987 resultados para Second corn crop
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The winter component of a year-round grazing system involving grazing of corn crop residues followed by grazing stockpiled grass-legume forages was compared at the McNay Research Farm with that of the winter component of a minimal land system that maintained cows in drylot. In the summers of 1995 and 1996, two and one cuttings of hay per year were harvested from two 15-acre fields containing “Johnston” low endophtye tall fescue and red clover. Two cuttings of hay in 1995 and one cutting in 1996 were harvested from two 15-acre fields of smooth bromegrass and red clover. Hay yields were 4,236 and 4,600 pounds of dry matter per acre for the tall fescue-red clover in 1995 and 1996, and 2,239 and 2,300 pounds of dry matter per acre for the smooth bromegrass-red clover in 1995 and 1996. Following grain harvest, four 7.5-acre fields containing corn crop residues were stocked with cows at midgestation at an allowance of 1.5 acres per cow. Forage yields at the initiation of corn crop grazing in 1995 and 1996 were 3,757 and 3,551 pounds of dry matter per acre for corn crop residues. Stockpiled forage yields were 1,748 and 2,912 pounds of dry matter for tall fescue-red clover and 1,880 and 2,187 pounds for smooth bromegrass-red clover. Corn crop residues and stockpiled forages were grazed in a strip stocking system. For comparison, 20 cows in 1995 and 16 cows in 1996 were placed in two drylots simultaneously with initiation of corn crop grazing, where they remained throughout the winter and spring grazing periods. Cows maintained in drylots or grazing corn crop residue and stockpiled forages were supplemented with hay as large round bales to maintain a body condition score of five. In both years, no seasonal differences in body weight and body condition score were observed between grazing cows or cows maintained in drylots, but grazing cows required 85% and 98% less harvested hay in years 1 and 2 than cows in drylot during the winter and spring. Because less hay was needed to maintain grazing cows, excesses of 12,354 and 5,244 pounds of hay dry matter per cow in 1995 and 1996 remained in the year-round grazing system. During corn crop grazing, organic matter yield decreased at 23.5 and 28.8 pounds of organic matter per day from grazed areas of corn crop residues in 1995 and 1996. Organic matter losses due to weathering were 6.8, 10.3, and 12.7 pounds per day in corn crop residue, tall fescue-red clover and smooth bromegrass-red clover in 1995 and 12.1, 10.7, and 12.1 in 1996. Organic matter losses from grazed and ungrazed areas of tall fescue-red clover and smooth bromegrass-red clover during stockpiled grazing were 6.9, 6.9, and 2.1, 2.9 in 1995 and 13.4, 4.3, and +6.9, 4.4 pounds per day in 1996.
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Berseem clover and oats were incorporated into a corncorn- oat/berseem clover rotation in 1994 and 1995. Two cuttings of oat-berseem clover hay were harvested during the summer before forage was allowed to stockpile for winter grazing. In 1995, a brown midrib sorghum x sudangrass hybrid was seeded into a field adjacent to a corn field. After corn grain harvest in 1994 and 1995, Charolais x Angus x Simmental cows in midgestation were allotted to replicated fields containing corn crop residues with no complementary forages at 2.5 acres/cow, or corn crop residues and stockpiled berseem clover (2:1) at 2.5 acres/cow to simultaneously graze, or to a drylot. In 1995, cows were allotted to fields containing corn crop residues and brown midrib sorghum x sudangrass (7:3) at 2.5 acres/cow. Berseem clover had greater concentrations of digestible organic matter and crude protein than corn crop residues at the initiation of grazing, but had a more rapid decrease in digestible organic matter concentration than corn crop residues. Brown midrib sorghum x sudangrass forage also had a higher initial concentration of digestible organic matter, but an equal rate of decrease in digestible organic matter concentration to corn crop residues in ungrazed areas of the field. Cows grazing berseem clover with corn crop residues had greater body condition score increases during the first half of the grazing season than cows grazing corn crop residues without complementary forages. Cows grazing corn crop residues without complementary forages required 2,786 and 1,412 less lb hay per cow than cows maintained in a drylot in 1994 and 1995. In 1994, simultaneous grazing of berseem clover with corn crop residues did not reduce hay feeding more than feeding corn crop residues alone. However, in 1995, grazing berseem clover or brown midrib sorghum x sudangrass with corn crop residues reduced the amount of hay required to maintain cows by 358 and 376 lb hay per cow compared with grazing corn crop residues without complementary forage.
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Berseem clover and oats were incorporated into a corn-oat/berseem clover rotation in 1994-1996. Two cuttings of oat-berseem clover hay were harvested during the summer before forage was stockpiled for winter grazing. In 1995, brown midrib sorghum x sudangrass hybrid was seeded into a field adjacent to a corn field. This was repeated in 1996 with a standard sorghum x sudangrass hybrid. After corn harvest in 1994–1996, Charolais x Angus x Simmental cows and heifers in midgestation were allotted to corn crop residue, corn crop residue-berseem clover, and corn crop residue-sorghum x sudangrass fields at 2.5 acres/cow, or to a drylot. Berseem clover had greater concentration of digestible organic matter and crude protein than corn crop residues. Corn crop residue digestible organic matter concentration was lower than berseem clover and the brown midrib sorghum x sudangrass, but was higher than that of the standard sorghum x sudangrass hybrid in 1996. Cows grazing corn crop residues without complementary forages required an average of 2,374 less lb. hay per cow than cows maintained in a drylot in 1994-1996. In 1994 and 1996, simultaneous grazing of berseem clover with corn crop residues did not reduce hay feeding more than feeding corn crop residues alone, yet did significantly reduce the amount of hay needed in 1995 to maintain cows by 358 and 376 lb. hay per cow compared with grazing corn crop residues without complementary forage.
Resumo:
The winter component of a year-round grazing system involving grazing of corn crop residues followed by grazing stockpiled grass legume forages was compared at the McNay Research Farm with that of the winter component of a minimal land system that maintained cows in drylot,. In the summer of 1995, two cuttings of hay were harvested from two 15-acre fields containing “Johnston” endophyte-free tall fescue and red clover, and two cuttings of hay were taken from two 15-acre fields of smooth bromegrass and red clover. Hay yields were 4,236 and 4,600 pounds of dry matter per acre for the tall fescue--red clover and smooth bromegrass--red clover. Following grain harvest four 7.5-acre fields containing corn crop residue were stocked with cows at midgestation at an allowance of 1.5 acres per cow. Forage yields at the initiation of corn crop grazing were 3,766pounds of dry matter per acre for corn crop residue, 1,748 pounds for tall fescue--red clover, and 1,.880 pounds for smooth bromegrass--red clover. Corn crop residues and stockpiled forages were grazed in a strip stocking system. For comparison, 20 cows were placed in two drylots simultaneously to the initiation of corn crop grazing where they remained throughout the winter and spring grazing seasons. Cows maintained in drylot or grazing corn crop residue and stockpiled forages were supplemented with hay as large round bales to maintain a body condition score of five. No seasonal differences in body weight and body condition were observed between grazing cows or cows maintained in drylot, but grazing cows required 87% and 84% less harvested hay than cows in drylot during the winter and spring respectively. Because less hay was needed to maintain grazing cows, an excess of 11,905 and 12,803 pounds of hay dry matter per cow remained in the year-round grazing system. During corn crop grazing, organic matter yield decreased at 27.3 pounds of organic matter per day from grazed areas of corn crop residue. Organic matter losses due to weathering were 9.4, 12.9, and 15.8 pounds per day in corn crop residue, tall fescue-red clover and smooth bromegrass-red clover. Organic matter losses from grazed and ungrazed areas during stockpiled grazing were 7.3 and 6.9 for tall fescue--red clover and 2.1, 2.9 for smooth bromegrass--red clover.
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Six wethers, fitted with ruminal and duodenal cannulae, were utilized in a 6 x 6 Latin Square metabolism trial to determine efficiency of microbial protein synthesis in the rumen of sheep fed forages with varying nutritional quality. Ground alfalfa hay, oat-berseem clover hay, and baled corn crop residues were fed at an ad libitum or limited intake level. Chromium-mordanted fiber, cobalt- EDTA, and purines were used to determine digesta flow and solid passage rate, dilution rate, and microbial protein production, respectively. Sheep fed alfalfa hay had greater organic matter (OM) intakes, and amounts of OM apparently and truly ruminally digested (g/d; P < .05) than sheep fed either oat-berseem clover or corn crop residues at the ad libitum intake level. Rates of slow solid and liquid passage, and postfeeding ruminal ammonia-nitrogen (N) and volatile fatty acids (VFA) concentrations were lower (P < .05) in sheep fed corn crop residues than those fed alfalfa or oat-berseem clover hay. Total duodenal flows (g/d) and efficiencies of ruminal synthesis (g crude protein/100 g of OM truly digested; P < .05) of microbial protein were less in sheep fed corn crop residues than in sheep fed alfalfa, and oatberseem clover ad libitum. Whereas total duodenal microbial-N flow was related to organic matter intake (OMI; r2 = .97) and OM truly digested in the rumen (OMTDR; r2 = .97), microbial efficiency was related to g of nitroge truly digested in the rumen (NTDR)/100 g of OMTDR (r2 = .82) and slow solid passage rate (r2 = .91).
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Many landowners ask about the process and costs for returning land to crop production after trees are cut for biomass. A field on the Squaw Creek bottom, Story County, Iowa was planted to hybrid poplar trees in spring 2000. The trees were planted in rows with a 10-ft spacing. The trees were cut in spring 2010. The resulting field was four acres, and this is the account of the first corn crop in 2011 on the area.
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Silagens de milho são mais propensas à deterioração quando expostas ao ar. As leveduras assimiladoras de ácido lático são frequentemente os primeiros microrganismos a iniciar a deterioração aeróbia nas silagens. Alguns estudos reportam que silagem de milho aerobicamente instável está associada à redução no consumo, na produção de leite e depressão no teor de gordura do leite. Portanto, o objetivo deste estudo foi avaliar a influência de inoculação de leveduras (Pichia norvegensis) e a exposição ao ar por 48 horas sobre o valor nutritivo das silagens e o desempenho de vacas leiteiras. O milho foi colhido com 34% de MS, tratado sem (Controle) ou com P. norvegensis, na dose 1×105 ufc/g MV (Levedura) e armazenado silos tipo bolsa (40 t/silo). Após 123 dias de armazenamento, os silos foram abertos e a silagem foi fornecida para vacas leiteiras. Diariamente, as silagens foram retiradas e fornecidas imediatamente (Fresca) ou após 48 horas de exposição (Exposta). Vinte vacas Holandesas foram distribuídas em 5 quadrados latinos replicados 4×4, com períodos de 21 dias (15 d para adaptação + 6 d para amostragem). As dietas foram formuladas para conter: 53% silagem de milho, 8% caroço de algodão, 18% farelo de soja, 9,5% polpa cítrica, 9% milho seco moído e 2,5% premix vitamínico e mineral. Os quatro tratamentos foram assim constituídos: silagem controle fresca (CF), silagem controle exposta (CE), silagem inoculada com levedura fresca (LF) e silagem inoculada com levedura exposta (LE). A inoculação com levedura aumentou as perdas de matéria seca (P<0,001) e reduziu o tempo de estabilidade aeróbia (P=0,03) das silagens de milho. No ensaio de desempenho animal, reduziu a produção de leite corrigida para 3,5% de gordura (P=0,03) e a eficiência alimentar (ELL leite/CMS) (P<0,01), porém não alterou o teor de gordura do leite. Quanto aos efeitos da exposição ao ar por 48 horas, estes reduziram a concentração de ácido lático (P<0,001), que consequentemente aumentou o pH (P=0,004) das silagens, além de reduzir outros produtos de fermentação. A exposição também reduziu a produção de leite corrigido para gordura (P=0,02) e a eficiência alimentar (P=0,10). Nenhum tratamento alterou o consumo de MS. Houve tendência para redução da digestibilidade da MS e FDN e do NDT, quando as silagens foram expostas ao ar. A inoculação com leveduras e a exposição ao ar por 48 horas deprimem o desempenho animal através da redução no valor nutritivo das silagens de milho.
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To achieve high yields the corn crop is dependent on nitrogen. Systems of cover crops preceding corn and form of land cultivation are essential for the best use of nitrogen by corn. This study aimed to evaluate the use or not of nitrogen fertilization in corn in succession to cover crops, planted in three cropping systems. The experimental design was randomized blocks with sub-divided portion where the main plots consisted of three cultivation systems (tillage, conventional tillage and minimum tillage), the subplots by four plant cover in monocrop (oat, hairy vetch, field peas and turnip) and sub-subplots by nitrogen fertilization (0 and 160 kg ha-1 N). Evaluations were performed, the cover crops, soil cover rate, dry matter, content and accumulation of nutrients. In corn we evaluated yield components, yield, chlorophyll and nutrient levels in leaves. Among the species coverage studied the oat showed hardiness in the experiment, covering ground faster and showing more dry matter, however vetch hairy showed higher concentrations of N, P and K and higher accumulation of N ha-1. The soil tillage system influenced the K leaf content. The interaction cultivation x coverage showed significance for the total chlorophyll of corn. In the absence of N, N content and chlorophyll were higher where the corn was sown on the pea and hairy vetch. The corn production, despite a higher average in the presence of nitrogen fertilization, did not differ significantly when used the pea and hairy vetch as a cover crop.
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RESUMO: O objetivo deste trabalho foi avaliar o efeito do tratamento de sementes com inseticidas sobre o manejo de Dichelops melacanthus e a produtividade da soja e do milho, cultivados em sucessão. O estudo foi realizado em campo, nas safras 2012/2013 (I) e 2013/2014 (II). Avaliaram-se os inseticidas imidacloprido, tiametoxam, tiodicarbe, fipronil e abamectina. Determinaram-se: a densidade populacional do percevejo, a produtividade de soja e milho, e a intensidade da injúria em milho. A densidade do percevejo permaneceu abaixo de um inseto por metro quadrado, na maior parte do ciclo da soja. Os picos populacionais foram observados nas primeiras semanas, após a emergência do milho, e atingiram 2,2 (safra I) e 6,7 (safra II) percevejos por metro quadrado. Na cultura da soja, os inseticidas não reduziram a densidade populacional do percevejo. Na cultura do milho, o imidacloprido reduziu a densidade do percevejo em 23,2% (safra I) e 38,8% (safra II), e a injúria em 61,8% (safra I) e 26,4% (safra II). O tiametoxam reduziu a densidade dos insetos em 27,8% (safra II) e a injúria em 42,7% (safra I). O tratamento de sementes com inseticidas não proporciona aumento de produtividade à soja e ao milho, portanto, não se justifica sua utilização nas condições deste estudo. ABSTRACT: The objective of this work was to evaluate the effect of seed treatment with insecticides on the management of Dichelops melacanthus on the yield of soybean and corn, grown in succession. The study was carried out in a field, in the 2012/2013 (I) and 2013/2014 (II) crop seasons. The evaluated insecticides were: imidacloprid, thiamethoxam, thiodicarb, fipronil, and abamectin. The following were determined: stink bug population density, soybean and corn yield, and corn injury. Population density remained below one stink bug per square meter, in most of the soybean cycle. Population peaks were observed in the first weeks, after corn emergence, and they reached 2.2 (crop season I) and 6.7 (crop season II) stink bugs per square meter. In the soybean crop, the insecticides did not reduce the stink bug population density. In the corn crop, imidacloprid reduced the stink bug density in 23.2% (crop season I) and 38.8% (crop season II), and injury in 61.8% (crop season I) and 26.4% (crop season II). Thiamethoxam reduced the insect population density in 27.8% (crop season II) and injury in 42.7% (crop season I). Seed treatment with insecticides does not provide increase for soybean and corn yields, therefore, their use is not justified in this study's conditions.
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Resumo: A cultura do milho sofre grande instabilidade de cultivo em regiões semiáridas, ocasionada, principalmente pela insuficiência de cultivares adaptadas. Á genética, busca a identificação de plantas mais adaptadas às condições em que serão cultivadas, para seleção de um melhor ideótipo. Verificou-se o potencial de variedades de milho, para produtividade de grãos e forragem, além de estimar as relações existentes entre os diferentes caracteres sob condição semiárida do norte do Ceará. Foram avaliados 30 tratamentos, sendo 25 variedades e cinco híbridos testemunhas. O Delineamento utilizado foi blocos ao acaso com duas repetições e com parcelas 0,75m entre linhas e 0,20 m entre plantas. Foram avaliadas 12 variáveis diferentes, em condições de pluviosidade de aproximadamente 500 mm e com períodos de estiagem inferiores a 10 dias até o estádio de florescimento. Identificou-se que em condições de baixa pluviosidade, as cultivares que apresentam maior teor de clorofila e massa fresca, proporcionam melhor desempenho produtivo e conforme observado não houve correlação entres as varriáveis Florescimento Feminino (MF) e Florescimento Masculino (FM) com produtividade de grão (PROD) e produção de Materia Seca (MS), desta forma vale salientar que nas condições em que o experimento , o ciclo fenológico não influênciou nos indices produtivos. [Phenotypic correlations between maize varieties variables in semi-arid conditions in the crop 2014]. Abstract: The corn crop suffers instability crop in semi-arid regions, caused mainly by the lack of adapted cultivars. Genetic seeks to identify more plants adapted to the conditions in which they are cultivated, for selecting a best ideotype. It was verified the potential of maize varieties for grain yield and foragein addition to to estimate the relationships between the different characters under semiarid conditions of northern Ceará. A total of 30 treatments, 25 varieties and five hybrids witnesses. We evaluated 30 treatments with 25 varieties and five hybrids as controls. The design was a randomized block design with two replications. With plots of 0.75 m between rows and 0.20 m between plants. We evaluated 12 different variables, conditions of approximately 500 mm and dry periods less than 10 days until the flowering stage. It was found that in low rainfall conditions, the cultivars with the greatest chlorophyll content and fresh pasta, provide better growth performance and as noted there was no correlation entres the Flowering varriáveis Female (MF) and Flowering Male (FM) with grain yield (PROD) and production of Dry Matter (DM), thus worth pointing out that under the conditions of the experiment, the phenological cycle did not influence the production indices
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Estudo feito pela Faculdade de Tecnologia (FATEC) de Pompeia-SP estimou perdas na colheita mecânica do milho de alta tecnologia em até 12 sacas por hectare. A maior parte desta quantidade ocorria na forma de espigas inteiras, e não de grãos soltos. Nosso objetivo foi identificar em que situação o procedimento da catação - recuperação manual das espigas perdidas durante a colheita mecanizada - é lucrativo ou não para o produtor.
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Dwindling water supplies for irrigation are prompting alternative management choices by irrigators. Limited irrigation, where less water is applied than full crop demand, may be a viable approach. Application of limited irrigation to corn was examined in this research. Corn was grown in crop rotations with dryland, limited irrigation, or full irrigation management from 1985 to 1999. Crop rotations included corn following corn (continuous corn), corn following wheat, followed by soybean (wheat-corn-soybean), and corn following soybean (corn-soybean). Full irrigation was managed to meet crop evapotranspiration requirements (ETc). Limited irrigation was managed with a seasonal target of no more than 150 mm applied. Precipitation patterns influenced the outcomes of measured parameters. Dryland yields had the most variation, while fully irrigated yields varied the least. Limited irrigation yields were 80% to 90%> of fully irrigated yields, but the limited irrigation plots received about half the applied water. Grain yields were significantly different among irrigation treatments. Yields were not significantly different among rotation treatments for all years and water treatments. For soil water parameters, more statistical differences were detected among the water management treatments than among the crop rotation treatments. Economic projections of these management practices showed that full irrigation produced the most income if water was available. Limited irrigation increased income significantly from dryland management.
