摘要:

Summary:Soil enrichment studies were conducted with nitralin [4‐(methylsulfonyl)‐2,6‐dinitro‐N,N‐dipropylaniline] with and without exogenous carbon and nitrogen. Bacterial isolates obtained were placed into three categories. Eight fungal isolates, notably Fusarium and Penicillium sp., were obtained from the enriched soil culture. Only one bacterial isolate (Erwinia trachelphila) and no fungal isolates appeared to degrade nitralin. The degradation product isolated was tentatively identified by TLC and radioautography as 4‐(methylsulfonyl)‐2,6‐dinitrophenol. No14CO2evolution from ring‐labelled nitralin was detected from an

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00416.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Summary:The herbicide Tordon 50D (picloram+2,4‐D) affected the integrity of the nucleus and cell membranes in Pinus radiata needle segments and caused the swelling of internal chloro plast membranes and the eventual disintegration of the chloroplasts. Tordon 22K (picloram) only affected chloro plast structure.Both herbicides had similar adverse effects on cell membranes and chloroplasts of Eucalyptus viminali

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00417.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Summary:The concentration of simazine in surface soil was determined on two occasions at a number of sites in a 2‐year‐old apple orchard under either conventional herbicide strip or overall herbicide soil management. There was no evidence of simazine re‐distribution in conventional herbicide strips. With overall herbicide management there was evidence of the movement of simazine from much of the area of the orchard and its accumulation in either small erosion channels or deposition areas. This was prevented by a thin litter of straw spread over the soil su

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00418.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Zusammenfassung:14C‐MCPA wurde beim Auspflanzen der Wurzelstückchen, und wenn die Pflanzen 3 cm, 5–7 cm und 12–15 cm lange Blätter entwickelt hatten, in die Wurzeln von Sonchus arvensis L. injiziert. Nach Extraktion mit 70%‐igem Äthanol und Trennung auf Dünnschichtplatten konnten durch Scanning drei hier als 1, 2 und 3 genannte Komponenten nachgewiesen werden. Komponente 2 chromatographierte wie MCPA und bestand aller Wahrscheinlichkeit nach aus dem nichtmetabolisierten Rest der injizierten Substanz. Komponente 3 wurde schneller als Komponente 1 gebildet, aber beide Komponenten wurden unter Einfluss von 1N HCl oder 1N NaOH+Wärme zur Komponente 2 (MCPA) verwandelt. Komponente 3 unterschied sich wieder von Komponente 1 durch ihre höhere Umwandlungsgeschwindingskeit.Der Metabolismus von MCPA verlief um so schneller, je älter die Pflanzen waren, und war in Mutterwurzeln rascher als in Tochterwurzeln und Blättern. Dormante Wurzeln zeigten eine Fähigkeit MCPA zu metabolisieren auf, die wenigstens nicht geringer als bei nicht‐dormanten Wurzeln war. Weiter verlief der Metabolismus schneller bei 23°als bei 70.Abspaltung von14CO2war ein langsamer Prozess, und nach 4 Tagen machte die Aktivität des ausgeschiedenen14CO2nur 1,3% der Gesamtaktivität aus.In Biotesten mit Raphanus sativus L. als Testpflanze, zeigte Komponente 3 eine entsprechende Phytotoxizität wie Komponente 2 (MCPA) auf, während die stabilere Komponente 1 sehr

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00419.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Summary:Suspensions of wettable powders of metribuzin and simazine were sprayed onto samples of two soils of two particle size grades,>2.5 mm and2.5 mm samples than the<0.5 mm samples, following application to dry soil, but by 48 h the differences were negligible. With simazine WRO soil did not show this effect at all and with Kirton soil only small differences were seen. If the soil was wet at the time of application, particle size had no effect except with simazine in Kirton soil.Generally metribuzin concentrations were higher after application to wet than to dry soils for at least 24 h after wetting whereas simazine concentrations were higher from initially dry soils and the differences had virtually disappeared 24 h after wetting.With the WRO soil herbicide concentrations in soil water were higher if the soil was wetted 1 h after spraying than if left for 1 week but the differences rarely persisted for 48 h. No such trend was observed with Kirton soil.It is concluded that the differences observed in these experiments could be responsible for variations in the performance of soil‐applied herbici

