Scholarly Work - Research Centers
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Item Comparisons of ecorational and chemical insecticides against crucifer flea beetle (Coleoptera: Chrysomelidae) on canola(2007-08) Antwi, Frank B.; Olson, D. L.; Carey, D. R.Studies were done comparing the insecticides SpinTor (spinosad), BotaniGard ( Beauveria bassiana ), Neemix (azadirachtin), and Surround (kaolin, a clay) with conventional chemical insecticides Capture (bifenthrin) and Helix XTra (thiamethoxam), all applied at seven rates in a 7-d assay to assess their impact on adult crucifer flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae). Lethal time (LT) required for 25, 50, and 75% mortality (LT 25 , LT 50 , and LT 75 ) and relative potencies for the insecticide concentration groupings (0, 1X–1.5X, and 2X–4X) were estimated for each treatment by using survival functions. P. cruciferae mortality increased in response to increasing concentrations, especially for Helix XTra, Capture and SpinTor. After 2 d of exposure in 2002, mortality ranged from 54 to 78% for Helix XTra, from 60 to 94% for Capture, and from 66 to 92% for SpinTor across concentrations. In 2003, flea beetle mortality ranged from 37 to 60%, from 29 to 63%, and from 23 to 52% on exposure to Helix XTra, Capture, and SpinTor, respectively, for 2 d. The LT 50 and relative potencies of the insecticides were in the order of Helix XTra, Capture, and SpinTor > BotaniGard, Neemix, and Surround. In 2002, LT 50 values were 1 and 2 d for Capture and SpinTor, 2 d for BotaniGard, and 3 d for Neemix and Surround. In 2003, LT 50 values occurred between 2 and 4 d after exposure to Helix XTra, Capture, and SpinTor, with LT 50 values of 5–7 d on exposure to BotaniGard, Neemix, and Surround. SpinTor seems to be a suitable ecorational insecticide in canola, Brassica napus L., for P. cruciferae management.Item Comparative evaluation and economic potential of ecorational versus chemical insecticides for crucifer flea beetle (Coleoptera: Chrysomelidae) management in canola(2007-06) Antwi, Frank B.; Olson, D. L.; Carey, D. R.From 2001 to 2004, field studies were conducted to evaluate the effect of the ecorational insecticides SpinTor (spinosad), BotaniGard ( Beauveria bassiana ), Neemix (azadirachtin), and Surround (kaolin) against crucifer flea beetle on canola, Brassica napus L., at the cotyledon stage. The ecorational treatments were compared with a standard foliar chemical insecticide, Capture (bifenthrin), and the chemical seed treatment insecticide Helix XTra (thiamethoxam). This study indicated that flea beetle injury was lower for Helix XTra, Capture, and the ecorational insecticide SpinTor. SpinTor was less effective when flea beetle populations were relatively high (200–300 per trap-week). Yields for chemical insecticide treatments were always greater than SpinTor, with differences being the smallest (68–374 kg/ha) at low levels of flea beetle feeding injury. Differences were greatest when canola seedling injury was high (775–1,364 kg/ha). Yield differences between the conventional insecticides and BotaniGard, Neemix, and Surround were 119–439 and 61–2,248 kg/ha at low and high flea beetle feeding injury, respectively. Although yield differences between SpinTor and chemical insecticides were relatively small at lower levels of flea beetle injury, net losses ranged from 03047 to 030151/ha when SpinTor was used as an alternative to a standard chemical seed treatment, Helix XTra. This suggests that SpinTor would not be a viable alternative to the chemical insecticide. Net losses ranged from 03030 to 030266/ha when BotaniGard, Neemix, and Surround were used as alternatives to the seed treatment.Item Risk assessments for the insect repellents DEET and Picaridin(2008-06) Antwi, Frank B.; Shama, Leslie M.; Peterson, Robert K. D.For the use of topical insect repellents, DEET and picaridin, human health risk assessments were conducted for various population subgroups. Acute, subchronic, and chronic dermal exposures were examined. No-observed-effect-levels (NOELs) of 200, 300, and 100 mg/kg body weight (BW) were used as endpoints for DEET for acute, subchronic, and chronic exposures, respectively. For picaridin, a NOEL of 2000 mg/kg BW/day for acute exposure and a NOEL of 200 mg/kg BW/day for subchronic and chronic exposures were used. Daily exposures to several population subgroups were estimated. Risks were characterized using the Margin of Exposure (MOE) method (NOEL divided by the estimated exposure), whereby estimated MOEs were compared to an MOE of 100. Estimates of daily exposures ranged from 2 to 59 mg/kg BW/day for DEET and 2 to 22 mg/kg BW/day for picaridin. Children had the lowest MOEs. However, none of the estimated exposures exceeded NOELs for either repellent. At 40% DEET for acute exposure, children ⩽12 years had MOEs below 100. For subchronic and chronic exposures children at ⩾25% DEET and at 15% picaridin had MOEs below 100. Therefore, we found no significant toxicological risks from typical usage of these topical insect repellents.Item Toxicity of δ- phenothrin and resmethrin to non-target insects(2009-03) Antwi, Frank B.; Petterson, Robert K. D.BACKGROUND: The susceptibility of adult house cricket, Acheta domesticus (L.), adult convergent lady beetle, Hippodamia convergens (Guérin-Méneville), and larval fall armyworm, Spodoptera frugiperda (JE Smith), to resmethrin and δ-phenothrin synergized with piperonyl butoxide (PBO) was evaluated in a laboratory bioassay procedure. RESULTS: The 1 day LC50 values for resmethrin + PBO were 23.2, 32.08 and 307.18 ng cm−2 for A. domesticus, H. convergens and S. frugiperda respectively. The 1 day LC50 values for δ-phenothrin + PBO were 26.9, 74.91 and 228.57 ng cm−2 for A. domesticus, H. convergens and S. frugiperdarespectively. The regression relationship between species mortality and concentration explained 51–81% of the variation for resmethrin + PBO and 72–97% of the variation for δ-phenothrin + PBO. The LC50 values decreased with time for these insecticides for all surrogate species. In terms of sensitivities among the insects to resmethrin + PBO and δ-phenothrin + PBO, A. domesticus was most sensitive, followed by H. convergens and then S. frugiperda. CONCLUSION: The results indicate that resmethrin + PBO was generally more toxic than δ-phenothrin + PBO. Based on the results, A. domesticus seems to be a good surrogate species for estimating potential non-target terrestrial insect impacts from exposure to pyrethroids used in public health applications.Item 2008 Oilseed Performance in Central Montana Trials(Central Agricultural Research Center, 2008) Wichman, David M.This paper evaluates 2008 Oilseed performance in central Montana trials. 2008 Central Montana crop growing conditions were generally less than ideal, particularly for spring crops. Droughty conditions of late 2007 persisted through early May and commenced again in mid-June following above average precipitation in May. Early spring weather consisted of frequent dry windy days with almost daily freezing and thawing of the surface soil through March and early April. The frequent freezing and thawing coupled with low relative humidity broke down the surface soil structure leaving it quite powdery. All five crops, camelina, canola yellow mustard, flax and safflower, had their highest 2008 yield from the April 17th seed date (Table 1). The germination and emergence of seedlings from the April 17th seed date occurred after area temperatures dropped below zero and wind driven snirt (snow & dirt) grated on emerged plant tissue. Earlier emerging seedlings experienced more weather related stress and some mortality. In general, Moccasin yields of cool season oilseeds, camelina, canola and yellow mustard are reduced when seeding is delayed till mid April (Table 2 & Fig. 1). The need to get cool season oilseed crops seeded in early spring may not be as critical in areas with similar growing season temperatures and deeper soils (greater plant available water) or more July precipitation.Item Evaluation of Fall Seeded Winter Pea and Lentil Line Performance (Western Regional Winter Dry Pea and Lentil Evaluation Trials) (2008)(Central Agricultural Research Center, 2008) Wichman, David M.; Chen, Chengci; Neill, Karnes E.; McPhee, K.; Short, R.W.; Vavrovsky, JoeThis paper evaluates winter hardiness of fall seeded winter dry pea and lentil lines. A difference in spring stand (visual evaluation) amongst the winter pea lines was exhibited, with Granger Austrian winter pea having the best stand, but was significantly similar to five other lines (Table 3). Upon visual observations, large differences in winter survival among the winter lentil lines were observed (Table 4). Turkish-type (“T”) lines LC02600449T and LC03600295T had the poorest spring stands with an average score of 1.6 and 1.8 (out of possible of 5), respectively.Item 2008 Western Regional Spring Dry Pea and Lentil Evaluations(Central Agricultural Research Center, 2008) McPhee, K.; Vandemark, G.; Chen, Chengci; Neill, Karnes E.; Heser, J.This paper evaluates dry pea and lentil selections from the USDA-ARS Grain Legume Genetics and Physiology program in Pullman, Washington, for grain production potential in Central Montana. Dry pea grain yields were much below long-term means and is thought to be due to poor sub-soil moisture, a hail storm, snow and record lows in mid-June, and an insect (pea leaf weevil) infestation. The trial grain yield mean was 1,038 lbs acre-1 (converted to 13% grain moisture - field grain moisture was 923 lbs acre-1; Table 3). The smooth