薏苡黑粉病发生规律与防治研究

薏苡黑粉病是系统性侵染病害,造成薏苡产量下降,米仁质量变劣。病害的初次侵染源来自带菌种子和土壤;孢荷量大、播种期土壤温度低、种子覆土过厚、病害发生重;土壤含水量对病害发生程度的影响作用较小。用25％百理通可湿性粉剂、25％百坦粉剂和50％多菌灵可湿性粉剂拌种,用量为种子重量的0.2—0.3％,防病效果达85.4—100％,对种子发芽和幼苗生长均无药害。     

立克秀拌种防治小麦纹枯病和全蚀病试验研究

１９９６～１９９７年分别在自然病地和土壤混合接菌条件下,应用立克秀６％悬浮种衣剂和２％湿拌剂拌种进行防治小麦纹枯病和小麦全蚀病试验,结果表明：立克秀悬浮种衣剂以１００ｋｇ麦种拌５０ｍＬ、６７ｍＬ,湿拌剂按种子重量０．２％拌种和对照药剂１０％三唑醇可湿性粉剂按种子重量０．４％拌种４个处理防效显著;尤以立克秀悬浮种衣剂６７ｍＬ／１００ｋｇ种子拌种防效最高,对纹枯病平均防效５０．７６％～６４．０３％,对全蚀病平均防效４５．２０％,增产幅度为１６．１３％～２２．１３％。而立克秀悬浮种衣剂较湿拌剂防病保产效果更为突出。立克秀拌种比三唑醇拌种安全性高,对小麦生长和发育无不良影响。     

粉锈宁拌种防治小麦腥黑穗病

1987年10月～1988年6月我们在河南省汲县李元屯进行了粉锈宁拌种防治小麦腥黑穗病试验。供试作物是对黑穗病敏感的豫原二号。药剂是用15％的粉锈宁可湿性粉剂、40％多菌灵胶悬剂。药剂用量用1/10000、2/10000、3/10000、4/10000拌种,多菌灵按种子重量的2/1000(均按有效成分计算)。试验田小区面积为0.3亩,播种量15kg/亩。小区随机排列,重复2次。试验过程中调查,室内发芽率测定、     

混合药剂处理棉种的田间应用

拌种方法,因地域和气候的差异,有所不同。长江流域棉区习惯干拌;黄河流域棉区习惯湿拌。无论干拌还是湿拌,都有种子附着药剂不牢的现象。脱落的药粉到处飞扬,不仅浪费药剂,也污染环境,影响人体健康。试验添加粘着剂甲基纤维素(为药剂重量的1％),有增强药剂粘着性,促进种子早发,提前出苗,减少病原菌侵染。充分发挥药效的作用。     

拌种双防治水稻恶苗病

本站于1986年进行了拌种双防治水稻恶苗病的试验,用40％拌种双可湿粉(南通农药厂),以种子量的0.2％拌稻种。对     

戊唑醇种子处理防治小麦纹枯病

种子处理是控制小麦纹枯病的有效措施,在小麦纹枯病的综合治理技术体系中起着举足轻重的作用。在苏南宜兴和淮北徐州,2％戊唑醇湿拌剂和6％戊唑醇悬剂胺10kg麦种拌药0.3-0.4g有效成分,对小麦的出苗没有显著影响,对根系和冬前分蘖具有促进作用。对小麦纹枯病的控制效果较为理想,表现为冬前效果显著,病析率防效60％－100％,从而有效地抑制了冬前发病高峰。戊唑醇处理区拔节期的病情指仍然极显著地低于对照区,亦显著低于对照药剂纹霉净,侵茎高峰明显推迟,最终的枯白穗防效突出,0.3-0.4g ai/10kg种子拌种的枯白穗防效达到85％以上。由于控病和对小麦生长调控的双重作用,保穗、保产效果明显,最终产量较对照增加10％－15％。     

丙环唑防治小麦全蚀病应用技术的研究

作者通过对11种杀菌剂室内外研究,从中筛选出丙环唑(Propiconazole)防治小麦全蚀病(Gaeumannomyces graminis var. tritici)效果显著;不同剂量试验结果,用25％丙环唑乳油按种重0.1％—0.2％拌种比较经济有效;不同施药方法中,丙环唑按种重0.1％—0.2％拌种或0.1％拌闷种防病效果优于浸种、茎叶喷雾;通过持效期、作用方式和药害试验证明,丙环唑用量低,持效期较长,以保护作用为主,也有一定的治疗作用,在上述用量范围内对小麦安全。大田防治示范结果,用25％丙环唑按种重0.2％拌种,控制白穗效果达90.70％以上,每ha平均增产1194.45kg,保产效果达32.35％,为小麦全蚀病综合防治提供了一项有效措施。     

