Effects of repeated applications of ten soil-active herbicides on weed population,residue accumulation and nitrification*     

M. HOROWITZ  T. BLUMENFELD  G. HERZLINGER  NIRA HULIN 《Weed Research》1974,14(2):97-109

Ten herbicides, bromacil, chlorthal-dimethyl, diphenamid, diuron, fluometuron, neburon, prometryne, pyrazon, simazine and trifluralin at two doses were repeatedly sprayed, in autumn and in spring, for 4 consecutive years on non-cultivated, sprinkler-irrigated field plots. Herbicidal effect was assessed at 1–2 month intervals on the natural weed population and after each observation a paraquat + diquat spray destroyed emerged weeds. The response of various weed species to herbicides varied markedly but a herbicide-induced shift in the composition of weed population did not occur, presumably because of the paraquat treatment. The overall phytotoxicity to weeds present was, in decreasing order: diuron, bromacil, simazine, trifluralin, prometryne, neburon, fluometuron, pyrazon, diphenamid, chlorthal-dimethyl. Persistence of herbicides was in decreasing order: diuron = bromacil, simazine, neburon (at higher rate), fluometuron, trifluralin, prometryne. Control produced by pyrazon improved with the number of applications, but that of diphenamid and chlorthal-dimethyl remained weak and short. After repeated applications, the activity of these herbicides increased or remained at similar level, but in no case decreased. Soil samples were taken 5 months after each application and bioassayed. Phytotoxic residues were detected beneath the disturbed top-soil from bromacil, diuron, fluometuron and simazine after the first application, and from neburon after the second application; residues from trifluralin were found in the top soil only after the fifth application. After the seventh spraying, residues of bromacil were found in the 45–60-cm soil layer. Ammonia content in soil samples taken from treated plots after the fourth, sixth and seventh application was generally similar to the untreated control. In these samples, nitrate content appeared to be correlated negatively with remaining weed number; the control thus contained less nitrate than efficient herbicidal treatments. Soil samples taken after the seventh application of bromacil, diuron, fluometuron, neburon and simazine, which contained appreciable residual concentrations, did not show significant differences from control, in an in vitro nitrification test.  相似文献   

Soil-incorporated trifluralin protects cotton (Gossypium hirsutum) from root-absorbed herbicides     

Y. KLEIFELD  B. RUBIN  T. BLUMENFELD  G. HERZLINGER  H. BUXBAUM  S. GOLAN 《Weed Research》1994,34(6):461-469

Mechanical incorporation of a tank mixture of trifluralin in combination with fluometuron, diuron or prometryne in the soil to a depth of 10 cm protected emerging cotton from the damage caused by these herbicides in the absence of trifluralin. The incorporated tank mixtures, which were activated by sprinkler irrigation, controlled weeds which were tolerant to trifluralin alone. The different reaction of weeds and cotton to the soil-incorporated herbicide mixtures corresponded to the reaction of their root systems to trifluralin. Weeds whose root system was shortened significantly by trifluralin were sensitive to the tank-mixed, soil-incorporated herbicides. La trifluraline incorporée au sol protége le coton (Gossypium hirsutum) des herbicides à absorption racinaire L'incorporation mécanique de mélanges de trifluraline avec du fluométuron, du diuron ou de la prométryne, à des profondeurs de sol 10 cm, protégeait le coton au moment de la levée contre les dommages occasionnés par ces herbicides en l'absence de trifluraline. Les mélanges incorporés, quiétaient activés par irrigation par aspersion, détruisaient les mauvaises herbes qui étaient tolérantes à la trifluraline seule. La réaction différente des mauvaises herbes et du coton aux mélanges d'herbicides incorporés correspondait à la réaction de leur système racinaire à la trifluraline. Les mauvaises herbes dont le systéme racinaire était raccourci par la trifluraline étaient sensibles aux mélanges d'herbicides incorporés. Schutz der Baumwolle (Gossypium hirsutum) vor wurzelabsorbierten Herbiziden durch eingearbeitetes Trifluralin Nach Einarbeitung von Tankmischungen von Trifluralin mit Fluometuron, Diuron oder Prometryn bis in 10 cm Bodentiefe blieben Baumwoll-Keimpflanzen von den sonst von diesen 3 letzgenannten Herbiziden verursachten Schaden frei, Mittels der Tankmischungen ließen sich gegenuber Trifluralin allein unempfindliche Unkrauter bekampfen. Die unterschiedliche Reaktion der Unkrauter und der Baumwolle auf die eingearbeiteten Herbizidmischungen entsprachen der Reaktion ihrer Wurzeln auf Trifluralin. Soweit die Entwicklung von Unkrautwurzeln durch Trifluralin signifikant gehemmt wurde, waren diese Arten gegenuber den eingearbeitenen Tankmischungen empfindlich.  相似文献   

