Effect of adjuvants on the performance of the new cereal fungicide,metconazole. II Field trials

Glasshouse trials had shown that the activity of metconazole formulations against cereal foliar diseases could be enhanced by alcohol ethoxylate adjuvants. A series of soluble liquid (SL) formulations of metconazole had been prepared containing adjuvant: metconazole ratios of 5:1, 7.5:1, 10:1, 15:1 m/m (SL1, SL2, SL3, SL4) which glasshouse trials had shown could give equivalent performance to an emulsifiable concentrate formulation, (ECM) of metconazole at application rates up to three- or four-fold lower than that of ECM alone. A field trials programme was undertaken to compare the performances of these SL formulations with ECM at 120 g AI ha^?1, through a range of application rates (48, 60, 72, 84 g AI ha^?1), in a non-orthogonal factorial trial design against diseases that occurred naturally (Septoria tritici Rob., Puccinia recondita Rob., Pyrenophora teres Drechs., Erysiphe graminis DC) or by artificial inoculation (Leptosphaeria nodorum Muell.), on either Triticum aestivum L. or Hordeum vulgare L. The results from trials in three locations showed that the commercially acceptable performance of ECM at 120 g AI ha^?1, in giving high levels of control of P. recondita, S. tritici and L. nodorum (both prophylactic and therapeutic activity) on T. aestivum. and of E. graminis and P. teres on H. vulgare, could be matched or improved by SL2, SL3 and SL4 at 72 g AI ha^?1. Furthermore, control of E. graminis f. sp. tritici Marchal by these SL formulations at this application rate was better than that by ECM at 120 g AI ha^?1, though the levels of control still remained below commercial acceptability for therapeutic activity. Nevertheless, substantial reductions in the application rate of metconazole have been achieved by using one-pack adjuvant-containing formulations in field trials, while still maintaining excellent control of a range of cereal foliar diseases. The choice between these SL formulations could therefore be made on other grounds such as cost/performance and ease of formulation.     

Efficacy of new EC formulations of neem oil and pungam oil for the management of sheath rot disease of rice

Neem oil (NO) and pungam oil (PO) based emulsifiable concentrate (EC) formulations,viz., neem oil 60 EC (acetic acid) [NO 60 EC(A)], neem oil 60 EC (citric acid) [NO 60 EC(C] and neem oil + pungam oil 60 EC (citric acid) [NO+PO 60 EC(C)], which had been developed at Tamil Nadu Agricultural University, were evaluated for their efficacy against sheath rot of rice. All three formulations effectively inhibited the mycelial growth of the pathogen,Sarocladium oryzae, underin vitro conditions. There was no significant difference between efficacy of the freshly prepared and stored formulations in arresting the growth ofS. oryzae; efficacy was maintained even after 9 months of storage. These formulations effectively controlled rice sheath rot and led to increased yield in five field trials. Among the various treatments, the formulation NO 60 EC(A) achieved the highest grain yield in four out of five field trials, with a pooled mean grain yield of 4684 kg/havs 3882 kg/ha in the control. NO 60 EC(A) achieved the maximum cost-benefit ratio of 1:4.8, followed by NO+PO 60 EC(C), with 1:3.3.     

不同营养基质配方对番茄幼苗抗盐性的影响

采用正交试验设计方法,以草炭、蛭石、珍珠岩(重量比3∶1∶1)为育苗基质,并配施生物有机肥、三元复合肥(N-P2O5-K2O,15~(-1)5~(-1)5)和硅钙肥等基质营养,研究不同肥料配方的育苗基质分别在0(对照)、100mmol·L~(-1) NaCl下对"石头168"番茄幼苗生长生理特征的影响。结果表明,相比其他育苗营养基质处理,营养基质﹟8(有机肥12.5g·kg~(-1)、三元复合肥5.4g·kg~(-1)和硅钙肥0.54g·kg~(-1))所育番茄苗的壮苗指数、根系干物质量、地上部分植株干物质量及叶绿素a/b等生长生理参数均表现较优,分别为1.199、1.000g·株~(-1)、10.700g·株~(-1)、1.065mg·(g·FW)~(-1);营养基质﹟4(有机肥6.75g·kg~(-1)、三元复合肥2.70g·kg~(-1)和硅钙肥1.08g·kg~(-1))的番茄幼苗植株生长速度相对较快,而叶片电解质相对外渗率则较低。因此,﹟8(有机肥12.5g·kg~(-1)、三元复合肥5.4g·kg~(-1)和硅钙肥0.54g·kg~(-1))和﹟4(有机肥6.75g·kg~(-1)、三元复合肥2.70g·kg~(-1)和硅钙肥1.08g·kg~(-1))番茄育苗营养基质均能明显改善幼苗的抗盐生长生理性状。     

Physicochemical characterization and formation of glyphosate-laden nano-emulsion for herbicide formulation

