冬枣园绿盲蝽绿色防控技术体系构建与示范

在山西临猗进行了枣园绿盲蝽Apolygus lucorum(Meyer-Dür)绿色防控技术的研究和示范。组建"冬剪残桩、寄生蜂释放、性诱剂诱捕、生物制剂喷施"为主要措施的枣园绿盲蝽绿色防控技术体系。结果表明,人工大量释放红颈常室茧蜂Peristenus spretus Chen et van Achterberg、绿盲蝽性诱剂等技术后,冬枣幼果(疏果前)和果实(疏果后)受害率在绿色防控园分别为14.4%和4.2%,与农户常规防治园的差异不显著;红颈常室茧蜂对绿盲蝽若虫的平均寄生率为37.5%,显著高于农户常规防治园的6.2%;每公顷枣园总计诱集到30 749头绿盲蝽成虫,平均每个诱捕器能诱捕到绿盲蝽成虫(683.3±23.1)头。6-8月绿色防控园绿盲蝽的数量(5.05±0.86)头/百枝,显著低于农户常规防治园(12.71±2.22)头/百枝。绿色防控技术完全替代化学防治,有效控制了枣园绿盲蝽的种群发生与为害。     

应用伪钝绥螨防治苹果全爪螨初报

伪钝绥螨是叶螨的有效天敌,1986年引入天水,1987、1988年在苹果园进行了释放试验,6月中、下旬按1:50的益害比释放于苹果树上,结果表明经过35～40天,苹果全爪螨从峰期(1987、7、31)7.79头/叶和(19888、2)21.84头/叶开始减退,至50～60天,分别减退为1.76头/叶和1.90头/叶,而对照树分别为19.43头/叶(8、20)和44.15头/叶(8、2)。该螨对苹果全爪螨越冬卵的控制效果明显,释放树平均一年生枝条单枝含卵量为15.95粒,化防树为93.64粒。     

利用腹管食螨瓢虫控制柑桔全爪螨的研究

本文报道分布于中国东南部的腹管食螨瓢虫Stethorus siphonulus Kapur大面积控制柑桔全爪螨Panonychus citri(McGregor)首获成功;试验示范面积2000多亩,证明保护食螨瓢虫,一般株有瓢虫20—40只者,可无需用药。在春季移殖散放食螨瓢虫,除能控制春季桔全爪螨外,尚可继续控制桔全爪螨的秋季种群,全年无需喷药防治。倘若单独在秋梢期散放食螨瓢虫,秋梢害螨亦可得到显著的控制。移殖散放食螨瓢虫的指标为叶平均有桔全爪螨(包含卵在内各虫态)10只以上,方能建立起瓢虫群落。一般30—40亩果园,只需集中在10株桔树上散放食螨瓢虫200只左右(每株20只),短期内即可繁殖扩散至全园。在大面积桔园,适时进行瓢虫转株再移殖,可以迅速扩大控制范围。     

苹果园混合覆盖植物对害螨和东亚小花蝽的影响

苹果园种植紫花苜蓿，为捕食性天敌提供了适宜的生存环境和补充猎物，使苹果园天敌数量增加，叶螨种群下降。夏至草是苹果园杂草的优势种，该杂草可提供天敌生存所需的花粉、花蜜和猎物，使东亚小花蝽发生时间提早，发育速度加快。在６月中旬前，东亚小花蝽可在夏至草上完成２代，在紫花苜蓿上完成１代。夏至草与紫花苜蓿的比例变化影响苹果园节肢动物物种数量，当混合植被中夏至草的覆盖度大于２５％时，对覆盖植物和苹果树冠捕食性天敌种群数量最为有利。夏至草与紫花苜蓿混合（１∶４），比单一紫花苜蓿上天敌的数量增加２～３倍，苹果树冠天敌数量增加７０％，苹果叶螨种群数量降低３０％     

Effect of six sanitation treatments on leaf litter density, ascospore production of Venturia inaequalis and scab incidence in integrated and organic apple orchards

A two-year study was conducted to determine the effect of six sanitation treatments on leaf litter density (LLD), relative ascospore production of Venturia inaequalis and scab incidence on spur-leaf clusters, leaves and harvested fruits, on two cultivars with low and high scab susceptibilities, in Hungarian integrated and organic apple orchards. The following sanitation treatments were used: sprays of lime sulphur in autumn, collecting fallen leaves in autumn, straw mulch cover in late winter, sprays of lime sulphur followed by mulch cover, collecting fallen leaves followed by mulch cover, collecting fallen leaves followed by covering the orchard floor with plastic foil, and non-sanitized control. LLD decreased continuously in all treatment plots by 0–23% by mid-May in both orchards and years; however, LLD reduction was 1.4–4.2 times higher in the organic orchard compared to the integrated one. All treatments, except for the lime sulphur treatment, resulted in significant (P < 0.05) reduction of LLD and ascospore production in both the integrated and organic apple orchards compared to non-sanitized plots. The most efficient treatment was leaf collection combined with plastic foil cover, followed by leaf collection combined with mulch cover, leaf collection alone, mulch cover alone, and lime sulphur spray combined with mulch cover, with a reduction in the ascospore production of >95, 72–92, 56–79, 24–38, and 27–46%, respectively, in the mean of both orchards and years. However, only treatments of leaf collection applied alone, or in combination with mulch or with plastic foil cover reduced significantly (P < 0.05) leaf and/or fruit scab incidence by 18–57% compared to non-sanitized plots. These three leaf collection treatments are recommended in both integrated and organic orchards and the possibilities of successfully incorporating these methods into orchard management practices are interpreted.     

The relative importance of conidia and ascospores as primary inoculum of Venturia inaequalis in a southeast England orchard

Apple scab, caused by Venturia inaequalis, can lead to large losses of marketable fruit if left uncontrolled. The disease appears in orchards during spring as lesions on leaves. These primary lesions are caused by spores released at bud burst from overwintering sources; these spores can be sexually produced ascospores from the leaf litter or asexual conidia from mycelium in wood scab or within buds. The relative importance of conidia and ascospores as primary inoculum were investigated in an orchard in southeast England, UK. Potted trees not previously exposed to apple scab were placed next to (c. 1 m) orchard trees to trap air‐dispersed ascospores. Number and position of scab lesions were assessed on the leaves of shoots from both the potted trees (infection by airborne ascospores) and neighbouring orchard trees (infection by both ascospores and splash‐dispersed, overwintered conidia). The distribution and population similarity of scab lesions were compared in the two tree types by molecular analysis and through modelling of scab incidence and count data. Molecular analysis was inconclusive. Statistical modelling of results suggested that conidia may have contributed approximately 20–50% of the primary inoculum in early spring within this orchard: incidence was estimated to be reduced by 20% on potted trees, and lesion number by 50%. These results indicate that, although conidia are still a minority contributor to primary inoculum, their contribution in this orchard is sufficient to require current management to be reviewed. This might also be true of other orchards with a similar climate.     

Comparison of laboratory methods for assessing numbers of apple rust mite (Aculus schlechtendali) overwintering on apple

During the winter of 1980/81 apple shoots from the preceding season's growth were collected from 19 orchards in Kent and East Sussex. Five buds from each of 10 shoots per orchard were dissected under a stereoscopic microscope at × 30 magnification and apple rust mites ( Aculus rchlechtendali ) were counted. These dissected buds were then used to test a more rapid method of extraction and counting. The buds were added to methanol and mixed with a vibrating machine, mites were then collected in sieves and counted. Counts of mites by this method were similar to those of the first method when there were fewer than 100 mites on 50 buds, but there was greater variation when mites were more numerous.
An even more rapid method using five other buds from the same 10 shoots was also tested; the buds were bisected, then vibrated in methanol, and the mites were collected in sieves and counted. Results were comparable with those obtained by the dissection/methanol method and can be used with similar confidence in advisory work on apple rust mite.     

荔枝密闭园和间伐园主要病害发生情况比较

回缩间伐是荔枝密闭园改造的一个有效措施,但改造后的病害发生情况尚未见有报道。为给荔枝密闭园改造提供病害防控方面的理论依据,本研究分别于荔枝花穗期、小果期、果实成熟期和冬梢期,在国家荔枝龙眼产业技术体系荔枝密闭园改造示范园,对4个荔枝品种于密闭园和间伐园发生的主要病害种类、病害危害程度进行了两年的调查。调查数据统计分析结果显示,间伐园与密闭园所发生的主要病害在种类上无差异,但各物候期间伐园的平均总病叶率、果实成熟期的平均总病果率均低于密闭园,其中3个品种的差异达到显著水平;从花穗期至果实成熟期,密闭园和间伐园的病害危害程度均逐渐升高,在果实成熟期达到最高峰,进入冬梢期时又有所下降;调查还表明对密闭园进行回缩间伐改造有利于荔枝病害管理,改造后果园的病害防治重点时期为花穗期至果实成熟期。     

Integrated control of the solitary carpenter worm,Paropta paradoxa H.-Schaeff. (Lep., Cossidae) on fig trees in Egypt

According to the new trend of insect pests control in fruit orchards, biological in addition to mechanical control were evaluated for their efficiency on the reduction ofP. paradoxa population on fig trees during 1996, 1997 and 1998. Primary trials using the bacterial biopreparations of Delfin, Dipel and Bactospeine at the concentration of 200g/100 l. w. resulted in 81.8, 75.8 and 72.3% reduction of pest infestation, respectively. Pruning the infested branches, worming the larvae inside their tunnels and both mechanical treatments together along two successive years, reduced the infestation by 17.5, 47.4 and 57.9%, respectively. A control programme ofP. paradoxa was conducted using the techniques of pruning and worming besides spraying with bacterial insecticides at a rate of 200g/100 l.w. The performed mechanical and biological treatments together for one year gave 79.2–94.5% reduction of infestation, that reduction increased to 83.0–98.1% when these treatments were applied two years successively.     

Integrated control of the solitary carpenter worm,Paropta paradoxa H.-Schaeff. (Lep., Cossidae) on fig trees in Egypt

According to the new trend of insect pests control in fruit orchards, biological in addition to mechanical control were evaluated for their efficiency on the reduction ofP. paradoxa population on fig trees during 1996, 1997 and 1998. Primary trials using the bacterial biopreparations of Delfin, Dipel and Bactospeine at the concentration of 200g/100 l. w. resulted in 81.8, 75.8 and 72.3% reduction of pest infestation, respectively. Pruning the infested branches, worming the larvae inside their tunnels and both mechanical treatments together along two successive years, reduced the infestation by 17.5, 47.4 and 57.9%, respectively. A control programme ofP. paradoxa was conducted using the techniques of pruning and worming besides spraying with bacterial insecticides at a rate of 200g/100 l.w. The performed mechanical and biological treatments together for one year gave 79.2–94.5% reduction of infestation, that reduction increased to 83.0–98.1% when these treatments were applied two years successively.     

2011年烟台苹果产区腐烂病发病情况调查与原因分析

为了解2011年烟台苹果产区腐烂病的发生情况,2011年5月,在腐烂病发病较重的栖霞、海阳等地选择21个农户的果园,对腐烂病的发生情况进行了调查.结果表明,21个果园中具有新病疤的病株率为68.20％,死株率为2.76％,平均受害枝量为23.98％,死枝量10.74％,病株率超过50％的果园占25％～30％,总体发病情况比一般年份严重.调查共发现967块新病疤,平均每株2.32块,其中源自剪锯口的病疤占80.04％,从旧病疤复发的病疤占60.29％.2010年秋季的连续阴雨、冬季低温和2011年春季干旱可能是导致烟台苹果产区2011年春季腐烂病大发生的主要原因.剪锯口是腐烂病菌侵染的主要途径,旧病疤复发是春季腐烂病发病的主体.     

Canker and wood rot pathogens present in young lemon orchards in south-west Arizona

Canker and wood rots are economically important preharvest diseases of lemons in south-western Arizona, where commercial lemon production is concentrated. However, the aetiology and epidemiology of canker and wood rots are not well understood. This study comprised a large survey of canker and wood rot incidence and severity in Arizona and the characterization of fungal species associated with the disease. A total of 5431 trees with ages ranging from 1 to 20 years old in 10 lemon orchards were surveyed from 2018 to 2020. Our survey results revealed that canker and wood rot occurred in all 10 lemon orchards studied. Canker and brown rots of twigs, branches, and trunks were the most prevalent symptoms of affected trees ranging from 1 to 20 years old. In contrast, canker and white rots of twigs and branches were observed mostly on 1- to 5-year-old trees. Disease incidence for both diseases was less than 2% on 1- and 2-year-old trees. Brown rot increased significantly in older trees, ranging from 62.9% to 100%. Fungi were isolated from canker and wood rot samples and identified based on morphological characters and DNA sequences. Fomitopsis meliae and Hypoxylon macrocarpum were the primary canker and wood rot pathogens isolated from the surveyed orchards, at frequencies of 89% and 11%, respectively. In pathogenicity tests, both fungi were capable of causing canker and wood rots on lemon cv. Lisbon branches and the necrotic length caused by F. meliae was twofold greater than that caused by H. macrocarpum.     

Mango Eriophyid mites in relation to inflorescence

Following the appearance of inflorescence malformations on mango trees in some orchards in Israel, a survey was carried out of the presence of Eriophyid mites on mango, and their possible effect on inflorescence malformation was studied. Two Eriophyid species were recorded for the first time from this area. One of them,Erio-phyes mangiferae, associated with mango trees, has no direct effect on inflorescence malformation, but its interaction with another biotic factor is not excluded.     

信息素迷向法规模化防治梨小食心虫

梨小食心虫是梨树和桃树上一种重要的蛀食性害虫,为了推动果园害虫的无公害防治,2010年在山东省莱阳市的桃园和梨园应用信息素散发器对梨小食心虫进行了迷向防治研究。在应用信息素散发器的桃园与梨园中,梨小食心虫发生数量明显低于对照园,使用密度增加,梨小食心虫的发生数量降低,迷向率增加。每公顷施用信息素散发器450、900、1350根的桃园,对梨小食心虫的迷向率分别为67.80%、80.14%、89.29%,而梨园中对梨小食心虫的迷向率分别为84.17%、93.41%、98.17%。桃园与梨园施用信息素散发器后,梨小食心虫的蛀果率明显低于对照园,桃园与梨园对梨小食心虫的防治效果分别在40.34%～73.57%和54.24%～92.38%之间。研究表明,梨园中信息素散发器对梨小食心虫的防治效果高于桃园。     

Agronomic techniques to controlLobesia botrana

The grapevine mothLobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) is a key pest of grapevines in Greece. As part of a broader study on integrated pest management, the effects were investigated of different cultural methods on the establishment and survival ofL. botrana, specifically: application of different nitrogen levels (30 and 100 units of ammonium sulfate or 70 units of Agrobiosol); summer leaf and shoot pruning; application of growth regulators (Regalis, prohexadione-calcium; or Falgro, gibberellic acid). There were significant differences among the three levels of N application. The lowestL. botrana infestation rates were found in plots treated with 30 units of (NH₄)₂SO₄ and plots that received some summer pruning. Following the application of plant growth regulators, the lowestL. botrana infestation levels occurred in the plots treated with Regalis or Falgro at the manufacturers’ recommended concentrations. On vines where growth regulators had been applied, the clusters had fewer berries than those not treated with growth regulators. http://www.phytoparasitica.org posting June 11, 2008.     

Arthropod populations and rice yields in direct-seeded and transplanted lowland rice in West Africa

Studies were conducted on the effect of pruning time, host age, urediniospore release and weather parameters on the incidence and intensity of mulberry leaf rust (Peridiopsora mori). Rust severity significantly increased with increasing shoot age, irrespective of pruning time. Maximum disease severity was observed in plants pruned during the third week of October, and minimum severity in plants pruned during last week of November. Apparent infection rate was higher in younger shoots. Infection rate was higher in plants pruned during the last week of November. Urediniospore release was influenced by prevailing climatic conditions. A higher rate of spore release was noticed during sunny days. Maximum spore release was found between 12.00 h and 14.00 h. Spore release was positively correlated with temperature and negatively correlated with relative humidity. Rust severity (34.97%) was higher in January and least (1.03%) during May. Rust severity was negatively correlated with both temperature and rainfall. An exponential model was developed for the prediction of rust severity which was accurate up to 96.60%.     

