钾肥施用量对脐橙产量和品质的影响   总被引：30，自引：0，他引：30  

鲁剑巍  陈防  万运帆  刘冬碧  余常兵  王耀群  宋发安  王运华  Rolf Hardter 《果树学报》2001,18(5):272-275

１９９６～１９９９年连续４年在湖北省秭归县进行了脐橙钾肥施用量田间试验。结果表明，尽管各处理脐橙产量年度变化很大，但施钾显著提高产量和经济效益，１９９７～１９９９年施钾平均增产２６．３％～４１．８％，施钾（Ｋ２Ｏ）１２５、２５０、３７５ｋｇ／ｈｍ２年均增加纯利 １０１１０、１５８４０、９９７０元／ｈｍ２，产投比分别为 １９．３８、１５．４０和７．０４；在试验条件下施钾（Ｋ２Ｏ）２５０ｋｇ／ｈｍ２增产效果最好；施钾有提高脐橙外观品质和内在品质的趋势，例如施钾提高或保持单果重、增加果皮厚度、提高维生素Ｃ含量等；但施钾对品质的影响年度间差异较大，尚需进一步研究。  相似文献   

The Influence of Organic and Integrated Production on Nutritional,Sensory and Agricultural Aspects of Vegetable Raw Materials for Food Production     

Stina Fjelkner-Modig  Håkan Bengtsson  Stig Nystrõm  Rolf Stegmark 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):102-113

In a six-year crop rotation trial organically and integrated grown vegetables were produced according to current good agricultural practices, taking quality and quantity aspects into consideration. The raw materials assessed focussed on materials used for industrial food production. Nutritional, sensory and agricultural aspects were evaluated. Carrot, cabbage, onion, pea and potato are possible to grow organically for industrial purposes. Depending on crop, the yield was lower (65-90%) for organically grown compared to integrated grown. Cultivation of organic spinach and dill turned out to be difficult due to problems with weed and discoloration. The chemical analyses included pesticide residues, nitrate, glycoalkaloid, dry matter, vitamin C and 25 different minerals and trace elements. Overall, the organically grown crops had higher dry matter content than the integrated grown. However, when examining the data for the different crops contradictory results were noted. No significant differences due to growing system were noticed for vitamin C and the other nutrients except for 4 of the trace elements. The growing system did not influence the sensory properties.  相似文献   

Applicability of ground‐penetrating radar as a tool for nondestructive soil‐depth mapping on Pleistocene periglacial slope deposits     

Rolf Gerber  Peter Felix‐Henningsen  Thorsten Behrens  Thomas Scholten 《植物养料与土壤学杂志》2010,173(2):173-184

Soil depth plays a decisive role in determining soil properties in mountainous regions for ecological site assessment. To evaluate the use of ground‐penetrating radar (GPR) for fast and high‐resolution mapping within mountainous regions, we examined the possibilities and limitations of GPR to determine soil depth over bedrock and to delineate individual substrate layers formed during the Pleistocene in a periglacial environment (Pleistocene periglacial slope deposits, PPSD). Selected catenae in representative subregions of the study area (Dill catchment, SE Rhenish Massif, Germany) have been successfully mapped using GPR. A practicable method was developed using a 400 MHz antenna to reach a mean penetration depth of 1.5 m and to map different substrates and layers of PPSD based on calibrations of the GPR at soil pits along 12 catenae. Colluvium, the three types of PPSD layers, as well as the in situ bedrock could be distinguished in most sections of the GPR surveys. Characteristic GPR facies caused by intrinsic material properties of the different substrates, such as stone content and soil moisture content, could be distinguished in different geomorphologic and lithological settings. A layer‐based velocity distribution was determined for characteristic substrate layers at soil pits enabling us to considerably enhance the accuracy of soil‐depth prediction. Compared to traditionally surveyed soil profiles, our results demonstrate an accuracy of layer thickness surveying within a standard deviation of approx. 0.1 m. It is demonstrated that the combination of GPR with conventional soil‐pit mapping is an efficient and valid method to produce high‐resolution data of substrate distribution.  相似文献   