yellow line PS03101822 had the greatest grain production at 13% moisture, averaging 1,282 lbs acre-1, but was not significantly greater than the smooth green line PS03101445 (based on LSD0.05). Lentil grain yields averaged (at 13% moisture) 1,688 lbs acre-1, which was the best Western Regional lentil production at Moccasin since the 2000 crop-year, which averaged an all-time best of 2300 lbs acre-1 at 13% grain moisture (Table 4). At field grain moisture, the Turkish-red line LC01601724T had the highst grain production (not significant). When yields were converted to 13% grain moisture, Eston had the greatest grain production (1,883 lbs acre-1; not significant based on LSD0.05).Item 2008 Statewide Spring Dry Pea and Lentil Variety Evaluations(Central Agricultural Research Center, 2008) Chen, Chengci; Neill, Karnes E.; Carlson, G. R.; Miller, John H.; Stougaard, Robert N.; Strang, L.; Westcott, M.; Knox, M.; Eckhoff, Joyce L.; Miller, Perry R.; Holmes, Jeffrey A.; Tarum, M.; Koenig, V.This paper evaluates spring dry pea and lentil varieties for grain production potential in diverse Montana environments. Dry pea grain yields were respectable among most of the testing sites (Table 3). Havre had the greatest production, with a trial average (converted to 13% moisture) of nearly 65 bushels acre-1 (65.6 bu/acre – 3,868 lbs/acre). Moccasin had the worst yield averaging less than 17 bushels acre-1 (16.1 bu/acre - 986 lbs/acre) which is much below long-term means and is thought to be due to poor sub-soil moisture, hail damage, snow and record lows in mid-June, and an insect infestation. As expected, no single entry was the top yielding variety at every location. However, the smooth yellow line PS9910140 did top the trial yields at three locations, and was among the top cultivars in the other locations. Lentil grain yields ranged from 450 to 2300 lbs acre-1 and were respectable across the state (Table 7), with the exceptions being Conrad (450 lbs acre-1), which had a poor stand establishment and Sidney (trial abandoned), which had poor soil moisture at seeding and experienced drought-like conditions through the growing season. Differences in grain yield between the dry pea and lentil trials at Moccasin can be attributed to planting of the lentil trial in a different field, which contained better stored soil moisture. The “Richlea”-type lentil line LC01602300R showed the greatest seed production at three of the six sites, with a grain yield ranging from 9.0 (at Conrad) to over 44 bushels acre-1 (Creston), but was not significant at any location (based on LSD0.05).Item 2008 India, Australia and Western Regional Chickpea Line Evaluations(Central Agricultural Research Center, 2008) McPhee, K.; Chen, Chengci; Neill, Karnes E.; Heser, J.This paper evaluates chickpea selections from the India, Australia and the USDA-ARS Grain Legume Genetics and Physiology program in Pullman, Washington, for grain production potential in Central Montana. Chickpea grain yields were exceptional at Moccasin, with the trial averaging 1,248 lbs per acre (at 13% grain moisture; Table 3). As a whole, the India and Australia Lines were superior to the USDA line and three check varieties. These lines are in the Small Kabuli and Desi-type chickpeas versus the traditional Large Kabuli-type, as are the check varieties and USDA-ARS lines. Historically, small Kabuli and Desi-type chickpeas perform better at CARC. The Australian Desi-type Line AC48111 had the greatest grain production (at 13% moisture) with 1,478 lbs acre-1, but was only significantly greater (based on LSD0.05) than six other India and Australia lines and all but one of the USDA-ARS lines.Item Western Regional Dry Pea, Lentil and Chickpea Trials (2007)(Central Agricultural Research Center, 2007) Wichman, David M.; Chen, Chengci; McPhee, K.; Muehlbauer, F.J.; Neill, Karnes E.; Short, R.W.; Vavrovsky, JoeThis paper evaluates dry pea, lentil and chickpea lines for grain production potential in dryland environments. Dry pea grain yields averaged 1,422 lbs of dry pea production per acre (Table 3). Delta smooth yellow pea had the highest grain production (1,627 lbs acre-1) but was not significantly higher than eight other pea lines (based on LSD(0.05)). Lentil yields were suppressed and may have been due to a growing nematode problem in adjacent fields (not confirmed in field trial established). The trial averaged 955.1 lbs per acre (Table 4). The “Brewer”-type lentil, Merrit, produced the most seed, averaging 1128.0 lbs acre-1, but was not statistically higher (based on LSD0.05) than eight other lines. Chickpea grain yields averaged 758.5 lbs of grain production per acre (Table 5.). Dylan kabuli-type chickpea produced the most grain (978.8 lbs acre-1), but was significantly similar to line CA0090B347C (based on LSD0.05).