柑橘喷施叶面肥对柑橘木虱､柑橘潜叶蛾和炭疽病发生的影响

柑橘生产上叶面肥的使用很普遍?为了评估喷施叶面肥对柑橘新梢期的主要害虫柑橘木虱Diaphorina citri和柑橘潜叶蛾Phyllocnistis citrella发生?为害的影响, 本文分别在养虫笼和网室条件下调查了以上2种害虫对喷不同叶面肥(尿素?复合氨基酸和葡萄糖)砂糖橘苗木的选择和为害, 以及柑橘炭疽病发生情况?试验结果表明:从木虱成虫选择性和产卵两个方面来看, 不同喷施处理的砂糖橘对木虱的吸引作用表现为尿素>复合氨基酸>葡萄糖>清水对照, 其中尿素和复合氨基酸处理吸引作用显著高于对照?喷施3种叶面肥后潜叶蛾为害程度均显著高于对照, 以葡萄糖处理的为害率和受害指数最高?另外, 尿素和复合氨基酸处理苗木的柑橘炭疽病病叶率和病情指数显著高于对照, 复合氨基酸处理病叶率显著高于葡萄糖?说明喷尿素?复合氨基酸叶面肥对柑橘木虱有较强的吸引作用, 同时加重柑橘炭疽病?另外, 与对照相比, 喷施3种叶面肥均能加重潜叶蛾的为害, 尤其是葡萄糖?     

Agroforestry in the Bolivian Altiplano: evaluation of tree species and greenhouse growth of wheat on soils treated with tree leaves

Severe environmental problems encountered in the highlands of Bolivia may be remedied through the adoption of agroforestry systems, never before studied adequately in this region. As a first step, seven tree species were tested for growth, survival and health at two elevations in the Bolivian altiplano. Species responded variably with Buddleja coriacea Remy., Pinus radiata D. Don. and Eucalyptus globulus Labill. (at the higher elevation) and E. globulus, Baccharis spp., Robinia pseudoacacia L. and B. coriacea (at the lower elevation), displaying high survival, growth and health. In a related greenhouse study, grain yields of wheat planted in soils amended with incorporated foliage of B. coriacea, P. radiata and E. globulus increased three-fold (0.3 g·plant⁻¹ to >1.0 g·plant⁻¹) over grain yields in unamended soils (B. coriacea > P. radiata = E. globulus). Grain nitrogen (mg·plant⁻¹) increased equally in soils amended with P. radiata and B. coriacea foliage (18 mg N⋅plant⁻¹ to 20 mg·plant⁻¹) but decreased in soils amended with foliage of E. globulus (18 g·plant⁻¹ to 9 g·plant⁻¹). This revised version was published online in June 2006 with corrections to the Cover Date.     

叶面损伤对茎瘤芥主要经济性状的影响研究

研究返青成活期、瘤茎膨大始期和盛期茎瘤芥叶片受损对其主要经济性状的影响,结果表明:在试验范围内,叶面损伤对茎瘤芥瘤茎形状、茎瘤芥产量、植株大小等有影响且规律性明显;叶片受损程度越大,受损时间越迟,影响越大。完全展开的叶片受损后对茎瘤芥主要经济性状的影响要低于未完全展开的叶片,完全展开叶全部受损后,未完全展开叶再受损影响更大,而且随着叶片受损程度的加重和时间的推迟影响增大。     

叶面肥的科学使用方法

阐述叶面肥的类型、优势、缺点、施用时机、使用方法,以供参考。     

叶面喷施肥对丝棉木生理效应的影响

以3年生丝棉木植株为试材,采用完全随机区组设计,设1%尿素,1%尿素+1%磷酸二氢钾,1%尿素+1%磷酸二氢钾+0.5%微量元素(铁、锌、铜、锰)3个处理,进行叶面喷施,清水喷施作对照,测定SOD、POD和PPO酶活性。结果显示,不同处理对丝棉木SOD酶活性的影响非常明显,配施高于单施,以多元肥为最优;施肥对苗木各器官内POD酶的影响十分明显,不同时期、不同器官喷施N、P、K肥能增强提高苗木体内POD酶活性;施肥可提高苗木体内PPO酶活性,增强苗木抗性,尤其不能忽略多元素复合肥的作用。总之,3种不同处理与对照相比对植株酶活性的效应显著,多元复合肥能够提高和延长丝棉木叶的酶活性,且更有利于提高苗木的抗逆性,促进苗木成活。     

Foliar nematode,Litylenchus crenatae ssp. mccannii,population dynamics in leaves and buds of beech leaf disease‐affected trees in Canada and the US

A foliar nematode, Litylenchus crenatae ssp. mccannii, is associated with beech leaf disease (BLD) symptoms. Information about the types of tissues parasitized and how nematode populations fluctuate in these tissues over time is needed to improve surveys as well as understand the nematodes role in BLD. During this study, the nematode was detected throughout the known range of BLD by researchers at both Canadian and US institutions using a modified pan method to extract nematodes. Monthly collections of symptomatic and asymptomatic leaves during the growing season (May–October), and leaves and buds between growing seasons (November–March), revealed that nematodes were present in all tissue types. Progressively larger numbers of nematodes were detected in symptomatic leaves from Ohio and Ontario, with the greatest detections at the end of the growing season. Smaller numbers of nematodes were detected in asymptomatic leaves from BLD‐infected trees, typically at the end of the growing season. The nematode was detected overwintering in buds and detached leaves. The discovery of small numbers of nematodes in detached leaves at one location before BLD was detected indicates that nematodes may have been present before disease symptoms were expressed. Other nematodes, Plectus and Aphelenchoides spp., were infrequently detected in small numbers. Our findings support the involvement of the nematode in BLD and indicate that symptoms develop only when certain requirements, such as infection of buds, are met. We also found that the nematode can be reliably detected in buds and leaves using the modified pan extraction method.     

核桃雄花源营养液对核桃营养生长和果实品质的影响

为探讨核桃雄花源营养液发挥最大肥效的使用方法及其对核桃营养生长和果实品质的影响,对‘温185’核桃叶面喷施不同处理的核桃雄花源营养液,分析其对核桃坐果率、营养生长、单株产量和果实品质的影响。结果表明:与清水对照相比,核桃雄花源营养液不同处理均能显著提高核桃坐果率,促进新稍生长,增加单株产量,提高单果重、出仁率和果实中粗脂肪、粗蛋白含量。其中,经GB2(生长期喷施300倍稀释的核桃雄花源营养液+3.6 g/L硼酸)、FB2(盛花期喷施300倍稀释的核桃雄花源营养液+3.6 g/L硼酸)处理后核桃坐果率、单果重和出仁率均显著高于其他处理;处理GB2对核桃百叶重、新梢直径和新梢长度、果实中粗脂肪和粗蛋白以及单株产量提升效果最好。综合分析得出,生长期对核桃叶面喷施300倍稀释的核桃雄花源营养液+3.6 g/L硼酸可促进‘温185’核桃树体营养生长,改善果实品质。     

