Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-26T08:51:35.107Z Has data issue: false hasContentIssue false

Studies in selective weed control IV. The control of weeds in fibre flax

Published online by Cambridge University Press:  27 March 2009

G. E. Blackman
Affiliation:
Agricultural Research Council Unit of Experimental Agronomy, Department of Agriculture, University of Oxford
K. Holly
Affiliation:
Agricultural Research Council Unit of Experimental Agronomy, Department of Agriculture, University of Oxford
E. G. Cox
Affiliation:
H.M. Norfolk Flax Establishment, King's Lynn

Extract

During the period 1942–50 some thirty-seven multifactorial field experiments have been carried out to determine the conditions under which weeds in fibre flax can be selectively controlled by herbicides. In order to assess the direct effects of treatment on flax, some experiments have been undertaken in weed-free crops, while others have been sited in weed-infested crops so that the increases in productivity following on weed suppression could be evaluated.

In almost all experiments, the total crop weight, the yield of de-seeded straw and the amount of scutched fibre per plot were determined, while in a proportion seed yield was also measured. Where weeds were present, counts were made to establish the degree of control.

The preliminary experiments demonstrated that sulphuric acid, ammonium sulphamate and ammonium thiocyanate were far too toxic to flax. An examination of a range of cupric salts suggested that the most promising compound was cupric chloride, while of the formulations of dinitro-o-cresol investigated only the sodium salt appeared to be sufficiently selective. It was also found that in terms of fibre production sodium 2-methyl-4-chlorophenoxyacetate was less toxic than sodium 2:4-dichlorophenoxyacetate. In consequence, the bulk of the investigations have related to determining the optimal conditions for the use of cupric chloride, sodium dinitro-o-cresylate and sodium methylchlorophenoxyacetate.

For all three compounds it has been observed that flax is least liable to injury at a height range of 2–6 in. There are limitations to the amounts which can be safely employed, namely, 20 lb. of cupric chloride or 6 lb. of sodium dinitro-o-cresylate applied in 100 gal. of spray solution per acre. With sodium methyl-chlorophenoxyacetate the corresponding limit is 1 lb./acre, and the evidence suggests that the crop may be injured if the volume of application is reduced below 25 gal./acre.

Within these limitations of concentration volume and stage of development of the crop, the suppression of annual weeds has led to significant increases in the yield of straw, seed and scutched fibre. Larger gains resulted from the use of sodium methyl-chlorophenoxyacetate and sodium dinitro-ocresylate. This superiority over cupric chloride is in part attributed to the wider range of weed species which are killed by the two sodium salts and in part due to the greater liability of crop damage if the limits on amount and time of application are not strictly observed.

The results have also clearly established that for fibre flax the weight of total crop, the yield of straw, the amount of seed or plant height cannot be taken as reliable criteria for the evaluation of herbicides, for while all these may be little affected by treatment yet there may still be large reductions in the amount of recoverable fibre. A preliminary anatomical examination of the internal changes in the stems of flax has shown that when treatment with dichlorophenoxyacetic acid is delayed, a marked but localized curvature of the stem results and in this zone fibre formation is abnormal: thus breakages either during pulling or processing may occur at this point of weakness.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1951

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Aberg, E., Hagsand, E. & Väärtnöu, H. (1948). Växtodling, 3, 8.Google Scholar
Anonymous (1949). Adv. Leafl. Minist. Agric. no. 345.Google Scholar
Barry, J. P. (1948). Ann. agron., Paris, 18, 484.Google Scholar
Black, M. A. (1944). N.Z. J. Sci. Tech. A, 25, 235.Google Scholar
Blackman, G. E. (1945). J. R. Agric. Soc. Engl. 108, 137.Google Scholar
Blackman, G. E. (1950). J. R. Soc. Arts, 98, 500.Google Scholar
Blackman, G. E. (1950). Sci. Progr. 38, 637.Google Scholar
Blackman, G. E. & Holly, K. (1948). J. Minist. Agric. 54, 538.Google Scholar
Blackman, G. E., Holly, K. & Roberts, H. A. (1949). Symp. Soc. Exp. Biol. 3, 283.Google Scholar
Blackman, G. E. & Roberts, H. A. (1950). J. Agric. Sci. 40, 62.CrossRefGoogle Scholar
Blackman, G. E. & Roberts, H. A. (1950). J. Agric. Sci. 40, 70.Google Scholar
Cashmore, A. B., Moore, R. M. & Lee, A. A. (1946). J. Coun. Sci. Industr. Res. Aust. 19, 269.Google Scholar
Crafts, A. S. & Reiber, H. G. (1945). Hilgardia, 16, 487.Google Scholar
Eyre, J. V. (1914). J. Bd Agric. 20 Supplement, 12.Google Scholar
Friederich, J. C. (1950). Vlasbode, 12 (353), 3.Google Scholar
Granhall, I. & Zienkiewicz, H. (1948). Växtodling, 3, 65.Google Scholar
Hagsand, E. & Väärtnöu, H. (1949). Växtodling, 4, 8.Google Scholar
Harris, L. E. & Hyslop, G. R. (1942). Bull. Ore. Agric. Exp. Sta. no. 403.Google Scholar
Hofsten, C. G. von (1947). Växtodling, 2, 186.Google Scholar
Jannin, . (1926). C.R. Acad. Agric. Fr. 12, 55.Google Scholar
Paatela, J. (1949). Valt. Maatalousk. Julk. 131.Google Scholar
Paatela, J. & Dunham, R. S. (1949). Maatalousk. Aikakausk. 21, 143.Google Scholar
Rabaté, E. (1926). Int. Rev. Sci. Pract. Agric. 4, 535.Google Scholar
Robbins, W. W., Crafts, A. S. & Raynor, R. N. (1942). Weed Control. New York: McGraw-Hill.Google Scholar
Simon, E. W. & Blackman, G. E. (1949). Sym. Soc. Exp. Biol. 3, 253.Google Scholar
Tandon, R. K. (1949). Agron. J. 41, 213.CrossRefGoogle Scholar
Thompson, H. E., Swanson, C. P. & Norman, A. G. (1946). Bot. Gaz. 107, 476.CrossRefGoogle Scholar
Ulbricht, H. (1938). Pflanzenbau, 15, 122.Google Scholar
Westgate, W. A. & Raynor, R. N. (1940). Bull. Calif. Agric. Exp. Sta. no. 634.Google Scholar