Effects of soil solarization on nematodes in Croatia

For the first time soil solarization was investigated in Croatia both in the field and in the greenhouse in 1991, 1992, 1993 and 1994. For two months (July and August), the soil was mulched with transparent polyethylene (PE) sheets of 0.015 or 0.050mm thickness. Soil temperatures at depths of 5, 10 and 20cm were recorded daily. In order to assess nematode population densities, soil samples were analysed before mulching and at the end of the mulching treatment. The results of these experiments showed that soil solarization drastically reduced the population of plant-parasitic nematodes (Meloidogyne, Pratylenchus, Paratylenchus, Tylenchus, Tylenchorhynchus spp.) by about 97–100% at a depth of 10cm and 92–97% at a depth of 20cm in the field, while in the greenhouse, the population of plant-parasitic nematodes was reduced by about 89–100% at a depth of 10cm and 98–100% at a depth of 20cm.In the same experiments, the population of saprophytic nematodes in the field was reduced by about 86–90% at a depth of 10cm and 72–89% at a depth of 20cm. In the greenhouse, the population of saprophytic nematodes was reduced by about 87–97% at a depth of 10cm and 87–93% at a depth of 20cm. This data shows that soil solarization was less effective in the control of saprophytic nematodes, which is considered to be an advantage.     

不同土壤填加剂及高温闷棚对防治根结线虫病的影响

为明确不同土壤添加剂及高温闷棚技术对防治根结线虫病的影响,2011年在甘肃省白银市进行了试验.结果表明,土壤覆膜+麦草+鸡粪处理5 cm土温显著高于对照约6℃,5 cm土层温度大于40、50℃和60℃的时间分别达18、8和5h,而对照大于40℃持续时间只有9h,且最高温度不超过50℃.从防治效果看,土壤添加麦草、碳酸氢铵、阿维菌素、石灰氮、噻唑膦、阿维·毒死蜱、甘蓝叶和鸡粪等后第一茬防效达100％,第二茬覆膜+麦草+鸡粪也达100％,防效显著,可以在生产中推广应用.     

不同土壤填加剂及高温闷棚对防治根结线虫病的影响

本文比较了室内和田间4种栽培模式:温室大棚、简易大棚+小拱棚、小拱棚、露地条件下黄板、糖醋酒液和清水3种方法对韭菜迟眼蕈蚊成虫的诱集效果,并研究了黄板尺寸、高度、方向对引诱效果的影响.室内试验结果表明,黄板的诱虫效果最好且持效期长,其次是糖醋酒液,清水最差.其中黄板水平放置的诱虫效果好于竖直放置.田间试验结果和室内结果一致,黄板尺寸、高度和数量对引诱效果具有一定的影响,其中390 cm2的黄板诱集效果优于其他尺寸,黄板平放于地面时的诱集效果好于离地面10 cm和20 cm的诱集效果.利用黄板诱杀后对下一代幼虫发生无影响,因此黄板可用于田间监测,不推荐用于防治.     

Effect of soil solarization on weeds and nematodes under tropical Indian conditions

