Correspondence     

Abdurrahman Saghir 《国际虫害防治杂志》2013,59(1):106-107

Abstract

Twenty-seven different herbicides were tested at the AUB Agricultural Research and Education Center in the Beqa'a, Lebanon, to determine their effects on weeds in wheat, barley, maize, onion and sugar beet. Each herbicide was tested at three different rates as pre-emergence and post-emergence applications. Unweeded and hand-weeded check plots were included. Data on yield, quality and other agronomic characteristics of the crops tested were recorded.

Concentrations of 1,000 and 10,000 ppm of 2, 4–D caused a significant decrease in the height and grain yield of wheat and barley when sprayed at the 3-leaf stage. At the 5-leaf stage, injury to wheat and barley occurred only when sprayed at 10,000 ppm, whereas an increase in the grain yield was obtained at 1,000 ppm of 2, 4–D acid equivalent (1 kg a.i./ha).

Pre-emergence treatments of atrazine and simazine at 2.5 kg a.i./ha caused a significant increase in the forage and grain yields of maize as compared to unweeded check plots. Wheat, oats, vetch and sugar beet were injured when planted after triazine-treated maize, whereas onions and soyabeans were tolerant. Other promising herbicides tested on maize were C 3095 (N–3–trifluoromethylphenyl–N'–methyl–N'–methoxyurea) and BV– 201 (1–(3′, 4′–dichlorophenyl)–3–methylpyrrolidin–2–one) applied as a pre-emergence spray at 1 and 2 kg/ha respectively.

Pre-planting treatment of EPTC and pre-emergence treatment of pebulate at 2 kg/ha gave a slight increase in the yield of roots of sugar beet. BV–201 and BV–207 (1–(3–chloro–4–methylphenyl)–3–methylpyrrolidin–2–one) were phytotoxic to beet.

In onions, nitrofen, BV–201 and BV–207 at 1–2 kg/ha were promising as pre-emergence and post-emergence sprays. DNOC and dinoseb at 1.5 kg/ha and ioxynil at 0.5 kg/ha sprayed post-emergence increased the yield of onions significantly over the check. No significant effects of these herbicides were observed on the bulb index, moisture content and total soluble solids of onions.  相似文献   

Residues of atrazine, simazine, linuron and diuron after repeated annual applications in a peach orchard     

P. B. MARRIAGE  W. J. SAIDAK  F. G. VON  STRYK 《Weed Research》1975,15(6):373-379

Annual applications of the herbicides atrazine, simazine, linuron and diuron at 45 kg/ha were made to the same plots for 9 consecutive years from 1963 to 1971 in a peach (Prunus persica (L.) Batsch.) orchard located on sandy loam soil near Harrow, Ontario. Soil samples from these plots were collected in late October for the last 3 years (1969–1971) and trees were cut down in December, 1969. Herbicide residues were determined by bioassays based on the fresh and dry weight of oats (Avena sativa L.) and in one year results were confirmed by chemical analysis. Significant accumulation of herbicides was not observed. The maximum residue levels measured in October over the 3 years of sampling were 7′3 kg/ha for diuron, 3–8 kg/ha for linuron, 1–6 kg/ha for simazine and 04 kg/ha for atrazine in the top 15 cm of the soil profile. Simazine and atrazine showed a rapid decrease in amount after treatment but diuron and linuron were degraded more slowly. Measurable residues of all herbicides were confined to the upper 15 cm of the soil profile and the majority of herbicide remained in the 0–5-cm soil layer. Oats were planted in the orchard plots from 1972 to 1974 to follow the disappearance of the herbicides. All herbicides caused highly significant yield decreases in 1972, atrazine causing the least (38%) and diuron the greatest (86%) reductions. Diuron reduced the yield of oats in 1973 and caused a highly significant decrease in the weight of young oat plants in 1974.  相似文献   

Control of Avena fatua and Fagopyrum tataricum with tank mixtures of linuron or linuron + MCPA and sequential applications of linuron, and post-emergence A. fatua herbicides     

P. A. O'SULLIVAN 《Weed Research》1981,21(5):211-217

Linuron (0.21 and 0.28 kg/ha) and linuron + MCPA (0.21+0.56 kg/ha) in a tank mixture with field rates of barban, difenzoquat and flamprop-methyl reduced the phytotoxicity of these herbicides to Avena fatua. When linuron was applied immediately following or 6 days after the A. fatua herbicides no reduction in phytotoxicity to A. fatua occurred, suggesting that the antagonism may be occurring as a result of physical or chemical incompatability when the herbicides are mixed together. The possibility of obtaining broad-spectrum weed control with one trip over the field by applying linuron and one of these wild oat herbicides separately but at the same time using a double-boom, double-tank system deserves evaluation. When linuron was applied in a tank mixture (0.21 and 0.28 kg/ha), immediately after, or 6 days after diclofop-methyl (0.70 kg/ha), there was no reduction of A. fatua control, and wheat tolerance to the tank mixture was good. This tank mixture offers potential for control under field conditions of A. fatua and some broad-leaved weeds in one spray operation. Linuron + MCPA (0.21+0.56 kg/ha) in a tank mixture severely reduced A. fatua control with diclofop-methyl. No loss of phytotoxicity to Fagopyrum tataricum occurred when the A. fatua herbicides tested were tank mixed with linuron or linuron + MCPA. Lutte contre Avena fatua et Fagopyrum tataricum avec des mélanges extemporanés de linuron ou de linuron + MCPA et des applications successives de linuron et d'herbicides de postlevée actifs contre A. fatua  相似文献   

Yield losses in weed-free wheat and barley due to post-emergence herbicides     

B. R. ELLIOTT  J. M. LUMB  T. G. REEVES†  T. E. TELFORD‡ 《Weed Research》1975,15(2):107-111

The tolerance of weed-free wheat and barley to a range of herbicides (bromoxynil, methabenzthiazuron, MCPA, bromoxynil + MCPA. linuron, prometryne, diuron, 2,4-D ester and 2,4-D amine) when applied at the crop three-leaf stage, was examined over the 5-year period 1968–72. All chemicals lowered grain yields to some extent, but the variation between chemicals was greater for wheat than for barley. In both crops, methabenzthiazuron was the safest chemical causing only small (<2·0%,) yield losses at rates up to 2·25 kg a.i./ha. At this rate of application yield losses of up to 36% were recorded for the substituted urea derivatives. Both crops had a low tolerance to 2,4-D ester and amine. Yield losses from bromoxynil, bromoxynil + MCPA and MCPA were similar, varying from 4 to 8% al 0·5 kg a.i./ha to 9–24% at 2·25 kg a.i./ha. Pertes de rendement dans le blé et l'orge provoquées, en l'absence de mauvaises herbes, par des herbicides de postlevée Pendant une période de 5 années (1968–1972) les auteurs ont examiné la résistance du béet de l'orge. Traités, en l'absence de mauvaises herbes, au stade 3 feuilles, avec une série d'herbicidcs (bromoxynil, méthabenzthiazuron, MCPA, bromoxynil-i-MCPA, linuron, prométrync. ditiron, 2,4-D ester et 2,4-D a mine). Tous ces produits ont diminué les rendements en grains dans des proportions variées, mais la variation entre produits a été plus grande pour le blé que pour l'orge. Pour les deux céréales, le méthabenzlhiazuron a été le produit le moins toxique, provotjuant seulement de faibles penes de rendement inférieurcs à 2,0%, à des doses allant jusquà 2,25 kg/m.a/ha. A cette dose d'application, des pertes de rendement allant jusquà 36% ont élé enregistrées avec des urées substituées. Les deux éréles ont manifesté uoe faible resistance au 2,4-D estr et amine. Les pertes de rendement provoquées par le bromoxynil, le bromoxynil + MCPA, et le MCPA ont été analogues, variant de 4 à 8% pour 0,5 kg/m.a./ha, jusqu’à 9 à 24% pour 2,5 kg/m.a./ha. Ertragsverluste durch Nachaufiatifherbizide in unkrautfreiem Weizen und Gerste In unkrautfreien Weizen- und Gerstebestánden wurde in fünfjáhrigen Versuthcn (1968–72) die Toleranz der beiden Arten gegenüber folgenden Herbiziden untersucht: Bromoxynil, Methabenzthiazuron, MCPA, Bromoxynil + MCPA. Linuron, Prometryn, Diuron, 2,4-D-Eister und 2,4-D-Amin- salz. Die Behandlung erfolgte jeweils im 3-Blattstadium. Alle Verbindungen erniedrigten zu einem gewissen Grad den kornertrag. Beim Weizen waren aber die Unterschiede zwischen den verschiedenen Herbiziden grösser als bei der Gerste. Methabenzthiazuron war bei Aufwandmengen bis zu 2.25 kg A.S./ha in beiden Getreidearten das sicherste Herbizid und verursachte nur geringe Ertragsdepressionen (<2%). Bei dieser Aufwandmenge wurden bei den Harn-stoffherbiziden bis zu 36% Ertragsverlust festgestellt. Gegen 2,4-D-Ester und 2,4-D-Aminsalz waren Weizen und Gerste wenig tolerant. Die Ertragsverluste durch Bromoxynil, Bromoxynil + MCPA und MCPA waren etwa gleich und betrugen 4–8% bei 0.5 kg A.S./ha bis 9–24% bei 2,25 kg A.S./ha.  相似文献   

THE INFLUENCE OF IRRIGATION, FERTILIZING AND MCPA ON THE COMPETITION BETWEEN SPRING CEREALS AND WEEDS     

H. SUOMELA  J. PAATELA 《Weed Research》1962,2(2):90-99

Summary. The average air-dry yield of weeds on fallow plots was about four times as large (2660 kg/ha) as the yield of weeds which developed among spring cereal crops (740 kg/ha). Application of fertilizers increased the number of weeds and their average weight on both irrigated and non-irrigated plots. Treatment with MCPA reduced the weed yield to 36% on fallow plots and to 26% on weedy cereal plots. It was more effective on fertilized plots than on unfertilized plots, but irrigation made little difference to its effectiveness. The space left by the destroyed weeds was mainly occupied by Agropyron repens . Oats were better able to compete with weeds than were wheat and barley. On unfertilized and non-irrigated plots spraying with MCPA (1-26 kg/ha) at the beginning of shooting significantly reduced the yields of weed-free barley. The yields of sprayed oats and wheat were also below the yields from the unsprayed although the reductions were not significant at the 5% level. However, on a number of fertilized and irrigated plots, both weedy and hand-weeded , on which the plants had better growing conditions, MCPA resulted in a significant increase in the grain yield of barley and oats.
Influence de l'irrigation, de la fertilisation et du MCPA sur la compétition entre céréales de printemps et mauvaises herbes  相似文献   