药剂处理小麦印度腥黑穗病原冬孢子萌发试验初报

小麦印度腥黑穗病 Neovossia indica(Mitra)Mund Kur 是我国尚未发现的危险性病害(1986年订为对外植物检疫对象)。它由种子远距离传播,还可经土传及气传,适应性强,难于防治,是为害麦类的一种危险性病害。自1983年以来,从墨西哥进口的小麦种子试验材料中不断发现小麦印度腥黑穗病菌的冬孢子及菌瘿。1984年墨西哥国际玉米小麦研究中心对麦种进行每公斤用75％五氯硝基苯可湿性粉剂2g、75％萎锈灵可湿性粉剂2.5g、75％福美双可湿性粉剂2g、80％可湿性西维因粉剂1g、代森锰锌5g等5种杀菌剂进行拌种。麦种处理后继续向我国出口。我们从墨西哥经过药剂处理过的小麦种子中,挑出菌瘿进行了冬孢子萌发试验获得成功。     

三唑酮种衣剂在小麦种表的超微分布及抗脱落淋失研究

 应用扫描电镜观察到三唑酮种衣剂(Tri SCF)以具网眼结构的膜状物包被于小麦种子表面,膜状物厚度约4~7.5μm,种表包被率达95%;对照处理三唑酮可湿性粉剂(TriWP)拌种在小麦种表呈点状或片状零散分布,种表被药剂覆盖率低于80%。振荡试验中TriSCF包衣药剂脱落率为2%,显著低于TriWP干拌种(43%)或湿拌种(25%)。放射性同位素示踪检测表明,TriSCF包衣处理的小麦种子在17%含水量砂床上发芽1~7d内,保持种子内的¹⁴C-二唑酮放射性强度显著高于TriWP拌种处理,而然失到砂床上的¹⁴C-三唑酮放射性强度低开Tri WP拌种处理。     

小麦茎基腐病发生影响因素及防控技术

通过比较2017-2019年小麦品种、耕作方式、播期、灌溉次数、不同生育期药剂处理对小麦茎基腐病的影响和控制效果,并提出综合防控技术.结果表明,采用清洁秸秆+深翻或轮作处理,晚播14 d,播前1kg小麦种子用剂量2 mL的27％苯醚·咯·噻虫嗪悬浮种衣剂拌种,并在在越冬前+返青期分别选用70％甲基硫菌灵可湿性粉剂或20...     

哈茨木霉拌种对冬小麦生长、土传病害及根际真菌群落的影响

为了明确哈茨木霉LTR-2拌种处理冬小麦的田间效果,为木霉拌种剂的推广应用提供依据,本试验从2016年－2018年连续3年,研究了哈茨木霉LTR-2拌种对小麦出苗率、幼苗生长、小麦纹枯病和茎基腐病发生情况和产量的影响,通过高通量测序和FUNGuild预测分析了木霉拌种对小麦根际土壤中真菌群落组成的影响。结果表明,哈茨木霉LTR-2拌种可以提高小麦的出苗率和冬前分蘖数;对小麦纹枯病的平均防效60%以上;对小麦茎基腐病的平均防效65%以上,优于6%戊唑醇悬浮种衣剂;与不拌种对照相比,哈茨木霉LTR-2拌种处理增产4.3%~6.34%,增产效果略高于6%戊唑醇悬浮种衣剂;木霉拌种可以降低小麦根际土壤中病原真菌的相对丰度,特别是土壤中镰孢属真菌的相对丰度。因此,哈茨木霉LTR-2可以作为化学拌种剂的绿色替代产品用于小麦生产。     

Assessment of the loose smut fungi (Ustilago nuda and U. tritici) in tissues of barley and wheat by fluorescence microscopy and real-time PCR

Loose smut fungi of barley and wheat (Ustilago nuda and U. tritici, respectively) colonize the plant without causing obvious disease symptoms before heading. The availability of diagnostic methods to detect and follow the growth of these pathogens in the plant would therefore be highly advantageous for both resistance breeding and the development of effective seed treatments. Using seed lots of barley and wheat highly infected with loose smut, we studied the early establishment of the loose smut pathogens in the plant by fluorescence microscopy. In hand-cut sections stained with the fluorochrome Blankophor?, fungal hyphae were observed to invade the shoot apical meristem and leaf primordia during the first days after the onset of germination. At the first node stage the ear and leaf primordia were generally extensively colonized. Hyphae of U. nuda were also regularly observed in high density in the nodes. A protocol was developed for the specific amplification of U. nuda and U. tritici DNA extracted from infected plant tissue. PCR screening of U nuda in seedlings from infected and healthy seed lots was compared to ELISA, microscopy and ultimately head infection of mature plants derived from tillers of the tested seedlings. The results indicated that a prediction of loose smut infection by real-time PCR is possible at the second leaf stage, and that the assay is equally suited for use with spring and winter varieties of barley and wheat.     

Influence of after-ripening environments on the germination characteristics and seed fate of Italian ryegrass (Lolium multiflorum)

Italian ryegrass ( Lolium multiflorum Lam.) is an exotic winter annual weed that recently has seriously infested wheat fields in central Japan. To understand the influence of tillage systems on the germination ecology and seedbank dynamics of naturalized Italian ryegrass, we compared the fate of the seeds that were after-ripened in the soil with that of the seeds on the soil surface, and then examined the germination characteristics of the seeds retrieved from both treatments by germination tests in both a light/dark (12 h photoperiod) condition and in constant darkness. The seedling emergence was greater initially for the seeds after-ripened on the soil surface than for the seeds in the soil. The component of emergent seeds after-ripened on the soil surface increased as time passed during the summer, whereas that of emergent seeds in the soil scarcely increased. This contrasting emergence was, in part, attributable to the ability of the seeds to germinate at higher temperatures in the light/dark condition than in constant darkness. These results suggest that untilled systems, which leave many seeds on the soil surface, might promote the rapid depletion of Italian ryegrass seeds through germination before wheat sowing in early winter. In contrast, seed burial by tillage might inhibit the germination of the seeds and form a large transient seed bank available to germinate during the wheat-growing season.     

Effect of burial depth and soil water regime on the fate of Lithospermum arvense seeds in relation to burial time

Lithospermum arvense is an increasing annual weed in winter crops of the semiarid region of southern Argentina under low impact tillage systems, an agricultural practice that has become popular in recent years. Seed distribution in the soil profile under conventional tillage will change when reduced tillage is implemented, thus affecting the germination microenvironment. The effect of seed burial depth and soil water regime on field germination, enforced dormancy, innate dormancy and seed decay was studied in relation to burial time in a field experiment. In addition, the effect of burial depth on seed germination and seedling emergence was examined under laboratory controlled conditions. Field germination of buried seed ranged from 55% to 65% for shallow (2 cm) and from 5% to 30% for greater depths (20 cm). Enforced dormancy levels were significantly higher among deeper seeds. The amount of innate dormant seeds was reduced to <10% after a year of burial. Lithospermum arvense seedbanks can be classified as short-term persistent. Germination in the laboratory was unaffected by burial depth, while seedling emergence reduction was adequately described by a sigmoidal model. Results indicate that agricultural practices that accumulate L. arvense seeds near the soil surface enhance seedling recruitment.     

The Relationship Between Wheat Seed Weight, Infection by Fusarium culmorum or Microdochium nivale, Germination and Seedling Disease

The distribution of seeds by weight for three lots of winter wheat cv. Avalon infected by Fusarium culmorum and three lots of winter wheat cv. Riband infected by Microdochium nivale was determined. The distribution of infected seeds within each seed lot was then determined by isolating F. culmorum from seeds on moist filter paper and M. nivale from seeds on potato dextrose agar. The distribution of M. nivale infected seeds between seeds of different weight was similar to that of the seed lot as a whole, whereas the distribution of F. culmorum was greater in light seeds than heavy seeds. The percentage germination of infected seeds decreased with seed weight. A similar situation was found with respect to seedling emergence in compost for F. culmorum infected seeds. However, with M. nivale infection, similar numbers of seedlings emerged from both light and heavy infected seeds. Seed treatment with guazatine increased seedling emergence for both light and heavy seed infected by M. nivale. However, seedling emergence from F. culmorum infected seed was poor even following treatment with guazatine. Poor emergence was most evident from light seed.     

