Sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} is used to control weedy grasses in red fescue (Festuca rubraL. # FESRU andF. rubrassp.commutata), an important seed crop in Oregon. The sethoxydim rate required to reduce growth rate of 11 cultivars of red fescue and four cultivars of bentgrass (Agrostis tenuisSibth. # AGSTE andA. stoloniferaL. var.palustris# AGSST), a common contaminant in red fescue fields, by 50% (GR50) was determined in greenhouse and laboratory experiments. Field experiments compared only red fescue cv. ‘Pennlawn’ and bentgrass cv. ‘Penncross'. The GR50values for Pennlawn red fescue in the field, the greenhouse, and the laboratory were 30 kg ai/ha, 15 kg/ha, and 5300 μM, respectively. Penncross bentgrass was approximately 400, 1400, and 12 900 times more susceptible than Pennlawn red fescue in the field, in the greenhouse, and in laboratory experiments, respectively. Plants were at different growth stages in the different experiments. The xylene and surfactant used as a solvent for the technical grade sethoxydim was as toxic to red fescue without sethoxydim as when sethoxydim was included. Cultivars of red fescue differed in their response to sethoxydim, but cultivars of bentgrass did not. The GR50's of other species tested in the greenhouse were >4 kg/ha for annual bluegrass (Poa annuaL. # POAAN), 0.22 kg/ha for tall fescue (F. arundinaceaSchreb. # FESAR), 0.37 kg/ha for downy brome (Bromus tectorumL. # BROTE), and 0.017 kg/ha for Italian ryegrass (Lolium multiflorumLam. # LOLMU).

This paper compares the relationship between temperatures at grain filling and grain-protein content for wheat and barley. Two similar statistical models have been developed using historical grain and climate data to reliably predict the protein content of wheat and barley at grain receival sites. Protein levels were predicted using multiple regressions with the same regression coefficients for all sites. The locality effect is absorbed in the regression intercept derived for each site. Australian Standard White (ASW) wheat data for 109 silos throughout South Australia for the years 1971-1991 were analysed in relation to rainfall and temperatures at the closest weather station. Rainfall from May to September was associated with a decrease in ASW wheat grain protein, and more importantly, the number of days in October above 30�C were positively associated with an increase in wheat grain-protein levels. Analysis of protein data from malting varieties of barley (1982-1991) from 160 South Australian hundreds (districts of about 260 km2) again showed that increased rainfall between July and September was associated with decreased grain protein. However, the dominating influence was the number of days in a row in November above 35�C, which was consistently associated with increased grain protein. This makes an interesting comparison with wheat where October temperatures were more important despite barley being harvested earlier than wheat.

Summary Various control strategies for Achillea millefolium L. (yarrow) were investigated in a dense stand of the weed at Lincoln College in 1977–1978. In early spring plots were either rotary cultivated or left undisturbed. In late spring, plots of both previous treatments were either left undisturbed, rotary cultivated or sprayed with glyphosate at 1·5 kg ha−1. The whole experiment was rotary cultivated twice 1 week later and sown with Hordeum vulgure L. cv. Zephyr (barley) at 144 kg seed ha−1. MCPA + dicamba at 0·9+0·15 kg ha−1 was applied to half of each plot when the second node was detectable (Zadok 32). Rotary cultivation and glyphosate both substantially reduced the regrowth of A. millefolium but glyphosate reduced regrowth by a greater proportion when applied to undisturbed plants than when applied to plants regenerating after cultivation. Both gave a more than 95% reduction compared to the control (rotary cultivation only at sowing time) in the amount of A. millefolium present in the barley stubble in the autumn. MCPA + dicamba caused seedling mortality but did not affect the numbers of primary shoots from rhizome fragments. The grain yield of the barley increased from 2·91 t ha−1 when A. millefolium was not controlled to 4·23 t ha−1 with good control. The barley yield appeared to be restricted by competition from regenerating A. millefolium and by a nitrogen deficiency induced in some regimes by nitrogen immobilization in decaying rhizomes.

Resume: ZusammenfassungBroadcast sprays of several herbicides were applied at difTerent times of the year at several sites in Hawkes Bay, Canterbury and Otago. For good Ihistle control, date of application was more important than types of herbicide. In Hawkes Bay. applications made in April, May and June tended to be the most effective. Under slightly cooler Canterbury conditions, April, September and October were the best application dates. In the Otago trials, spring emergence of thistle seedlings meant that the mosl consistent results came from September or October applications. At all sites, applications made in July or August were relatively ineffective, probably because of low winter temperatures and slow thistle growth rates. MCPA (potassium salt) at 1 -0 kg ha ' was the standard herbicide used In all experiments, MCPA at 0-5 kg ha"', MCPB (sodium salt) at 0-5 and 1 0 kg ha ' and 2,4-D at 0-5 kg ha"' did not kill as many thistles as MCPA at 1-0 kg ha"'. MCPA at 1-5 kg ha ' and MCPB (butyl) ester + clopyralid at 0-5 + 0-015 or I 0 + 0-03 kg ha ' gave consistently better control than MCPA at 1-0 kg ha '2.4-Dal 1-0 or 15 kg ha'. MCPB at 15 or 20 kg ha', and MCPA + MCPB at 033+ ID or 0 67 + 0-5 kg ha ' gave results very

No abstract