Weed control in direct-seeded lowland rice under poor water control conditions     

I. OKEZIE AKOBUNDU 《Weed Research》1981,21(6):273-278

Several herbicides applied singly and in combination were evaluated for weed control and for their effects on crop yield in direct-seeded lowland rice under poor water management conditions characteristic of the conditions in which lowland rice is grown by most farmers in West Africa. Several herbicides including cyperquat at 3.0 kg/ha, a mixture of cyperquat and 2,4-D at 2.0 + 0.5 kg/ha, bentazon at 2.0 kg/ha and avirosan satisfactorily controlled sedges in the 3-year study. Crop yield was consistently high in plots where weeds were controlled with post-emergence application of MCPA + propanil at 1.0+1.7 kg/ha, propanil + thiobencarb 2.2+1.2 kg/ha, oxadiazon 1.5 kg/ha, bentazon 2.0, granular 2,4-D at 1.0 kg/ha, and a pre-emergence application of bifenox at 2.0 kg/ha. Crop yields in plots treated with these herbicides were generally better than with two hand-weedings.  相似文献   

FIELD EXPERIMENTS TO INVESTIGATE LONG-TERM EFFECTS OF REPEATED APPLICATIONS OF MCPA, TRI-ALLATE, SIMAZINE AND LINURON: REPORT AFTER 6 YEARS     

J. D. FRYER  K. KIRKLAND 《Weed Research》1970,10(2):133-158

Summary. In five long-term field experiments begun in 1963, each of four herbicides was applied to plots either planted with the same crop each year or uncropped. The following treatments were applied annually: MCPA at 24 oz/ac to barley at the 5-leaf stage, triallate at 24 oz/ac to barley pre-emergence, simazine at 24 oz/ac to maize pre-emergence, linuron at 12–24 oz/ac to carrots preand post-emergence. The main assessments reported in this paper are crop yield and persistence of herbicide residues. In the fifth experiment, these herbicides were applied twice each year at about double the above these to plots kept as far as possible free from all vegetation. MCPA did not affect the yield of barley and disappeared from the soil within 2–3 weeks of each application. In the uncropped plots, the time for the applied dose (3 lb/ac) to reach the limit of detection was reduced from 3 weeks in 1964 (after three previous applications) to 4 days in 1968 (after ten previous applications). Tri-allate did not affect the yield of barley. Soil residues could be detected for 5–6 months following each dose of 24 oz/ac. When applied at 48 oz/ac twice yearly, a residue persisted but with no progressive build-up during the 6-year period. Agreement between bioassay and CLC methods of determining residues varied from good to a factor of 4, with CLC usually, but not always, providing a higher figure. No residues of pre-allate could be detected in the barley straw or grain. Simazine did not influence the yield of maize during 1963–67. In 1968 there was a significant reduction in yield of foliage and stems but not in grain yield. Simazine applied to maize disappeared from the soil rapidly during the first 6 weeks; after this period 20–25% of the applied dose could be recovered. The remaining residues declined slowly and 1–2 oz/ac could be detected 23–50 weeks after application. No residues were found below the 0–2 in. soil level. When 48 oz/ac was applied twice annually a residue persisted varying from 8 to 27 oz/ac/6 in. There was no accumulation from year to year and no evidence that repeated treatment influenced breakdown rate. Most of the simazine remained in the 0–2 in. soil level. In three out of four determinations there was good agreement between CLC and bioassay results. Linuron reduced the yield and % dry matter content of carrot roots in 1965 and 1966 probably because of exceptional short-term phytotoxicity, otherwise there was no effect. Half the applied dose of 8–16 oz/ac disappeared from the soil within 8 weeks and residues were undetectable after 6 months. The residues in the uncropped plots did not fall below 11 oz/ac. Most remained in the 0–2 in. layer of soil but some herbicide was found in the 2–4 and possibly 4–6 in. layers. Progressive build-up of residues did not occur and repeated treatment did not influence breakdown rate. No linuron could be detected in carrot roots in 1965; in 1966, following an abnormally late application, 05 ppm was found. Chemical analyses of soil samples taken at regular intervals during 1964–67 showed that no major changes had been caused by the herbicide treatments in the levels of available potassium, nitrate nitrogen, ammonium nitrogen, available phosphorus or in pH. Information is presented on the variation in the deposit on the soil surface of applied herbicides immediately after spraying, also on subsequent distribution in the soil. It is concluded that this work provides an encouraging contribution to the evidence that these four herbicides, when used at the recommended rates, are unlikely to have any injurious effect on the capacity of soil to produce healthy crops. Six armies d'expériences au champ pour étudier les effets & long terme d'applieations répétiés de MCPA, tri-allate, simazine et linuron Résumé. Dans cinq expériences de longue durée effectuées en plein champ depuis 1963, chacun des quatre herbicides fut appliqué sur des parcelles, soit replantées chaque année avec la mème culture, soit non cultivées. Les traitements suivants furent appliqués chaque année: du MCPA à 1,680 kg/ha sur de I'orge au stade 5 feuilles; du tri-allate à 1,680 kg/ha en pré -levée sur de I'orge; de Ia simazine à 1,680 kg/ha en pre-levee sur du mais; du linuron à 0,840 et 1,680 kg/ha sur des carottes en pre-levee et en post-levée. Les principaux résultats mentionnés dans cette publication concernent les rendements et la persistance des résidus herbicides. Dans la cinquiéme expéerience, les herbicides ont été appliqués deux fois chaque année, à des doses approximativement doubles de celles indiquées ci-dessus, sur des parcelles maintenues autant que possible sans végétation. Le MCPA n'affecta pas le rendement de l'orge et disparut du sol dans les 2 à 3 semaines qui suivirent chaque application. Dans les parcelles non cultivées, le temps pour que la dose appliquée (3,3 kg/ha) décroisse jusqu à la limite de detection fut réduit de 3 semaines en 1964 (aprés trois traitements) à 4 jours en 1968 (aprées dix traitements). Le tri-allate n'afFecta pas le rendement de l'orge. Les résidus dans le sol purent étre détectés durant les 5 à 6 mois qui suivirent chaque traitement à la dose de 1,680 kg/ha. Quand ce produit fut appliqué 2 fois par an à 3,360 kg/ha, un résidu persista, mais sans qu'il en resulte une accumulation progressive, durant les 6 années de l'expérience. Entre les essais biologiques et les méethodes chimiques de détermination des résidus, la concordance fut tantôt bonne, tantôt correspondant à un coefficient 4, les méthodes chimiques fournissant généralement, mais pas toujours, des ehiffres plus élevés. Aucun résidu de tri-allate ne put être décelé dans la parcelle ou les grains de l'orge. La simazine n'influenca pas la production du mais durant la péeriode de 1963 à 1967. En 1968. il y cut une réduction significative de la production de tiges et de feuilles, mais non de la production de grain. La simazine appliquée sur le mais disparut du sol rapidement durant les six premiéres semaines; aprés cette période 20 à 25% de la dose appliquee pouvaient être retrouvês. Les résidus restants diminuérent lentement et 70 à 140 g/ha purent être de'celes 23 à 50 semaines apres l'application. II ne fut pas trouvé de résidus au-dessous de la couche située entre 0 et 5 cm à partir de la surface du sol. Aprfes les traitements à 3,360 kg/ha, appliqués deux fois par an, un résidu persistant, variant de 0,560 kg/ha à 1,890 kg/ha sur une profondeur de 15 centimétres. 11 n'eut pas d'accumulation d'une année à l'autre et pas d'indice de modification du taux de degradation resultant de la repetition des traitements. La plus grande partie de la simazine resta localisee entre 0 et 5 cm au-dessous de la surface du sol. Dans trois essais sur quatre, il y cut une bonne concordance entre les dosages chimiques et les dosages biologiques. Le linuron réduisit le rendement et le pourcentage de matére séche des racines de carottes en 1965 et 1966, probablement en raison d'une exceptionnelle phytotoxicitéà court terme. Les autres années, il n'y eut pas d'effet. La moitié de la dose appliqué e (dc 0,560 kg/ha 1,12 kg/ha) disparut du sol durant les 8 premieres semaines et il ne fut plus possible de detecter des résidus apres 6 mois. Les résidus dans les parcelles non cultivées ne descendirent pas en-dessous de 0,770 kg/ha. La plus grande partie restait entre 0 et 5 cm au-dessous de la surface du sol, maia des traces d'herbicide furent retrouvees dans la couche 5 à 10 cm et peut-être dans la couche 10 à 20 cm. II n'y et pas d'augnientation progressive des résidus et la répétition des traitements ne modifia pas le taux de dégradation. II ne fut pas décelé de linuron dans les racines de carottes en 1965; en 1966; à la suite d'une application anormalement tardive, il en fut trouvé 0,5 ppm. Des analyses chimiques d'échantillons de sols préieves à intervalles réguliers entre 1964 et 1967 montrirént que les traitements herbicides n'avaient pas provoqué de changements importants dans les taux de potassium utilisable, d'azote nitrique ou ammoniacal, de phosphore utilisable; le pH ne fut pas non plus affecté. Des informations sont présentées, eoncernant la variation du depot en surface des herbicides appliqués, immédiatement aprés le traitement, et aussi sur la distribution qui en résulta dans le sol. En conclusion, ce travail apporte une contribution encourageante à la preuve que ces quatre herbicides, quand ils sont utilisés aux doses recommandées, n'ont trés probablement pas d'effet nuisible sur la capacié du sol à produire des récoltes saines. Feldversuche zur Untersuchung der langfristigen Auswirkung wiederholter Applikationen von MCPA, Triallat, Simazin und Linuron. Bericht nach sechs Versuchsjahren Zusammenfassung. In fünf 1963 angelegten langfristigen Feldversuehen wurden vier Herbizide jeweils auf Flächen mit permanenter Monokultur und auf Brachflächen ausgebracht. Foigende Behandlungen erfolgten jährlich: 1,68 kg/ha MCPA zu Gerste im 5-Blattstadium, Vorauflaufbehandlung mit 1,68 kg/ha Triallat 2u Gerste, Vorauf-laufbehandlung mit 1,68 kg/ha Simazin zu Mais, Vorund Nachaufiaufbehandlung mit 0–84 bis 1,68 kg/ha Linuron zu Mohren. Die in dieser Arbeit berichteten Aus-wertungen beziehen sich vorwiegend auf den Ertrag und die Persistenz der Herbizid- Rückstände. Im fünften Versuch wurden die Herbizide zweimal jährlich in ungefähr doppelter Aufwandmenge auf weitgehend vegetationslosen Fläehen angewandt. MCPA beeinflusste den Ertrag von Gerste nicht und verschwand aus dem Boden innerhalb von zwei bis drei Wochen nach jeder Behandlung. Auf den Brachflachen war die Zeit des Abbaus bis zur Nachweisgrenze der ausgebrachten Menge (3,36 kg/ha) von drei Wochen im Jahr 1964 (nach drei vorausgegangenen Applikationen) auf vier Tage im Jahr 1968 (nach zehn vorausgegangenen Applikationen) zurückgegangen. Triallat beeinflusste den Ertrag von Gerste nicht. Rückstände im Boden waren fünf bis sechs Monate lang nach jeder Applikation von 1,68 kg/ha festzustellen. Wurden 3,36 kg/ha zweimal jährlich ausgebracht, so war eine permanente Ruckstandsmenge, jedoch keine Akkumulation im Verlaufe der sechs Versuchsjahre festzustellen. Die Oberein-stimmung zwischen Biotest und GLG-Methode zur Riickstandsbestimmung variiertc von gut bis zu einem Faktor vier, wobei mit GLG gewohnlich, jedoch nicht iminer, ein höherer Wert ermittelt wurde. Keine Triallat-Ruckstande waren in Stroh und Korn von Gerste nachzuweisen. Simazin beeinflusste den Ertrag von Mais in der Versuchszeit von 1963 bis 1967 nicht. 1968 war eine signifikante Ertragsminderung bei Blatt und Stengel, nicht jedoch beim Korn, eingetreten. Simazin verschwand in den Maisparzellen innerhalb der ersten sechs Wochen rasch aus dem Boden; danach konnten noch 20 bis 25% der ursprunglich ausgebrachten Menge wiedergefunden werden. Die verbliebenen Rückstandsmengen verschwanden nur langsam und 0,07 bis 0,14 kg/ha konnten noch 23 bis 50 Wochen nach der Behandlung nachgewiesen werden. Keine Ruckstande waren unterhalb 5 cm Bodentiefe festzustellen. Wurden 3,36 kg/ha zweimal jährlich ausgebracht, so war eine permanente Ruckstandsmenge von 0,56 bis 1,89 kg/ha ca. 15 cm vorhanden. Es konnte jedoch keine Akkumulation und kein durch die wiederholte Behandlung bedingter beschleunigter Abbau beobachtet werden. Das Simazin blieb vorwiegend in den obersten 5 cm des Bodens. In drei von vier Analysen war die Üereinstimmung zwischen Biotest und GLG-Methode gut. Linuron beeinträchtigte 1965 und 1966 Ertrag und % Trockengewicht der Möhren-wurzeln vermutlich wegen einer aussergewohnlichen, kurzfristigen, phytotoxischcn Wirkung des Mittels. Sonst war keine Beeinflussung der Möhren zu beobachten. Die Hälfte der ausgebrachten Menge von 0,56 bis 1,12 kg/ha verschwand aus dem Boden innerhalb von acht Wochen und nach sechs Monaten waren keine Rückstande mehr festzustellen. Die Ruckstande auf Brachflachen fielen nicht unterhalb 0,77 kg/ha. Linuron verblieb weitgehend in den obersten 5 cm des Bodens, doch war eine gewisse Menge auch in 5 bis 10 cm und möglicherweise auch in 10 bis 15 cm Bodentiefe nachzuweisen. Akkumulation trat ebensowenig auf wie beschleunigter Abbau nach wieder-holter Anwendung. 1965 waren keine Linuron-Rückstände in Mohrenunrzeln nachzuweisen; 1966 wurde nach einer anomal spaten Applikation eine Ruckstandsmenge von 0,5 ppm gefunden. Die chemische Analyse von Bodenproben, die von 1964 bis 1967 in regelmassigen Abstanden gezogen wurden, ergab keine grosseren herbizidbedingten Veranderungen im pH sowie im Gehalt an veräugbarem Kalium, Nitratund Ammonium-Stickstoff sowie Phosphor. Es werden weiterhin Informationen gegeben über die Variation der Herbizidmengen auf der Bodenoberfläche unmittelbar nach der Behandlung und über die anschliessende Verteilung der Herbizide im Boden. Es wird gefolgert, dass diese Arbeit einen ermutigenden Beitrag zu der Tatsache darstellt, dass diese vier Herbizide in praxisüblichen Auiwandmengen kaum negative Auswirkungen auf die Bodenfruchtbarkeit haben.  相似文献   

THE EFFECT OF REPEATED FIELD APPLICATIONS OF FOUR HERBICIDES ON THE EVOLUTION OF CARBON DIOXIDE AND MINERALIZATION OF NITROGEN IN SOIL     

E. GROSSBARD 《Weed Research》1971,11(4):263-275

The effect of repeated annual applications over 7-8 years of MCPA, triallate, simazine and linuron to field plots on the evolution of CO₂ and mineralization of nitrogen in soil samples incubated in the laboratory is described. The plots were either cropped and treated with standard doses, or uncropped and sprayed with doses 3-4 times above the level used in agricultural practice. While the applications of MCPA and tri-allate did not exert any inhibitory effects in soils from the uncropped plots those of simazine and linuron led to a lowering in CO₂ output in several instances and in mineral N on infrequent occasions. These effects are assumed to be the result of a difference in the content of easily-degradable organic matter between the treated plots and the controls. A direct anti-microbial action of the two herbicides is not very probable because in laboratory experiments with simazine up to 512 ppm the output of CO₂ and the mineralization of N was not affected while linuron at 500 ppm gave only a minor depression in CO₂ evolution. Effects on soil fertility are unknown but seem unlikely in view of the small extent and infrequency of the reductions observed. On the cropped plots the MCPA and tri-allate treatment showed no effects. With linuron and simazine a significant lowering in respiration and mineralization of N occurred on single occasions only, during a 5-year period.  相似文献   

Asulam mixtures for weed control in flax     

P. N. P. CHOW 《Weed Research》1977,17(1):55-60

Five field experiments were conducted from 1972 to 1975 to evaluate weed control in flax (Linum usitatissimum L.) using post-emergence treatments of asulam [methyl (4-aminobenzenesulphonyl) carbamatel alone and in combination with other herbicides. The ¹⁴C-asulam absorption by leaf segments and roots of glasshouse grown wild oats (Avena fatua L.) was also investigated. Asulam at 1.12 kg/ha gave good wild oat control and acceptable control of green foxtail (Setaria viridis (L.) Beauv.). However, wild oat control was poorer when asulam was combined with other herbicides: on a 3-year average, as compared with asulam alone at equal rates, the asulam+MCPA mixture resulted in a greater antagonism and a significant 6% reduction in flax seed yield, whereas the asulam+bromoxynil/MCPA mixture gave the least antagonistic effect, improved broadleaf weed control and increased yield by 13%. In mixtures, the potassium salt of MCPA was more compatible with asulam for weed control than the amine form. Both leaf segments and roots of wild oats absorbed and distributed less ¹⁴C-asulam from solutions containing MCPA than from those containing bromoxynil or bromoxynil/MCPA.  相似文献   

Tests of soil fertility following repeated applications of MCPA, tri-allate, simazine and linuron     

J.D. FRYER  J.W. LUDWIG  P.D. SMITH  R. J. HANCE 《Weed Research》1980,20(2):111-116

The following herbicides were applied annually from 1963 to experimental plots of appropriate crops grown in monoculture: MCPA 1.7 kg ha^?1, triallate 1.7 kg ha^?1, simazine 1.7 kg ha^?1 and linuron 0.84 kg ha^?1 (applied twice per year). Before the eighth treatment in 1970, nutrient status, pH and growth in greenhouse tests of a range of plants were similar in soils from treated and control plots. There were no significant differences in yield when several test crops were grown in the field plots in 1977. In a similar experiment which ran for 6 years, the same herbicides were applied twice per year at twice the above rates on each occasion (three times a year at 1.7 kg ha^?1 in the case of linuron) to uncropped plots. Three years after the last treatment, there were no differences in extractable nutrients, pH, soil structure and crop yield on treated or control plots. These results support the conclusion from the main monitoring of the experiments reported elsewhere that annual treatments with these herbicides have had no adverse affect on the soil.  相似文献   

TRIAZINE HERBICIDES ON MAIZE AND THEIR RESIDUAL EFFECTS ON FOLLOWING CROPS*     

A. R. SAGHIR  A. H. CHOUDHARY 《Weed Research》1967,7(4):272-280

Summary. Pre-emergence application of 2–5 kg/ha (a.i.) of atrazine or simazine was the most effective treatment for control of broad-leaved weeds in maize. Other triazines injured maize at all rates tested. Among the crops following maize treated with atrazine or simazine at 2–5 kg/ha, sugar beet was injured whereas wheat, oats, vetch, onions and soybeans were not. Post-emergence application of triazine herbicides was not effective and did not increase maize yields significantly over those of the unweeded plots. Wheat, oats, vetch and sugar beet were injured when following maize treated with post-emergence sprays; onions and soybeans showed no visible injury except from atrazine or simazine at 5 kg/ha or more, and from mixtures of atrazine+prometryne or atrazine+ametryne at 12–5 kg/ha. Les triazines herbicides sur le mais et leurs arrière-effets sur les cultures suivantes  相似文献   

CHEMICAL WEED CONTROL IN MAIZE     

M. EDDOWES  R. L. HARPUR 《Weed Research》1965,5(1):33-42

Summary. From 1959 to 1962 the effects of some triazine and growth regulator herbicides applied pre-emergence and post-emergence to maize grown for silage were studied in field experiments on light to medium loam soils at Harper Adams College, Shropshire.
Atrazine applied pre-emergence at 1–1.5 lb/ac gave good control of annual weeds and was superior to simazine at equivalent rates. Soil moisture and rainfall after spraying were found to influence the activity of the triazines, but both were completely tolerated by maize. In 1960, 1961 and 1962 atrazine was much more effective against annual weeds than post-emergence applications of MCPA and 2,4-D. However MCPA and 2,4-D gave adequate control of a range of annual and perennial weeds under favourable conditions in 1959 and 1960 but results were poor in the two following years due to the presence of resistant and late germinating weeds .
The effect of the herbicides on development and yield of ihe maize are discussed.
Le désherbage chimique dans le mais  相似文献   

Response of spring cereal crops to soil residues of ethofumesate*     

E. E. SCHWEIZER 《Weed Research》1977,17(5):339-345

For evaluation of soil residues of ethofumseate [(±)2-ethoxy-2,3-dihydro-3,3-dimethylbenzofuran-5-yl-methylsulphonate], spring barley (Hordeum vulgare L.) and spring wheat (Triticum aestivum L.) were sown in soil planted 11 months previously with sugar-beet (Beta vulgaris L.) and previously treated with band or broad-cast applications of the herbicide at rates of 1.68-4.48 kg/ha. The height of barley and wheat was suppressed only where ethofumesate was applied broadcast and the soil was not ploughed after sugar-beet harvest. Three months after sowing, the 4.48 kg/ha rate suppressed the height of barley 18% and wheat 34%. In another experiment, barley grew normally on soil treated the previous year with pre-planting and post-emergence applications of ethofumesate where ploughing followed sugar-beet harvest. For all treatments, yields of straw and grain were not significantly lower than those of the untreated check plots. The dissipation of ethofumesate 24 weeks after application to sugar-beet was 89–100% when applied on a band compared to 85-95% when applied broadcast.  相似文献   

