ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00001.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Summary.The object of the work described in this paper was to obtain information on the relationship between the effects of crop competition and barban treatment on oats growing in another cereal. The work was carried out on barley cross‐drilled with cultivated oats. Variation in crop competition was obtained by using different barley seed‐rates and nitrogen levels. Increasing the seedrate of barley without applying barban resulted in a reduction of the initial oat population. This reduction applied to weight of individual shoots, number of shoots and panicles per unit area and number of spikelets per panicle. The application of barban at selective rates gave an independent reduction of oats of the order of 80%. This value proved almost constant at each seedrate of barley. Crop competition and barban accordingly seem to art independently and their effects appear to be simply additive. The barley fresh weights per unit area increased substantially when oat competition was reduced by barban treatment. The highest increase occurred on the plots with the lowest barley seedrate in spite of the fact that these plots still appeared infested with oats at harvest time. Nitrogen application stimulated the growth of barley and oats to a similar degree and did not in consequence lead to a selective suppression of oats.Etude de l'influence de la densité du Semis, du taux de fertilisation azotée et du traitement au barbane, sur la concurrence entre une Orge et une

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00002.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Summary.Seeds ofAvena fatuaandA. ludovicianawere sown at a depth of 15 cm or mixed into the top 5 cm of soil in small field‐plots at Rothamsted and subjected to 5 different regimes of depth and frequency of cultivation for 3 years, after which all plots were dug to 15 cm in spring and autumn for a further 4 years. Seedlings were counted and no plants were allowed to produce seeds. After 7 years, soil‐samples showed that very few intact seeds ofA. fatuaand none ofA. ludovicianaremained, although less than 20% of the seeds sown had produced seedlings. Laboratory tests after 4 to 8 years’dry slorage showed seeds of both species to be viable. The maximum survival of viable seeds, estimated by seedling‐emergence, was 61 months forA. fatuaand 33 months forA. Indoviciana. Seeds ofA. fatuasurvived slightly longer at 15 cm than in the top 5 cm of soil. Survival ofA. ludovicianawas less affected by depth and cultivation, except that birds ate some shallow‐sown spikelets in the first fortnight after sowing.A. fatuagerminated in spring and autumn, andA. tudovicianain winter, irrespective of age of seed and cultivation of soil. Frozen soil delayed emergence ofA. ludovicianaseedlings lor varying periods between December and March. Seedlings ofA. ludovicianawere slightly more winter‐hardy thanA. fatua. More seedlings ofA. fatuaappeared in the second spring than at any other time, but 80% of the seedlings ofA. ludovicianaappeared in the first autumn and winter.Effets de la profondeur d'enfouissement des graines et de la fréquence des façons culturalles sur la longévité et la germination des semences de Folle‐Avoine(Avena fatuaL. etA

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00003.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00004.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Zusammenfassung.Es wurden Untersuchungen über die gegenseitige Beeinflussung von Kulurpflanzen und Uukräutern in Wasserkultur durchgeführt. Hierbei wurde eine Methodik verwendet, die es gestattete, die Ursachen einer gegenseitigen Beeinflussung auf den Wurzelbereich zu beschränken und gleichzeitig die Wirkung einiger Konkurrenz‐faktoren (z.B. Licht, Raum) ausz.uschalten. Von insgesamt 57 untersuchten Pflanzen‐kombinationen (Ergebnisse s. Tab. 1‐4) zeigten etwa ein Drittel keine gesicherten Symptome einer gegenseitigen Beeinflussung. Bei allen anderen Versuchen war ein mehr oder weniger ausgeprágter Hemm‐ bzw. Förderungseffekt festzustellen. Die Ursache dieser Erscheinung konnte in einigen Fallen als Náhrstoffkonkurrenz (Nr. 5, 6, 7, 23, 44d. Tabellen) erkannt werden, wáhrend bei anderen Versuchen (Nr. 12, 13, 15, 18, 23, 45, 46) mit der Beteiligung allelopathischer Faktoren (Abgabe organischer Verbin‐dungen aus lebenden und abgestorbenen Wurzelzellen) gerechnet werden muss. Die Wachstumshemmung bzw.‐ förderung war in einigen Fällen dann besonders deutlich (Nr. 46, 47, 51), wenn dem einen Partner durch Vorkultur ein gewisser Entwicklungs‐vorsprung gegeben wurde. Obwohl einige der vorliegenden Ergebnisse mit Befunden aus der Praxis gut übereinstimmen (Nr. 12, 13, 18), kann man aus naheliegenden Gründen (Abbau von Wurzelstoffen durch Mikroorganismen, Absorptionsverhältnisse im Boden usw.) die in Wasserkultur erzielten Resultate nicht unmittelbar auf die natürlichen Verhältnisse übertragen, Um jedoch den möglichen Ursachen einer gegenseitigen Beeinflussung von Kulturpflanzen und Unkräutern überhaupt einmal náher zu kommen, ist cine getrennte Untersuchung der in Frage kommenden Faktoren unumgánglich.Experiments on the interaction between cultivate

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00005.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Summary.In 3 years and in three nurseries, experimental plots sown with conifer seed were weeded by hand at intervals from 1½ to 12 weeks. Assessments of the seedlings at the end of each year showed a reduction in numbers and height only on plots left for 12 weeks between successive weedings. The total time taken to weed plots during the growing season was least for plots weeded at intervals of 3‐4 weeks and greatest for plots weeded at the longest intervals. Data on the total weight of weeds, the total number of weeds, the species composition and the stage of weed growth at weeding are also given and discussed.Essais de désherbage dans les pépin

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00006.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Summary.Published literature on diquat (9,10‐dihydro‐8a, 10a‐diazonia phenanthrene dibromide; 1,1′‐ethylene‐2,2′‐dipyridylium dibromide) and related dipyridyl herbicides is reviewed. Their activity is probably connected with the formation of stable free radicals on reduction and both photosynthetic and respiratory processes may be associated with free radical formation in the plants. These herbicides are rapid‐acting translocated desiccants and kill the aerial parts of most plants, but are safe as soon as they touch the ground, having no residual effect through the soil. Possible uses are as desiccants, in place of cultivation to clear fallows and seedbeds before sowing, in pre‐emergence weedkilling, for weeding round trees and bushes and, with directed spraying, for inter‐row weeding in row crops.Revue des essais effectués avec le Diquat et

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00007.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00008.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00009.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1961.tb00010.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY