Control of potato cyst-nematode, Heterodera rostochiensis, in three soils by small amounts of aldicarb, Du Pont 1410 or Nemacur applied to the soil at planting time

Aldicarb or Du Pont 1410 (S-methyl 1-(dimethylcarbamoyl)-N-[(methylcarbamoyl) oxy] thioformimidate) at 2.6–11.2 kg a.i./ha applied to the soil at planting time controlled potato cyst-nematode, Heterodera rostochiensis, in sandy loam, peaty loam and silt loam and greatly increased tuber yields of susceptible potatoes. Nemacur (O-ethyl-O-(3-methyl-4-methylthiophenyl) isopropylamido-phosphate) controlled potato cyst-nematode in sandy loam at 2.9–10.3 kg a.i./ha and in silt loam at 11.2 kg a.i./ha but did not control the nematode well in peaty loam even at 22.4 kg a.i./ha. In peaty loam aldicarb and Nemacur were more effectively incorporated by rotavation than by a modified power harrow.     

Control of potato cyst-nematode, Heterodera rostochiensis, in sandy loam, by Du Pont 1410 (S-methyl l-(dimethylcarbamoyl)-N-[(methylcarbamoyl) oxy] thioformimidate) applied to the soil at planting time

When applied to heavily infested sandy loam soil at planting time, as little as 5 ppm Du Pont 1410 (5-methyl I-(dimethylcarbamoyl)-N-[(methylcar-bamoyl) oxy] thioformimidate) in pots, or 2–5 ppm in field plots, effectively controlled potato cyst-nematode, Heterodera rostochiensis Woll., and greatly increased the growth and yield of susceptible potatoes. Dipping the shoots of potted King Edward potatoes once in aqeuous solution containing 2000 ppm did not control potato cyst-nematode. Nematode control was not increased when 2 or 4 kg a.i./ha was sprayed on the foliage of young Pentland Crown potatoes growing in soil already treated with the nematicide.     

Incorporation of granular nematicides in soil to control pea cyst-nematode, Heterodera goettingiana

Experiments at four sites in England compared control of pea cyst-nematode, Heterodera goettingiana, on peas, Pisum sativum, obtained when 10% granules of aldicarb or oxamyl were applied to the soil in different ways. The nematode was controlled best when the granules were incorporated in the soil by rotary cultivation (L-bladed rotavator). The granules were incorporated too shallowly by rotary harrowing (Lely Roterra); applying granules in the seed furrows during sowing, or broadcasting them at the sowing depth of 5 cm, was only effective in 1975 when heavy and prolonged rain followed sowing.     

Control of potato cyst-nematode, Heterodera rostochiensis, in silt and peat loams by ten pesticides applied to the soil at planting time

Incorporated in silt or peat loam top-soil in spring before susceptible potatoes were planted, three carbamoyl oximes, aldicarb, Tirpate (2,4-dimethyl-2-formyl 1-1,3-dithiolane oxime iV-methylcarbamate) and Du Pont 1410 (S-methyl i-(dimethylcarbamoyl)-N-((methylcarbamoyl) oxy) thioformimidate) and one organophosphate, Nemacur (O-ethyl-O-(3-methyl-4-methylthiophenyl)-isopropylamidophosphate) all at n-2 kg a.i./ha greatly increased the yield of tubers and effectively controlled potato cyst-nematode (Heterodera rostochiensis Woll.). At the same dosage thionazin was as effective in the peat loam but was ineffective in the silt loam; phorate and Mocap (O-ethyl S,S-dipropyl phosphorodithioate) were less effective and chlorfenvinphos, diazinon and a coarse granule formulation of fensulphothion were ineffective in controlling potato cyst-nematode.     

Control of beet cyst-nematode, Heterodera schachtii, by aldicarb applied to the soil by a vertical band-reciprocating harrow technique or by rotary cultivation

As little as 0.8 kg aldicarb ha^-1 applied to bands of soil 15 cm wide × 15 cm deep, in which sugar beet seeds were sown, increased beet yields as much as did 2.6 or 5.0 kg ha^-1 rotary cultivated into the top 15 cm of soil lightly or moderately infested with beet cyst-nematode, Heterodera schachtii. In a very heavily infested soil, 1.7 kg ha^-1 applied to the bands of soil increased beet yields as much as 2.6 kg ha^-1 rotavated into the top 15 cm of the soil; yields were further increased by 5.0 and 9.9 kg ha^-1 rotavated in but not by 3.5 kg ha^-1 in the bands of soil. Soil populations of the nematode increased little or not at all whether the soil was treated with aldicarb or not. The band treatment was achieved by a vertical band- reciprocating harrow technique, which is described. The advantages of this new technique for the control of beet cyst-nematode and other soil pests of widely spaced row crops are safer application of less pesticide, thereby minimising cost of treatment and any risk to the environment, faster seedbed preparation and adequate control of pest population increase on the susceptible crop, especially if coupled with biological control.     