Insecticidal control of hessian fly (Mayetiola destructor say: Dipt., Cecidomyiidae) on wheat and barley in cyprus     

P. T. Walker 《Pest management science》1971,2(6):267-275

Hessian fly was controlled to a maximum of 95% with organophosphate insecticides, in terms of the number of puparia and percentage tiller infestation at harvest. Granules: phorate at 1.68 kg/ha (1 1/2 lb/acre) as 10% granules in the seed furrow was most effective on durum wheat in 1967–8, with 69–92%, control, of tillers infested. 1.12 kg/ha gave 74–89% control, 0.56 kg/ha in the seed furrow 35–54%. Seed furrow treatment was more effective than band or broadcast treatment over young plants, although granules broadcast over young barley at 1.68 kg/ha of phorate gave 74% control in 1967–8. Fonofos (Dyfonate) granules at 1.55 kg fonofos/ha were most effective on barley in 1968–9, with 66% control. After fonofos and phorate, disulfoton at 1.68 kg disulfoton/ha was next in effect, with up to 86%, control in 1967-8 and 24% in 1968–9, but variable and not much more effective than at 0.56 kg/ha. Other insecticides were less effective. Seed dressings: disulfoton was the most effective, giving 79% control in 1967-8 on wheat and 77% on barley at a high rate of application that was phytotoxic in 1968–9. Diazinon, bromophos and ethion gave 15–38%, control and chlorfenvinphos and dimethoate less. Carbaryl dust at 1.12 kg carbaryl/ha gave 32% control. Yields were poor, but grain yield was increased by up to 33% in wheat in 1967-8, averaging about 15%. Barley yield was increased by 7% in 1967–8, and from 9–23% in 1968-9 by fonofos and phorate granules. Insect control reduced the number of tillers, increased the number of heads and increased the grain weight per head. In observation plots, chlormequat (CCC) spray alone at the 5-leaf stage reduced infestation of wheat by between 22% and 43%, but CCC with fertilizer, and fertilizer alone had no conclusive effect. High fly populations are partly due to leaving crop residues in the field at harvest. When these can be ploughed in, infestation should decrease. The use of insecticides may not be economic unless more consistent increases in yield can be obtained.  相似文献   

THE USE OF A LOW DOSE OF ATRAZINE ALONE AND IN MIXTURES WITH OTHER HERBICIDES IN THE MAIZE CROP     

J. W. LUDWIG 《Weed Research》1973,13(1):12-18

Summary. Linuron, 2,4-D-aniine, propachlor, pyriclor and cypromid, singly and mixture with atrazine, were compared with atrazine and fluromidine alone for effectiveness of weed control in maize on Oxford clay soil. Pre-emergence applications were made under wet conditions and atrazine, even at 0·28 kg/ha a.i. gave an excellent control of three main weeds, Stellaria media, Veronica spp. and Polygonum aviculare , and at 0·56 kg/ha also killed Aethusa cynapium. Fluromidine was comparable with atrazine, but linuron,2,4-D-amine, propachlor and pyriclor were less effective. Post-emergence treatments were less satisfactory. High doses of atrazine were needed for good weed control. Acynapium was resistant to pyriclor and cypromid and P. aviculare to fluromidine. 2,4-Daminewas ineffective, but atrazine/2,4-D-amine mixtures were more effective than the individual components for the control of P. aviculare. Pyriclor, at 0·56 kg/ha pre-emergenceand cypromid at 2·24 kg/ha post-emergence directly reduced the yield of the crop.
Utilisation de I'atrazine à faible dose, seule et en mélange avec d'autres herbicides, dans les culturesde maïs  相似文献   

Soil persistence experiments with [¹⁴C]2,4-D in herbicidal mixtures, and field persistence studies with tri-allate and trifluralin both singly and combined     

ALLAN E. SMITH 《Weed Research》1979,19(3):165-170

The persistence of [¹⁴C]2,4-D at a rate equivalent to 1 kg/ha was studied in the laboratory on a heavy clay and a sandy loam at 85%of field capacity and 20°C both alone and in the presence of 1 kg/ha dicamba, dichlorprop, difenzoquat, TCA, and 2,4,5-T. The persistence of 2,4,5-T was also monitored in both soils under the same conditions in the presence and absence of [¹⁴C]2,4-D. All soils were extracted at weekly intervals using aqueous acidic acetonitrile and analysed for [¹⁴C]2,4-D remainining radiochemical techniques. The extracts containing 2,4.5-T were additionally analysed gas chromatographically for that herbicide. In each soil type the half-life of the 2,4-D was similar regardless of whether applied singly or in combination with the five herbicides tested. Similarly, [¹⁴C]2,4-D did not affect the breakdown of 2,4,5-T in either soil type. The persistence of tri-allate (1·5 kg/ha) and trifluralin (0·75 kg/ha) both singly and in combination were compared using small field plots at two locations in Saskatchewan. Applications were made during May of 1977 and 1978 and the plots were sampled and analysed for herbicide(s) remaining after 10 and 20 weeks, respectively. The results indicate that within experimental error the loss of both tri-allate and trifluralin from the plots treated with the mixture was the same as from plots treated with the individual compounds.  相似文献   