Biological communities at the Florida escarpment resemble hydrothermal vent taxa   总被引：4，自引：0，他引：4  

Paull CK  Hecker B  Commeau R  Freeman-Lynde RP  Neumann C  Corso WP  Golubic S  Hook JE  Sikes E  Curray J 《Science (New York, N.Y.)》1984,226(4677):965-967

Dense biological communities of large epifaunal taxa similar to those found along ridge crest vents at the East Pacific Rise were discovered in the abyssal Gulf of Mexico. These assemblages occur on a passive continental margin at the base of the Florida Escarpment, the interface between the relatively impermeable hemipelagic clays of the distal Mississippi Fan and the jointed Cretaceous limestone of the Florida Platform. The fauna apparently is nourished by sulfide rich hypersaline waters seeping out at near ambient temperatures onto the sea floor.  相似文献   

Die Prophylaxe in der Dasselbekämpfung     

Dr. Rolf Kühl 《Journal of pest science》1949,22(12):185-190

Zusammenfassung a) Geselich vorgeschrieben ist bisher nur die Stallabdasslung vor Weide- und Alpauftrieb. Sie kann im Rahmen eines Gesamt-Bekämptungsplanes jedoch nur als Teil einer Gesamtanfgabe gewertet werden.b) Die Ausrottung der Rinderdasselfliegen kann nur durch zusäliche und planmäßige Sommerabdasslung auf Weide und Alpe erreicht werden.c) Die prophylaktische Anwendung von Sprühemulsionen auf kontaktinsektizider Basis gestattet, den zukü nftigen Befall stark herabzuseen oder schlagartig zu verhüten.d) Neben dem individuellen Schaden kann somit der Herden- und Häuteschaden merklich herabgeset oder gänzlich vermieden werden.e) Der methodische Wert der Einzelbeulenbehandlung gewinnt durch Prophylaxis weiter an Wert. Dadurch steigt der Erfolg planmäßiger Abdasslungen mit dieser Methode. Im Verein mit der Prophylaxis erscheint es möglich, die Gesamtbekämpfungszeit der Rinderdasselfliegen innerhalb eines Gebietes bis zur gänzlichen Ausrottung stark abzukürzen.f) Die Weidebeständigkeit der Rinderdasselffiegein bedarf nah neuen bioklimatologischen Beobachtungen einer Nachprüfung.g) Günstig beurteilte Folgen der prophylaktischen Besprühungen geälpter Tiere auf deren Fleisch- und Entwicklungszustand durch gleichzeitige Fernhaltung bzw. Bekämpfung der Weidefliegen nnd Bremsen (8) bedarf weiterer Untersnchungen.h) p. o.-Versuche können noch nicht als abgeschlossen gelten.  相似文献   

Novel inhibitors of sterol C-14 demethylase and Δ14 Reductase/Δ8 → Δ7 isomerase for cereal disease control     

Petr Masner  Christopher C. Steel  Rolf Furter  Hans Peter Isenring  Gottfried Oesterhelt  Hugo Ziegler  Peter Zobrist 《Pest management science》1992,35(4):339-347

The activity of five experimental fungicides combining structural elements responsible for sterol C-14 demethylase inhibition and sterol nuclear double-bond transformations has been investigated by examining sterol accumulation in Ustilago maydis (DC.) Corda, inhibition of sterol-biosynthesis enzymes in Saccharomyces cerevisiae Meyer using a cell-free system and protective activity in cereals against Erysiphe graminis DC. and Puccinia coronata Corda. Combining the fenpropidin/fenpropimorph basic structure with a pyridine moiety offered no advantage in fungicidal activity. However, the combination of the pyrifenox structure with a morpholine moiety yielded a compound which was a good inhibitor of C-14 demethylase and Δ⁸ → Δ⁷ isomerase in vitro and gave good cereal protection.  相似文献   

