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FACTORS AFFECTING THE SELECTIVITY OF 2,3‐DICHLOROALLYLDIISOPROPYLTHIOLCARBAMATE (DI‐ALLATE) AGAINST AVENA SPP. IN WHEAT AND BARLEY
Author(s) -
PARKER C.
Publication year - 1963
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/j.1365-3180.1963.tb00247.x
Subject(s) - avena fatua , sowing , coleoptile , agronomy , avena , weed , germination , plough , selectivity , biology , weed control , main stem , botany , biochemistry , catalysis
Summary. A series of pot experiments has been undertaken to assess the selectivity of 2,3‐dichloroallyldiisopropylthiolcarbamate (di‐allate) against Avena spp. in wheat and barley. It is shown that depth of incorporation, depth of sowing, variety and temperature can all influence the degree of selectivity. When di‐allate is incorporated deeply before sowing, there is good selectivity against Avena fatua L. (wild oat) in barley, but the order can be influenced by the depth at germination of both crop and weed, since the susceptibility of both species increases with increasing depth. Wheat does not exhibit the same response to depth of sowing but variety and temperature are important; the variety ‘Svenno’ is particularly susceptible, and both ‘Svenno’and‘Atte’are much more susceptible at 20° C than at 10° C. As A. fatua is slightly more susceptible at 10° C than at 20° C, selectivity is greater at the lower temperature. Shallow incorporation of di‐allate after sowing gives a much more general selectivity in both barley and wheat, but there is still some element of risk in wheat. Whereas for barley a layer of only 0.5 in. of untreated soil above the seed is adequate protection against damage by di‐allate, 1–1.5 in. of untreated soil may be required above the seed of wheat, depending on variety and temperature. The success of shallow incorporations is explained on the basis that the most sensitive region of the plant is the 10–15 mm above the coleoptile node, which includes the stem apex and developing leaf tissue. This region is moved up in the soil rapidly in Avena spp. by elongation of the ‘mesocotyl’, whereas in wheat and barley, the stem apex is only moved up considerably later by elongation of the internode above the coleoptile node. 2,3,3‐Trichloroallyldiisopropylthiolcarbamate (tri‐allate) as compared to di‐allate has a greater selectivity in barley when the compounds are incorporated deeply; also it has greater selectivity in both wheat and barley when shallowly incorporated after sowing. Facteurs influençant la sélectivité du diisopropylthiolcarbamate de 2,3‐dichloroallyle (di‐allate) appliqué sur blé et sur orge contre Avena spp.