Weed seedling emergence in contrasting fodder crop systems following 30 years of cultivation in the lowlands of Northern Italy

Five fodder crop systems of different intensity (ranging from a double annual crop of Italian ryegrass + silage maize to a permanent meadow) were adopted for 30 years in the lowlands of Northern Italy under two input levels, differing mainly in their provision of organic fertiliser (manure). Herbicides were used in the maize crops included in all systems, except the meadow. After 30 years, the weed seedbank of all systems and input levels were assessed by the seedling emergence technique on soil samples from each plot. The cropping systems determined the abundance and composition of the weed assembly. Relatively few, frequent species made up the majority of the emerged seedlings in all systems, and there was no relationship between the total number of emerged seedlings and the mean number of species recorded in the different systems. Arabidopsis thaliana and Oxalis corniculata were abundant in the annual double crop and in the 3- and 6-year rotations that also comprised the annual double crop. These weeds, however, were unlikely to represent a major threat to the crops, due to their vigour and growth period. The permanent meadow tended to greater weed biodiversity than the other systems. The application of manure favoured the seedbank of species such as Lolium multiflorum, Digitaria sanguinalis and A. thaliana. Weed communities in the different systems were mainly determined by herbicide application, (through the ability of weeds to avoid its effects, determined by the weed life history and emergence period) and manure application (with its possible dual effect of spreading weed seeds and favouring nitrogen-responsive weeds).     

植保无人机在江苏农垦稻麦病虫草害防治中的应用及展望

植保无人机作为一种新型施药工具,以作业高效安全、节水省药环保等特点于近几年迅速发展,并已广泛应用于农作物病虫草害防治。本综述重点对我国植保无人机的施药发展现状、近年来江苏农垦植保无人机的应用情况和植保无人机应用过程中存在的问题进行阐述,并对植保无人机应用的未来发展趋势进行展望。     

Interactions between rodents and weeds in a lowland rice agro‐ecosystem: the need for an integrated approach to management

Rodents and weeds are important pests to rice crops in Southeast Asia. The interaction between these 2 major pests is poorly documented. In temperate cereal systems, seeds of grass weeds can be an important food source for rodents and weed cover along crop margins provides important refuge for rodents. In 2012 and 2013, a replicated study (n = 4) in Bago, Myanmar compared 4 treatments (rodents and weeds; no rodents and weeds; rodents and no weeds; no rodents and no weeds) each of 0.25 ha in transplanted rice. Weeds were managed with hand weeding in the wet season, and hand weeding and herbicides in the dry season. Plastic fences were installed to exclude rodents. We examined the weed cover and relative abundance of weed species, rodent damage, rodent population dynamics and rice yield loss caused by rodents and weeds. The dominant rodent species was Bandicota bengalensis. In the dry season, Cyperus difformis was dominant at the tillering stage and Echinochloa crus‐galli was the dominant weed species at the booting stage. In the wet season E. crus‐galli was a dominant weed throughout the season. Damage by rodents was higher in the dry season. There were larger economic benefits for best weed management and effective rodent control in the dry season (258 US$/ha) than in the wet season (30 US$/ha). Concurrent control of weeds in and around rice fields combined with coordinated community trapping of rodents during the early tillering stage and ripening stage of rice are recommended management options.     

天祝天然草地3种有毒植物提取物对粘虫的生物活性

测定了3种有毒植物露蕊乌头,铁棒槌和马先蒿的4种溶剂的提取物对粘虫的杀虫活性。结果表明：露蕊乌头甲醇、乙醇提取物对粘虫均具有一定的触杀活性,LC50分别为3．63、5．79g／L;露蕊乌头甲醇提取物,马先蒿丙酮提取物和铁棒槌甲醇提取物对粘虫的胃毒活性表现较强,杀虫活性LC50分别为2．13,2．82和3．22g／L,马先蒿和铁棒槌的石油醚提取物对粘虫无胃毒活性。3种植物的4种溶剂的提取物对粘虫均表现出一定的拒食活性,其中甲醇提取物的拒食活性都较高,露蕊乌头甲醇提取物对粘虫的拒食活性明显高于其他提取物,当质量浓度达到0．2g／mL时,拒食率为97．6％。而3种植物石油醚提取物的拒食活性均较差。     

陇东子午岭天然草地野生有毒植物调查

经调查统计,陇东子午岭天然草地中野生有毒植物有65科127属171种.就陇东子午岭天然草地上对家畜有毒的植物种类分布及有毒成分等方面进行了调查,并提出了防治措施.     

