不同施氮水平下硅肥对谷子抗倒伏能力、产量和品质的影响

[目的]倒伏严重影响谷子产量和品质。探究不同施氮水平下硅肥提高谷子茎秆强度、产量及品质的作用,为谷子高产高效施肥提供技术方案。[方法]以晋谷21和张杂13为供试谷子品种,在山西太谷进行大田试验。在常规施氮量N_(1)(180 kg/hm^(2))和高施氮量N_(2)(450 kg/hm^(2))下,分别设置不施硅、施用硅酸钠(Si_(1),SiO_(2) 68.85 kg/hm^(2))和硅钙肥(Si_(2),SiO_(2) 67.2 kg/hm^(2)),共6个处理。在谷子成熟期测量其株高、抗倒伏能力相关指标、光合特性、产量和品质相关指标,并观察茎秆横切面显微结构。[结果]N_(1)水平下,施用硅肥降低了谷子基节长度,增加了茎粗、茎秆抗折力和穿刺力,晋谷21和张杂13两品种前五基节的节间长度分别降低了4.1%~30.1%和9.5%~11.5%,茎粗分别增加5.3%~19.4%和13.0%~34.1%;晋谷21抗倒性在N_(1)-Si_(1)处理较强,第一、第二基节抗倒伏指数较N_(1)-Si_0处理分别增加37.4%和35.8%,张杂13在N_(1)-Si_(2)处理时较强,第一、第二基节抗倒伏指数较N_(1)-Si_0处理分别增加136.0%和94.7%。N_(2)水平下,施用硅肥后晋谷21和张杂13前五基节的节间长度分别降低了9.6%~30.3%和10.6%~14.9%,茎粗分别增加了9.56%~23.9%和16.2%~31.0%,茎秆扁平度降低。硅钙肥对谷子茎秆强度影响大于硅酸钠,N_(2)-Si_(2)处理晋谷21的第二基节抗折力、穿刺力和抗倒伏指数比N_(2)-Si_0分别增加97.9%、77.6%和83.3%,张杂13的第一基节抗折力、穿刺力和抗倒伏指数比N_(2)-Si_0分别增加74.0%、66.8%和128%。施硅后谷子茎秆中机械组织增厚,维管束数量增多且排列均匀,向茎秆中心延伸,且在N_(2)水平下,硅钙肥作用效果优于硅酸钠。硅可促进谷子穗码发育,增加穗粗、穗粒数和千粒重,在高氮水平下硅钙肥处理使晋谷21和张杂13的产量分别增加23.8%和24.0%。施用硅肥能够提高谷子脂肪、蛋白质和氨基酸含量,在高氮水平下可以降低谷子直链淀粉/支链淀粉值。[结论]在高氮条件下,施用硅钙肥使谷子前五基节长度降低,茎粗增加,机械强度增加,进而提高抗倒伏能力;施用硅肥还可增加光合速率和蒸腾速率,促进物质积累和运输,增加产量,改善品质。

山西省晋中市春播谷田杂草发生情况调查与分析

为明确山西省晋中市春播谷田杂草发生情况,在晋中市春播谷子种植区选取具有代表性的4个县、乡镇,共12块样地,采用倒置“W”取样方法,对杂草发生情况进行调查与分析。结果表明:晋中市春播谷田杂草共有14科30属31种,其中禾本科杂草7种,占杂草总量22.58%,阔叶杂草24种,占杂草总量77.42%;一年生杂草23种,占74.19%,多年生杂草8种,占25.81%。优势杂草为稗草(Echinochloa crusgalli)、反枝苋(Amaranthus retroflexus)、藜(Chenopodium album)、狗尾草(Setaria viridis)4种。不同县、乡镇杂草种类和相对优势度存在一定差异。

Responses of the antioxidant system to fluroxypyr in foxtail millet (Setaria italica L.) at the seedling stage

Foxtail millet （Setaria italica L.） is an important food and fodder crop in semi-arid areas. However, there are few herbicides suitable for use on weed control in field-grown foxtail millet during the post-emergence herbicides stage. The present study was conducted using four concentrations （0.5, 1, 2, and 4 L ai ha-1） of foliar-applied fluroxypyr, and the effect of fluroxypyr on selected metabolic and stress-related parameters in foxtail millet were assessed after 15 days. In this study, increasing concentrations decreased plant height and accumulation of chlorophylls. Our results also showed that malondialdehyde （MDA） accumulated in response to fluroxypyr application, demonstrating increased lipid peroxidation due to excessive reactive oxygen species production. In response to this oxidative stress, the activities of antioxidant enzymes were generally enhanced. Non-enzymatic antioxidant defense systems, which function in concert with antioxidant enzymes, can also protect plant cells from oxidative damage by scavenging reactive oxygen species （ROS）. In conclusion, the hybrid variety （Zhangzagu） exhibited a greater tolerance to fluroxypyr than did the conventional variety Jingu 21, which might be associated with the antioxidant mechanisms of Zhangzagu hybrid millet.

油菜素内酯对施用苯磺隆后杂草防效及谷子产量的影响

[目的]明确油菜素内酯(BR)影响苯磺隆在谷田杂草防效及谷子产量方面的作用。[方法]在大田条件下,谷子3~5叶期时叶面喷施3个不同浓度的苯磺隆,喷施等量清水为对照,施药后3 d喷施不同浓度的油菜素内酯,分别于施药后7、14、21、35 d调查杂草株防效及鲜质量防效,谷子收获后进行考种测产。[结果]随着单用苯磺隆浓度升高,藜、反枝苋的株高抑制率、株防效、鲜质量防效均逐渐升高。施药后7~21 d,BR可以减缓、推迟苯磺隆对藜的作用,但35 d时株防效高于单施苯磺隆。BR与苯磺隆在防除反枝苋中表现出协同作用,提高了苯磺隆对反枝苋的防除效果。150 mL/hm^(2)BR+300 g/hm^(2)苯磺隆、225 mL/hm^(2)BR+300 g/hm^(2)苯磺隆增产效果较高,分别较单施300 g/hm^(2)苯磺隆增产34.61%、8.26%,较对照增产52.41%、22.57%。[结论]BR可延长苯磺隆对藜的防效时间,提高对反枝苋的防除效果,增加谷子产量。