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Baton Rouge, LA, United States

Mailander M.,Ag Center | Moriasi D.,U.S. Department of Agriculture
Journal of Cotton Science | Year: 2011

Site specific crop management involves closely monitoring the local environment and determining crop input needs for each portion of the field to economically optimize crop yields and reduce adverse environmental impacts of the production system. A key measure in this system is yield information determined by crop yield monitors. Current seedcotton yield monitors use optical and microwave sensing techniques to measure yield. However, the cotton yield monitors based on light emission require regular cleaning during the season and the microwave-based systems are expensive. The objective of this study was to test the use of velocity pressure to measure cotton-mass flow. The eventual goal is to provide an alternative approach for cotton yield monitoring. A cotton-harvester yield monitor concept was developed based on the relationship between air velocity pressure and the mass of seedcotton conveyed. The sensor was tested on a stationary cotton picker with seedcotton at two moisture contents, 5.9% and 8.5% wet basis. Regression analysis on the means of the data signals resulted in a coefficient of determination of 0.43 for the lower moisture content and 0.84 for the higher moisture content. Frequency and moving average filters were applied to the signals but did not improve the correlation. A method of compensating for gaps in the material stream resulted in an increased coefficient of determination of 0.52 and 0.87 for seedcotton at a moisture content of 5.9% and 8.5%, respectively. These results indicate the potential of air velocity pressure as an alternative approach for cotton yield monitoring. © The Cotton Foundation 2011.

Clay T.A.,Nicholls State University | Clay T.A.,University of Arkansas at Little Rock | Suchy M.D.,Nicholls State University | Ferrara A.M.,Nicholls State University | And 3 more authors.
Journal of the World Aquaculture Society | Year: 2011

Alligator gar, Atractosteus spatula, are a new aquaculture species with many aspects about rearing unknown. Alligator gar are cannibalistic during their larval stage and methods to minimize cannibalism should be developed to increase overall survival. Growth and survival were determined for larvae fed pelleted floating food only or fed pelleted floating food supplemented with live Artemia spp. nauplii for the first 7 d of exogenous feeding (5 d after hatching [d.a.h.] to 12 d.a.h.). Total length, weight, condition, and specific growth rate (SGR) was determined at 12 and 20 d.a.h. Fish supplemented with Artemia were larger by 12 d.a.h. and continued to be at 20 d.a.h. than fish fed only floating food. SGR was higher at both 12 and 20 d.a.h. for fish that received the Artemia supplement. Survival was higher for fish supplemented with Artemia (71%) than for the floating food only treatment (43%). Cannibalism was the primary cause of mortalities and was higher in fish fed floating food only (44%) compared to Artemia supplemented fish (19%). Artemia may elicit a stronger feeding response and improve acceptance of pelleted floating foods. Results suggest an improved feeding regime compared to previous feeding regimes used in rearing larval alligator gar. © by the World Aquaculture Society 2011.

Meredith W.R.,U.S. Department of Agriculture | Boykin D.L.,U.S. Department of Agriculture | Bourland F.M.,University of Arkansas | David Caldwell W.,Ag Center | And 7 more authors.
Journal of Cotton Science | Year: 2012

Since the 1960s, many changes in cotton (Gossypium hirsutum L.) cultivar tests have been made. This study partitioned the total variation for 26 traits into environment (E), genotype (G) and genotype X environment (GE) variance components for the 2001 through 2007 Regional High Quality (RHQ) tests with 98 genotypes. It evaluated 26 traits and 56 year-location environments. There were four yield traits, five yield components, six traditional breeder-geneticists (BG) fiber traits, seven High Volume Instrumentation (HVI) fiber traits, and four gossypol traits. Yield variance components for lint, seed, oil, and N were similar with an average of 87, 5, and 8% of the total variance due to E, G, and GE, respectively. Lint %s E, G, and GE were 57, 33, and 10%, respectively and were similar to oil% E, G, and GE which were 53, 37, and 10%, respectively. Length, strength, and micronaire's G components for BG fiber was 28, 52, and 16%, respectively. For the HVI samples, G was similar with 36, 48, and 18%, respectively. Average G for total gossypol and its two isomers, plus (+) and minus (-) was 36, 47, and 29%, respectively. The plus (+) percent of total gossypol was 17, 72, and 11% for E, G, and GE, respectively. This was the lowest E% and highest G% of all the 26 traits. The results of this study suggested that during the last 50 yrs, little changed in E, G, and GE variance components occurred. © The Cotton Foundation 2012.

Salmeron M.,University of Arkansas | Gbur E.E.,University of Arkansas | Bourland F.M.,University of Arkansas | Buehring N.W.,Mississippi State University | And 13 more authors.
Agronomy Journal | Year: 2014

Growing conditions in the U.S. Midsouth allow for large soybean [Glycine max L. (Merr.)] yields under irrigation, but there is limited information on planting dates (PD) and maturity group (MG) choices to aid in cultivar selection. Analysis of variance across eight (2012) and 10 (2013) locations, four PD, and 16 cultivars (MG 3–6), revealed that the genotype by environment (G×E) interaction accounted for 38 to 22% of the total yield variability. Stability-analysis techniques and probability of low yields were used to investigate this interaction. Planting dates were grouped within early- and late-planting systems. Results showed that MG 4 and 5 cultivars in early-planting systems had the largest average yields, whereas for late-planting systems, late MG 3 to late MG 4 cultivars had the largest yields. Least square means by MG within planting systems at each environment showed that MG 4 cultivars had the greatest yields or were not significantly different from the MG with the greatest yields in 100% of the environments for both early- and late-planting systems. Yields of MG 5 cultivars were similar to those of MG 4 in 100% of the environments with an early planting but only in 20% of the environments with a late planting. The MG 3 cultivars were the best second choice for late plantings, with similar yields to MG 4 cultivars in 55 to 75% of the environments. These results have profound implications for MG recommendations in irrigated soybean in the U.S. Midsouth and indicate the need to reconsider common MG recommendations. © 2014 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved.

Tewari S.,University of Massachusetts Amherst | Johnson S.J.,University of Massachusetts Amherst | Johnson S.J.,Ag Center
Journal of Aquatic Plant Management | Year: 2011

A field study was conducted in 2005 and 2006 to evaluate the impact of the herbivores Cyrtobagous salviniae Calder and Sands and Samea multiplicalis (Guenée) on common salvinia (Salvinia minima Baker) in south Louisiana. Our study revealed that treatments consisting of C. salviniae and S. multiplicalis feeding both independetly and together significantly reduced plant biomass of common salvinia. The lowest biomass was recorded for the treatment with both C. salviniae and S. multiplicalis feeding on common salvinia in October during 2005 and 2006. Biomass showed a significant linear trend for the treatment consisting of feeding by both C. salviniae and S. multiplicalis in 2005 and significant treatment by month interaction in both 2005 and 2006. Percent-age terminal-damage and percentage mat-green showed significant treatment effect in 2005 and 2006.

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