ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00103.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:The vegetative growth of Japanese millet (Echinochloa utilisOhwi et Yabuno) was much lens reduced by pre‐emergent treatments of thiobencarb (S‐eithyl hexahydro‐1,4‐azepine‐l‐thiolcarbamate) and molinate (S‐(4‐chlorobenzyl)‐N.N‐diethylithiolcarbamate] when the herbicides were applied at<4 l a.i. ha−1over rice stubble ash. The effcct was caused by adsorption of the herbicides onto activated carbon in the ash and occurred alike in field and pot experiments.The reduction in herbicide activity was quantified in the pot experiment. There the ash rendered at least 60% of the applied herbicide bio

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00104.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:Field trials were conducted to evaluate herbicides for weed control in groundnut from 1977 to 1979. The pre‐emergence herbicides used were alachlor and metolachlor, applied alone or mixed with terbutryne. Some treatments were followed either by post‐emergence bentazone or by one supplementary hoe‐weeding. In the southern Guinea savanna zone, where early grass weed control was more important, alachlor or metolachlor at 1.5 kg ha−1gave adequate weed control and pod yields comparable with that of the hoe‐weeded check. There was no advantage in adding terbutryne, or in supplementary hoeweeding or post‐emergence bentazone application. In the northern Guinea savanna zone, grass and broad‐leaved weeds were equally important. Application of alachlor, metolachlor or mixtures with terbutryne (2:1) at 1.5 kg ha−1required post‐emergence application of bentazone or supplementary hoe‐weeding for effective weed control and high pod yield. The reduction in pod yield on untreated control plots ranged between 18 and 70% of the best treatm

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00105.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:The effect on seed dormancy of exposing the mother plants to different environmental conditions was studied inDatura ferox. Reducing incident radiation and withholding water to provoke water stress, during the period from fruit set until seed ripening, caused a decrease in the degree of dormancy of the harvested seeds. A significantly smaller amount of the basic fraction inhibitors was found in the seeds with the lesser degree of dormancy. It is suggested that one of the ways in which the environmental conditions to which the mother plants are exposed can influence seed behaviour is by changing the endogenous inhibitor levels

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00106.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:The influence of pyrazon. norflurazon and glyphosate on post‐luminescence decay and fluorescence emission was studied. Pyrazon and norflurazon significantly increased post‐luminescence decay in wheat (Triticum vulgare L) and cuckoo flower (Cardamine pratensis L.). Pyrazon was much more active than norflurazon m this respect, No influence of’glyphosate on post‐luminescence and the emission ol” fluorescence was observed.Measurements of post‐luminescence decay and fluorescence emission can serve to define some aspects of herbicidal pbyto‐toxicity and provide information on the initial action of those compounds that inhibit p

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00107.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:Inheritance of resistance to simazine was investigated in reciprocal pair crosses of resistant and susceptible genotypes ofSenecio vulgaris. The simazine resistant genotypes had been selected in a screening experiment and were unaffected by 2.8 kg ha−1˜’a.i. simazine. Reciprocal differences for resistance and susceptibility to simazine inF2families showed that resistance is maternally inherited. The practical implication of maternal inheritance is that a resistant field population will build up very rapidly from a very low initial frequency of the resistant geno

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00108.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:The consequences of using two pre‐emergence herbicides on autumn‐sown perennial ryegrass (Lolium perenne L.) were measured over 3 years in a field experiment. Ethofumesate (2‐ethoxy‐2,3‐dihydro‐3,3‐dimethylbenzofuran‐5‐yl melhylsul‐phonate) and methabenzthiazuron [N‐(benzothiazol‐2‐yl)‐N, N'‐dimethylurea] were each applied at 0, 0.8, 1.6 and 3.2 kg ha−1one week after drilling the grass seed. Monthly counts of plants per unit area and tillers per plant were made until the following April and the herbage dry weights of the major species were recorded at seven harvests.Heavy infestations ofStellaria media(L.) Vill. andPoa annuaL. occurred on untreated plots. Ethofumesate, and to a lesser extent methabenzthiazuron, proved effective in suppressing these weeds, only low rates being needed to controlS. media. Both weeds needed to be controlled to achieve full benefits to the crop; control resulted in a 4‐fold increase in ryegrass tiller density by the first spring and a 6‐fold increase in ryegrass herbage was recorded at the first harvest in May. Some yield benefits were carried over into the second year but not into the third. In total, an extra 4.16 t ha−1of ryegrass dry‐matter was harvested from plots treated with ethofurnesate at 0.8 kg ha−1compared with the controls. The results are discussed in terms of defining optimum crop densiti

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00109.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:A bioassay technique based onPoa annuagrowth showed that ethofumesate applied at 2.0 kg/ha in October to a newly‐sown ryegrass (Lolium perenne) sward had a half‐life of just over 8 weeks. After 7 months there was still sufficient herbicide present to cause about a 50% reduction inP. annuagrowth. The movement of ethofumesate, as measured in soil cores taken 15 months after spraying, was confined mainly to the upper 2 cm of the soil profile. Seeds on the soil surface at spraying were very sensitive to ethofumesate. The implications of the findings for weed control in newly‐sown grass leys are disc

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00110.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:The chlorophyll content increased with time in callus cultures of soybean (Glycine maxL., cv. Chippewa) and tobacco (Nicotiana tabacumL., cv. White Gold) grown in the light on a standard medium. Addition of 0.5 mmol/1 glyphosate [N‐(phosphonomethyl) glycine] to the medium completely inhibited chlorophyll accumulation in the tobacco callus. Soybean callus required 40 times more glyphosate to initiate inhibitory effects on chlorophyll content. The inhibition was not reversed by simultaneous addition of casein hydrolysate or aromatic amino acids, suggesting that aromatic amino acid levels were not limiting for chlorophyll synthesis. In leaf discs of soybean and tobacco, glyphosate accelerated chlorophyll degradation in the light, but not in the dark; there was little difference in response between the two plant species. Young leaves of tobacco were more sensitive than mature leaves to glyphosate effects with glyphosate‐induced net losses of chlorophyll of 24 and 14% respectively after 5 days. Such rates of loss cannot explain the complete inhibition of chlorophyll accumulation in the callus tissue, suggesting that there was an inhibition of chlorophyll synthesis by glyphos

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00111.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Summary:The effects of different concentrations of aqueous leachate ofDatura stramoniumseeds and leaves on germination and radicle elongation ofLinum usitatissimumwere examined.Germination and radicle elongation ofL. usitatissimumwere depressed at high leachate concentrations. Radicle elongation usually appeared more sensitive to the effects of the leachate than did germination. Preliminary investigations showed thatD. stramoniumleaf leachate had similar effects to those of seed leachate.Chemical analysis of the leachates by spot‐tests and by high‐voltage electrophoresis indicated the presence of tropane alkaloids, in particular scopolamine. The presence of both scopolamine and hyoscyamine was confirmed by gas chromatography/mass spectrometry. It was shown that varying concentrations of pure scopolamine and scopolamine plus hyoscyamine solutions had effects similar to those of seed and leaf leachates on germination and radicle elongation ofL. usitatissi

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1981.tb00112.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY