热水处理对丁香疫霉和脐橙的处理效果研究初报

本文研究了热水浸泡处理对丁香疫霉活性和对脐橙品质的影响。结果表明:当热水处理温度≥50℃,处理时间≥1 min时,可完全抑制丁香疫霉菌丝体的生长。50℃热水处理脐橙2 min,脐橙发病率为0%,显著低于对照处理的69%发病率,且对脐橙品质没有影响。研究表明,热水检疫处理在丁香疫霉检疫处理领域具有潜在的应用价值。     

Differential effect of hot water treatment on whole tubers versus cut setts of yam (Dioscorea spp.)

BACKGROUND: The use of thermotherapy or hot water treatment (HWT) is recommended for the management of plant‐parasitic nematodes and other pathogens for a range of planting material, especially vegetatively propagated crops including yams, Dioscorea spp. The sprouting (germination) and consequent viability of yam following HWT, however, appear to be influenced by the post‐treatment method of planting (whole or cut setts) and cultivar. The present study was established to evaluate the sensitivity of the most popular yam cultivars in Benin and Nigeria, West Africa, to HWT at 50–53 °C for 20 min. RESULTS: Sprouting of both setts and whole tubers of most cultivars was affected by HWT. Across experiments, 47% of HWT material, compared with 61% of non‐HWT material, sprouted over 8 weeks. When cut into setts, 41% of HWT or untreated tubers sprouted, compared with 72% of whole tubers. Whole, untreated tubers had highest sprouting rates (84%), and setts following HWT had the lowest (38%). Yam planting material was also not completely free of parasitic nematodes following HWT. The reaction to HWT or cutting was highly cultivar specific. CONCLUSION: Yam cultivars vary in their sensitivity to hot water therapy. Care is therefore advised in selecting yam cultivars for HWT, especially when using cut setts. Copyright © 2009 Society of Chemical Industry     

热水处理对扶桑棉粉蚧的致死作用

本文研究了热水处理对扶桑绵粉蚧的杀灭作用,结果表明,在49℃、50℃、51℃、52℃和53℃时扶桑绵粉蚧1龄若虫死亡率达到100%的处理时间分别为240min、150min、60min、40min和6min。分析显示,热水温度和处理时间长度的复合作用导致了扶桑绵粉蚧的死亡。建立了热水温度(X1)、处理时间(X2)和扶桑棉粉蚧死亡率(Y)之间的模型方程为Y=-9.466+0.192X1-0.0000240X22+0.000218X1X2。给出了不同温度热水处理时扶桑绵粉蚧100%死亡的时间长度。     

应用热水处理技术对进境木瓜作杀虫处理

应用热水处理技术，木瓜在其果心温度升至46℃时浸泡10min，可完全杀死进境木瓜中携带的木瓜实蝇（Bactrocera papayae），该热水杀虫处理条件，经测定对木瓜果实不造成损害。     

Effect of hot water treatment on peach volatile emission and Monilinia fructicola development

The effect of hot water treatment (HWT) to control peach brown rot was investigated. Peaches were dipped in water at 60°C for 60 s and artificially inoculated with Monilinia fructicola conidia. HWT failed to control brown rot if applied before inoculation and microscopic observations revealed a stimulatory effect on germ tube elongation of M. fructicola conidia placed immediately after HWT on the fruit surface, compared to the control. The influence of fruit volatile emission due to HWT was performed on the pathogen conidia exposed to the headspace surrounding peaches. The results showed an increase of M. fructicola conidial germination ranging from 33 to 64% for cultivars Lucie Tardibelle and Red Haven heat‐treated peaches, respectively, compared to the control. The volatile blend emitted from heat‐treated fruit was analysed by solid‐phase microextraction/gas chromatography‐mass spectrometry (SPME/GC‐MS) and proton transfer reaction‐time of flight‐mass spectrometry (PTR‐ToF‐MS). Fifty compounds were detected by SPME/GC‐MS in volatile blends of cv. Lucie Tardibelle peaches and significant differences in volatile emission were observed among heated and control fruit. Using PTR‐ToF‐MS analysis, acetaldehyde and ethanol were detected at levels 15‐ and 28‐fold higher in heated fruit compared to unheated ones, respectively. In vitro assays confirmed the stimulatory effect (60 and 15%) of acetaldehyde (0·6 μL L^?1) and ethanol (0·2 μL L^?1) on M. fructicola conidial germination and mycelial growth, respectively. The results showed that volatile organic compounds (VOCs) emitted from heat‐treated peaches could stimulate M. fructicola conidial germination, increasing brown rot incidence in treated peaches when the inoculation occurs immediately after HWT.     