Dissipation of residues of MCPA and cyanazine in three forage grasses following post-emergence application as a mixture in the establishment year     

Allan J. Cessna  A. Lloyd Darwent  James R. Moyer  Dan E. Cole 《Pest management science》1994,40(2):127-132

The dissipation of MCPA and cyanazine in smooth bromebrass (Bromus inermis Leyss.), Russian wild ryegrass (Elymus junceus Ficsch.) and intermediate wheatgrass (Agropyron intermedium) (Host) Beauv.) grown at three sites in western Canada was monitored for an eight-week period following post-emergence application of the herbicides as a mixture at 0.56 + 0.28 kg ha ?1. The grasses were in the two- to six-leaf stage at the time of application. MCPA, as its methyl ester, was detected using electrolytic conductivity detection whereas N-specific alkali-ionization detection was used for cyanazine. Foliar MCPA residues decreased more rapidly than those of cyanazine. At 56 days after application, MCPA residues were non-detectable in all three grass species at all sites. Corresponding residues of cyanazine were of the order of the limit of quantification (0.02 mg kg ?1 or less.  相似文献   

Yield responses of spring cereals to reduced herbicide doses     

J. SALONEN 《Weed Research》1992,32(6):493-499

Reduction of the dose of MCPA/mecoprop and MCPA/fluroxypyr mixtures to half or one-third of the recommended rates still provided good weed control efficacy in spring wheat (Triticum aestivum L.) and particularly in spring barley (Hordeum vulgare L). The average yield of treated plots was 8% higher in wheat and 1% higher in barley compared with untreated plots. However, yield reductions were observed in 32% of wheat plots and in 43% of barley plots treated with herbicides. The yield responses were poorly correlated with the weed density of mixed weed flora at the time of spraying. No reliable threshold density for chemical weed control was found. Réponses au rendement de céréales de printemps, à des doses d'herbicides réduites La réduction de la dose de MCPA/mecoprop et MCPA/fluroxypyr a la moitié ou au tiers des taux recommandés a encore assure une bonne efficacité herbicide chez le blé de printemps (Triticum aestivum L.) et specialement chez l'orge de printemps (Hordeum vulgare L.). Le rendement moyen des parcelles traitées était de 8% plus élevé chez le blé et de 1%élevé chez l'orge que dans les parcelles non traitees. Cependant, des reductions de rendement ont été observées dans 32% des parcelles de blé et dans 43% des parcelles d'orge traitées aux herbicides. Les reponses du rendement étaient faiblement liées a la densité en adventices d'une flore mixte au moment du traitement. Aucune densité seuil-sérieuse pour le desherbage n'a été trouvée. Ertragsbildung von Sommergetreide bei reduziertem Aufwand von Herbiziden Eine Reduzierung des Aufwands von MCPA-Mecoprop- und MCPA-Fluroxypyr-Mischungen auf die Halfte oder ein Drittel des empfohlenen Aufwands ergab in Sommerweizen (Triticum aestivum L.) und besonders in Sommergerste (Hordeum vulgare L.) noch eine gute Unkrautbekampfung. Im Mittel war der Ertrag der behandelten Parzellen beim Weizen um 8% und bei der Gerste um 1% höher als in den unbehandelten, aber in 32% der Herbizidparzellen mit Weizen und in 43% der mit Gerste wurden Ertragsminderungen beobachtet. Die Ertragsbildung stand kaum in Beziehung zur Unkrautdichte zur Zeit der Behandlung. Es wurde keine verläßliche Schadensschwelle gefunden.  相似文献   

THE CHEMICAL CONTROL OF BARLEY GRASS IN DRYLAND LUCERNE     

O. R. SOUTHWOOD 《Weed Research》1971,11(4):231-239

In a field trial, different doses of five herbicides applied in autumn and late winder were compared for the control of barley grass (Hordeum leporium Link) in dryland Lucerne. Diuron at 1·1, 2·2, and 4·5 kg/ha and atrazine at 1·1 kg/ha were more effective in increasing Lucerne production than linuron at 4·5 kg/ha and various rates of dalapon and paraquat. Autumn application generally resulted in greater Lucerne production than late winter application. Most treatments reduced the amount of barley grass in the Lucerne. Diuron and atrazine also eliminated reduced the amount of barley grass in the Lucerne. Atrazine, diuron and linuron had a strong residual effect and reduced the density of subterranean clover and barley grass in the autumn following treatment.  相似文献   

Difenzoquat, 1,2-dimethyl-3,5-diphenylpyrazolium ion,a selective herbicide for the control of wild oats (Avena spp.) in wheat and barley     

Robert J. Winfield  Jeremy J. B. Caldicott 《Pest management science》1975,6(3):297-303

The results of a series of replicated trials and of a series of commercial grower trials conducted in the United Kingdom during 1972 and 1973, established the effectiveness of difenzoquat (1,2-dimethyl-3,5-diphenylpyrazolium ion) as the methyl sulphate as a selective post-emergence herbicide for the control of wild oats in wheat and barley. Doses of 0.75 to 1.0 kg cation/ha applied at 200 or 400 litre/ha and at 2.1 or 3.5 kg/cm² gave good to excellent results when applied at crop growth stages 3 to 5 (Feekes—Large scale) for spring crops and at crop growth stages 4 to 6 for winter crops. In these experiments wild oats over a range of stages from 1st leaf to tillering were well controlled.  相似文献