利用钾吸收基因表达评价葡萄叶面喷施钾肥效果和喷施浓度

【目的】叶面喷施钾肥可以快速、 高效地为葡萄补充钾营养,促进葡萄的高产和优质,已经被广泛应用于葡萄生产中。本实验通过对葡萄叶面喷施不同种类及浓度钾肥,测定葡萄叶片和果实等生理指标变化,以及钾吸收相关基因的表达变化,从生理和基因水平上评价这些钾肥的喷施效果,为葡萄生产中钾肥的施用提供一定指导。【方法】本实验以‘夏黑’葡萄为试材,选择两个葡萄生长关键时期盛花期和果实膨大期分别对葡萄叶片喷施0.2%、 0.5%和0.8%三种浓度的K2SO4、 K2CO3、 K2SO4·2MgSO4和KCl。然后对葡萄叶片和新梢的生长率,坐果率,叶绿素含量,单粒重,可溶性固形物等生理指标进行统计分析,并利用荧光定量PCR技术分析4个钾吸收相关基因VvHAK13、 VvKEA2、 VvSIRK和VvSORK的表达情况。【结果】叶面喷施4种钾肥后,葡萄叶片和新梢的生长率,坐果率,叶绿素含量,单粒重,可溶性固形物等各项生理指标均有不同程度的提升。钾肥种类不同,最适喷施浓度不同,同种钾肥在葡萄盛花期和果实膨大期的最适喷施浓度也有所不同,四种钾肥在果实膨大期的最适喷施浓度普遍高于盛花期。四个钾吸收相关基因在喷施不同种类及浓度钾肥后也表现出不同的表达模式,总体来讲VvKEA2、 VvSIRK 、 VvSORK的表达上调,而VvHAK13的表达下调。果实膨大期,需喷施较高浓度的钾肥,钾吸收相关基因才表现出较强烈的响应,而在盛花期则只需喷施较低浓度的钾肥。综合生理指标和基因表达两方面结果,得出4种钾肥效果依次为K2SO4·2MgSO4＞K2SO4＞K2CO3＞KCl。盛花期K2SO4和K2CO3的最适喷施浓度为0.5%,K2SO4·2MgSO4和KCl的最适喷施浓度为0.2%; 果实膨大期K2SO4、 K2SO4·2MgSO4和KCl的最适喷施浓度为0.5%,K2CO3的最适喷施浓度为0.8%。【结论】葡萄叶面喷施钾肥可以有效促进葡萄叶片和果实的生长发育,四种钾肥的效果依此为: K2SO4·2MgSO4＞K2SO4＞K2CO3＞KCl。盛花期K2SO4和K2CO3的最适喷施浓度为0.5%,K2SO4·2MgSO4和KCl的最适喷施浓度为0.2%; 果实膨大期K2SO4、 K2SO4·2MgSO4和KCl的最适喷施浓度为0.5%,K2CO3的最适喷施浓度为0.8%。适宜的喷施浓度可以有效提高钾吸收相关基因的表达,是其提高钾吸收利用的机理之一。     

施用钾肥对叶菜产量和品质的影响

Over a period of two years, field experiments were conducted on four silty loam soils grown with foliar vegetable crops including Chinese cabbage (Brassica pekinensis Rupr., cv.Lu-Bai 3), autumn greens (B. chinensis L., cv.Piao-Geng-Bai), winter greens (B. var.rosularis Tsen et Lee, cv.You-Dong-Er), and summer greens (B. chinensis L., cv.Zao-Shu 5), respectively. Each experiment included one CK treatment without K, N and P fertilizers applied, and four treatments with from low to high doses, 0~300 kg hm^-2 for Chinese cabbage, 0~150 kg hm^-2 for autumn and winter greens and 0~180 kg hm^-2 for summer greens, of K fertilizers in the form of sulfate of potash (SOP) applied together with N and P fertilizers. One treatment of K fertilizer in the form of muriate of potash (MOP) applied at high levels (150 or 180 kg hm^-2) together with N and P fertilizers was included in the experiments of autumn, winter and summer greens, respectively, in order to compare the effects of SOP and MOP. The market yields of the tested crops increased significantly with the increasing rate of K application. The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application. K fertilization increased not only K contents but also the amounts of N, P and K absorbed in shoots of autumn, winter and summer greens, which were statistically significantly correlated to their yields. It can also be found that potassium improved the quality of the foliar vegetable crops as their dry mater contents were generally increased and Vc contents obviously increased and nitrate contents markedly decreased. As compared to MOP, SOP was more effective on the yields and quality of autumn, winter and summer greens at the high levels of fertilization.     

Growth responses and foliar sensitivities of native herbaceous species to ozone exposures

This paper reports on open-top chamber studies investigating the effects of different O₃ exposures on native herbaceous plant species. Plants were grown up from seeds, potted into natural soils and exposed to near-ambient O₃ levels during one growing season. A wide range of visible symptoms was apparent during the exposures. Species such as Rumex obtusifolius, Senecio vulgaris or Sonchus asper showed leaf colorations (e.g. reddish pigmentation) that probably indicate a non-specific stress response. In other species especially of the genera Malva and Cirsium the symptoms produced by O₃ appeared to be similar to those characteristic for O₃-specific foliar injury (stippling, flecking). In almost all species tested, O₃ caused premature leaf senescence, which was sometimes associated with premature leaf abscission. However, earlier senescence did not necessarily result in changes in plant growth. Of all species tested, Malva sylvestris was found to be the most sensitive in terms of growth reduction and lower seed production.