热水处理对薯蓣红斑病病原——咖啡短体线虫的影响

采用水浴法,对离体咖啡短体线虫、薯蓣块根内咖啡短体线虫以及薯蓣块根在不同温度条件下的敏感性进行测定。结果表明,在47、50、52、55 ℃处理条件下,杀死100%离体咖啡短体线虫的处理时间分别为6、2.5、1.5、1.5 min,而杀死100%薯蓣块根内线虫的处理时间分别为19、15、11、10 min;同时在上述温度下,分别处理35、30、25 min和25 min对薯蓣发芽没有影响。在同一温度处理中,随着处理时间延长,线虫的死亡率增加;而在不同温度处理中,随着温度升高,杀死线虫的时间逐渐缩短。综合上述试验结果,建议生产上防治薯蓣种薯内咖啡短体线虫的处理方法以52～55 ℃处理15～20 min为宜。     

热水处理对3种进口苗木的损伤及抗氧化酶系的影响

为了探明热水浸泡处理对进口南洋参、香龙血树和百合苗木的影响,本试验分别利用45℃60min、48℃10 min、48℃30 min和48℃60 min,4组时间和温度组合对3种进口苗木进行热水浸泡处理,然后测定处理后各供试苗木叶片中丙二醛(MDA)含量,过氧化物酶(POD)活性、过氧化氢酶(CAT)活性和超氧化物歧化酶(SOD)活性。而后对处理后各供试苗木进行复种,3周后观察复种苗木的生长情况。结果表明:3种供试苗木各处理组MDA含量均比对照组有所增加;POD活性仅有南洋参部分处理组比对照组有所增加,南洋参其他处理组以及香龙血树和百合各处理组均比对照组有明显下降;CAT活性南洋参和香龙血树各处理组与对照组之间均差异不显著,百合各处理组均比对照组有所增加;SOD活性百合各处理组相比对照组均出现了明显的下降。经过热水浸泡处理后复种的各供试苗木,南洋参和香龙血树均能够正常生长,百合均死亡。上述研究表明南洋参和香龙血树对热耐受性较高,可利用热水浸泡进行检疫除害处理,百合耐受性较差,不能采用热水浸泡进行检疫除害处理。     

不同灌水处理对小桐子生长及蒸散耗水特性的影响

为了探讨不同灌水处理对小桐子生长及蒸散耗水特性的影响,文中开展了小桐子5个灌水处理(W1:(0-20%)θf,W2:(20-40%)θf,W3:(40-60%)θf,W4:(60-80%)θf,W5:(80-100%)θf)的盆栽试验。结果表明:与高水处理W5相比,水分处理为W1、W2、W3和W4时小桐子的株高、叶干重、叶面积、根系干重和总干重均有不同程度的降低,蒸腾量和蒸散量也相应降低。各种处理下小桐子蒸散量的日变化与环境中气象因子关系密切。W1处理下小桐子水分胁迫严重,不利于其生长;W3处理较W5节约灌溉用水达40%,小桐子生长并没有受到明显影响,而蒸腾量和蒸散量却显著下降,水分利用效率最高,节水效果明显,抗旱性显著提高。     

针叶类木质包装热浸泡处理试验

为摸索木材热浸泡处理方法,分别用56℃、66℃、76℃的恒温水浴浸泡木段,检测其中心温度,当水浴温度76℃,持续处理时间2h时,直径10cm供试松木中心温度能保持56℃以上30min;水浴52℃条件下,供试松材线虫在5min内被100%杀死.     

甘蔗种茎热水处理脱除宿根矮化病菌及其对再生苗的影响

50℃2 h热水处理黑皮果蔗、黄皮果蔗和粤糖93-159双芽段种茎,结果表明:黑皮果蔗全部丧失出苗能力;黄皮果蔗出苗时间延迟,但最终出苗率与对照无差异;而粤糖93-159出苗率和出苗速度均不受影响。两个品种的热处理再生苗生长早期株高和茎径均显著低于对照,但随着生长时间的增加,这种差异逐渐缩小。采用高灵敏度的巢式PCR技术检测再生植株体内的宿根矮化病菌,在再生苗生长前期的120 d内所有经热处理植株均呈阴性,其后部分植株呈阳性,至播种200 d时,黄皮果蔗阳性率为50%,粤糖93-159阳性率为100%。试验还发现,种茎热水处理能增强再生植株中后期抗旱能力。本研究指出,虽然种茎热水处理能减少生长早期再生苗体内宿根矮化病菌含量但难以实现所有种茎完全脱菌,在进行脱菌效果评价时,要对生长中后期的再生苗进行检验;生产上采用该措施防病,要充分考虑不同品种耐热性能的差异。     

于蔗种茎热水处理脱除宿根矮化病菌及其对再生苗的影响

50℃2h热水处理黑皮果蔗、黄皮果蔗和粤糖93-159双芽段种茎，结果表明：黑皮果蔗全部丧失出苗能力；黄皮果蔗出苗时间延迟，但最终出苗率与对照无差异；而粤糖93-159出苗率和出苗速度均不受影响。两个品种的热处理再生苗生长早期株高和茎径均显著低于对照，但随着生长时间的增加，这种差异逐渐缩小。采用高灵敏度的巢式PCR技术检测再生植株体内的宿根矮化病菌，在再生苗生长前期的120d内所有经热处理植株均呈阴性，其后部分植株呈阳性，至播种200d时，黄史果蔗阳性率为50％，粤糖93-159阳性率为100％。试验还发现，种茎热水处理能增强再生植株中后期抗旱能力。本研究指出，虽然种茎热水处理能减少生长早期再生苗体内宿根矮化病菌含量但难以实现所有种茎完全脱菌。在进行脱菌效果评价时，要对生长中后期的再生苗进行检验；生产上采用该措施防病，要充分考虑不同品种耐热性能的差异。     

The selective effect of heat treatment on the microflora of a greenhouse soil

Detailed information about the heat tolerance of soil micro-organisms, both pathogens and their nonpathogenic antagonists, is needed for the practice of soil pasteurization.A device for testing the thermal death point of micro-organisms in soil is described.The selective effect of heat treatment on the total numbers of bacteria, actinomycetes and fungi of a greenhouse soil (loam) was estimated. Of these groups the fungi proved to be the most sensitive to heat treatment. The heat tolerance of the species of this group was examined in more detail. In comparing the thermal death points of fourteen pathogenic fungi with those of the saprophytic fungal flora many species of the latter proved to be more heat-tolerant.Samenvatting In verband met de toenemende belangstelling voor pasteurisatie van kasgrond is een grondige kennis omtrent de afstervingstemperaturen van de bodemorganismen-zowel pathogenen als hun niet-pathogene antagonisten-noodzakelijk. In een voor dit doel geconstrueerd apparaat werd vochtige lucht van verschillende temperaturen door kleine hoeveelheden kasgrond geblazen. Daarna werd de grond geanalyseerd op de overlevende microflora. De schimmels bleken als groep verhitting minder goed te kunnen doorstaan dan de bacteriën en de actinomyceten. Vooral de Oömyceten waren zeer gevoelig. Zeer tolerant waren enkele donkersporige Deuteromyceten en diePenicillium-enAspergillus-soorten, welke een perfecte vorm hebben. De als antagonisten van pathogenen beroemdeTrichoderma-soorten bleken weinig tolerant.De afstervingstemperaturen van veertien pathogene schimmels bleken lager te liggen dan die van veel saprofyten.     

Controlling Rumex obtusifolius by means of hot water

Hot‐water treatment of broad‐leaved dock (Rumex obtusifolius) was developed as an alternative to manual digging out in organic farming. During treatment, the top region of the root was heated so that the plants would die back. The aim of this study was to validate the efficacy of the hot‐water treatment of dock roots. The trials were carried out with a commercially available hot‐water high‐pressure cleaner and a rotating nozzle for water application. The target plant control rate assessed 12 weeks after treatment was set at >80%. The appraisal covered 1330 treated plants of varying size from four sites with three different soil texture classes. Parameters which influenced the control rate were water temperature, amount of water, soil moisture and soil texture. Additional parameters recorded were the amount of fuel oil consumption and working time requirements. A reassessment of the plants 1 year after treatment yielded information concerning the ground cover, the possible germination of new dock plants from buried seeds and the soil structure of the site treated. In order to achieve the target control rate of >80%, it is recommended that the temperature of the water leaving the equipment should exceed 80°C. The amount of water required depends on root size and soil moisture. On average, 131 plants per hour can be treated with no negative effects on regrowth or soil structure. Hot‐water treatment is the first functional control alternative to manual digging out R. obtusifolius for organic farming.     

水分处理对不同专用型小麦籽粒灌浆特征和产量的影响

采用盆栽方法,研究了不同水分处理(田间最大持水量的40%、60%和80%)对不同专用型小麦籽粒灌浆特征和产量的影响。结果表明,在各处理下不同专用型小麦籽粒灌浆过程呈“S”型变化趋势,并用三次多项式对其进行模拟,其中,不同专用型小麦籽粒灌浆特征参数受水分处理影响不同。当水分处理为田间最大持水量的40%时,提高(早)了豫麦34籽粒各项灌浆参数,提高了豫麦49灌浆速率和粒重,提早了最大灌浆速率出现时间,提高了豫麦50灌浆持续期和粒重;60%处理下增加了豫麦49灌浆持续期,提早了豫麦50最大灌浆速率出现时间;80%时增加了豫麦49有效灌浆持续期,提高了豫麦50的灌浆速率。同时,豫麦34和豫麦50粒重与各灌浆参数均呈正相关,但差异均不显著;豫麦49粒重与灌浆持续期呈显著负相关,与平均灌浆速率呈显著正相关。豫麦34产量在60%处理下最高,且差异达显著水平;豫麦49和豫麦50产量在80%处理下最高,且差异分别达显著和极显著水平。     

膨润土改性沥青覆盖地面的水分效应试验

根据盆钵法试验蒸发现象和双环发试验入渗现象,表明原用于建筑业屋面防渗目的的膨润土改性沥青乳剂在土壤表层覆盖后可以剧烈降低土壤水分蒸发和地面水分入渗用于防止蒸发目的的乳剂原液稀释比例不宜小于１：４,用于防止渗透目的的乳剂原液稀释比例可达到１：１０。     

天然抗病毒组合制剂对柿椒病毒病防效试验

经过筛选从苦丁茶、板兰根、酸膜叶蓼、椿叶、摩萝、香菇菌丝体和亚麻油渣中获得几种具抗病毒活性的生物材料。将上述材料抽提物经抗病毒效果及对病毒的作用方式试验,初步明确这些材料具有抗病毒侵染能力。把不同作用点的抗病毒材料经复配得到复配剂G,以烟草花叶病毒为防治对象,田间试验结果证明,复配制剂G可以控制病毒的侵染,对柿椒病毒病防治效果达81.12％,比单独使用各抗病毒材料制剂效果增加16％～58％。     

The effect of soil aggregate size and water content on herbicide concentration in soil water

Suspensions of wettable powders of metribuzin and simazine were sprayed onto samples of two soils of two particle size grades, > 2.5 mm and <0.5 mm. The soils were either air-dry or at a water content of 12%. After either 1 h or 1 week, water was added to give a soil to water ratio of 1:1. Samples of solution were analysed after 1, 24 and 48 h. With metribuzin the intial concentration for both soils after wetting was greater from the >2.5 mm samples than the <0.5 mm samples, following application to dry soil, but by 48 h the differences were negligible. With simazine WRO soil did not show this effect at all and with Kirton soil only small differences were seen. If the soil was wet at the time of application, particle size had no effect except with simazine in Kirton soil. Generally metribuzin concentrations were higher after application to wet than to dry soils for at least 24 h after wetting whereas simazine concentrations were higher from initially dry soils and the differences had virtually disappeared 24 h after wetting. With the WRO soil herbicide concentrations in soil water were higher if the soil was wetted 1 h after spraying than if left for 1 week but the differences rarely persisted for 48 h. No such trend was observed with Kirton soil. It is concluded that the differences observed in these experiments could be responsible for variations in the performance of soil-applied herbicides.     

The effect of potato leafroll virus on the biology of Myzus persicae

Since potato leafroll virus multiplies in the green peach aphid,Myzus persicae, the effect of the virus on the biology of its vector was investigated. Observations were made regarding the longevity and the reproduction rate of viruliferous and non-viruliferous aphids on leafroll-diseased and healthy plants ofPhysalis floridana. The same matters were investigated for both viruliferous and non-viruliferous aphids on seedlings of Chinese cabbage (Brassica pekinensis). It was shown that on leafroll-diseased plants ofP. floridana the aphids produced more progeny than on healthy ones, although the average number of progeny produced per day in both cases was almost the same. On healthy Chinese cabbage seedlings there was no difference in average length of the larval and adult stages, number of progeny per aphid, and number of progeny per day, between viruliferous and non-viruliferous aphids. Evidence was obtained that the virus does not influence the development of its vector. Measurements of oxygen consumption of both viruliferous and non-viruliferous aphids point in the same direction.     

Influence of developmental stage and time of assessment on hot water weed control

Summary The influence of plant developmental stage in hot water weed control was studied on the test weed Sinapis alba in field experiments. The dose was measured as thermal energy in the hot water (kJ m⁻²) and the response as reduction in plant weight. The energy dose for a 90% reduction in plant weight was 340 kJ m⁻² at the two-leaf stage, which is one-third of the energy required for the same reduction at the six-leaf stage. Treatment at an early stage saves energy, increases the driving speed and lowers the costs. Hard surface areas with naturally developed weeds were used to study the required treatment interval and the influence of time of assessment on the reduction in weed cover. The required treatment interval was 25 d on average, which is similar to that of flame weeding. A longer lasting effect requires a higher energy dose. A 50% higher energy dose was needed to obtain a 90% reduction in weed cover that lasted for 15 d instead of 7 d. After 3–4 weeks, hardly any reduction could be recorded because of regrowth of perennial weeds. However, hot water weed control has a potential on urban hard surfaces and railroad embankments, especially where the use of herbicides is restricted.