A nano-emulsion system was developed for pesticide formulation. Pseudoternary phase diagrams were constructed consisting emulsion system of long-chain fatty acid methyl esters (LFAMEs)/mixed surfactant/water and a quarternary component, glyphosate isopropylamine (IPA) as a herbicide active. Isotropic (L) regions were formed in the phase diagrams using mixed surfactant long-chain alkylpolyglucosides (LAPG) and ethoxylated 3-(3-hydroxypropyl)-heptamethyltrisiloxane (organosilicone) at the ratios of 9:1, 8:2 and 7:3. Pre-formulation concentrates were chosen from the L regions with less than 20% (w/w) of inerts (LFAMEs + mixed surfactant) and were characterized with regard to particle size, particle aging rate and thermostability study. A pre-formulation concentrate with the lowest aging rate and stable at high temperature (54 °C) was selected for the mechanisms study of the pre-formulation concentrate in conjunction with the development of nano-emulsion formulation. The transmission electron microscopy (TEM) result showed that the pre-formulation concentrate appeared as a polymerized multi-connected network. Upon water dilution of the pre-formulation concentrate with gentle stirring (low-energy emulsification method), well-dispersed nanoparticles were formed with no needle structure being observed. The nano-emulsion particles were incorporated well with the glyphosate IPA thus inferring that this nano-emulsion system could ameliorate the bioactivity and bioavailability of the herbicide.     

不同剂型卫生杀虫剂产品登记药效试验类别

根据不同剂型卫生杀虫剂产品的使用方式和使用范围特点,明确其在登记药效试验过程中需完成的药效试验项目类别,包括室内试验、模拟现场试验和现场试验中的一种或几种,为卫生杀虫剂产品登记的科学评审提供参考。     

Determination of carbofuran in pesticide formulations by flow injection spectrophotometry

A flow injection spectrophotometric method for the determination of carbofuran in commercial pesticide formulations was developed. The determination involves on‐line hydrolysis of the extracted carbofuran at room temperature with sodium hydroxide. The resulting carbofuran‐phenol is coupled with diazotized 4‐aminobenzoic acid in order to achieve an appropriate selectivity and sensitivity for the spectrophotometric measurements. The calibration curve is linear over the range 1–10 mg litre⁻¹ of carbofuran. The proposed method has a detection limit of 0.15 mg litre⁻¹ of carbofuran and a sample frequency of 120 injections per hour. The relative standard deviation of six independent determinations of a sample containing 1 mg litre⁻¹ carbofuran was 0.6%. The suitability of the proposed procedure for the determination of carbofuran in commercial pesticide formulations was studied. The procedure provides results comparable to those obtained by liquid chromatographic analysis. © 2000 Society of Chemical Industry     

玉米种衣剂研究进展

综述了玉米种衣剂对种子发芽率和幼苗生长发育的影响、防病治虫效果、增产保产情况等方面的研究进展,并对玉米种衣剂的前景进行了展望。     

辣椒有机生态型无土栽培基质配方试验

以炉渣、玉米秸秆、发酵牛粪、食用菌栽培废料、沼渣、糠醛渣为材料,研究了辣椒有机生态型无土栽培基质的最佳配方。结果表明:炉渣∶玉米秸秆∶牛粪∶菌棒∶糖醛=0.6∶0.6∶1∶1∶0.6(V/V)配方较为适宜辣椒有机生态型无土栽培。     

Bioavailability of the herbicide 2,4-D formulated with organoclays

Research on organoclays as sorbents of pesticides has shown the usefulness of these materials as pesticide supports to prolong the efficacy of soil-applied pesticides and to reduce the large transport losses that usually affect pesticides applied in an immediately available form. Nevertheless, little information exists on the availability of organoclay-formulated pesticides for bacterial degradation. In this work, laboratory experiments were conducted to determine the adsorption-desorption behavior of two hexadecyltrimethylammonium-treated Arizona montmorillonites (SA-HDTMA₅₀ and SA-HDTMA₁₀₀) for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), and to evaluate the ability of these organoclays to slow the release of the herbicide and to reduce herbicide leaching losses as compared to the free (technical) compound. The kinetics of mineralization of free and formulated 2,4-D by adapted bacteria was also determined. Organoclay-based formulations of 2,4-D displayed slow release properties in water and reduced herbicide leaching through soil columns, while maintained a herbicidal efficacy similar to that of the free (technical) 2,4-D. The total amount of ¹⁴C-2,4-D mineralized at the end of the biodegradation experiment (t=130 h) ranged between 30% and 46% of the formulated herbicide, which represented 53-81% of the amount of free 2,4-D mineralized in the same conditions. The release, leaching, and mineralization patterns of the formulated herbicide were found to depend both on the affinity of the organoclay for the herbicide and on the degree of interaction promoted during the preparation of the herbicide-organoclay complex. This suggests the possibility to select diverse preparations to achieve the desired release, leaching and biodegradation behavior.