25%噻·多·唑醚种子处理悬浮剂及成膜助剂的制备与性能

Preparation and properties of 25% thiamethoxam·carbendazim·pyraclostrobin suspension concentrate and phragmoid addition agent for seed treatment

为制备直播棉种子用25%噻虫嗪·多菌灵·吡唑醚菌酯种子处理悬浮剂(25%噻·多·唑醚FS),分别采用流点法及正交试验设计对主要助剂进行筛选,并合成了可溶性淀粉-苯乙烯二元共聚物成膜剂,对25%噻·多·唑醚FS质量指标进行了测定,评价其对棉花种子发芽率、幼苗叶绿素、游离脯氨酸含量的影响.所制备制剂中,有效成分噻虫嗪、多菌灵和吡唑醚菌酯分别为10%、10%和5%,润湿分散剂W600和D800、黏度调节剂黄原酸胶和硅酸镁铝的质量分数分别为2.5%和4.0%、0.18%和0.30%,防冻剂乙二醇5%,色浆海舒液体红2R 2%.经测定,25%噻·多·唑醚FS黏度为204.21 mPa·s,粒径D90、D50、D10分别为1.25、0.82、0.35μm,离心沉淀率为8.34%,悬浮率96.02%,热贮析水率4.72%,脱落率为3.35%.成膜剂的成膜时间为11.33 min,包衣均匀度为91.67%.以药种比为1:50处理棉种,发芽率为95.67%,比空白对照提高了1.78%;棉幼苗叶绿素含量增加了70.54%;游离脯氨酸含量增加了77.55%.25%噻·多·唑醚种子处理悬浮剂成膜稳定性好,对棉花种子安全,发芽率高,有利于促进棉花幼苗发育生长.

To prepare 25% thiamethoxazine carbendazim pyraclostrobin suspension concentrate(25% thi car pyr FS) for cotton seeds treatment for direct seeding, the main additives in the formulation were screened by flow point method and orthogonal design. The soluble starch-styrene binary copolymer film former was synthesized and the performance of the film former was determined. The quality index of 25% thi car pyr FS was determined and its effect on cotton seed germination rate, seedling chlorophyll content and free proline content was evaluated. The active ingredients thiamethoxazine, carbendazim, and pyraclostrobin accounted for 10%, 10%, and 5%, respectively. The mass fractions of wetting and dispersing agents W600 and D800 were 2.5% and 4.0%, respectively and the mass fractions of viscosity modifiers xanthan gum and magnesium aluminum silicate were 0.18% and 0.30%, respectively. The mass fraction of antifreeze glycol was 5%, of color paste Haishu liquid red 2R 2%. The viscosity of thi car pyr FS was 204.21 mPa·s, the particle size D90, D50, D10 were 1.25, 0.82, 0.35 μm, the centrifugal sedimentation rate was 8.34%, the suspension rate was 96.02%, the water extraction rate was 4.72%, and the shedding rate was 3.35%. The film forming time of the film former was 11.33 min, and the uniformity of coating was 91.67%. When the drug to species ratio was 1∶50, the germination rate was 95.67%, under which the germination rate increased by 1.78%, the chlorophyll content of cotton seedlings increased by 70.54%, and the free proline content increased by 77.55%, compared to the blank control. The prepared seed treatment suspension 25% thi car pyr FS has good film formation stability, and is safe to cotton seeds, which can ensure high germination rate and promote the growth and development of cotton seed.