The control of weeds and nematodes by solar heating of the soil using transparent polyethylene (PE) sheets was studied in the field during the summer of 1990. PE mulching for 32 days decreased the emergence from seed of the dominant weeds Dactyloctenium aegyptium (L.) P. Beauv., Acrachne racemosa (Roem. & Schult.) Ohwi, Trianthema monogyna L. and Cyperus rotundus L. by over 90%. Emergence of C. rotundus from tubers was increased by the mulching treatments. Mulching for 16 days also decreased weed emergence but to a lesser extent than the 32-day treatment. The main solarization effect was restricted to the 0–5 cm layer of soil. Solarization reduced the population of plant-parasitic nematodes (Tylenchus, Heterodera, Xiphinema, Hoplolaimus, Pratylenchus and Ro-tylenchus spp.) by about 90% and of saprophytic nematodes by about 60% but, after 70 days, the nematode levels had largely recovered. The mean maximum soil temperatures recorded at 5 cm were higher when mulching followed irrigation. Data are given on the soil temperatures recorded over the 32-day period. The growth of soybean was improved and seed yield increased by up to 78% following solarization. Effet de la solarisation du sol sur les mauvaises herbes et les nematodes en conditions tropicales indiennes La lutte contre les mauvaises herbes et les nématodes par solarisation du sol à l'aide de films de polyéthylène transparent (PE) a étéétudiée au champ pendant l'été 1990. Trente deux jours de solarisation diminuaient de plus de 90% la levée à partir de graines des mauvaises herbes dominantes Dactyloctenium aegyptium (L.) P. Beauv., Acrachne racemosa (Roem. & Schult.) Ohwi, Trianthema monogyna L. et Cyperus rotundus L. La levée de C. rotundusà partir de tubercules était accrue par la solarisation. Seize jours de solarisation diminuaient aussi la levée des mauvaises herbes, mais dans un moindre mesure. L'effet de solarisation s'exerçait principalement dans les 5 centimètres superficiels du sol. La solarisation réduisait d'environ 90% la population de nématodes parasites des plantes (Tylenchus, Heterodera, Xiphinema, Hoplolaimus, Pratylenchus et Rotylenchus spp.) et d'environ 60% la population des nématodes saprophytes. Après 70 jours, les populations de nematodes étaient pratiquement reconstituées. Les moyennes des températures maximales du sol enregistrées à 5 cm de profondeur étaient plus élevées quand l'installation du film polyéthylène suivait une irrigation. Des données concernant la température du sol sur 32 jours sont communiques. La croissance du soja était accrue et le rendement en grains augmentait jusqu'à 78% après solarisation. Wirkung der Bodensolarisation auf Unkräuter und Nematoden unter tropischen Bedingungen Die Bekämpfung von Unkräutern und Nematoden durch Solarisation mittels farbloser Polyethylenfolia (PE) wurde im Sommer 1990 im Freiland untersucht. Nach 32tägiger Solarisation nahm die Keimung der vorherrschenden Unkräuter Dactyloctenium aegypticum (L.) P. Beauv., Acrachne racemosa (Roem. & Schult.) Ohwi, Trianthema monogyna L. und Cyperus rotundus L. um über 90% ab. Der Austrieb von Cyperus rotundus aus Knollen wurde gefördert. Eine l6tägige Solarisation war nicht so wirkungsvoll. Die Wirkung war auf die oberste Bodenschicht bis 5 cm Tiefe beschränkt. Gegen pflanzenparasitische Nematoden (Tylenchus, Heterodera, Xiphinema, Hoplolaimus, Pratylenchus und Rotylenchus spp.) betrug die Wirkung der Solarisation etwa 90%, gegen saprophytische Nematoden rund 60%, aber nach 70 Tagen hatten sich die Nematodenpopulationen wieder weitgehend erholt. Nach Bewässerung wurde in 5 cm Tiefe eine höhere Bodentemperatur erreicht. Für die 32-Tage-Periode werden die Temperaturdaten wiedergegeben. Nach der Solarisation war das Wachstum von Sojabohne verbessert, und die Erträge stiegen um bis zu 78%.     

土壤药剂处理结合阳光消毒防治番茄根结线虫技术评价

为了筛选安全、高效、实用的化学防治技术,对国内外生产的5种杀线虫剂(棉隆、1,3 二氯丙烯·氯化苦、威百亩、噻唑磷、溴甲烷)土壤处理结合阳光消毒防治番茄根结线虫的效果进行了评价。结果表明,使用98%棉隆微粒剂450 kg/hm2或10%噻唑磷颗粒剂30 kg/hm2防治番茄根结线虫(Meloidogyne incognita),结合夏季高温进行阳光消毒,能有效地降低番茄根结线虫的数量,减轻根结线虫的危害程度,节省农户的生产成本,提高番茄的产量和农户的经济效益,是夏季防治番茄根结线虫的有效措施。     

Plant-parasitic nematodes of Croatia1

Investigations on the distribution of nematodes were carried out mostly in the northern and eastern parts of Croatia up to 1991. Sampling was performed in the following crops: maize, wheat, barley, sugarbeet, soybean, sunflower, rape, tobacco, potato, alfalfa, blackberry, onion, carrot, cucumber, lettuce, tomato, capsicum, oak, chrysanthemum, tulip, rose, grapevine, peach, apple, plum, pear, cherry, poplar, willow, clover, nettle, grass, meadow, woodland, many species of weeds, various glasshouse crops and vegetation in a nature reserve. 63 genera of nematodes with 81 species were detected. The most numerous representatives of plant parasitic nematodes were: Anguina, Aphelenchoides, Aphelenchus, Criconemoides, Ditylenchus, Gracilacus, Helicotylenchus, Hemicycliophora, Heterodera, Longidorus, Macroposthonia, Meloidogyne, Paratylenchus, Pratylenchus, Rotylenchulus, Rotylenchus, Trichodorus, Tylenchorhynchus, Tylenchus and Xiphinema.     

Long term effect of soil solarization on soil properties and cauliflower vigor

The effect of soil solarization on physical, chemical and biological properties of soil was studied, along with the response of cauliflower seedlings following solarization. Nursery beds were covered with transparent polyethylene sheet and soil temperature and moisture were recorded. Soil samples were collected five times for analysis. Three cauliflower nurseries were raised at 30-day intervals; germination was recorded 10 days after sowing and seedling length 30 days after sowing. The maximum temperature in solarized soil ranged from 40.2–47.2°C, with an increase of 5.2° to 9.9°C over non-solarized soil. There was a conservation of 5.48% moisture in solarized soil as compared with non-solarized. Solarization significantly increased electrical conductivity, organic carbon, nitrogen and potassium over pre-solarized soil. The mean pH, EC, Ca, Mg, N, P, K and C recorded in solarized soil was higher than in non-solarized. Soil solarization reduced the population of fungi from 25.68 x 10⁴ to 4.8 x 10⁴, bacteria from 20.28 x 10⁶ to 5.66 x 10⁶, actinomycetes from 31.60 x 10⁵ to 4.40 x 10⁵, and reduction in population was recorded even after 90 days, when compared with non-solarized soil. Solarization effectively reduced (>97%) population of plant parasitic and free living nematodes. Cauliflower seedlings in solarized soil had a better vigor index than non-solarized soil. Present findings reveal that soil solarization could be exploited for nutrient management and soilborne pests control, with a better vigor index of vegetable nursery.     

Effect of solarization and fumigant applications on soilborne pathogens and root-knot nematodes in greenhouse-grown tomato in Turkey

A study was conducted in two greenhouses with a history of Fusarium crown and root rot (Fusarium oxysporum f.sp.radicis-lycopersici, Forl) and root-knot nematodes (Meloidogyne javanica andM. incognita). During the 2005–06 growing season, the effectiveness of soil disinfestation by solarization in combination with low doses of metham-sodium (500, 750, 1000 and 1250l ha⁻¹) or dazomet (400 g ha⁻¹), was tested against soilborne pathogens and nematodes in an attempt to find a suitable alternative to methyl bromide, which is soon to be phased out. Solarization alone was not effective in the greenhouse with a high incidence ofForl. In the greenhouse with a low level ofForl, all the treatments tested reduced disease incidence, and were therefore considered to be applicable for soil disinfestation. In addition, root-knot nematode density decreased with all the treatments tested in both of the greenhouses.     

The effects of soil solarization on sclerotial populations of Sclerotinia sclerotiorum

Solarization reduced the populations of sclerotia of Sclerotinia sclerotiorum in soil and reduced the ability of the surviving sclerotia to form apothecia. The greatest reductions occurred in the top 5 cm layer of soil but significant effects were seen at 10 and 15 cm depths. These reductions were due mainly to microbial colonization and degradation of sclerotia weakened by the sublethal temperatures produced by solarization. A beneficial side-effect was a significant reduction in the population of weeds in solarized plots.     

Effect of soil solarization on the control of Phytophthora root rot in avocado

Phytophthora root rot is of paramount importance in avocado orchards of southern Spain. Soil solarization has been demonstrated to control the pathogen in infested areas from which infected trees had been removed. We aimed to determine whether soil solarization in established avocado orchards controls the disease. Soil solarization increased average maximum hourly soil temperatures by 6.5–6.9°C in unshaded areas of avocado orchards in coastal areas of southern Spain, depending on depth and year. The corresponding temperatures in shaded areas were c. 2–3°C lower. P. cinnamomi in soil, on infected avocado rootlets, and in a nutrient substrate buried at 30–60 cm depth was reduced to negligible amounts after 6–8 weeks of solarization in both unshaded and shaded locations of avocado orchards. P. cinnamomi could not be detected in avocado rootlets up to 14 months later, suggesting a long-term effect. Soil solarization did not affect growth of the trees, and fruit yields were increased as compared with control plots. Following soil solarization for 3 weeks from mid-July 1994, when maximum hourly temperatures reached 33–36°C, P. cinnamomi could not be recovered from a depth of up to 45 cm in unshaded areas or from a depth of up to 30 cm in shaded areas after the initial 10-day period. The viability of inoculum of the pathogen buried at depths between 15 and 60 cm in bare soil was determined by sequential sampling in two solarization experiments starting 12 June and 4 July 1995, respectively. In the first experiment, P. cinnamomi could not be detected at any depth after 4–8 weeks of solarization in unshaded areas but could be recovered at all depths except 15 cm in shaded areas. In the second experiment, where temperatures were higher and the soil surface not shaded, P. cinnamomi could not be recovered after 2 weeks at 15 and 30 cm.     

转Bt水稻种植与杀虫剂使用对土壤线虫群落的影响

为明确转Bt水稻对稻田土壤生物群落的生态风险性,于2012—2013连续2年大田试验调查研究了杀虫剂与转Bt水稻双因子对土壤线虫群落的影响。2年共监测到土壤线虫29个属,其中潜根线虫属Hirschmanniella、托布利线虫属Tobrilus、矛线线虫属Dorylaimus和丝尾垫刃线虫属Filenchus为优势属,相对多度分别为27.12%~37.92%、18.33%~24.19%、10.94%~14.87%和4.59%~15.76%;植物寄生类线虫和捕食-杂食类线虫为优势营养类群,相对多度分别为35.38%~47.62%和39.23%~48.52%;食细菌类线虫和食真菌类线虫的相对多度较低,分别为11.09%~15.20%和0.57%~1.69%。稻田土壤线虫数量、各个营养类群数量、组成以及群落生态指数随季节变化明显;在施用或不施用杀虫剂下转Bt水稻与非转Bt水稻间的土壤线虫数量及群落多样性指数无显著影响;但与不施用杀虫剂的稻田相比,施用杀虫剂的转Bt水稻或非转Bt水稻的土壤线虫数量均显著减少。研究表明,转Bt基因水稻对土壤线虫群落的影响较小,而杀虫剂影响较大。     

Effects of seed potato tuber treatment with imidacloprid on some soil and foliar insects in Croatia

The treatment of seed potato tubers by imidacloprid, as well as the standard granular insecticides applied in the furrow, did not, in four years of trials, sufficiently prevent damage from wireworms, noctuid larvae and mole crickets to potato tubers. The main reason for this failure is the spatial and temporal distance between the application of insecticides and the moment when their action is needed. On the other hand, the effects of imidacloprid applied as seed tuber treatment on the larvae of the Colorado potato beetle was very good: depending upon conditions, it lasted from at least 55, to 70 days at the most. It protected the foliage from any substantial damage from the entire first generation, and ensured high yields. Therefore a decision on seed tuber treatment with imidacloprid in Croatia should primarily depend upon the cost/benefit calculation based on damage expected from the CPB (or aphids), and not from soil insect pests.     

Effects of seed potato tuber treatment with imidacloprid on some soil and foliar insects in Croatia

The treatment of seed potato tubers by imidacloprid, as well as the standard granular insecticides applied in the furrow, did not, in four years of trials, sufficiently prevent damage from wireworms, noctuid larvae and mole crickets to potato tubers. The main reason for this failure is the spatial and temporal distance between the application of insecticides and the moment when their action is needed. On the other hand, the effects of imidacloprid applied as seed tuber treatment on the larvae of the Colorado potato beetle was very good: depending upon conditions, it lasted from at least 55, to 70 days at the most. It protected the foliage from any substantial damage from the entire first generation, and ensured high yields. Therefore a decision on seed tuber treatment with imidacloprid in Croatia should primarily depend upon the cost/benefit calculation based on damage expected from the CPB (or aphids), and not from soil insect pests.     

The effects of soil solarization and soil fumigation on Fusarium wilt of watermelon grown in plastic house in south-eastern Spain

The effects of pre-planting solarization or fumigation with metham-sodium of sand-mulched soil on fusarium wilt of watermelon in plastic house culture were investigated at Almeria, south-eastern Spain. In two trials, 2 months' solarization increased the average maximum soil temperature by c. 5°C to 44-48° C at 10 cm depth and by 4-5° C to 40-42° C at 20-30 cm. The amount of Fusarium oxysporum in the upper 15 cm of a naturally infested soil was reduced by solarization and by fumigation. During the 9 months following treatment, the F. oxysporum population stabilized at a low level in soil solarized for 2 months, but fluctuated in soil solarized for 1 month and increased in fumigated soil. The amount of wilt in watermelon sown into this soil after treatment was generally low; plants growing in solarized or fumigated soil suffered less wilt than plants in untreated soil but the differences were not significant. In a soil artificially infested with the highly pathogenic race 2 of F. oxysporum f. sp. niveum, F. oxysporum populations were greatly reduced following solarization or fumigation, and fluctuated erratically thereafter. Solarization for 2 months completely controlled wilt in watermelon and gave a fruit yield almost five times that of plants in untreated soil. Solarization for 1 month only slowed disease development slightly but gave a yield more than twice that in untreated soil. Fumigation with metham-sodium retarded disease development considerably and tripled fruit yield. Plant performance was significantly better in soil solarized for 2 months than in uninfested control soil, suggesting beneficial effects of this treatment additional to wilt control.     

土壤日晒在绿色植保中的应用与展望

土壤消毒主要用于土壤病虫草害防控。过去几十年,土壤主要采用化学药品熏蒸消毒,不合理使用容易造成环境污染。土壤蒸汽消毒、火焰消毒和热水浇灌等需要专门的仪器设备,且存在能耗较高、灭生性强、容易破坏土壤结构等缺点。目前,土壤日晒技术受到意大利、美国、以色列等70多个国家农业科学家的广泛关注,但在中国依然处于初级阶段。本文总结了国内外学者关于土壤日晒对农业病虫草害、土壤肥力、农作物产量等方面的影响与应用,分析了土壤日晒存在的局限性,并对土壤日晒在未来农业绿色防控上的应用前景进行了展望,以期为农产品无公害生产提供理论依据和实践参考。     

Effect of soil solarization on the survival of fungal antagonists of Verticillium dahliae1

