渭北富士苹果偏斜果的影响因素

为了明确引起渭北富士苹果果形偏斜的原因,于2009~2010年在西北农林科技大学白水苹果试验站,以16~17年生的乔化富士苹果为主要试材,从授粉受精和果实类型两方面对其果形进行研究。结果表明:除粉红女士授粉外,秦冠、嘎拉、新红星3个品种授粉都均降低富士苹果的果形偏斜指数,改善果形;柱头数对富士果实形状有明显影响,人为去除3~4个柱头会明显减少果实种子数,导致果实发育畸形。种子数和种子在心室中的分布决定了果实的形状,端正果每个心室几乎均有种子分布,偏斜果至少有1个心室种子败育,畸形果至少有2个心室中的种子败育。比较长、中、短果枝果形,长果枝果实的果形指数明显大于中、短果枝,而果形偏斜指数小于中、短果枝,但差异不显著。下垂果多为果形高桩的端正果,畸形果少,果形偏斜指数明显小于侧生果。     

植物生长调节剂芸薹·吲乙·赤霉素在苹果树上的应用研究

植物生长调节剂0.136%芸薹·吲乙·赤霉素WP在40～120 mg/kg的对水浓度范围内,对增加苹果叶片重量和厚度,提高坐果率、果形指数、高桩果率及改善苹果品质有一定效果,优于对照药剂赤霉素.     

苹果蜜蜂授粉和绿色防控增产技术的集成与应用示范

通过开展示范,明确了苹果花期蜜蜂授粉和全生育期病虫害绿色防控技术的集成应用效果,苹果坐果率提高,果实发育良好,种子饱满,果形端正,苹果树腐烂病、金纹细蛾等病虫得到有效控制,果品产量提高,品质改善,效益显著。     

防治苹果轮纹烂果病药剂筛选及用药技术

经过两年室内药效测定 ,初步建立起部分杀菌剂对苹果轮纹烂果病菌丝抑制作用的毒力档案 ,选出防效较高的几种单剂 ,并通过两年田间用药技术研究 ,明确果实生长前期 ,喷洒多菌灵、苯菌灵 ,中后期波尔多液与多菌灵、苯菌灵、福星等加三乙膦酸铝交替使用 ,对防治苹果轮纹烂果病有良好防治效果。同时探讨了只在果实潜伏侵染病菌开始活化扩展期喷药 ,对防治苹果轮纹烂果病的可能性     

甲氰菊酯、辛硫磷混合剂在苹果中的残留降解

甲氰菊酯、辛硫磷及其混剂分别在苹果上使用后 ,定期取样气相色谱测定苹果上的残留量。研究结果表明单剂及混剂甲氰菊酯在苹果上的半衰期分别为 19.3天和 18.1天 ,单剂辛硫磷和混剂辛硫磷在苹果中的残留半衰期分别为 1.54及 1.4 6天 ,甲氰菊酯和辛硫磷单独使用或混合使用在苹果中的降解规律及降解速率常数没有显著差异。从甲氰菊酯和辛硫磷在苹果上残留角度考虑两者混合使用对环境是安全的。     

苹果缩果病症状及防治

苹果缩果病症状及防治韩学俭（陕西省农科院植保所７１２１００）苹果缩果病是由硼素不足引起的生理病害，我国各苹果产区均有发生。除苹果外，梨、桃、葡萄、柑桔等都可表现出缺硼症状。属山地及砂质偏碱土壤果园表现为最，常遭此病损失。近年来，有些果园由于偏施氮肥，...     

智利首次报道由Neofabraea perennans引起的苹果牛眼果腐病

苹果牛眼果腐病病原包括明孢盘菌属多种真菌:Neofabraea perennans、N.malicorticis、N.kienholzii和N.vagabunda(Phlyctema vagabunda),在欧美苹果产区广泛存在,我国尚未发现。根据《Plant Disease》2020年3月发表的文章,2018年7月,智利中部奥希金斯地区(O'Higgins)的苹果('Cripps Pink')上观察到苹果牛眼果腐病症状,经鉴定引起苹果牛眼果腐病的病原为苹果牛眼果腐病菌(Neofabraea perennans)。     

富士苹果烂果多的原因及防治措施

近几年,我区富士苹果烂果特别多,据调查烂果率一般在20％～30％,严重者达到50％～60％。从1994年开始我们对烂果发生的原因及防治措施进行了调查,现简报如下：一、烂果原因1．病害因素。据田间调查,引起烂果的主要病害是苹果轮纹病和炭疽病。多雨的气候条件是两种病害流行     

黄绿色球形诱捕器诱杀柑橘大实蝇技术应用效果

本试验利用球形诱捕器进行柑橘大实蝇成虫诱杀,以食物诱剂为对照,比较诱杀成虫数及虫果率,以评价其防效。结果表明,在成虫发生期,球形诱捕器共诱杀5 991头成虫(雌虫2 884头、雄虫3 107头),食物诱剂诱杀总数为1 859头(雌虫942头、雄虫917头)。两种诱杀方式均能有效诱杀雌雄成虫,雌雄比值分别为0.93和1.03;两种防控措施防治后虫果率分别为2.7%(球形诱捕器)和6.2%(食物诱饵),未采取任何措施的对照组虫果率为28.6%。说明两种防治措施均能显著降低虫果率,且球形诱捕器诱杀效果更好。     

豫西地区苹果蛀果害虫重发生原因浅析及防治对策

三门峡市位于豫西丘陵山区 ,是全国苹果的主要产区。因受地理、环境条件影响 ,苹果病虫种类多 ,为害重。主要有叶螨、蚜虫、金纹细蛾、蛀果害虫和轮纹烂果病、早期落叶病。其中曾经得到有效控制的蛀果类害虫 ,再度呈严重发生为害趋势。1　豫西地区苹果蛀果害虫发生状况豫西地区苹果蛀果害虫在 80年代、90年代中期经过大面积的综合治理 ,得到了有效控制 ,虫果率一直保持在 3 %以下。自从 1 997年以来 ,以桃小食心虫为主的蛀果害虫再度猖獗 ,虫果率一般为 1 5%～ 2 0 %,偏远地区、管理粗放的果园 ,虫果率高达 50 %,苹果年产量损失为 90 0 0万…     

480g/L毒死蜱乳油对苹果绵蚜及桃小食心虫的防治效果

为明确480 g/L毒死蜱乳油对苹果绵蚜及桃小食心虫的防治效果,特选取虫害发生较重的苹果园进行了田间药效试验。结果表明,480 g/L毒死蜱乳油1 500倍液药后21 d对苹果棉蚜的防效最高可达89.70%,药后15 d对桃小食心虫的防效最高可达94.34%,防效较好且对果树安全。     

Alternative disease control agents induce resistance to blue mold in harvested 'red delicious' apple fruit

ABSTRACT Alternative control agents, including UV-type C (254 nm) irradiation, yeasts antagonistic to fungal growth, chitosan and harpin, were evaluated for their ability to induce resistance in cv. Red Delicious apple fruit against postharvest blue mold caused by Penicillium expansum. Freshly harvested and controlled atmosphere (CA)-stored fruit were treated with these agents at different doses and concentrations or with paired combinations of the agents. Treated fruit were inoculated with P. expansum 24, 48, or 96 h following treatment, and stored at 24 degrees C in the dark. The fruit were evaluated for development of disease every 2 days for 14 days by measuring the diameter of lesions that formed. The area under the disease progress curve (AUDPC) was calculated and analyzed statistically. All treatments were effective in reducing the AUDPC; UV-C was most effective, followed by harpin, chitosan, and the yeasts, respectively. Regardless of treatment, fresh fruit were more responsive to treatments than CA-stored fruit. There was a clear time-dependent response of the fruit to the treatments, in which treatments applied 96 h before inoculation provided the best results. In a few situations, the combinations of agents did provide an additive effect, but no synergistic effects were detected. Moreover, disease severity in fruit treated by any combination was markedly better than that in the controls. Although the combinations of treatments was overall less effective than the single treatments, they did provide significant reductions of the progress of disease in comparison with the controls. Because the fungus did not come into contact with any of the control agents, this study showed conclusively that the agents studied were able to induce resistance in the fruit rather than merely inhibit the pathogen directly. It also showed, for the first time, that harpin is able to induce resistance in harvested apple fruit. The use of these control agents may minimize the costs of control strategies and reduce the risks associated with the excessive use of fungicides in harvested apple fruit.     