Control of potato cyst-nematode, Heterodera rostochiensis, in peaty loam soil by D-D, aldicarb and a resistant variety of potato

In peaty loam soil in Cambridgeshire, 5.2 or 10.3 kg aldicarb/ha incorporated in the top-soil before potatoes were planted controlled potato cystnematode (Heterodera rostochiensis Woll.) better than 384, 769 or 1153 kg D-D/ha injected 15 cm deep into the top-soil in the preceding autumn. 10.3 kg aldicarb/ha applied in 1968 and 1969 permitted King Edward potatoes (susceptible to H. rostochiensis) to grow well in infested soil and prevented multiplication of pathotypes of H. rostochiensis on Maris Piper potatoes (resistant to H. rostochiensis pathotype A). Although large amounts of D-D applied in 1968 and 1969 increased the yield of King Edward potatoes in both years they did not control potato cyst-nematode in the second year.     

Control of potato cyst-nematodes, Globodera rostochiensis and G. pallida, in different soils by small amounts of oxamyl or aldicarb

In eleven field trials on peaty, sandy or silt loam soils, aldicarb or oxamyl, incorporated in the soil to 15 cm deep before susceptible potatoes were planted, controlled potato cyst-nematodes (Globodera rostochiensis (Woll.) Mulvey & Stone, 1976 and G. pallida (Stone) Mulvey & Stone, 1976) better at 5–6 kg than at 3–4 or 2-2 kg a.i./ha. Incorporated in the soil to 7-5 cm deep 5–6 kg/ha of aldicarb or oxamyl controlled the nematodes less effectively at some sites. At 3–4 kg a.i./ha there was no difference in nematode control between the two incorporation depths.     

Control of potato cyst-nematode, Heterodera rostochiensis, in sandy, peaty and silt loam soils by dazomet and Telone applied in different ways

Dazomet applied in the ridges in autumn or in spring, before potatoes were planted in them, controlled potato cyst-nematode (Heterodera rostochiensis), British pathotype A, better in sandy loam and peaty loam than Telone (1,3-dichloropropene mixture). In sandy loam dazomet controlled potato cyst-nematode as well when applied in spring as when applied in autumn and as well when the soil was ridged after treatment as when it was not. Telone was as effective when applied to ridges in autumn as when applied to ridges in spring. In peaty loam potato cyst-nematodes were least abundant after a crop of Maris Piper potatoes. The yields of King Edward potatoes were greatly increased and nematode multiplication was greatly reduced by dazomet incorporated in the ridges in autumn. Two equal doses of dazomet, one incorporated in the topsoil before, the other after ploughing, controlled potato cyst-nematode as well and increased the yield of King Edward potatoes more than an equivalent amount of dazomet applied after ploughing. Dazomet applied to silt loam soil in two dressings, one before, the other after, ploughing, controlled potato cyst-nematode better than an equal amount applied as a single dressing after ploughing. The nematode was controlled best by two large dressings of dazomet or by a combined treatment of dazomet and Telone.     

Effects of D-D, Telone or dazomet applied to potato ridges in spring on potato cyst-nematode, Heterodera rostochiensis, in sandy loam and silt loam soils

Large amounts of dazomet (329, 439 kg/ha) applied to potato ridge soil in spring, before potatoes were planted, controlled potato cyst-nematode (Heterodera rostochiensis) in sandy loam and silt loam more effectively than large amounts of D-D (359, 448 kg/ha). In heavily infested sandy loam, 329 kg dazomet/ha or 857 kg methyl bromide/ha applied in spring 1969 or 439 kg dazomet/ha applied in autumn 1968, greatly decreased the number of larvae able to invade potato roots, so Majestic potatoes grew and yielded well without increasing the number of nematodes left in the soil after harvest. Large amounts of D-D or Telone applied to the topsoil in autumn or to the ridges in spring were less effective in controlling potato cyst-nematode or increasing potato yields. Applied in spring 1969 to silt loam ridges, 439 kg dazomet/ha had more effect than 448 kg D-D/ha on potato cyst-nematode and on the increase in yield of Majestic potato. The yield of Maris Piper potatoes (resistant to H. rostochiensis pathotype A) in infested silt loam was increased greatly by D-D, as much by 112 as by 224 or 448 kg/ha.     

Control of potato cyst-nematode, Globodera pallida, on tomatoes grown under glass, by applying steam or chemical nematicides to the soil

In a sandy loam under glass, potato cyst-nematode, Globodera pallida, was controlled in soil to 20 cm deep, and tomato yields were greatly increased by sheet steaming for 4 h, by 977 kg methyl bromide ha^-1 or by 448 kg Telone (1,3-dichloropropene mixture or Di-Trapex CP (20% methyl isothiocyanate: 15% chloropicrin:65% dichloropropene-dichloropropane mixture) ha^-1 followed by 441 kg dazomet or 11.2 kg oxamyl ha^-1. Sheet steaming, unlike the other treatments, had relatively little effect on the nematode in soil 20 to 40 cm deep. Until the apices of the plants were cut off production of fruit was curvilinear against time in all treated soil but linear against time in untreated soil.     

Control of stem nematode, Ditylenchus dipsaci, in onions, by granular nematicides applied to the soil

Aldicarb at 1.4–5.6 kg a.i. ha^-l or oxamyl at 1.3–5.2 kg a.i. ha^-1 applied over the seed furrows during sowing prevented much of the damage resulting from stem nematode attack in spring-sown onions. Rotting of bulbs in store due to stem nematode infestation was sometimes lessened by these treatments. Neither sowing onion seeds on soil ridges, nor applying aldicarb in two equal doses, one over the seed furrows during sowing, the other over the plants mid-season, controlled the nematode better or increased onion yields more than a single equivalent dose over the seed furrows. Applied as two doses in this way, aldicarb was sometimes more effective against the nematode in summer-sown onions than was an equivalent amount applied over the seed furrows during sowing. Only 2.5 kg or less aldicarb ha^-1 can be applied to onions without leaving unacceptable residues (>0.15 μg g^-1) in the harvested bulbs.     

Control of clubroot by soil partial sterilization with particular reference to the treatment of small natural foci of infection

Experiments were made on field plots with four soil partial sterilants applied at different dose rates or as combination treatments. The effects of treatments on clubroot were assessed by growing cabbages on the field plots or in a glasshouse in soil removed from the plots. In two experiments, no plants grown on plots or seedlings grown in soil samples from plots treated with Dowfume M.C.2 or Telone were infected with clubroot, whilst only one infected seedling was found in soil samples from those plots treated with chloropicrin. Although relatively few infected plants were recovered from Basamid treated plots, many infected seedlings were found in soil samples from those plots. The effectiveness of these treatments as indicated by seedling survival was Dowfume M.C.2 < chloropicrin < Telone < Basamid. At five sites a combination of Dowfume M.C.2 at 98 g/m² with 40 g/m² Basamid resulted in all cabbage seedlings grown in soil samples being disease free.     

Tolerance or immunity to a tumor antigen expressed in somatic cells can be determined by systemic proinflammatory signals at the time of first antigen exposure.

Mice transgenic for the E7 tumor Ag of human papillomavirus type 16, driven from a keratin 14 promoter, express E7 in keratinocytes but not dendritic cells. Grafted E7-transgenic skin is not rejected by E7-immunized mice that reject E7-transduced transplantable tumors. Rejection of recently transplanted E7-transgenic skin grafts, but not of control nontransgenic grafts or of established E7-transgenic grafts, is induced by systemic administration of live or killed Listeria monocytogenes or of endotoxin. Graft recipients that reject an E7 graft reject a subsequent E7 graft more rapidly and without further L. monocytogenes exposure, whereas recipients of an E7 graft given without L. monocytogenes do not reject a second graft, even if given with L. monocytogenes. Thus, cross-presentation of E7 from keratinocytes to the adaptive immune system occurs with or without a proinflammatory stimulus, but proinflammatory stimuli at the time of first cross-presentation of Ag can determine the nature of the immune response to the Ag. Furthermore, immune effector mechanisms responsible for rejection of epithelium expressing a tumor Ag in keratinocytes are different from those that reject an E7-expressing transplantable tumor. These observations have implications for immunotherapy for epithelial cancers.     

Supplementary foliar N, P and K, applied individually or in combinations, and the tolerance of potatoes to infection by the potato cyst nematodes Globodera rostochiensis and G. pallida

The use of supplementary foliar N, P and K to ameliorate the reduced nutrient uptake of potato plants infected by potato cyst nematode (PCN) were investigated. The potato cv. Pentland Dell achieved yields in plots not treated with oxamyl similar to those found in plots treated with oxamyl when supplementary foliar N or N plus K was applied to plots infested with 13 eggs g^-1 soil of Globodera pallida. Yield improvements from foliar N applications were attributed to increased leaf area index but the reason for yield increases from foliar N plus K applications could not be clarified. In a second experiment, where PCN infestation was 76 eggs g^-l soil, the potato cv. Sante gave yields up to 19% higher than a standard fertiliser practice when supplementary foliar N was applied to plots not treated with oxamyl. Nutrient analysis showed that without oxamyl there were significantly lower concentrations of N, P and K in whole plant dry matter at 58 days after planting (DAP) but higher levels of N in the fourth leaf dry matter at 98 DAP. Emergence was significantly advanced by the use of oxamyl in both experiments. Sante dramatically reduced populations of Globodera rostochiensis from an average of 76 eggs g^-1 soil to 7 eggs g^-1 soil. Foliar application of nutrients is a promising method of ameliorating the effects on potatoes of PCN invasion but the nutrient concentrations and timing of individual sprays need to be more closely matched to crop requirement than was possible in our experiments     

Infectivity, distribution, and persistence of the entomopathogenic nematode Steinernema carpocapsae all strain (Rhabditida: Steinernematidae) applied by sprinklers or boom sprayer to dry-pick cranberries.

We evaluated infectivity, distribution, and persistence of commercially produced Steinernema carpocapsae (Weiser) All strain applied through solid set sprinkler irrigation or boom sprayer to 2 dry-pick cranberry farms on peat soil in British Columbia in 1993. Most infectivity assays used Galleria mellonella (L.) larvae. When possible, larvae of the target pest, Otiorynchus sulcatas (F.) were used as assay organisms. Nematodes in almost all samples of nematode suspensions diluted from shipping containers, from spray tanks, or collected in cups after passage through application equipment were infective to G. mellonella larvae. When O. sulcatus larvae were used as assay organisms, 93% (n = 14) of assays from the spray tank and 67% (n = 12) of assays after application showed infectivity. In the spring, sprinklers delivered nematodes to only 15 of 20 sample points on the 0.2-ha plot; delivery by the boom sprayer was better but 2 of 20 points on the 0.2-ha plot received approximately twice as many nematodes as the other points. In the fall, nematode delivery by both systems was more even. However, the average number of nematodes per milliliter of sprayed water collected from the 20 samples on each farm after each application did not correspond to the rates of nematodes applied. Persistence of nematodes in the soil was encouraging, but percentage of infectivity was lower than expected. After application in the spring, assays using G. mellonella larvae showed the presence of infective nematodes in soil samples (0-5 and 5-10 cm deep) on each sampling day (0, 3, 7, and 25) after application by boom sprayer, and on days 0, 3, and 7 after application through sprinklers. In the fall, G. mellonella assays showed infective nematodes in soil samples on each sampling day (0, 3, 7, and 25) after application by boom sprayer, and on days 0, 3, 7, 35, 60, 135, and 250 after application through sprinklers. In the spring, when assays lasted 4 d, percentage of infectivity rose to a maximum of 45% on the 3rd d after application by boom sprayer and declined thereafter. In the fall, when assays lasted 10 d, percentage of infectivity rose to a maximum of 58% on the 7th d after application through sprinklers and remained between 20 and 58% until day 135, declining thereafter; infectivity after boom application remained between 37 and 45% on days 3 and 7, and began to decline on day 25. Nematode infectivity was not compromised in peat soil, muck, or silty clay loam, but infectivity in loam (that may have contained nematicide residues) was very low. We suggest that the inconsistent control of O. sulcatus by S. carpocapsae on British Columbia cranberry farms may be partially explained by problems associated with application and factors related to nematode entry into the soil.     

Multiple, small exposures of far-ultraviolet or mid-ultraviolet light change the sensitivity to acute ultraviolet exposures measured by cell lethality and mutagenesis in V79 Chinese hamster cells

Chinese hamster V79 cells (subline MI2G) were exposed repeatedly to fractionated doses of germicidal 254 nm light (far-uv) at 6 J.m-2/fraction/day or sunlight-simulating 290-330 nm (mid-uv) at 150 J.m-2/fraction/day and sensitivities to cell killing action and mutation of far-uv and mid-uv were examined. As the number of exposure fractions increased, the cell cultures became resistant to cell killing induced by both far-uv and mid-uv. Increases in both Do and Dq were observed. Treatment with exposures of 6 J.m-2 far-uv is more efficient in yielding cell cultures that are resistant than exposures of 150 J.m-2 mid-uv. In contrast to the cells exposed to repeated far-uv, the cells exposed to repeated mid-uv were relatively more resistant to cell killing effects of mid-uv than far-uv, suggesting a possible role of photolesions other than pyrimidine dimers. When mutants resistant to 6-thioguanine were assayed during repeated exposure to far- or mid-uv light, the yield was initially linear with accumulating dose. At high total accumulated doses, the frequency decreased gradually (6 J.m-2 mid-uv) or reached a plateau (150 J.m-2 mid-uv). The sensitivity of N80 cells (exposed to 80 fractions of mid-uv) to mutation induction by uv light is higher than that of the original MI2G cells, whereas U81 cells (exposed to 81 fractions of far-uv) have a sensitivity similar to that of the original cells. Although an initial decrease in resistance to cell killing was observed, resistant cells retained their characteristics after 100 days in culture without further exposure. Cross-resistance to X rays was not shown. The data in this paper suggest that the capacity for repair of photolesions in DNA by repair processes was enhanced in cell cultures by repeated exposure to far-uv or mid-uv and that this altered the cells' ability to cope with lethal and mutagenic lesions. It remains to be seen if these changes in cell sensitivity were brought about by selective or inductive processes or a combination of both.     

Assignment of the human small inducible cytokine A2 gene, SCYA2 (encoding JE or MCP-1), to 17q11.2-12: evolutionary relatedness of cytokines clustered at the same locus

The JE gene, cloned from platelet-derived growth factor (PDGF)-treated mouse 3T3 cells, was the first PDGF-inducible gene to be described. Its human homolog (gene name "small inducible cytokine A2" [SCYA2]) encodes the monocyte specific chemotactic factor MCP-1 (or MCAF) which is structurally related to a recently described family of cytokines. By a combination of in situ hybridization and study of somatic cell hybrids, we have assigned the human SCYA2 gene to 17q11.2-12, the locus to which other members of this family have been mapped. We have also reconstructed a phylogenetic tree relating the members of this family to each other and to their murine homologs which suggests that these genes arose by duplication and divergence prior to the murine/human divergence. Four of the five members of this subfamily have now been assigned to the same locus (and the fifth to chromosome 17), while several of the members of a related gene family have been assigned to 4q. We propose that the two subfamilies be designated the 17q and 4q subfamilies.     

Evidence for plasma membrane impermeability to small ions in acrosome-intact mouse spermatozoa bound to mouse zonae pellucidae, using an aminoacridine fluorescent pH probe: time course of the zona-induced acrosome reaction monitored by both chlortetracycline and pH probe fluorescence

Previous studies have shown that capacitated mouse spermatozoa bind to zonae pellucidae of mouse eggs with acrosomes apparently intact. The question addressed in this study was the following: are the membrane permeability barriers of the apparently acrosome-intact sperm still retained or is there a preliminary stage of the acrosome reaction in which these barriers are lost and the intracellular space becomes accessible to extracellular substrates? The experimental approach was to use the fluorescent pH probe 9-amino-3-chloro-7-methoxyacridine, which accumulates in intracellular spaces of lower pH than the suspending medium with the result that the cells become fluorescent. Freshly capacitated mouse spermatozoa bound to isolated zonae showed uniform fluorescence over the head and midpiece with this fluorescent probe at early times of binding. The fluorescence was abolished by NH4+ and nigericin, agents that equilibrate H+ across cell membranes. At these early times of binding, the acrosomes were fully intact as judged by chlortetracycline fluorescence pattern, which itself was unaffected by either N4+ or nigericin. The time course of the loss of this chlortetracycline pattern characteristic of acrosome-intactness was closely paralleled by loss of fluorescence of 9-amino-3-chloro-6-methoxyacridine over the first 90 min; thereafter, loss of the chlortetracycline pattern was somewhat more rapid. This result shows that acrosome-intact sperm bound to zonae pellucidae retain the permeability barriers of the plasma membrane to small cations; no evidence was found for an early stage of membrane "leakiness" preceding the acrosome reaction. The ionophore A23187 induced a very rapid acrosome reaction in sperm bound to isolated zonae, as judged with both fluorescence probes. This rapid reaction was partially inhibited by 3-quinuclidinyl benzilate, which, in the absence of ionophore, completely blocks the occurrence of the acrosome reaction in sperm bound to zonae. This suggests involvement of a specific calcium entry mechanism in the acrosome reaction of mouse sperm induced by mouse zonae pellucidae.