Talaromyces flavus, a fungal antagonist of Verticillium dahliae, naturally occurring in clay loam artichoke fields or sandy loam olive groves, is able to survive following application of soil solarization. Survival was almost always linked to an increase in T. flavus populations detected in the rhizosphere of artichoke plants or olive trees with a verticillium wilt history as compared with the untreated control soils. It was evident that soil solarization resulted in the control of the disease in artichoke fields and the recovery of olive trees from V. dahliae infection. It was furthermore proved that solarization had a beneficial long-term effect in controlling V. dahliae for a period of 2 or 3 consecutive years. This could at least partially be attributed to the activity of T. flavus in inhibiting the germination of microsclerotia or causing their death. Aspergillus terreus, another potential V. dahliae antagonist, was also found to survive and occasionally increase following the application of the technique.     

Induced resistance to foliar diseases by soil solarization and Trichoderma harzianum

The effect of soil solarization and Trichoderma harzianum on induced resistance to grey mould (Botrytis cinerea) and powdery mildew (Podosphaera xanthii) was studied. Plants were grown in soils pretreated by solarization, T. harzianum T39 amendment or both, and then their leaves were inoculated with the pathogens. There was a significant reduction in grey mould in cucumber, strawberry, bean and tomato, and of powdery mildew in cucumber, with a stronger reduction when treatments were combined. Bacillus, pseudomonad and actinobacterial communities in the strawberry rhizosphere were affected by the treatments, as revealed by denaturing gradient gel electrophoresis fingerprinting. In tomato, treatments affected the expression of salicylic acid (SA)‐, ethylene (ET)‐ and jasmonic acid (JA)‐responsive genes. With both soil treatments, genes related to SA and ET – PR1a, GluB, CHI9 and Erf1 – were downregulated whereas the JA marker PI2 was upregulated. Following soil treatments and B. cinerea infection, SA‐, ET‐, and JA‐related genes were globally upregulated, except for the LOX genes which were downregulated. Upregulation of the PR genes PR1a, GluB and CHI9 in plants grown in solarized soil revealed a priming effect of this treatment on these genes' expression. The present study demonstrates the capacity of solarization and T. harzianum to systemically induce resistance to foliar diseases in various plants. This may be due to either a direct effect on the plant or an indirect one, via stimulation of beneficial microorganisms in the rhizosphere.     

Long-term effect of soil solarization in controlling verticillium wilt of globe artichokes in Greece

Soil solarization, either singly or in combination with a reduced dosage (34 g/m²) of methyl bromide, was effective in controlling verticillium wilt of globe artichokes for three successive cropping seasons. Both treatments resulted in greatly reduced natural populations of Verticillium dahliae microsclerotia, which were positively correlated with significant reductions in diseased plants as well as with the early formation of primary artichoke heads and increased yield. Propagules of Talaromyces flavus increased and survived better in solarized than in solarized and fumigated soils and could be partially involved in the effectiveness of solarization. Propagules of Aspergillus terreus invariably increased in treated plots but their involvement in the longevity of the treatment is questionable.     

Controlled laboratory system to study soil solarization and organic amendment effects on plant pathogens

ABSTRACT A controlled laboratory system for simulating soil solarization, with and without organic amendment, was developed and validated using physical, chemical, and biological parameters. The system consists of soil containers that are exposed to controlled and constant aeration, and to temperature fluctuations that resemble those occurring during solarization at various depths. This system enables a separate analysis of volatiles and other components. We recorded a sharp decrease in oxygen concentration in the soil atmosphere followed by a gradual increase to the original concentration during solarization in the field and heating in the simulation system of soil amended with wild rocket (Diplotaxis tenuifolia) or thyme (Thymus vulgaris). The combined treatment of organic amendment and solarization (or heating in the controlled system) was highly effective at controlling populations of Fusarium oxysporum f. sp. radicis-lycopersici. Changes in soil pH, enzymatic activities, and microbial populations followed, in most cases, trends which were similar under both solarization and the heating system, when exposed to controlled aerobic conditions. The reliability and validity of the system in simulating physical, chemical, and biological processes taking place during solarization is demonstrated.