AbstractEmissions of nitrous oxide (N20) and dinitrogen (N2) from irrigated fields were monitored during the 1982 and 1983 cropping season to assess the magnitude of N loss by denitrification. Miniplots were established within larger fields of corn (Zea mays L.) in 1982, and barley (Hordeum vulgare) in 1983. Soil inside the miniplots was amended at a rate of 200 kg N ha−1 as 99 atom % 15N ammonium sulfate, and the vertical N20 and N2 fluxes were measured periodically by sampling gases from a soil cover method, and analyzing the N20 by gas chromatography and the N2 by mass spectrometry. Maximum N20 emissions occurred in May for barley and in July for corn, and emissions for both crops increased with increasing soil‐water content. During 1982, total volatile N loss of N20 + N2 from the moderately well‐drained clay loam soil was about 2.5% of the applied fertilizer N, and about 70% of the total was N20. From the barley field in 1983, about 1% of the applied fertilizer N was emitted with about equal amounts of each gas. These data suggest that the role of denitrification as a N loss mechanism has been historically overemphasized for soils in this area.

Eight commercial sugarbeet (Beta vulgaris L.) cultivars consisting of both diploid 2N = 2X = 18 and triploid 2N = 3X = 27 hybrids were studied for 2 years for their response to three herbicide regimes. The specific registered sugarbeet herbicides consisted of preplanting applications of 1) cycloate (S‐ethyl‐N‐ethylthiocyclohexanecarbamate) (3.4 kg/ha), 2) ethofumesate [(± >2‐ethoxy‐2,3‐dihydro‐3,3‐dimethyl‐ 5‐benzofuranyl methanesulfonate] (2.2 kg/ha), and 3) a mixture of ethofumesate (2.2 kg/ha) + diclofop |2‐{4‐{2,4‐dichlorophenoxy) phenoxy] propanoic acidsj (1.7 kg/ha), each followed by a post‐emergence mixture of desmedipham [ethyl m‐hydroxycarbanilate carbanilate (ester)] and phenmedipham (methyl m‐hydroxycarbanilate m‐methylcarbanilate) both applied at 0.6 kg/ha. A fourth treatment regime was that of no herbicide application. The six characters examined were 45‐day plant dry weight, harvest root weight, foliar suppression, stand count, sucrose, and purity. Differential herbicide and cultivar response was evidenced by significant year ✕ herbicide, year ✕ cultivar, and herbicide ✕ cultivar interactions for several of the six characters analyzed. Although a significant second order interaction was detected for foliar suppression, none of the yield components (root weight, sucrose, purity) exhibited significant second order interactions. Certain cultivars were suppressed significantly less than others at 45 days and recovered the most by harvest time. Under favorable soil moisture and temperature conditions, the eight commercial cultivars showed reductions in total 45‐day plant weight of 39 to 55% of their nontreated equivalent controls. In both years, early season suppression was mostly, but not entirely, overcome by harvest. Reductions averaged about 5%.

Fifteen sugarbeet (Beta vulgaris L.) populations consisting of five inbred lines, five F1 hybrids, and five commercial cultivars were evaluated 2 years for their response to certain herbicide regimes. The populations were assessed primarily by determining the nature and magnitude of first and second order interactions. The treatment regimes consisted of cycloate (3.4 kg/ha) or ethofumesate (2.2 kg/ha) applied preplant followed by a postemergence mixture of desmedipham and phenmedipham each applied at 0.6 kg/ha. A third treatment regime was that of no herbicide application. The 10 characters examined were: root weight, sucrose, purity, sodium, potassium, nitrate, betaine, amino N, chloride, and foliar suppression. Genetic control of the response to herbicide application was exemplified by significantly different population reactions for the majority of the 10 characters studied. When the entire array of 15 populations was analyzed, a significant year ✕ population interaction was detected for eight characters. Further, significant first order interactions were those of year ✕ herbicide for root weight and herbicide ✕ population for foliar suppression. No significant second order interactions were found. Several chemical components of juice, foliar suppression, and root weight showed significant first order interactions, but only in the group of five commercial cultilvars. In general, root weight, sucrose, and purity were slightly reduced, whereas chloride, nitrate, and betaine were increased following herbicide application. The most prominent effect of herbicide treatment was suppression of foliar growth. Both pre- and postemergence treatments suppressed the population groups in the order: inbreds > F1 hybrids > commercial cultivars.

AbstractAus den Diketo‐monohydrazonen (I) und den ungesättigten Ketonen (II) entstehen die Azine (III), die in bekannter Weise zu den N‐substituierten Pyrazolen (IV) führen.

Summary:Persistence of ethofumesate [(±)2‐ethoxy‐2.3‐dihydro‐3,3‐dimethylbenzofuran‐5‐yl‐methansulphonate] in soil was associated with soil temperature. Ethofumesate applied at 4.5 kg/ha in November persisted about twice as long in soil as that applied the following March. In another field study, 88–91% of the herbicide had dissipated after 24 weeks in sandy loam soil, compared to 72–77% in loam soil when it was applied at rates of 2.2, 3.4, 4.5, and 9.0 kg/ha. The rate of degradation was independent of the initial rate of chemical applied. The time required for 50% of the herbicide to dissipate in sandy loam and loam soils was 7.7 and 12.6 weeks, respectively. The movement of ethofumesate in these two soils over a 24‐weeks sampling period was confined mainly to the upper 7.5 cm of the soil profile.

AbstractSalicylaldehyd (I) liefert in Gegenwart von Alkali mit 1,4‐Dibrombutan (II) den Äther (III), der mit Triphenylphosphin zum Salz (IV) substituiert wird.

Summary: Résumé: ZusammenfassungResponse of weeds and sugarbeets (Beta vulgaris L.) to post‐emergence treatments of phenmedipham and mixtures of phenmedipham plus EP 475 applied alone and as a complementary treatment with cycloate was evaluated in two field studies. The mixtures of phenmedipham plus EP 475, applied at 0.84 and 1–12 kg/ha a.i., reduced the stand of red‐root pigweed (Amaranthus retroflexus L.) three to five times more than did phenmedipham. Post‐emergence treatments of phenmedipham alone, or mixtures of phenmedipham plus EP 475, applied as complementary treatments with cycloate reduced the average stand of foxtails (Setaria spp.), redroot pigweed, and kochia (Kochia scoparia (L.) Schrad.) by 82 to 94 %. With the complementary treatments, this level of weed control was obtained by reducing the rate of either cycloate or the post‐emergence herbicide treatment. Complementary treatments of cycloate plus phenmedipham, or the mixtures of phenmedipham plus EP 475, reduced sugarbeet seedling vigour temporarily, but they did not reduce the stand or yield.Désherbage des betteraves sucriéres avec le cycloate, le phenmédiphame et le produit EP 475La réaction des mauvaises herbes et des betteraves sucrieres (Beta vulgaris L.) a étéévaluée dans deux essais au champ, à la suite de traitements effectues avec le phenmédiphame et des melanges de phenmfediphame et de EP 475 appliqués seuls et comme traitements compléementaires du cycloate. Les mé1anges de phenmé diphame plus EP 475, appliques a 0,84 et 1,12 kg/ha m.a. ont réduit le dé veloppement de l'amarante (Amarantus retroflexus L.) 3 à 5, fois plus que le phenmédiphame. Les traitements de post‐levé e avec le phenmédiphame seul ou avec les mélanges phenmé diphame EP 475 appliqués en complément d'un traitement avec le cycloate ont rdduit le développement moyen des sétaires (Setaria spp), de l'amarante et du Kochia (Kochia scoparia (L.) Schrad.) de 82 à 94%. Avec les traitements complé‐mentaires ce niveau de désherbage a été obtetiu en réduisant le taux soit du cycloate soit du traitement herbicide de post‐Ievée. Les traitements compl6mentaires avec le cycloate plus le phenmédiphame ou les mélanges de phenmédiphame plus EP 475 ont réduit temporairement la vigueur des plantules de betteraves mais n'ont pas eu d'influence sur le développement ni sur le rendement.Unkrautbekämpfung in Zuckerrüben mit Cycloat, Phenmedipham und EP 475In zwei Feldversuchen wurde die Reaktion von Unkräutern und Zuckerruben (Beta ulgaris L.) auf Nachauflauf behand‐lungen mit Phenmedipham und Mischungen von Phenmedipham mit EP 475 sowohl bei alleiniger Ausbringung als auch nach zusätzlicher Behandlung mit Cycloat unter‐sucht. Die Mischungen von Phenmedipham mit EP 475 in Aufwandmengen von 0–84 und 1.12 kg/ha A.S. fuhrten zu einer drei‐ bis fünffach stärkeren Reduktion des Zurück‐gekrümmten Fuchsschwanzes (Amaranthus retrofiexus L.) als Phenmedipham. Wurden Phenmedipham allein oder Mischungen von Phenmedipham und EP 475 als zusStzliche Nachauflauf‐Behandlung zu Cycloat gegeben, so verringerte sich der durchschnittliche Bestand an Borstenhirsen (Setaria spp.) und Besenkraut (Kochia scoparia (L.) Schrad.) um 82 bis 94%. Bei den Zusatzbehandlungen wurde der gleiche Wirkungsgrad mit verringerten Aufwandmengen von Cycloat Oder dem im Nachauflauf eingesetztem Herbizid erzielt. Die zusatzlichen Behandlungen von Cycloat plus Phenmedipham Oder den Mischungen aus Phenmedipham und EP 475 hemmten zeitweilig das Wachstum der Keimpflanzen von Zuckerruben, die Bestandesdichte und der Ertrag wurden jedoch nicht beeinflusst.

Aus den Vinylphosphonium‐Salzen (I) erhält man mit Natriumäthylat die Äther (II), die mit Benzaldehyd (III) zu Triphenylphosphinoxid (IV) und den Allyläthern (V) reagieren.

AbstractDie beiden Phosphoniumsalze (I) liefern mit Base die beiden Cyclisierungsprodukte (II) und (III).

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