Borkenkäferbekämpfung an Alleebaumpflanzungen im Sinne der guten fachlichen Praxis im Pflanzenschutz

Zusammenfassung Zur gezielten Anwendung von Insektiziden gegen Borkenkäfer an Ziergehölzen sind Pyrethroid-Präparate zugelassen, die in Streichapplikation aufgebracht werden sollen. Mit Hilfe eines im Handel angebotenen Kleingerätes wurde vom Autor und von Garten- und Landschaftsbau- bzw. Baumschul-Unternehmen die Anwendung praktiziert und die gute Verwendbarkeit des technischen Hilfsmittels festgestellt. Auch die Anwendung eines zur Docht-Streichbehandlung zugelassenen Herbizides wurde erprobt. Ökonomische und ökologische Vorteile des Gerätes im Sinne der guten fachlichen Praxis werden aufgezeigt.     

Leaf Responses to Reduced Iron Availability in Two Tomato Genotypes: T3238FER (Iron Efficient) and T3238fer (Iron Inefficient)

Abstract

The present work is aimed at evaluating some effects induced by different levels of iron availability in the growth medium for two different tomato (Lycopersicon esculentum Mill.) genotypes, the T3238fer (Tfer), unable to activate mechanisms for iron mobilization and uptake known as “strategy I,” and its correspondent wild‐type T3238FER (TFER). By using different iron concentration in the growth solution, the most suitable iron level to induce phenotypic differences between the two genotypes without being lethal for the mutant was found to be 40 µM Fe‐Na‐EDTA. The analyses were carried out also on plants grown with 80 µM Fe‐Na‐EDTA, an iron concentration at which the two genotypes showed no phenotypic differences. A significant decrease in total leaf iron and chlorophyll content was detected in both genotypes following reduction of iron concentration in the nutrient solution, and was particularly evident in Tfer40, which showed symptoms of chlorosis. The photo‐electron transport rate of the whole chain was significantly affected by growth conditions as well as by genotype, the lowest activity being detected in Tfer40 plants. Chlorophyll a fluorescence analysis revealed an increase in non‐photochemical quenching (q _NP) of Tfer plants grown at both iron concentrations, indicating the activation of photoprotective mechanisms, which, however, were not sufficient to prevent photoinhibition when plants were grown at 40 µM iron, as indicated by significant reduction in PSII photochemistry (F _v/F _m) and photochemical quenching (q _P). The actual quantum yield of PSII (Φ_PSII) and the intrinsic PSII efficiency (Φ_EXC) showed the same behavior of q _P and F _v/F _m ratio. A significant effect of mutation and iron supply on all the pigments was detected, and was particularly evident in the mutant grown at 40 µM iron. A different behavior was shown by the three pigments involved in the xantophyll cycle, violaxanthin being less affected than chlorophylls and the other carotenoids, and zeaxanthin even increasing, due to the xanthophyll cycle activation. In conclusion, the interaction between iron deprivation and fer mutation induced functional alterations to the photosynthetic apparatus. Anyway, as far as concerns the photo‐electron transport activity, the influence of fer mutation seemed to occur independently from iron supply.     

冬小麦-夏玉米轮作中长期定位施肥的土壤钾素变化研究

基于25年的长期定位试验, 研究了非石灰性潮土区冬小麦—夏玉米轮作中长期定位施肥的土壤钾素变化。结果表明, 单施有机肥及有机肥配施无机氮肥, 都能明显提高土壤缓效钾的含量; 无机钾肥与氮肥配施能显著提高水溶态钾的含量。土壤速效钾与全钾呈显著正相关, 与土壤缓效钾、交换态钾呈极显著正相关。单施氮肥的土壤, 速效钾、缓效钾含量均降低, 全钾含量变化不明显。     

广东省农用化肥投入及效益趋势分析

考察了中山市、惠州市及梅州市所代表的平原、丘陵到山区不同类型地区农用化肥投入与农业（种植业）产值的变化趋势及两者之间的关系，并与中国整体的情况进行了比较。结果表明，在20世纪90年代早中期以前，广东省不同类型地区农业产值的增长与化肥投入的增长有依存关系，此后化肥投入呈现下降的趋势，但种植业的增长仍然较为强劲；从农用化肥投入的效益看，经历了70年代至至80年代实的降低和90年代中后期的回升过程。认为广东省的农业已进入了以依靠科技进步为主、促进农业增长的良性阶段。中国整体的情况有所不同，农业产值的增长还未脱离与化肥投入增长的基本依存关系，化肥投入的效益自70年代末降低以后，目前还没有出现显著的回升趋势，中国整体的农业现代化进程滞后于广东省。     

不同有机肥对橡胶中小苗寒害树生长的影响

对2011年橡胶IAN873品系中小苗寒害树的4种不同配方有机肥的肥效进行试验,结果表明：肥料C(鱼粉＋磷肥＋尿素＋功能菌＋有机肥,施2.3 kg/株)处理的橡胶中小苗寒害树的茎增粗显著高于常规施肥(鱼粉＋磷肥＋有机肥,施3 kg/株)和肥料A(花生麸＋磷肥＋有机肥,施3 kg/株)处理,与肥料D(花生麸＋鱼粉＋磷肥＋有机肥,施3 kg/株)处理差异不明显,但从树体长势程度来看肥料C处理显著优于其它肥料处理。     

细链格孢菌拮抗细菌枯草芽孢杆菌XL12菌株发酵产抗菌蛋白条件研究

为了提高细链格孢菌[Alternaria alternate（Fr）Keissler]拮抗细菌枯草芽孢杆菌（Bacillus subtilis）XL12菌株的发酵产抗菌蛋白量,采用单因素法对XL12菌株的培养条件进行了优化,最终确定XL12最适宜的发酵条件为：基础培养基碳源和氮源（摩尔比）的比例为30∶1,接种量为0.5%,配制后灭菌前,培养液的pH调节在6.95~7.05,发酵温度为30~35℃,220 r.min-1摇床振荡培养72 h,用70%硫酸铵对XL12菌株发酵液上清液进行盐析,可以沉淀最多的抗菌蛋白。