THE INFLUENCE OF IRRIGATION, FERTILIZING AND MCPA ON THE COMPETITION BETWEEN SPRING CEREALS AND WEEDS     

H. SUOMELA  J. PAATELA 《Weed Research》1962,2(2):90-99

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 by Agropyron 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 and hand-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 mauvaises herbes  相似文献   

Studies on the effect of thyroid on vitamin A metabolism. II. Mechanism of decrease of vitamin A in tissues of rats treated with desiccated thyroid     

C Ushimi  N Yoshida 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1964,26(1):7-13

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Inheritance of tolerance to halo blight in bean     

P N Patel  J C Walker 《Phytopathology》1966,56(6):681-682

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Electron microscopy of dark green spots on leaves of Nicotiana glutinosa induced by tobacco mosaic virus     

T Hayashi  C Matsui 《Phytopathology》1966,56(2):192-196

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THE USE OF HERBICIDES IN ALTERNATE HUSBANDRY AS A SUBSTITUTE FOR PLOUGHING     

R. A. ARNOTT  C. R. CLEMENT 《Weed Research》1966,6(2):142-157

Summary. It is practicable to use herbicides as an alternative to ploughing grass swards for the preparation of a seedbed for the sowing of cereals and kale. The yields of spring barley and kale following a glaass/clover sward killed with 10 lb/ac amitrole-T were similar to those obtained following ploughing. Yields of tip to 40 cwt/ac of winter wheat were obtained following grass swards killed with amitrole-T compared with up to 45 cwt/ac after ploughing.
The ideal herbicide must kill all plants in a sward and have no residual toxicity to the subsequent crop. At 10 lb/ac, amitrole-T killed most plants in the sword, but it was considered necessary to delay sowing for at least 3 weeks after spraying to minimize the danger of residual toxicity. Ploughing gave the lowest incidence of grasses persisting from the sward. Paraquat did not control clover and Agropyron repens , while broad-leaved weeds were more common on the ploughed than on the sprayed land.
There were differences in the amount of nitrogen mineralized in ploughed and In undisturbed soil, but these were insufficient to affect crop yields materially. When a lower yield followed herbicidal destruction of the sward, this was not accompanied by a reduced percentage nitrogen content.
L'emploi des déherbants pour la rénovation des prairies  相似文献   

CHEMICAL AND BIOLOGICAL PROPERTIES OF TWO NEW HERBICIDES—IOXYNIL AND BROMOXYNIL     

K. CARPENTER  HELEN J. COTTRELL  W. H. DE  SILVA  B. J. HEYWOOD  W. G. LEEDS  K. F. RIVETT  MARGERY L. SOUNDY 《Weed Research》1964,4(3):175-195

Summary. The preparation of ioxynil, bromoxynil, and their salts is described, and information on solubilities and stability to storage is summarized. Although the toxicology of the herbicides is to be reported in greater detail, a preliminary statement is made here. Evidence of herbicidat activity under glasshouse conditions is indicated briefly, and supports the conclusion that both compounds are effective when applied to the foliage of a wide range of dicotyledon weed species. Seedlings of some weed species resistant to the phenoxy alkanoic acids are controlled under glasshouse conditions at doses as low as 0.125 lb/ac, and ioxynil has a wider range of activity than bromoxynil at these low doses. Graminaceous species tolerate 4–8 lb/ac of both herbicides without injury, and certain leguminous crops tolerate one or other herbicide at doses of 0.5–0.75 lb/ac. The contact action of the herbicides is rapid, there are also slower systemic effects, and seed germination is inhibited. In susceptible species the level of post-emergence activity is shown to be influenced by the growth stage of the weed, the distribution of herbicide on the foliage, and environmental factors of which light intensity appears to be most important.
Propriétés chimiques et biologiques de deux nouveaux herbicides: ioxynil et bromoxynil  相似文献   

Studies on the cowpox-like disease outbreak in Hokkaido, Japan. II. Properties and identification of the isolates     

M Soekawa  H Izawa  H Iwabuchi  K Matsumoto  K Takahashi 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1964,26(6):295-314

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An attempt to reduce calcium phosphate deposits on cobaltic oxide pellets by citric acid treatment     

E D Andrews  B J Stephenson  C E Isaacs 《New Zealand veterinary journal》1964,12(5):113-117

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Mycotoxicoses. 3. Antifungal and antimycotoxic activity of 8-hydroxyquinoline under laboratory and simulated field conditions     

J Forgacs  H Koch  R H White-Stevens 《Avian diseases》1963,7(1):56-66

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Studies on in Vitro Erythrocyte Uptake of I131-Labelled 1-Triiodothyronine as A Test of Thyroid Function in Dairy Cattle     

Lars Ekman  C. B. Thorell 《Acta veterinaria Scandinavica》1965,6(1):30

Uptake of I¹³¹-labelled triiodothyronine by erythrocytes (EU test) as a test of thyroid function has been studied in cattle. The normal EU value for 141 Swedish Red-and-white cows was 6.99 ± 0.95 (range 4.45–10.23) at an incubation time of one hour. Statistically significantly higher values were obtained for newly-calved cows. The EU values for calves are significantly higher but by 12 to 18 months of age decline to the same level as for older cows.The principle of the test is described and the results obtained compared with those for human beings. The EU test is suitable for screening thyroid function for large groups of animals and for studying associations between thyroid activity and different production qualities.  相似文献