不同地区禾谷孢囊线虫对不同类型杀线剂的敏感性

为明确不同地区禾谷孢囊线虫对不同类型杀线剂的敏感性,采用浸渍法分别测定了灭线磷、噻唑膦、涕灭威、丁硫克百威、阿维菌素及甲维盐六种药剂对河南清丰、河北保定、安徽颍上、山东泰安和青岛五个地区的禾谷孢囊线虫二龄幼虫的室内毒力。结果表明,六种杀线剂对五个地区线虫的毒力表现为:甲维盐>阿维菌素>灭线磷>涕灭威>噻唑膦>丁硫克百威。灭线磷、噻唑膦、涕灭威和丁硫克百威对各地区线虫的LC50值都在582.7mg.L-1以上,不同地区线虫对同一药剂的敏感性存在一定差异,但相对毒力指数均在1.31以下;阿维菌素对各地区线虫的LC50值为26.0～66.3mg.L-1,甲维盐对各地区线虫的LC50值为20.1～35.3mg.L-1,不同地区线虫对这两种药剂的敏感性存在较大差异,相对毒力指数最高达2.55。     

Influence of treatment of soil with carbofuran on the subsequent performance of insecticides against cabbage root fly (Delia radicum) and carrot fly (Psila rosae)

A sandy loam soil was treated with 2·5 kg carbofuran/ha on each of five occasions between May and October 1984. In 1985, the field performance of benfuracarb, carbofuran, carbosulfan, chlorfenvinphos and furathiocarb against cabbage root fly (Delia radicum) and carrot fly (Psila rosae) was studied in this soil and in identical but previously untreated soil by applying exponentially increasing doses of granular formulations to radish and carrots at drilling. Chlorfenvinphos reduced numbers of larvae of both pests by >90% in both soils but the performance of all the carbamates was significantly worse in the previously treated soil than in the previously untreated soil. Dazomet, a partial soil sterilant, was applied to part of the experimental area in October 1985 and the performance of aldicarb, carbofuran, carbosulfan, chlorfenvinphos and thiofanox against cabbage root fly was assessed in 1986. The efficiency of aldicarb and chlorfenvinphos was not affected by any of the pre-treatments but that of carbofuran and carbosulfan was reduced in all the pre-treated soils, including the soil treated with dazomet. Carbofuran residues in radish were detectable only in plants grown in previously untreated soil. In laboratory incubations, a dustless base formulation of carbofuran was degraded more quickly in pre-treated than in untreated soils but a granular formulation was degraded more slowly and at a similar rate in both soils.     

Field and laboratory studies on the control of nematode and aphid virus vectors in potatoes by pesticides applied as side-bands

Field trials were undertaken with a prototype machine to determine whether virus vector nematodes and aphids were controlled by the carbamoyl oxime pesticides aldicarb (Temik 10G) and oxamyl (Vydate 10G) incorporated into the ridge of a growing potato crop. The treatments were applied at tuber initiation (7 or 8 weeks after planting) and were compared with similar amounts of the same pesticides applied in-furrow at planting. All aldicarb treatments significantly decreased the incidence of tobacco rattle virus spraing transmitted by trichodorid nematodes. However, the side-banded treatments were less effective than the in-furrow treatments applied at similar rates. Numbers of aphids infesting the crop were significantly and similarly decreased by both methods of application. Pesticide treatments did not significantly increase yield, and total tuber yields from the standard infurrow and the side-banded treatments were similar. To provide further information on the efficacy and movement of carbamoyl oxime pesticides between different isolated root systems on single parent tubers, replicated pot experiments were made. Parent tubers were maintained with a physical barrier between a root system treated with pesticide and another left untreated. In a nematode bioassay Meloidogyne incognita was added to both the treated and untreated root systems to test for the presence of nematicidal activity. The number of root-galls which developed in 8 weeks were counted. Both aldicarb and oxamyl decreased the number of galls on the treated root system. However, little evidence of translocation through the parent tuber was found, the number of galls on the untreated roots being largely unaffected. The roots of plants grown from tubers treated in a similar manner were tested for the presence of aldicarb and oxamyl residues by gas-liquid chromatography. No translocated pesticide was detected. In aphid bioassays, using excised leaves, 3–5 weeks after applying aldicarb at 20 and 40 mg a.i./pot or 4–9 weeks after applying aldicarb at 80 mg a.i./pot, aphid survival was always significantly less on treated stems than on non-treated stems growing at the opposite end of the tuber or on control stems growing from untreated tubers. However, there was some evidence for translocation through the parent tuber as fewer aphids survived on leaves from non-treated stems than from untreated control stems.     

Accelerated degradation of aldicarb and its oxidation products in previously treated soils

The persistence of aldicarb, aldicarb sulphoxide and aldicarb sulphone was studied in soils used for crops grown commercially and in experimental soils with different histories of treatment with a granular formulation of aldicarb. Total aldicarb residues declined more rapidly in incubations in all the previously treated soils (initial 50% loss in 5–17 days at 15°C) than in the corresponding untreated soils (initial 50% loss in 25–50 days). This was largely because of more rapid breakdown of aldicarb sulphoxide and, to a lesser extent, of aldicarb sulphone. Accelerated degradation was induced more readily by pretreatment with carbofuran than with aldicarb or thiofanox and seemed to be influenced at least as much by dose level as by frequency of pretreatment. It is concluded that rotation of chemical usage should suppress development of the phenomenon with commercially recommended doses of aldicarb but that the potential for cross-enhancement is still little understood.     

Accelerated degradation of carbofuran in previously treated field soils in the United Kingdom

The persistence of carbofuran in eight UK soils with different histories of treatment with this insecticide was studied under controlled conditions. Degradation was influenced little by the concentration of insecticide and was always quicker in the previously treated soils than in the corresponding untreated samples. The insecticide was most persistent in a soil treated annually with a soil sterilant as well as carbofuran. It is concluded that the rapid breakdown was probably related to changes in the populations of soil micro-organisms rather than to differences in soil properties.     

The effect of nematicides onPratylenchus penetrans and potato yields

Aldicarb applied as Temik 10% or 15% granular at 1.68, 2.24 or 3.36 kg/ha active ingredient (a.i.) in the row at planting reduced the size of populations ofPratylenchus penetrons in experimental plots and commercial fields. Both aldicarb and the soil fumigant, Telone-II, were associated with yield increases of about 40% in Superior and Sebago potatoes in experimental plots in 1978, but there were no significant increases in yield in 1979 and 1980. A comparison was made between areas treated with aldicarb 10% granular at 2.24 kg/ha a.i. or disulfoton 15% granular at 3.36 kg/ha a.i. in 24 commercial fields. Average yields from the combined results of Kennebec, Superior, Sebago, and Russet Burbank cultivars were about 13% higher in the aldicarb treatments. Yields in six fields where aldicarb was applied at 3.36 kg/ha a.i. were not different from yields in adjacent fields treated with the lower rate of aldicarb. Superior potatoes inoculated withP. penetrons, or uninoculated, were grown in pots in the greenhouse in fine sandy loam at moisture levels of 35–55% or 70–100% field capacity. The lower soil moisture level and the nematode treatment reduced tuber weights. The nematode-soil moisture interaction was significant in one of the two experiments.     

Control of stem nematode, Ditylenchus dipsaci, in tulip bulbs with aldicarb and oxamyl

In the Netherlands complete elimination of the stem nematode Ditylenchus dipsaci (Kühn, Filipjev) in tulip by destruction of infested lots and sterilization of infested soil is the aim of the Plant Protection Service. Elimination of stem nematode in narcissus bulbs is achieved by hot-water treatment, but this treatment is not appropriate for tulip bulbs because these are damaged at temperatures of 43 · 5°C and higher. As the effects of the systemic nematicides aldicarb and oxamyl looked promising, these were investigated further. Aldicarb, 6 kg a.i./ha, was applied once in the autumn and once in spring. Oxamyl, 2 · 88 kg a.i./ha, was applied three times in spring. The efficacy of these nematicides was shown not only by a reduction in the numbers of infested bulbs but also by a reduction in nematode numbers in the bulbs, shown here in the frequency distribution of infested bulbs over nematode numbers. However in some bulbs, probably those which had the highest number of nematodes before planting, a few stem nematodes could still be detected, having survived high dosages of nematicides. Therefore, complete elimination of stem nematodes from infected bulbs with very high nematode numbers is probably impossible. It is expected, however, that repeated treatment will increase the percentage of nematode-free bulbs and will lead to almost healthy tulip-bulb stocks.     

Influence of stem canker (Rhizoctonia solani Kühn) on tuber yield,tuber size,reducing sugars and crisp colour in cv. Record

Summary In eight experiments in 4 years, inoculating seed tubers withR. solani caused stem canker and in seven experiments decreased the total yield and the yield of tubers 40–70 mm. Yields of larger tubers were usually increased. In most experiments inoculating increased the reducing sugar content of the tubers and darkened the colour of crisps, but did not consistently affect the amounts of sucrose. Treating soil with aldicarb or oxamyl before planting also slightly increased the total reducing sugars.     

Row treatment of potatoes with systemics for meadow nematode (Pratylenchus penetrans) control

Granular aldicarb and carbofuran, systemic carbamate insecticides, were applied at 3 lbs active per acre to compare their control of the meadow nematode (Pratylenchus penetrans). These systemic pesticides were applied either in two bands 2–3 inches from both sides of and at the lower plane of the seed-piece or in one band 4–5 inches wide and 1/2 inch above the seed. Two months after planting, nematode populations were greatly reduced in soil and roots from plots treated with either chemical and with both placement methods. Aldicarb provided effective control longer into the growing season than did carbofuran. When compared with carbofuran, aldicarb-treated potao plants lived longer and produced a greater increase in yield over the untreated plots. Yield increases were greater when either systemic was applied in side bands than when placed over the seed.     

Effects of row application of insecticides at sowing on leaf miner (Pegomya betae) injury to sugar beet

Injury to the leaves of sugar-beet seedlings caused by the mining of Pegomya betae larvae was greatly decreased by applying insecticide granules in the furrow with the seed: carbofuran, carbosulfan, terbufos and aldicarb were very effective but bendiocarb was only partially effective. Carbosulfan applied as a band spray along the row was less effective than the better granule treatments, while band sprays of gamma-HCH, quinalphos and oxamyl were ineffective or even increased the incidence of damage.     

Effects of systemic insecticides on potato growth and their interaction with metribuzin

Effects of the soil systemic insecticides aldicarb, phorate, and disulfoton on potato growth were measured from 1984–1986 on the cultivars Russet Burbank and Centennial. In all seasons, aldicarb was observed to cause a significant promotion of flowering and in one season also caused increased haulm growth. Phorate caused a reduction in these growth parameters in one season. Temporary effects on early season yields were observed from the aldicarb treatment in one year but final yields were never significantly affected by insecticide use alone. During 1985–1986 additional treatments were investigated involving insecticide combinations with the herbicide metribuzin to determine possible insecticide-herbicide interactions. Phorate-metribuzin combinations caused synergistic metribuzin injury symptoms, decreased haulm growth and yield in 1986. Metribuzin also decreased yields of aldicarb treated potatoes in 1986 and disulfoton treated potatoes in 1985. Disulfoton-metribuzin combinations decreased flowering in 1985. These data suggest that soil systemic insecticides can have direct effects on potato growth, independent of effects on pest suppression, and that they may interact with other crop protection chemicals.     

Effects of insecticides applied to control cucumber beetles (Coleoptera: Chrysomelidae) on watermelon yields

Foliar insecticides applied to control the striped and spotted cucumber beetles, Acalymma vittatum (Fab.) and Diabrotica undecimpunctata howardi Barber, on watermelon, Citrullus lanatus, were of little or no value in three studies conducted in two locations over 2 years. However, an at-planting application of the systemic, soil insecticide carbofuran resulted in higher early yields, although the differences were not statistically significant in small plots. In 1991, large plots comparing carbofuran-treated watermelons with untreated watermelons in two commercial fields showed large and statistically significant increases in melon yield when carbofuran was applied, especially in early yield. Studies in 1992 and 1993 showed that the application of carbofuran at planting stimulated root and shoot growth after transplating and increased yields when compared with untreated plots, plots treated with methyl bromide, or another soil insecticide, terbufos. These studies suggest that carbofuran may be acting as a growth stimulant, as well as an insecticide.     

The joint action of nitrogen and nematicides onPratylenchus penetrans and potato yield

The joint action of nitrogen fertilizer and nematicides onPratylenchus penetrons and yield was investigated using three potato varieties (Superior, Onaway and Russet Burbank), three rates of nitrogen (84, 168 and 336 kg/ha), five edaphic pesticides (disulfoton, aldicarb, 1,3-D + MIC, carbofuran and thiofanox), and an insecticide spray to minimize the role of foliar feeding insects In 1977, disulfoton, aldicarb, and disulfoton plus 1,3-D + MIC significantly increased the yield of Superior at all nitrogen rates. The yield increases ranged from 37–56% for Superior, 15–35% for Onaway and 13–27% for Russet Burbank. Nitrogen had no detectable influence on yield. Population densities ofP. penetrans were significantly reduced by disulfoton plus 1,3-D + MIC and by aldicarb. Superior was most susceptible toP. penetrans, Onaway intermediate, and Russet Burbank moderately tolerant. Neither the potato variety or nitrogen significantly influenced the population densities ofP. penetrans In 1978 aldicarb, 1,3-D + MIC and thiofanox significantly increased yields of Superior at all nitrogen rates. Nitrogen also significantly increased yields, but only where aldicarb and 1,3-D + MIC were applied. Total yield was increased 12–14% and 17–23% by 1,3-D + MIC and aldicarb at 168 and 336 kg N/ha, respectively. Aldicarb, 1,3-D + MIC, and thiofanox appeared to increase tuber set, while nitrogen increased tuber size. Although all of the nematicides provided some control ofP. penetrans, aldicarb had the highest degree of efficacy and gave excellent season-long control     

Effect of nematodes on the sustained production of sugarcane in South Africa

An attempt is made to quantify the long-term benefit from the sustained production of sugarcane in South Africa using nematicides to reduce the damage caused by nematodes in each crop. The study was conducted using data from the plant crop and four or five ratoon crops from two trials located on similar sandy soils. Treatments comprised aldicarb and an untreated control, applied to a total of 10 sugarcane cultivars. Two cultivars were common to both sites. The plant parasitic nematode communities were similar at both sites except that Meloidogyne javanica was absent from one site. Yield of ratoon crops was correlated with the yield of the plant crop. Annual losses from nematodes were similar over successive crops. Data from both sites showed there to be a significant, positive correlation between yield of the nematicide treated plots and size of the response to treatment. Over a 4-year period, M. javanica alone was responsible for 30% of the losses, equivalent to 15 t cane/ha per year. The long-term effect of nematodes on sugarcane production was measured after calculating a logarithmic function from the observed yields of successive ratoons. Without a nematicide the time taken for the yield to decline to a threshold of 40 t cane/ha per year ranged from a minimum of 1 year in the M. javanica infested site to a maximum of 9 years in the other site. Treatment with a nematicide increased this period considerably. On the site with M. javanica it took a projected 20 years before the yield of one of the cultivars reached the threshold and 43 years for the same cultivar at the other site. The use of a nematicide increased long-term production, on average, by a factor of 3 at the M. javanica infested site and a factor of 5 at the other site. Differences between cultivars in the rate at which ratoon yields declined meant that, over time, the best cultivars at both sites were not the ones which gave the greatest annual yields during the first few crops after planting.     

Lesion nematode suppression with the butte potato and relationships to verticillium wilt

Field studies conducted over a 5 yr period to compare the effect of continuous cropping of several potato clones (Butte, Russet Burbank, Targhee, A66107-51, and A68113-4) showed Butte to be highly resistant toPratylenchus neglectus while being highly susceptible toVerticillium dahliae. This was further evidenced during the 6th yr when Russet Burbank was cropped over all plot-locations. Populations ofP. neglectus were shown to be significantly less (0.05 P) in both soil and roots when Russet Burbank was grown over sites previously cropped with the Butte potato than over site-locations cropped by either Russet Burbank, Targhee, A66107–51, or A68113–4. Additional field and greenhouse studies corroborated the high degree of resistance of Butte toPratylenchus spp. In addition toP. neglectus resistance, a greenhouse investigation also showed resistance to P. penetrans. A field study designed to compare the effects of Butte with nematicides showed that Butte reducedP. neglectus populations in both soil and roots when compared with Russet Burbank. This degree of reduction was equivalent to the effects of either of two systemic nematicides (aldicarb and isofenphos) at 3.4 to 4.0 kg a.i./ha, respectively. Results demonstrate biological control with the Butte potato clone forP. neglectus suppression. Although populations ofP. neglectus were reduced by either nematicides or Butte, wilt severity was higher with Butte than Russet Burbank. Results showed wilt suppression andP. neglectus reduction with treatments of either nematicide, while having no significant effect on the colonization of potato stems byV. dahliae.     

Systemic insecticides,soil fumigation,and nitrogen fertilization for verticillium wilt control

Fumigation of Verticillium infested soils with Telone®+chloropicrin in 1966 increased yields of Russet Burbank potatoes 178 and 147 cwt/a (200 and 165 q/ha) over yields in unfumigated plots near Othello and Prosser, Washington, respectively. Systemic insecticides disulfoton and aldicarb banded at planting, sidedressed after planting, or applied in combination treatments did not increase yield at either location. Plots fumigated with Telone®+chloropicrin and fertilized with ammonium nitrate (150 and 350 lb N/a?168 and 392 kg N/ha) in 1967 significantly increased yields over that of the unfumigated, fertilized plots. Application of disulfoton and aldicarb to plots fertilized with ammonium nitrate (150 and 350 lb N/a?168 and 392 kg N/ha) did not increase yields over that of fertilized plots receiving no systemic insecticide.     

Effects of nematicides on the chemical composition of the fruits of egg-plant (Solanum melongena L.)

Five nematicides — aldicarb, carbofuran, phorate, fensulfothion and DBCP — were studied in a field experiment to investigate their effect on the chemical composition of the fruits of egg-plant. There were no significant differences in the dry matter content of fruits from different treatments. A significant decrease in the crude protein content was observed with nematicide treatments. Phenolic compounds increased on application of phorate while all other treatments, except carbofuran, decreased these compounds. A significant increase over control in solasodine content of fruits was observed with all treatments.     

Response of Potatoes to Soil-Applied Insecticides, Fungicides, and Herbicides

Non-target impacts of pesticides are well documented in crops such as soybeans and corn. However, little effort has been made to evaluate these impacts in potatoes. Field trials were conducted at the Parma and Aberdeen Research and Extension Centers during 2005 and 2006 to evaluate the potential for systemic insecticides, fungicides, and herbicides to affect disease development, crop injury, and tuber yield. The first set of trials evaluated six insecticide treatments (aldicarb, oxamyl, phorate, imidacloprid, thiamethoxam, and non-treated) in a factorial combination with in-furrow application of the fungicide azoxystrobin. Azoxystrobin significantly decreased Rhizoctonia stem canker, while aldicarb and phorate tended to increase it compared to the non-treated control. There was a significant insecticide by fungicide interaction due to a bigger reduction in disease index by the fungicide when certain insecticides were used. Despite the association of these insecticides with increased disease incidence, there was no significant impact on yield. In the second set of trials, sulfentrazone herbicide was applied just prior to plant emergence to potatoes treated with the same six insecticides to evaluate the potential for the in-furrow treatments to increase plant injury. Sulfentrazone caused stunting and visible plant injury, but the level of plant injury was influenced by insecticide treatment in only one out of four trials.     

The effects of pesticides and crop rotation on the soil-inhabiting fauna of sugar-beet fields. Part I: The crop and macroinvertebrates

The effects of two insecticide treatments (seed-furrow aldicarb, and gamma-HCH sprayed overall), herbicide and crop rotation on pest attack to sugar-beet seedlings, and pest and predator populations, were studied in a 3-year field trial. On continuous-beet plots without insecticide, seedling establishment declined sharply from the first to the third year of the trial due to a build-up in the numbers of pygmy beetles, Atomaria linearis Steph., a sugar-beet pest. Crop rotation, and both insecticides, decreased damage by the pest and thereby increased establishment considerably, in the second and third years of the trial whereas herbicide had no effect. The effects of the insecticides on numbers of creatures caught in pitfall traps varied with species and with insecticide. For example, more Bembidion lampros Herbst., a carabid beetle, were trapped on plots treated with gamma-HCH than on untreated plots, whereas the effect was less marked on aldicarb-treated plots and was not observed in other carabid species with either insecticide.     

Influence of the growth retardant B 995 on growth and yield of potatoes

Summary Stem elongation in a potato crop can be reduced by spraying the growth retardant B 995 on the foliage. This treatment generally did not change the total dry matter production. Only in the last period of growth did B 995-treated plots show a higher total dry weight than the untreated ones. This was caused by a slightly later senescence of the treated plots. The B 995 treatment caused a marked change in the dry matter distribution: stem weight was decreased and tuber weight increased, but leaf weight was generally not influenced. With plants showing considerable vegetative growth, these effects resulted in an increased tuber yield. High nitrogen plots treated with B 995 combined a long productive periode with a favourable dry matter distribution, producing a very high tuber yield at the end of the growing period.