摘要:

Summary.The spraying with DNOC as a herbicide in a young crop of winter rye results in an increased grain yield, even in weed‐free trials. In order to trace the sequence of reactions by which treatment in winter affects the yield next summer, growth, development and yield of treated and untreated plants were examined in a single weed‐free experiment which included the study of several seed rates.As a result of the DNOC treatment, vegetative growth was retarded at first, but later the treated plants recovered and surpassed the control plants in fresh and dry weight. Since their dry matter percentage was somewhat lower and their nitrogen content a little higher, the crop appeared both more vigorous and more youthful. Leaf blade area and chlorophyll content of leaves and culms were increased and chlorophyll breakdown at ripening was delayed.No effect could be observed on the rate of development of the young spike, but heading, flowering and ripening were retarded.Yield increase on the DNOC‐treated plots was 10% on an average. The analysis reveals that on these plots 3% more culms were formed, each of which bore 5% more kernels; the average kernel weight was unaffected. The increase in ear density can be ascribed to the more luxuriant vegetative growth, while the kernel weight per car is correlated with the nitrogen content of the culm.It is concluded that the yield increase is due to a stronger vegetative growth together with a prolonged period of generative development.Effets d'un traitement au DNOC sur la croissance, le développement el le rendement d'un seigle

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00185.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.The average air‐dry yield of weeds on fallow plots was about four times as large (2660 kg/ha) as the yield of weeds which developed among spring cereal crops (740 kg/ha). Application of fertilizers increased the number of weeds and their average weight on both irrigated and non‐irrigated plots. Treatment with MCPA reduced the weed yield to 36% on fallow plots and to 26% on weedy cereal plots. It was more effective on fertilized plots than on unfertilized plots, but irrigation made little difference to its effectiveness. The space left by the destroyed weeds was mainly occupied byAgropyron repens. Oats were better able to compete with weeds than were wheat and barley. On unfertilized and non‐irrigated plots spraying with MCPA (1‐26 kg/ha) at the beginning of shooting significantly reduced the yields of weed‐free barley. The yields of sprayed oats and wheat were also below the yields from the unsprayed although the reductions were not significant at the 5% level. However, on a number of fertilized and irrigated plots, both weedy andhand‐weeded, on which the plants had better growing conditions, MCPA resulted in a significant increase in the grain yield of barley and oats.Influence de l'irrigation, de la fertilisation et du MCPA sur la compétition entre céréales de printemps et m

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00186.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.Pre‐emergence applications on a wide range of mineral soil types with a proprietary formulation of an endothal/propham mixture established a relationship between the amounts of coarse sand and clay in a soil and the rate of use of the chemical required for optimum results. The effectiveness of a given dose for any one soil type was found to be dependent on adequate rainfall between time of application and weed emergence. The minimum rainfall required varied with the date of the application. A wide range of seedling weeds was adequately controlled and treated areas which exhibited a good control of weeds at emergence were found to be still weed‐free as long as 14 weeks after treatment.Etudes sur l'application en pré‐émergence aux betteraves d'un mélange endotha

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00187.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.A study of the emergence and development ofAvena fatuain winter wheat showed that after the mild winter of 1960/61 autumn‐germinated wild oats constituted a far more serious weed problem than spring‐germinated plants. It was concluded that the application of barban should be timed in relation to these autumn‐germinated plants. As an extension of their work on spring cereals, the authors investigated the effect of barban on the yield ratio of winter wheat and cultivated winter oats grown as a mixture. A reduction in the oats fraction as a result of barban treatment was accompanied by an increase in wheat giving a total yield which was almost the same as untreated. Experimental data are also presented on the occurrence, and significance of an interesting variation in crop tolerance during the winter. No obvious correlation was found between increased crop sensitivity and development stage or temperature. The capacity of the crop to recover was found to be high.Quelques données sur l'utilisation du barbane dans la lutte contre la folle avoine dans le blé

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.Freshly collected ripe seeds ofAvena fatuawere first kept out of doors on the surface of the soil for 0 to 3 monehs, and then stored dry in the laboratory for 0 to 6 months before testing for dormancy and viability. Results from six European countries agreed well. Only 10% of ripe seeds germinated immediately alter collection and germination rose to 50% by December or January in all countries except Denmark. Viability was scarcely affected by age or storage conditions, except that many seeds died out of doors during winter in Denmark and Germany. The percentage of dormant seeds in December was greater in Denmark than elsewhere, possibly because the seeds were of a different type. Seeds may not behave the same in normal agricultural conditions as they did in this experiment.Une expérience internationale sur l'influence de l'âge et des conditions de conservation sur la viabilité et la dormance de semencesd'Avena fa

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00189.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Zusammenfassung.Substituierte N‐Cycloalkylharnstoffverbindungen wurden auf ihre Verwendung zur Bekämpfung unerwünschten Pflanzenwuchses untersucht. Die Herbizidwirksamkeit ist abhängig von der Grösse des Cycloalkylringes und der Art der Ringsubstituenten, sowie von deren Stellung und sterischen Anordnung am Ring. Das Wirkungsoptimum liegt bei 8 Ringkohlenstoffatomen. Die wirksamen Vertreter dieser Klasse eignen sich zur Bekämpfung von Unkrautwuchs in Hackfrucht‐ und Sonderkulturen.Relationship between the structure and herbicidal properties of N‐cyclo

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00190.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Summary.Results obtained on the growth response of biotypes ofCynodon dactylonto trichloroacetic acid (TCA) and 2,2‐dichloropropionic acid (dalapon), both formulated as the sodium salt, have indicated that the tetraploid biotypes are more resistant than the triploid, and that biotypes of the same chromosome number also differ in their response to these herbicides.Investigations on the effects of adding non‐ionic, cationic and anionic wetting agents to aqueous Solutions of the herbicides in which the leaves of plants were immersed showed that, in general, the wetting agents did not significantly increase the phytotoxicity of either herbicide.Studies on bud dormancy revealed that uptake of TCA and dalapon via the roots is through the transpiration stream and that in tetraploids the dormant period induced by the acids is shorter than in triploids.Eludes sur les biotypes deCynodon dactylon (L.) Pers. II. Les réactions aux acides trichloracétique et 2,2‐dichloropro

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00191.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00192.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00193.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1962.tb00194.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY