduction varied from only 2% with DCPA at 4.5 kg/ha in 1991, to 71% with 1.1 kg/ha of pendimethalin in 1992. DCPA (4.5 and 9.0 kg/ha) would be recommended for preemergence weed control, depending on soil type, when direct seeding guayule. Based on row spacing recommendations for transplants, at least three established seedlings/m would be required for an acceptable guayule stand. Seeding rate could be reduced and still allow for effective preemergence weed control.     

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.     

The effects of elemental sulphur on flowering and pod maturation in groundnut (Arachis hypogaea L.) under irrigation

Field experiments were carried out for two consecutive seasons (1980/81–81/82) in order to study the effects of elemental sulphur on flowering and pod maturation in groundnut under irrigation. Four rates of elemental sulphur (0, 50, 100, 150 kg S/ha) were used. Each rate was applied either at sowing, at maximum flowering or split equally between these two stages. Flower number per plant, total and mature pod number per plant as well as seed weight were significantly increased by sulphur when applied at sowing. Sulphur applied at flowering had no effect on these attributes. In addition, protein and total sulphur content of seeds were significantly increased by all sulphur treatments. The greatest response was obtained at or below 50 kg S/ha but above this rate there was no further increase in response.     

Efficiency of nitrogen fertilizer use under rainfed maize and irrigated wheat at Kadawa,northern Nigeria

Field trials were conducted at Kadawa, northern Nigeria, during 1975–77 to study the efficiency of nitrogen fertilizer use under maize (Zea mays L.)—wheat (Triticum aestivum L.) rotation; the study also examined the impact of continuous N use on some soil properties. Grain and straw dry matter yields, grain N content, crop N uptake and whole plant N concentration of wheat at different growth stages increased significantly with increasing levels of N application. Per cent increases in mean grain yield of N treated plots over control were 77, 131 and 141 for maize and 195, 308 and 326 for wheat at 60, 120 and 180 kg N per ha levels, respectively. The calculated N rates for maximum yield were 177.5 and 164.0 kg N per ha for maize and wheat, respectively. Short-term beneficial effect of dung on maize yield was ascribed to its additional N supply. Urea and calcium ammonium nitrate (CAN) were equally good for both maize and wheat; full and split N application gave no significant difference in yield. The values for mean fertilizer N recovery over all the crops were 64, 58 and 44% respectively, at 60, 120 and 180 kg N per ha levels.Nitrogen application at the highest rate (180 kg per ha) reduced the soil pH significantly in the top 40 cm of the soil profile. The magnitude of soil acidification at levels of N below 120 kg per ha was not appreciable in this study. High N application also depleted the soil of its cations at differential rates. Other factors such as N source, time of N application and addition of dung along with N fertilizer did not have much influence on the rate of short-term soil acidification due to N fertilizer use.     

气相色谱质谱联用仪测定玉米中2,4-滴异辛酯的残留量及消解动态

[目的]建立玉米中2,4-滴异辛酯残留量气相色谱质谱检测方法,并研究了其在植株和玉米中的消解动态和最终残留。[方法]样品用丙酮提取后,三氯甲烷萃取,经弗罗里硅土和活性炭层析柱净化,用气相色谱质谱联用仪进行测定。[结果]2,4-滴异辛酯在0.1~2.0 mg/L质量浓度范围内呈线性,相关系数0.9993;添加3个不同质量分数,平均回收率为88.7%~101.7%;变异系数为7.2%~9.0%。施药剂量为推荐剂量的1.5倍(3,058.5 g a.i./hm2)时,2,4-滴异辛酯在玉米植株中的半衰期为2.4~6.7 d,68%乙草胺.2,4-滴异辛酯.莠去津悬浮剂2,038.9、3,058.5 g a.i./hm2两个剂量,施药1次,测得收获期植株、玉米中2,4-滴异辛酯的残留量均低于美国规定的MRL0.5 mg/kg。[结论]按照推荐剂量2,038.9 g a.i./hm2处理,建议我国2,4-滴异辛酯在玉米上的MRL值可暂定为0.5 mg/kg,施药次数1次。     

N8161 萃取铼(Ⅶ)的热力学

以萃取剂N8161、稀释剂正庚烷研究了萃取铼的热力学. 在N8161 (NH4)ReO4 n C7H16 HCl H2O体系中,在温度278.15~298.15 K和离子强度0.1~2.0 mol/kg范围内,以NH4Cl为支持电解质,在HCl体系中测定了萃取平衡水相中的ReO4 浓度和pH值. 计算了萃取反应的标准平衡常数K0,并得到经验公式logK0 23.0353 4330.282T 1 0.04831T, 同时计算了萃取反应的其它热力学量,指出焓和熵是该萃取过程的推动力.     

Fertilizer rates for increased pineapple production in the tropical ferrallitic soils of South Western Nigeria

The investigation studied the optimal fertilizer rates and mixtures for maximum production of smooth cayenne pineapples in the tropical ferrallitic soil.Fertilized pineapples were significantly (P = 0.05) superior in growth and fruit yield to the unfertilized control. Nitrogen and potassium were the most critical nutrients. Nitrogen deficiency manifested within 6 months of planting as reduced, thorny and pink coloured leaves resulting in over 10 months delayed plant crop harvest and over 38% reduction in fruit yield. Less than 20% of pineapples which lacked nitrogen remained productive during the first ratoon crop. However, when nitrogen was increased twofold (100 to 200 kg/ha/year), the fruit of the plant crop doubled with 15-10% increased fruit lodging. Potassium significantly (P = 0.05) reduced fruit lodging and improved fruit yield and flavour.Nitrogen further enhanced the effective utilization of P and K for significant yield increases. Thus, the interaction between high nitrogen (200 kg/ha/year) and low phosphorus (50 kg/ha) or high potassium (200 kg/ha) respectively, significantly (P = 0.05) increased the yield of pineapples, while P and K interaction retarded growth, delayed crop maturity and reduced the fruit yield and quality. Pineapples which received fertilizer mixture of NPK 200-50-200 produced the highest and best quality fruits and was therefore recommended for optimum yield of pineapples in the tropical ferrallitic soils.     

Relationship between electroultrafiltration (EUF) extractable nitrogen,grain yield,and optimum nitrogen fertilizer rates for winter wheat

The objective of the investigation was to examine whether there exist relationships between the optimum nitrogen fertilizer rate for winter wheat and soil nitrogen fractions extracted by electroultrafiltration (EUF) from autumn samples of the upper soil layer (0–30 cm). Optimum nitrogen fertilizer rates were derived from grain yield curves of field trials carried out with increasing nitrogen fertilizer rates on 19 different sites in 1985/86 and 1986/87. Most soils were luvisols derived from loess, two soils were brown earths and one a pararendzina. Total Nitrogen fertilizer rates were 0, 40, 80, and 120 kg N/ha applied twice before ear emergence. The final nitrogen rate at ear emergence was the same for all treatments, namely 60 kg N/ha.Optimum nitrogen fertilizer rates were derived from the grain yield curve fitted to a modified Mitscherlich equation. The optimum nitrogen fertilizer rates were correlated with the nitrogen fractions extracted by EUF. The regression equation thus obtained showed that NO ₃ ^- , the organic N fraction (EUF Norg), and the EUF Norg-quotient each had a highly significant impact on the optimum nitrogen fertilizer rate. The higher the amounts of EUF-N extracted the lower the optimum nitrogen rate. Substituting the EUF Norg-fraction for total nitrogen concentration in the upper soil layer gave a poorer relationship between the optimum nitrogen fertilizer rate and the soil data. In absolute terms the EUF Norg-fraction had by far the greatest impact on calculating the optimum nitrogen fertilizer rate. The investigation shows that the EUF method is a suitable technique for the determination of available soil nitrogen from which optimum nitrogen fertilizer rates can be derived for winter wheat cultivated under soil and climatic conditions typical for cereal growing areas in central Europe.     

Phosphorus management of a rice-wheat cropping system

A long term field experiment was conducted on a sandy loam soil from 1983 to 1987 to determine how to best apply phosphorus fertilizer in a rice-wheat cropping system. The treatments included 9 combinations of phosphorus application either to both rice and wheat or to rice or wheat alone. Direct application of phosphorus at 13 kg/ha to both the crops resulted in significantly higher total productivity of the rice-wheat cropping system as compared with 26 kg P/ha applied either to rice or wheat alone. Phosphorus at 13 kg/ha for rice and 26 kg/ha for wheat was as efficient as 13 kg P/ha for rice and 13 kg P/ha for wheat. The higher rate of P (26 kg/ha) applied to both rice and wheat resulted a decline in the total productivity. The residual effects of phosphorus applied to either rice or wheat were significant to the succeeding crop but was inferior to its direct application. Phosphorus increased the leaf area index, chlorophyll content of leaves, and interception of more photosynthetically active radiation (PAR) which resulted in increased grain yield of rice and wheat. Phosphorus status of the surface soil declined markedly, in the absence of P application from 15.4 to 6.4 kg P/ha. Phosphorus applied at 26 kg P/ha to both the crops resulted a build up of the available P status of soil. Phosphorus application at 13 kg/ha to both rice and wheat maintained the phosphorus status of the soil at original level.