Behaviour and persistence of trifluralin in soil     

M. HOROWITZ  NIRA HULIN  T. BLUMENFELD 《Weed Research》1974,14(4):213-220

The growth response of sorghum to trifluralin, on various soils and soil mixtures, was significantly correlated with organic matter (ranging from <0–1% to 20–4%) but not with clay content (ranging from 3% to 63%). However, in soils with a similar, low organic matter content, the activity of trifluralin increased with increasing clay content. No correlation was found between phytotoxicity of trifluralin and lime content of soils. The persistence of trifluralin incorporated in soil was examined by repeated reseedings of sorghum. Phytotoxicity lasted longer in soil dried and mixed at each interval between seedings than in soil left undisturbed; after 2 months about 50% of the original 4 ppm trifluralin remained in undisturbed soil vs 60 % in repeatedly mixed soil. The rate of degradation, after 2 months of incubation at 50% field capacity, increased with temperatures from 10°to40° the concentration of trifluralin required for a given growth reduction was approximately eight times greater after incubation at 40° than at 10°C. Comportement et persistattce de la trifluraline dans le sol Les effets de Ia trifluraline sur la croissance du sorgho cultivé dans divers sols ou mélanges de sol se sont révlés être en corrélation significative avec la matiere organique (entre < 0,1 % et 20,4 %) mais pas avec la teneur en argile (de 3 % A 63 %). Toutefois dans les sols contenant un taux analogue et faible de matiére organique, l'activité de la trifluraline s'est accrue en même temps que Ia leneur en argile. Aucune corrélation n'a été constatée entre la phytotoxicité de la trifluraline et la teneur en calcaire des sols. La persistance de la trifluraline incorporée dans le sol a été examinée au moyen de ressemis répétés de sorgho. La phytotoxicité dura plus longtemps dans le sol séché et remuéà chaque intervalle entre les semis que dans le sol non travaillé; au bout de 2 mois, 50% environ des 4 ppm de trifluraline apportés à. I'origine restaient dans le sol non remué contre 60% dans le sol plusieurs fois remué. Le taux de degradation, aprés deux mois d'inciibation à 50% de la capacityé au champ, augmenta avec la température de 10°à 40°C; la concentration de trifturaline nécessaire pour obtenir une réduction de croissance donnée fut approximativement huit fois plus grande aprés incubation. à 40° qu'aprés incubation à 10°C. Verhalten und Perststenz von Trifluralin im Boden Die Wachstumsreaktion von Hirse gegenubcr Trifluralin in verschiedenen Böden und Bodenmischungen war signifikant mit dem Gehalt an organischer Substanz (<0–1 %–20–4%) korreliert, nicht aber mit dem Tongehalt (von 3%-63%). Jedoch nahm in Böden mit annähernd gleich niedrigen Gehalten an organischer Substanz die Wirksamkeit von Trifluralin mit steigendeni Tongehalt zu. Zwischen der Phytotoxizität von Trifluralin und dem Kalkgehalt der Böden wurde keine Korrelation gefunden. Die Persistenz von in den Boden eingearbeitetem Trifluralin wurde durch wiederholte Einsaat von Hirse untersucht. Die Phytotoxizität dauerte im Boden, der jeweils zwischen den Einsaaten getrocknet und gemischt worden war, langer an als im nicht derartig behandelten Boden. Nach 2 Monaten waren im letzteren Boden ungefähr 50% der ursprüinglichen 4 ppm Trifluralin verblicben gegenüber 60% im wiederholt durchmischten Boden. Nach 2 Monatlen Inkubation bei 50% Feldkapazität stieg die Abbaurate, wenn die Temperatur von 10° auf 40°C stieg; die für eine gegebene Wachstumsreduktion benötigte Trifluralinkonzentration war bei 40° annShernd achtfach grösser als bei 10°C.  相似文献   

Orobanche aegyptiaca control in tomato fields with sulfonylurea herbicides     

HERSHENHORN  GOLDWASSER  PLAKHINE  ALI  BLUMENFELD  BUCSBAUM  HERZLINGER  GOLAN  CHILF  EIZENBERG  DOR  & KLEIFELD 《Weed Research》1998,38(5):343-349

Field experiments were conducted from 1994 to 1997 at two locations to study the effectiveness of chlorsulfuron and triasulfuron applied through different irrigation methods (chemigation) for control of Orobanche aegyptiaca Pers. in tomato ( Lycopersicon esculentum Mill). Three split applications of chlorsulfuron at 2.5 g a.i. ha⁻¹ and of triasulfuron at 7.5 g a.i. ha⁻¹, through conventional sprinkler irrigation systems, 10–14 days apart followed immediately by sprinkling with water, controlled O. aegyptiaca by about 90% and 80% and increased crop yield 25–47% and 30%, respectively, without any crop injury symptoms. Repeated applications of the same herbicides at half rates resulted in slightly higher O. aegyptiaca control and crop yield than only one herbicide application at double rate. Chemigation by the sprinkler systems (microsprinklers, 60 m³ ha⁻¹) slightly increased the herbicide efficiency as compared with the high volume spray (800 m³ ha⁻¹). O. aegyptiaca control from sulfonylureas applied by drip chemigation was poor, as this probably requires very accurate timing and the herbicide distribution in the soil was not uniform.  相似文献