结合药液表面张力与苹果树冠层参数预测喷雾药液用量的方法及应用

为了保证果树精准施药,减少药剂流失,通过4种常用表面活性剂调节药液的表面张力,借助界面张力仪、微重力天平和植物冠层扫描仪等测定手段建立了药液表面张力与苹果叶片最大稳定持液量 (R_m) 之间的关系,并结合果树常用冠层参数,提出了一种预估果树施药液量的方法。结果表明:生长前期苹果叶片近轴面的R_m值明显高于生长后期;在同一生长期,苹果叶片远轴面的R_m值均高于近轴面,且R_m值随叶倾角的增大而减小;生长前期苹果叶片远轴面的R_m值受药液表面张力的影响大于近轴面,但随着叶倾角的增大,叶片近、远轴面的R_m受药液表面张力的影响减小。当药液中表面活性剂的浓度未达到其临界胶束浓度 (cmc) 时,药液的表面张力与苹果叶片的R_m值成正相关关系,由此可建立一元线性回归方程,结合果树平均叶片倾角、叶面积指数和冠层地面投影面积等植物冠层参数,可以估算果树的最大施药液用量。采用4种常用的农药制剂验证了所建方法的实用性。该研究结果可以为苹果园喷雾施药时预估药液用量、减少药剂流失提供理论依据。     

Analysis of the Apple Value Chain in Albania

Apple production is an important activity for Albanian agriculture in terms of cultivated area and production. Apple represents the most important fruit in the Albanian average consumer basket. There is an increasing tendency of both domestic production and consumption. Despite the growth in production and the local customer preferences for the domestic apple, apple imports remain significant. The food demand of emerging middle-class consumers is resulting in increased consumption and production requirement for high quality apples. On the other hand, gradual consolidation of the retail sector and the recent establishment and expansion of the first supermarket chains has strong implications for agriculture—imposing more restrictions for quality and quantity of supplied apples.     

Mapping Quantitative Field Resistance Against Apple Scab in a 'Fiesta' x 'Discovery' Progeny

ABSTRACT Breeding of resistant apple cultivars (Malus x domestica) as a disease management strategy relies on the knowledge and understanding of the underlying genetics. The availability of molecular markers and genetic linkage maps enables the detection and the analysis of major resistance genes as well as of quantitative trait loci (QTL) contributing to the resistance of a genotype. Such a genetic linkage map was constructed, based on a segregating population of the cross between apple cvs. Fiesta (syn. Red Pippin) and Discovery. The progeny was observed for 3 years at three different sites in Switzerland and field resistance against apple scab (Venturia inaequalis) was assessed. Only a weak correlation was detected between leaf scab and fruit scab. A QTL analysis was performed, based on the genetic linkage map consisting of 804 molecular markers and covering all 17 chromosomes of apple. With the maximum likelihood-based interval mapping method, eight genomic regions were identified, six conferring resistance against leaf scab and two conferring fruit scab resistance. Although cv. Discovery showed a much stronger resistance against scab in the field, most QTL identified were attributed to the more susceptible parent 'Fiesta'. This indicated a high degree of homozygosity at the scab resistance loci in 'Discovery', preventing their detection in the progeny due to the lack of segregation.     

Molecular Identification of a Sexual Interloper: The Pear Pathogen, Venturia pirina, has Sex on Apple

ABSTRACT Venturia pirina (the pear scab pathogen) and V. inaequalis (the apple scab pathogen) were detected as ascospores discharged from apple leaf litter in New Zealand (spring 1998). Pseudothecia of both species were located on dead apple leaves; however, only those of V. inaequalis were associated with scab lesions. V. pirina was identified by rDNA sequence analyses, because morphological characters could not distinguish this fungus from V. asperata (a rare saprophyte on apple) and other Venturia spp. pathogenic on rosaceous fruit trees. Species-specific polymerase chain reaction primers designed to the 18S end of the internal transcribed spacer 1 region differentiated Venturia fruit tree pathogens reliably. V. pirina field isolates were pathogenic on pear, but only weak saprophytes on apple. In rare instances, when appressoria of V. pirina appeared to penetrate the cuticle of apple leaves, epidermal cells responded with a localized hypersensitive response (HR). To our knowledge, this is the first report of induction of HR-like events by V. pirina on its nonhost, apple, and also the first record of sexual reproduction of V. pirina on apple. It is assumed that V. pirina pseudothecia formed from saprophytic lesions in senescing apple leaves when active defense mechanisms such as HR were no longer induced.     

The Influence of Fungicide Sprays on Infection Of Apple cv. Bramley's Seedling By Nectria galligena

In 1990, a long-term trial was initiated by planting young apple trees, cv. Bramley's Seedling, inoculated, at single sites in the leader shoots, with Nectria galligena. The effect of spring–summer and autumn fungicide spray programmes, applied during 1991–1993, on the development of new cankers was assessed up to May 1994. Spring–summer fungicide programmes, applied as for the control of apple scab, reduced numbers of new cankers by between 65% and 76% compared with the untreated control. Sterol demethylation inhibiting fungicides (hexaconazole, myclobutanil, penconazole) had a similar effect on canker to dithianon. Autumn application of copper oxychloride at 5% and 50% leaf-fall further reduced numbers of new cankers. The combination of a spring–summer benzimidazole (carbendazim or thiophanate-methyl) with a scab fungicide (dithianon) and autumn copper oxychloride did not improve canker control compared with applying copper oxychloride after spring–summer myclobutanil+mancozeb. The percentage of fruit which developed rots in long-term storage was decreased by spring–summer benzimidazole application, but not by other fungicide programmes even those which achieved similar levels of canker control.     

Production of Monoclonal Antibodies against Apple Proliferation Phytoplasma and their Use in Serological Detection

Two monoclonal antibodies were obtained against the apple proliferation phytoplasma that provide easy, rapid, specific and sensitive serological detection. They reacted specifically by using ELISA and immunofluorescence techniques with apple proliferation-infected periwinkles and apple trees from different regions in northern Italy and Slovenia, but not with several other phytoplasma isolates. We did not observe any monoclonal antibody reaction even using phytoplasmas belonging to the same phylogenetic group such as European stone fruit yellows and pear decline. Two serological techniques, immunofluorescence and ELISA, were compared with DAPI staining and PCR. From July until leaf fall ELISA was as sensitive as PCR but was more rapid and convenient than PCR; immunofluorescence was useful for specific detection of apple proliferation phytoplasma on roots throughout the year. Serological techniques could be conveniently applied in the roots, stems and leaves of apple trees depending on specific phenological stages of the plants.     

Latency- and Defense-Related Ultrastructural Characteristics of Apple Fruit Tissues Infected with Botryosphaeria dothidea

ABSTRACT Apple fruit tissues infected with Botryosphaeria dothidea were examined by transmission electron microscopy using susceptible cv. Fuji and resistant cv. Jonathan. Immature (green) and mature (red) fruits of cv. Fuji with restricted or expanding lesions were also examined to reveal subcellular characteristics related with latent and restricted disease development. In infected susceptible mature fruits, cytoplasmic degeneration and organelle disruption commonly occurred, accompanying cell wall dissolution around invading hyphae. Cell wall dissolution around invading hyphae in subepidermis was rare in immature, red halo-symptomed cv. Fuji and resistant cv. Jonathan fruits. In infected immature fruits of cv. Fuji, presumably at the latent state of disease development, cellular degeneration was less severe, and invading hyphae contained prominent microbody-lipid globule complexes or the deposition of thin electron-dense outer layer around cell wall of intercellular hyphae. Both mature fruits with red halos and resistant apple fruits formed cell wall protuberances at the outside of cell walls. In addition, electron-dense extramural layers were formed in the resistant apple fruits. Aberrant hyphal structures such as intrahyphal hyphae were found only in resistant fruit tissues, indicating the physiologically altered fungal growth. These ultrastructural changes of host tissues and fungal hyphae may reflect the pathogenesis of apple white rot under varying conditions of apple fruits.