Ineffectiveness of pruning to control citrus huanglongbing caused by <Emphasis Type="Italic">Candidatus</Emphasis> Liberibacter americanus

The huanglongbing (HLB) disease of citrus trees, caused by Candidatus Liberibacter asiaticus and Ca. Liberibacter americanus, was first reported in Brazil in March, 2004. The presence of the disease has caused serious concerns among growers. Pruning experiments were conducted to determine if removal of symptomatic branches or the entire canopy (decapitation) would eliminate infected tissues and save HLB-affected trees. Pruning was done in five blocks on a total of 592 3- to 16 year-old ‘Valência’, ‘Hamlin’ or ‘Pêra’ sweet orange trees showing no symptoms or with two levels of symptom severity. Ten decapitated trees per block were caged and all trees were treated with insecticides to control the psyllid vector, Diaphorina citri. Mottled leaves reappeared on most symptomatic (69.2%) as well on some asymptomatic (7.6%) pruned trees, regardless of age, variety, and pruning procedure. Presence of the pathogen (Ca. Liberibacter americanus) in all symptomatic trees was confirmed by PCR. In general, the greater the symptom severity before pruning the lower the percentage of trees that remained asymptomatic after pruning.     

Branch cankers on citrus trees in Spain caused by Phytophthora citrophthora

Considerable losses of citrus trees have been observed in the major citrus-growing areas of Spain. Samples were collected from 132 orchards, and isolations and pathogencity tests were conducted to determine the aetiology of a serious canker disease. Affected trees showed cankers on the scion that frequently began on the branches. Three Phytophthora species were identified based on their morphological, cultural, physiological and molecular profiles. Phytophthora citrophthora was the main species associated with this new syndrome in 114 orchards. Phytophthora nicotianae (syn. P. parasitica ) was isolated from nine orchards as the sole Phytophthora species and in coinfection with P. citrophthora from another nine orchards. Phytophthora citricola was isolated only from one orchard. In stem-inoculation studies conducted under greenhouse conditions, clementine mandarin cv. Hernandina and sweet orange cv. Navel Late were more susceptible to P. citrophthora than sour orange and Carrizo citrange rootstocks. Clementine cv. Hernandina was also highly susceptible in field inoculation experiments. In agreement with field surveys, clementine mandarin cultivars were the most affected, their rootstocks remaining healthy. Phytophthora citrophthora was found to be the predominant species in orchard soils; however, P. nicotianae was also isolated. This information changes the scenario of diseases caused by Phytophthora spp. in Spain and consequently, the present knowledge of epidemiology and the effectiveness of the current control measures should be reassessed.     

生草园捕食性天敌东亚小花蝽的人工操纵技术

在北京巨山农场果园中，分别在６月初和６月中旬，刈割苹果树行间的紫花苜蓿并将其放在树冠下后，东亚小花蝽既向割草区周围的紫花苜蓿上扩散，也向割草区苹果树上迁移。割草后３天，割草区周围紫花苜蓿上小花蝽数量增加２０％～１１９％，其增加量随距割草区距离的增加而减少，割草区苹果树冠上小花蝽数量比割草前增加２～３倍，蝽螨比可提高１４倍，树冠小花蝽增加的数量受小花蝽扩散能力和割草时间的影响。试验结果表明，适时刈割苹果园中的紫花苜蓿，对控制害螨有明显的作用     

Factors Affecting the Spread of Plum pox virus Strain M in Peach Orchards Subjected to Roguing in France

ABSTRACT We evaluated the impact of roguing on the spread and persistence of the aggressive Plum pox virus strain M (PPV-M) in 19 peach orchard blocks in Southern France. During a 7- to 10-year period, orchards were visually inspected for PPV symptoms, and symptomatic trees were removed every year. Disease incidence was low in all orchards at disease discovery and was <1% in 16 of the 19 orchard blocks. The spread of Sharka disease was limited in all 19 blocks, with an annual disease incidence between 2 and 6%. However, new symptomatic trees were continuously detected, even after 7 to 10 years of uninterrupted control measures. An extended Cox model was developed to evaluate to what extent tree location, orchard characteristics, environment, and disease status within the vicinity influenced the risk of infection through time. Eleven variables with potential effect on tree survival (i.e., maintenance of a tree in a disease- free status through time) were selected from survey data and databases created using a geographical information system. Area of the orchard, density of planting, distance of a tree from the edge of the orchard block sharing a boundary with another diseased orchard, and distance to the nearest previously detected symptomatic tree had a significant effect on the risk for a tree to become infected through time. The combined results of this study suggest that new PPV-M infections within orchards subjected to roguing resulted from exogenous sources of inoculum, disease development of latent infected trees, as well as infected trees overlooked within the orchards during visual surveys. A revision of the survey and the roguing procedures used for more effective removal of potential sources of inoculum within the orchards and in the vicinity of the orchards would improve disease control suppression of PPV.