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The wheat grain industry is Australia's second largest agricultural export commodity. There is an increasing demand for accurate, objective and near real-time crop production information by industry. The advent of the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite platform has augmented the capability of satellite-based applications to capture reflectance over large areas at acceptable pixel scale, cost and accuracy. The use of multi-temporal MODIS-enhanced vegetation index (EVI) imagery to determine crop area was investigated in this article. Here the rigour of the harmonic analysis of time-series (HANTS) and early-season metric approaches was assessed when extrapolating over the entire Queensland (QLD) cropping region for the 2005 and 2006 seasons. Early-season crop area estimates, at least 4 months before harvest, produced high accuracy at pixel and regional scales with percent errors of -8.6% and -26% for the 2005 and 2006 seasons, respectively. In discriminating among crops at pixel and regional scale, the HANTS approach showed high accuracy. The errors for specific area estimates for wheat, barley and chickpea were 9.9%, -5.2% and 10.9% (for 2005) and -2.8%, -78% and 64% (for 2006), respectively. Area estimates of total winter crop, wheat, barley and chickpea resulted in coefficient of determination (R(2)) values of 0.92, 0.89, 0.82 and 0.52, when contrasted against the actual shire-scale data. A significantly high coefficient of determination (0.87) was achieved for total winter crop area estimates in August across all shires for the 2006 season. Furthermore, the HANTS approach showed high accuracy in discriminating cropping area from non-cropping area and highlighted the need for accurate and up-to-date land use maps. The extrapolability of these approaches to determine total and specific winter crop area estimates, well before flowering, showed good utility across larger areas and seasons. Hence, it is envisaged that this technology might be transferable to different regions across Australia.
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La mosquita de la panojas del sorgo, Stenediplosls sorghicola (Coq.) es una de las plagas mas importantes que atacan al sorgo en Nicaragua. Varios estudios fueron conducidos en el pacifico de Nicaragua durante 1998 y 1999 para determinar hospederos y la actividad de esta plaga durante la segunda fecha de siembra de este cultivo (Postrera). Hembras oviposltaron en sorgo desde mediados de Septiembre hasta los últimos dfas de Diciembre. Cuando sorgo no se encontraba presente, hembras ovipositaron en sorgo escobero, Sorghum bicolor (L.) o pastoJonson, Sorghum halepense L. Pasto Jonson florea durante todo el ano y puede servir como hospedero mientras las otras especies de sorghum no se encuentran en el campo. Cuando estos tres hospederos estaban floreando al mismo tiempo, las hembras exhibieron una fuerte preferencia para ovlpositar en sorgo. Basado en estas observaciones la mosquita de la panoja del sorgo puede estar activa durante todo el ano en el pacifico de Nicaragua. Conocimiento de la ocurrencia y comportamiento de la mosquita en el area, es muy Importante para el desarrollo de estrategias de manejo de esta plaga.
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European corn borer (ECB) [Ostrinia nubilalis (Hubner)] (Lepidoptera: Crambidae) is known to infest Irish potato (Solanum tuberosum L.) but only causes economic damage during the first generation in East Coast potato producing areas. However, in Nebraska, second generation ECB infest potato plants during the bulking period and may reduce yield and/or potato quality. Experiments were conducted in 2001, 2002, and 2003 to examine physiological and yield effects of second generation ECB injury to potato in Nebraska. Pike, Atlantic, and three Frito Lay proprietary varieties (FL1867, FL1879, and FL1833) were used. Experimental plots were infested with four ECB egg masses per plant to simulate ECB infestation by second-generation larvae; controls received no egg masses. Photosynthetic rates, tuber weights, tuber size grades, solids, and fry quality were measured. Potato plants with ECB infestation had significantly reduced photosynthetic rates on ECB-infested stems and on uninfested stems on the same plant when larvae were in the fifth instar. When insects were in the fourth instar, photosynthetic rates were reduced only on ECB-infested stems. In 2001, ECB infestation reduced the average mass of large tubers and increased the amount of small tubers in FL1867 and FL1879. In 2002, significant yield reductions were not observed. Across both years, ECB-infested plots produced fewer large (65- to 100-mm diam.) tubers than control plots. Other tuber properties and chip qualities were unaffected. This study indicates that second generation ECB infestation of approximately 30% infested plants results in economic loss for some chipping varieties and affects tuber bulking. In contrast to east coast growers, Midwest potato farmers must be concerned with second generation ECB.