Evaluating the accuracy of mapping weeds in seedling crops using airborne digital imaging: Avena spp. in seedling triticale

Airborne multispectral imaging has been used to map patches of Avena spp. (wild-oats) in a field of seedling triticale (X Triticosecale , Wittmack). Images of the target field were acquired using a four-camera airborne digital imaging system, recording in the infrared, red, green and blue wave-bands. Spectral information derived from images of 0.5-, 1.0-, 1.5- and 2.0-m spatial resolution were correlated with detailed on-ground weed density measurements to investigate the effect of image resolution on mapping accuracy. Comparisons between normalized-difference vegetation index (NDVI) or soil-adjusted vegetation index (SAVI) images and weed data achieved correlations of up to 71%. The highest correlation was achieved with the 0.5-m-resolution images and the lowest with the 2.0-m-resolution images. At 0.5-m resolution, NDVI images could not reliably discriminate weed populations of less than 28 weeds m^–2 from weed-free regions, while SAVI images could not discriminate populations of less than 17 weeds m^–2. At 1.0-, 1.5- and 2.0-m resolution, SAVI images could not discriminate populations of less than 23 weeds m^–2, while NDVI images again demonstrated a higher discrimination threshold. Results suggest that airborne multispectral imaging could be used as part of a stratified weed sampling system.     

南京地区草坪主要杂草初步调查

经过近３年时间的调查,观测和鉴定,发现南京地区草坪的主要杂草有２３科５３属５４种 ,其中,夏,秋季危害草坪的主要杂草有马唐,牛筋草,画眉草,狗尾草,白茅,双穗雀,李氏禾,三叶草,空心莲子草等;冬,春季危害草坪的主要杂草有泥胡菜,猪殃殃,雪见草,附地菜,蘩蒌,稻槎菜,看麦娘,粘毛卷耳,大巢菜,婆婆纳等,不同建植年限和管理水平下的草坪杂草分布特点不同。     

复方三氮唑核苷注射液对大白鼠的亚慢性毒性试验

将复方三氮唑核苷主射液按高,中,低剂量分别给大白鼠皮下注射,每天１次,连续注射３０ｄ,观察试验鼠的生理状态及活动情况测定增重及血液生理生化指标,并进行病理解剖及病理组织学检查。结果表明,复方三氮唑核苷注射液对大白鼠的生理活动血液生理生化指标均无不良影响;病理组织学检查,仅高剂量组有１０％大白鼠发生肾小管上皮细胞轻度颗粒变性,其它组各器官均未见异常。     

30%苄嘧·丙草胺乳油等量施药的次数及时间对稻田除草效果的影响

为探索如何提高稻田除草剂使用效率, 实现除草剂减量使用, 本试验以30%苄嘧·丙草胺乳油为供试药剂, 以‘甬优1540’为供试水稻, 保持除草剂总量一致的前提下, 利用大田试验和温室盆栽试验, 通过设置插秧前?插秧时?插秧后单次施用100%推荐剂量, 插秧前和插秧后各施用50%推荐剂量, 插秧前及苗期各施用50%推荐剂量, 以及不施用除草剂的6种处理, 研究不同施药次数及施药时间对稻田禾本科?阔叶类?莎草科三类杂草及其总草防除效果的影响?温室盆栽试验表明, 与其他处理相比, 采用30%苄嘧·丙草胺乳油于移秧后3 d施药50%推荐剂量及苗期再施50%推荐剂量的处理, 可使水稻移栽后24 d时的稗草?千金子和耳叶水苋发生量明显少于其他施药方式, 说明该施药方式对稻田杂草具有明显的抑制作用; 此外, 大田试验表明, 采用上述同样的施药方式, 可使水稻在移栽后36 d时的分蘖在各处理中达到最大量, 为16.90万/667m2, 且杂草总发生量最少, 为17.00株/m2, 杂草株防效最高, 为84.17%?本研究表明, 30%苄嘧·丙草胺乳油在移秧后3 d施用50%推荐剂量, 及苗期再施50%推荐剂量, 对稻田杂草防除效果较好?