Integrated pest management in a cotton-growing area in the Southern Rift Valley region of Ethiopia: development and application of a supplementary food spray product to manage pests and beneficial insects

Cotton crop Ethiopia is a high-value crop and the strategy for pest control is insecticide-dependent with no consideration of beneficial insects. We carried out a study in 2013 and 2014 to determine the effectiveness of a food spray product developed with local ingredients from Benin (BFP), a food spray product developed from Ethiopian ingredients (EFP), and mixtures of the individual food spray products with and without neem extracts. Applications of BFP and of EFP alone attracted and retained beneficial insects and significantly reduced the number of pests, and increased cotton yields and profitability. The net margins of 18,418 and 18,642 Ethiopian birr (ETB)/ha were achieved from the plots treated with BFP and EFP, respectively, and 13,000 ETB (US$1 = 19 ETB) was achieved from the unsprayed plots. Addition of neem extract to the food spray products decreased the number of beneficial insects attracted to the food spray plots. In conclusion, food sprays can be used as part of integrated pest management (IPM) for managing cotton pests and can result in significant increases in crop yields and profitability.     

基于光电传感器的精密播种机排种性能监测系统的研究

【目的】针对玉米、大豆等作物单粒精密播种过程中出现的漏播、重播以及播种量不精准的问题,设计一种基于光电法的单粒精密播种机排种性能监测系统。【方法】采用红外检测装置获取种子下落时的脉冲信号,脉冲信号经单片机处理后统计种子下落时间间隔,并与设定理论时间间隔相比较,计算漏播率、重播率及播种量。以垂直勺轮式排种器为对象,对监测系统进行单粒漏播、重播及播种量监测试验。【结果】该监测系统的单粒监测精度达到98.8%;与排种器性能检测试验台架检测结果相比,监测系统的漏播率监测误差小于0.3%,重播率监测误差小于0.6%;播种量监测精度大于94.4%。【结论】此监测系统工作稳定,监测精度较高。     

航空喷施与人工喷施方式对水稻施药效果比较

【目的】找出小型无人直升机航空喷施雾滴在水稻植株的沉积分布规律,并比较农用无人机航空喷施方式和人工喷施方式的不同。【方法】通过喷施试验研究了市场上主流的2种不同型号无人机(油动单旋翼和电动单旋翼小型无人直升机)、不同作业参数对水稻冠层雾滴沉积分布结果的影响,并比较了不同农用无人机航空喷施方式和人工喷施方式的效果和效率。【结果】航空喷施方式下的作业参数对雾滴沉积量和穿透性均有着相同的影响趋势,均表现出作业速度越慢,雾滴在植株间的沉积量越多,穿透性越好;作业高度越低,沉积量越多,但穿透性较差。但由于不同类型无人机旋翼风场强度的不同,油动单旋翼小型无人直升机喷施作业时作业高度对雾滴的沉积均匀性影响明显,而电动单旋翼小型无人直升机喷施作业时作业速度对雾滴的沉积均匀性影响明显。人工喷施作业的雾滴在水稻植株上、中、下3层的沉积均匀性最差,且雾滴在水稻植株间的穿透性也最差,为110.42%,人工喷施雾滴大部分都沉积在植株上层,只有3.27%的药液量到达植株的底部,而航空喷施作业有10%~30%的药液量能到达植株的底部。【结论】从不同喷施作业方式的效果和效益来看,航空喷施雾滴沉积效果优于人工喷施雾滴沉积效果,作业效率约为人工喷施方式的10倍,且成本低,效益高。     

不同播量对机播免间定苗棉花成铃以及产量和品质的影响

采用常规抗虫棉花品种中571,在郑州市黄河滩区一年一熟、地膜覆盖的栽培条件下,设计小播量(6.75kg·hm~(-2))、中播量(9.00 kg·hm~(-2))、大播量(11.25 kg·hm~(-2))3个免间定苗处理,以常规播量(22.5 kg·hm~(-2))间定苗为对照,研究了不同播量对机播免间定苗棉花成铃及产量和品质的影响。结果表明,大播量免间定苗处理的子棉和皮棉产量最高,子棉产量和皮棉产量分别比对照增加5.10%和4.93%。但3个播量机播免间定苗处理与对照的子棉和皮棉产量差异均不显著,而小播量免间定苗比大播量免间定苗处理的子棉显著减产。免间定苗处理对棉花纤维品质无不良影响。大播量免间定苗处理增产的主要原因是总成铃数显著增加,而铃重和衣分差异不显著。且大播量免间定苗处理成铃时空分布更加合理,有利于集中成铃和早熟。在本试验条件下,加大播量可以弥补免间定苗形成的株距分布不均,中571采用11.25 kg·hm~(-2)的播量免间定苗较为适宜,播量低至6.75 kg·hm~(-2)时造成棉花减产。     

油菜气力滚花滚筒式精量集排器充种性能仿真分析与试验

为提高油菜气力滚筒式精量集排器的充种性能,设计1种滚花排种滚筒,确定了滚花排种滚筒的结构参数,构建了充种区强制带动层种子的力学模型。EDEM仿真分析滚花结构、排种滚筒转速和充填高度对种群充填角、拖带角和动力学特性的影响。结果表明:滚花排种滚筒拖带角随排种滚筒转速增大而增大,且大于无滚花排种滚筒;种群充填角随排种滚筒与种群间的摩擦力增加而增加。同时,随排种滚筒转速的增加,种群所受合力、法向力和切向力以及种群速度线性增加;随充填高度的增加,种群所受合力和种群速度线性增加,且排种滚筒转速或充填高度一定时,滚花排种滚筒的种群动力学特性优于无滚花排种滚筒。台架试验表明:当排种器负压为-2 500Pa、正压为500Pa、充填高度为-5mm、排种滚筒转速为30r/min时,合格指数90.10%,漏播指数1.56%;当排种滚筒转速在15~50r/min范围内时,各行排量一致性变异系数和总排量稳定性变异系数分别低于5.5%和2.0%,种子破损率低于0.2%。田间试验结果表明,以滚花排种滚筒为关键部件的集排器能满足油菜播种机技术要求。     

Tomato growth responses to foliar application of ammonium sulfate in hydroponic culture

This study was done to evaluate the growth responses of tomato plants (Lycopersicon esculentum Mill.) to foliar application of ammonium sulfate in different concentrations of 0, 50, 100, or 200 mM once per week, as well as 50 mM in every other day under greenhouse and hydroponic culture system. The results showed that foliar application of ammonium restricted the plant height, yield, and vitamin C content of fruits, but it increased the chlorophyll content in treated plants. The highest and the lowest yield were obtained from zero (control) and 200 mM treated plants, respectively. Fruit hardness was not affected by treatments, while blossom end rot disorder was increased by higher concentrations of ammonium sulfate. In general, the result indicated that tomato plant is rather sensitive to foliar application of ammonium sulfate particularly to higher concentrations and application numbers.     

森林质量精准提升综述

精准提升森林质量,不仅能使管理精细化、技术精细化,而且可以高效、省时、省力,实现森林的多种功能和效益的最大化,满足人类的生态需求,促进经济和社会发展.本文通过阐述森林质量的概念和内涵,介绍了现存的森林质量评价指标和体系,分析了我国现今森林质量低下的问题和提升森林质量的难题,并综述了前人提出的提升森林质量的―精准‖方式和建议,提出森林质量提升的实现需要从―管理‖加―技术‖这两大模块分别进行强化和实施,在细化―管理‖加―技术‖的情况下,精准提升森林质量.本研究提出森林质量可理解为:各种林分内的森林资源不仅存在和谐、有序、稳定的生态系统,而且尽可能最大限度地满足人类有形与无形的需求,持续使生态、经济和社会效能最大化.在提升森林质量方法上,本研究提出:要精准提升森林质量,首先要构建一整套系统的完善的评价指标体系,而后从―管理‖和―技术‖这两大模块出发,进行细化研究来提升森林质量,指出管理上从国家和企业层面分析,寻求能促进森林质量精准提升的方法,技术上可从育种、培育、高科技应用等方面精准提升森林质量.     

Producing nitrogen (N) uptake maps in winter wheat by combining proximal crop measurements with Sentinel-2 and DMC satellite images in a decision support system for farmers

Responsive fertilisation of winter wheat (Triticum aestivum L.) is often adopted, with N applied two or three times between the developmental stages of tillering and booting. Satellite-based decision support systems (DSS) providing vegetation index maps calculated from satellite data are available to aid farmers in adjusting the topdressing nitrogen (N) rate site-specifically to the current season and to variations in growth conditions within the field. One example is the freely available CropSAT DSS used in Scandinavia, which provides farmers with raster maps of the modified soil-adjusted vegetation index (MSAVI2) calculated mainly from data obtained from satellites Sentinel-2 (ESA, EU) and DMC (DMCii Ltd, Guildford, UK). This study investigated the possibility of calibrating MSAVI2 maps with data from handheld proximal sensor measurements of N uptake covering the main agricultural regions in Sweden during growth stages Z30-45 on the Zadok scale, in order to facilitate farmers’ decisions on N rate. More than 200 N-sensor measurements acquired during 2015 and 2016 in seven different winter wheat cultivars were combined with MSAVI2 values from CropSAT. It was found that N uptake could be predicted in a general, national model, i.e. for sites and dates other than those for which the calibration model was parameterised, with a mean absolute error of 11–15?kg?N?ha^?1. A cultivar-specific model performed better than this general model, but a regional model showed no improvement compared with the model parameterised with national data. Vegetation indices calculated from the two narrow bands of Sentinel-2 in the red edge-near infrared region of the crop canopy reflectance spectrum proved to be promising alternatives to the broadband index MSAVI2. Based on the results, we suggest that data from a monitoring programme involving handheld N sensor measurements can be integrated with a satellite-based DSS to upscale N uptake information.     

免耕播种机播种质量红外监测系统设计与试验

为了对播种机播种质量进行监测,实现精量播种,该文采用红外检测技术,设计了一种对射式传感器,研制了配套播种质量监测系统,并进行了田间播种作业试验研究。该监测系统由多路传感器、监控终端、播种传动传感器组成,结构合理,安装方便,对播种过程出现的堵塞、漏播、缺种等现象,可发出声光报警信号,及时指示故障的位置。田间试验中监测数据与实际测量对比结果表明:该监测系统能够适应田间工作环境,播种质量监测准确率可达95%以上,能够解决人工难以实时监测播种质量的问题,可避免漏播断条现象发生,提高播种机的工作效率和播种质量。     

不同植保机械喷雾雾滴沉积分布对小麦病害的防治效果

通过比较自走式喷杆喷雾机、无人植保飞行器、背负式弥雾机3种植保机械喷雾在小麦上的农药雾滴沉积分布,分析其对小麦病害防治效果的影响。结果表明,自走式喷杆喷雾机雾滴沉积密度和雾滴覆盖率都较高,是植保飞行器的8~10倍,自走式喷杆喷雾机雾滴沉积密度为136.19~167.53个/cm~2,雾滴覆盖率为12.96%~28.13%,雾滴覆盖率上部与中部高于下部叶片。对小麦病害防治效果较好,小麦纹枯病病指防效达61.60%,赤霉病防效达71.43%,白粉病防效达78.02%。植保飞行器喷雾在小麦上、中、下部位的雾滴沉积密度分别为14.28、13.15、18.42个/cm~2,雾滴覆盖率分别为2.45%、2.08%、1.46%,植保飞行器喷雾在小麦上、中、下部雾滴分布均匀。植保飞行器喷雾对小麦病害防效较好,纹枯病病指防效达63.26%~75.20%,赤霉病病指防效达85.71%,白粉病病指防效达70.33%。背负式弥雾机喷雾在小麦上的雾滴沉积密度为81.21~147.12个/cm~2,雾滴覆盖率为7.26%~28.76%,总体表现为上部中部下部,且差异性显著。