Biological activity of immunostimulatory CpG DNA motifs in domestic animals   总被引：15，自引：0，他引：15  

Mutwiri G  Pontarollo R  Babiuk S  Griebel P  van Drunen Littel-van den Hurk S  Mena A  Tsang C  Alcon V  Nichani A  Ioannou X  Gomis S  Townsend H  Hecker R  Potter A  Babiuk LA 《Veterinary immunology and immunopathology》2003,91(2):89-103

Bacterial DNA contains a much higher frequency of CpG dinucleotides than are present in mammalian DNA. Furthermore, bacterial CpG dinucleotides are often not methylated. It is thought that these two features in combination with specific flanking bases constitute a CpG motif that is recognized as a "danger" signal by the innate immune system of mammals and therefore an immune response is induced when these motifs are encountered. These immunostimulatory activities of bacterial CpG DNA can also be achieved with synthetic CpG oligodeoxynucleotides (ODN). Recognition of CpG motifs by the innate immune system requires engagement of Toll-like receptor 9 (TLR-9), which induces cell signaling and subsequently triggers a pro-inflammatory cytokine response and a predominantly Th1-type immune response. CpG ODN-induced innate and adaptive immune responses can result in protection in various mouse models of disease. Based on these observations, clinical trials are currently underway in humans to evaluate CpG ODN therapies for cancer, allergy and infectious disease. However, potential applications for immunostimulatory CpG ODN in species of veterinary importance are just being explored. In this review, we will highlight what is presently known about the immunostimulatory effects of CpG ODN in domestic animals.  相似文献   

Influence of low phosphorus intake during early lactation on apparent digestibility of phosphorus and bone metabolism in dairy cows   总被引：1，自引：0，他引：1  

Adrienne Ekelund  Rolf Sprndly  Kjell Holtenius 《Livestock Science》2006,99(2-3):227-236

In this study, the effects of reducing the dietary phosphorus (P) supply during the first 4 months of lactation on P balance and bone metabolism were investigated in dairy cows during a full lactation, including the dry period. Twenty-two multiparous cows of the Swedish Red and White Breed were included in the experiment. Eleven cows received a dietary P concentration of 0.43% of DM during the whole lactation (NP), and 11 cows received a dietary P concentration of 0.32% of DM during the first 4 months of lactation, followed by 0.43% of DM during the rest of lactation (LP). Total collection of faeces was carried out during five different stages of lactation, for 5 consecutive days at each occasion. The dynamics of bone metabolism was investigated by monitoring one bone-formation marker, identifying osteocalcin (OC), and one bone-resorption marker identifying C-telopeptide fragments of collagen type I (CTx) in blood plasma. At the two first collection periods, 3–7 and 11–15 weeks after parturition, the apparent digestibility of P was higher in the LP cows (52%) than in the NP cows (42%). During the following collection periods, no difference in the apparent digestibility could be noted between the two groups of cows. Phosphorus retention did not differ between treatments at any collection period. The highest retention was observed during late lactation and during the dry period. The profiles of the bone metabolism markers indicated a net resorption of bone during early lactation, but there were no differences in marker concentrations between the groups during early lactation, indicating that the LP diet did not induce a further elevated net bone resorption.  相似文献   

The impact of grade of laryngeal function immediately prior to laryngoplasty and ipsilateral ventriculocordectomy on postoperative performance: 623 Thoroughbred racehorses (1998-2013)     

Ali H. Broyles  Rolf M. Embertson  J. Brett Woodie  Vinicius Machado 《Equine veterinary journal》2022,54(5):856-864

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Stocking control concepts in uneven-aged silviculture   总被引：2，自引：0，他引：2  

O'Hara  Kevin L.; Gersonde  Rolf F. 《Forestry》2004,77(2):131-143

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