Phalaris minor seedbank studies: longevity, seedling emergence and seed production as affected by tillage regime

Studies were conducted to investigate seed longevity, seedling emergence and seed production of the weed Phalaris minor in wheat in northern India. The longevity of P. minor seeds buried in bags in the field was often limited to less than 1 year, although many seeds buried at 30 cm depth in a rice–wheat rotation remained viable for longer. The application of direct seeding in wheat reduced the seedling emergence rate of P. minor , when compared with conventional ploughing and sowing. However, a larger P. minor seedbank in the upper soil layer in plots under direct seeding partly reversed this positive effect in one of the two studies. Besides differences in relative distribution of weed seeds through the soil profile, it was likely that other factors such as reduced soil disturbance and soil characteristics associated with the application of direct seeding were also involved in regulating the emergence rate. Mature P. minor plants in wheat were found to invest a stable part (27%) of their aboveground biomass in seed, so that total seed weight was strongly linearly correlated with the aboveground biomass of the mother plant. Individual seed weight, however, was little affected by the weight of the mother plant.     

Seed-borne Pathogens on Wheat (Particularly Smuts) in Turkey1

The important seed-borne diseases of wheat in Turkey are common bunt ( Tilletia caries and T. foetida ), loose smut ( Ustilago nuda tritici ), dwarf bunt ( T. contraversa ) and flag smut ( Urocystis tritici ). Seed treatment against common bunt is widely used in Turkey. The damage is about 10–15 %, sometimes 90 % in some fields where seeds are sown without treatment. About 10 % of wheat fields were infected with bunt during 1972–1974. Seed treatment with carboxin (Vitavax) is recommended against loose smut of wheat in Turkey, but has not yet been used. Some wheat varieties, especially Siirak (1593/51) wheat, are highly susceptible to loose smut. The proportion of smut-infected heads reached 30–40 % in this variety and about 32 % of wheat fields were infected with loose smut during 1972–1974. The damage was about 6 % in infected fields. Yield losses were at least 35,000 tons. Dwarf bunt is distributed at high altitude (1300–2000 m) in eastern Turkey; 2500 ha of wheat fields are infected with dwarf bunt. The disease causes 1–80 % losses in some fields. The wheat variety Yayla 305 is recommended for infected areas. Flag smut is present in some areas of Turkey, but yield losses are not important. Seed treatment is effective against seed-borne spores.     

鹅观草种子萌发及出苗特性

在实验室和温室条件下研究不同温度、光照、水势、盐分对鹅观草种子萌发以及埋土深度对鹅观草出苗的影响。结果表明,鹅观草种子萌发的昼/夜温度范围为20℃/10℃~35℃/25℃,最适昼/夜温度为25℃/15℃;黑暗条件下,鹅观草种子萌发率较光照下略有提高,说明鹅观草萌发不需要光照;鹅观草种子对水势胁迫较敏感,水势从0下降至-0.8 MPa时,发芽率从93%直线下降至0;鹅观草种子对盐分胁迫具有一定耐受性,当NaCl浓度≤50 mmol/L时,种子均能保持80%以上的萌发率。50%萌发抑制率时的水势和NaCl浓度分别约为-0.4 MPa和100 mmol/L。埋土深度为0.5 cm时,鹅观草出苗率最高,埋土深度≥3 cm时出苗率显著下降。表明鹅观草种子萌发具有较强的环境适应性,通过耕作将其种子带入4 cm以下土层,可有效抑制鹅观草的危害。     

不同贮藏条件下龙葵种子的季节性休眠特性

龙葵是农田恶性杂草?为明确龙葵种子休眠与季节温度的关系, 研究了室内和室外不同贮藏条件下其种子萌发对温度的响应规律?结果表明, 室外贮藏条件下的龙葵种子萌发呈季节性变化, 从10月到翌年5月, 龙葵种子萌发率均在95%以上, 随着夏季温度的升高, 萌发率从6月开始下降, 9月达到最低值(25.4%), 由此进行年际间休眠和非休眠周期的循环?夏季6月-9月的高温可诱导龙葵种子进入休眠状态, 而秋冬季的相对低温有利于解除种子休眠, 使种子恢复萌发状态?龙葵种子休眠和非休眠状态之间的切换受季节性温度变化的影响?室内贮藏的种子, 由于环境温度较为稳定, 其萌发率年际变化较小, 在20%~50%之间?本文明确了龙葵种子休眠的周期性变化规律, 有助于精准预测其出苗时间, 研究结果可为阐明龙葵种子休眠萌发机制和制订基于萌发调控的绿色防控策略提供依据?