【Objective】 To explore the effects of new composite hydrogel on the physiological characteristics of tobacco seedlings under drought stress, and to provide theoretical basis for alleviating the toxicity of drought stress to tobacco. 【Method】 A total of 10 treatments including CK control and three different hydrogels added at 0.1%, 0.5% and 0.9% of soil dry mass: commercial hydrogel HS, new composite hydrogel HM (polyvinyl alcohol-acrylic acid-molecular sieve hydrogel) and HB (polyvinyl alcohol-acrylic acid-biochar hydrogel) were designed by pot experiment to study the effects of new composite hydrogels on tobacco under drought stress The effects of the new composite hydrogels on biomass accumulation, root development, photosynthetic system and oxidative stress of tobacco under drought stress were investigated. 【Result】 Under the same dosage conditions, HM and HB treatments were effective in increasing the fresh mass, dry mass and total water content of tobacco under drought stress compared to HS treatment. Compared with CK, HM and HB treatments could increase the fresh mass by a maximum of 153.91% and 126.34%, respectively. Under the same dosage conditions, HM and HB treatments significantly increased the total root length, total root surface area, average root diameter, root tip number and root volume, and improved the root vigor of tobacco compared with HS treatments; photosynthetic parameters and SPAD values of tobacco increased significantly and improved leaf stomatal status; SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase) activities and soluble protein amounts of tobacco increased and MDA (malondialdehyde) amounts decreased significantly, which enhanced the resistance of tobacco. 【Conclusion】 Adding 0.9% HM and HB hydrogels to soil dry weight can effectively reduce the impact of drought stress on tobacco and improve tobacco drought resistance.

【Objective】 Drought is the most common abiotic stress affecting agricultural production in most countries, and alleviating its detrimental effect is critical to safeguarding crop growth. The purpose of this paper is to compare the efficacy of water adsorption polymer in improving soil water retention and growth of tobacco seedlings. 【Method】 Water adsorption polymer particles with diameter in the range of 0.3~1.0 mm (T1), 1.0~2.5 mm (T2), and 2.5~4.75 mm (T3) were mixed with soil thoroughly prior to planning, respectively, with soil not being amended as the control (CK); plants in all treatments were under water stress. The field water capacity, water retention rate, as well as the growth and development of the tobacco seedlings were measured in each treatment. 【Result】 The field capacity maximized when the particle diameter was in the range of 2.5~4.75 mm, up 30.49% higher than that in the CK. Mixing soil with polymer particles with diameter in the range of 1.0~2.5 mm gave the highest soil water retention capacity. Soil amended by polymer particles with diameter in the range of 1.0~2.5 mm can effectively alleviate drought stress, promoting biomass accumulation in the plant. Soil amendment increased its total water content, relative water content and free water content in tobacco leaves by 4.93%, 24.35% and 11.81%, respectively, while reduced bound water, bound technique/free water, and water saturation deficit by 5.25%, 16.18%, and 63.51%, respectively. Compared with CK, soil amendment with the polymer also reduced the activities of SOD, POD, CAT, MDA, and soluble protein in the plant by 114.86%, 211.93%, 67.05%, and 273.29%, 27.73% respectively. 【Conclusion】 Amending the soil with water absorbent polymer particles with diameter in the range of 1.0~2.5 mm is most effective to improve the field capacity and water-retention capacity of the soil, effectively alleviating drought stress to tobacco seedlings.

烟叶农药残留是影响卷烟原料质量的关键因素.目前农业生产过程中病虫害防治一般以化学防治为主,造成环境污染和农药残留超标现象.本文分析了烟草农药残留的来源和控制方法,以期为烟叶高质量发展提供参考.

为筛选出适宜豫西烟区生态条件的烤烟新品种,于2019年,以当地主栽品种秦烟96、云烟87为对照,对延安1号、云烟116、NC89、云烟99、豫烟13号和秦烟201这6个引进品种的生态适应性进行对比分析.结果表明:豫烟13号大田生育期最长,烟株顶部6片叶一次成熟,叶片成熟度最好,叶片宽圆,耐烘烤,原烟质量高,产量、均价、上等烟比例等经济性状和抗病性均高于对照秦烟96和云烟87.秦烟201大田长势强,生育期适中,叶片大茎秆粗细适中,大田通风透光好,叶片数较多,高抗病毒病,主要经济性状和抗病性均优于秦烟96和云烟87.延安1号生育期适中,田间长势强,团棵期长势旺,田间长势整齐一致,叶片多,单叶重,高抗根黑腐病,中抗TMV、黑胫病、气候斑,产量、产值均高于秦烟96和云烟87.综合评价,豫烟13号、秦烟201、延安1号对豫西烟区具有一定生态、生产适应性,可推广种植.

为研究光强衰减对豫西烟区烤烟色素降解及品质特征的影响,以云烟87为材料设计5种光照强度水平(100％、80％、60％、40％、20％)的大田试验.结果表明:质体色素残留量在80％ 光强处理条件下与自然光强差别不大,光强继续降低色素残留量显著升高;类胡萝卜素降解产物总量变化趋势与叶绿素降解产物新植二烯含量一致,均为随光照强度的降低而减少.经遮光处理,在80％ 光强以下,烤烟品质特征显著下降.可见不低于80％ 光照强度最有利于优质烟叶的生产.