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00420.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Summary:The native perennial shrub, Bassia birchii. occurs as a weed over large areas of semi‐arid eastern Australia. Its germination requirements and seedling growth were investigated and related to field observations and to possible means of control. Seeds cannot germinate until the woody fruit has broken down. Laboratory experiments showed that seeds would germinate throughout the year with most germinating at autumn and spring temperatures. Seedling deaths in the field are attributed to poor root growth, before the effects of water stress occurs. The spasmodic appearance of Bassia birchii infestations, particularly after droughts, is related to the dependence on the death of mature plants to provide propagules and fruit breakdown for germination. The unpredictable infestation pattern and the early development of spined fruits and basal buds on seedlings hinder control. Short period rotational or strategic grazing are suggested as possible means of control of seedlings in areas where perennial pastures can be establishe

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00421.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Summary:The effects on plant growth of applying trifluralin or nitralin combination with simazine, atrazine, prometryne and linuron to the upper 5‐cm root region of vetch (Vicia sativa L.), pea (Pisum sativum L.) and soybean (Glycine max) were investigated. Foliar injury due to herbicides of the second group was markedly reduced in each species by simultaneous treatment with trifluralin or nitralin both of which inhibited lateral root growth without affecting aerial plant growth or tap root extension growth. This inhibition of lateral root growth in roots treated with trifluralin or nitralin was associated with reduced uptake and subsequent transport to the foliage of14C‐labelled simazine in vetch and pea and14C‐labelled atrazine in soybean. This probably accounted for the reduction in simazine and atrazine phytotoxicity.In the presence of trifluralin or nitralin comparatively higher amounts of radioactivity were retained in the roots of pea and soybean and this reduced the amount of14C available for transport to the foliage. This was not evident in

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00422.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Summary:Echium plantagineumL. is a widespread, persistent, and often dominant volunteer species in southern Australia. This paper describes laboratory and field experiments investigating seed germination in E. plantagineum and a commonly associated species, Trifolium subterraneum L. In the laboratory, E. plantagineum germination was favoured by relatively high temperatures, and the seed showed considerable innate and temperature‐enforced dormancy. In the field, this dormancy appeared to prevent some germination in response to rainfalls immediately after seed formation, and permitted sporadic germination during summer and autumn in subsequent years. In 1972 and 1974, both species emerged well in autumn whilst E. plantagineum was favoured in summer and T. subterraneum was favoured in winter. No seedlings emerged in spring. Emergence appeared to be controlled primarily by moisture availability and temperature but also was affected by cultivation and removal of soil‐surface litter. The results of these seed germination studies show that E. plantagineum is well adapted to persist in a Mediterranean‐type climate, and will be favoured in years with early seasonal breaks. T. subterraneum is likely to be favoured with later b

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00423.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Summary:Annual weeds germinating after planting strawberry (Fragaria chiloensis (L.) Duch. cv. Cambridge Favourite) in late March had no effect on crop growth if removed by late May. Dense weed cover thereafter severely inhibited stolon growth, virtually eliminating it if allowed to remain beyond mid‐August. Shading by weeds inhibited leaf production and caused etiolation of existing leaves. New leaves appeared shortly after weed removal and few plants died unless weed cover persisted for most of the growing season. Further weed germination was allowed on some plots. Although not removed until late autumn, these weeds only had adverse effects on crop growth where initial weeding had occurred before mid‐June.In one experiment, delaying weed removal until 6 July, 31 August or 2 November in the first year reduced fruit yield in the second (weed‐free) year by 34%, 54% and 67% respectively. In a later experiment, competition from weeds until July or later in the first growing season gave fruit yields similar to those in the first experiment, but totally weed‐free plots and those kept clean after weeding in mid‐June produced less fruit than plots which remained weedy between mid‐June and mid‐August. It is suggested that competition from uncontrolled stolon growth in this experiment severely inhibited crown and hence truss production on plots which did not suffer weed competition. Unless left untouched until early September, weeds had less adverse effect on truss production than the stolons which they displaced.The results are interpreted in relation to improving the efficiency of weed contr

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00424.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1976.tb00425.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY