Elliott N.,U.S. Department of Agriculture |
Brewer M.,U.S. Department of Agriculture |
Brewer M.,Texas AgriLife Research Center |
Seiter N.,U.S. Department of Agriculture |
And 17 more authors.
Southwestern Entomologist | Year: 2017
Sorghum, Sorghum bicolor (L.) Moench, is an important summer grain crop in the United States. In 2014, the U.S. produced 432 million bushels of sorghum valued at1.67 billion on more than 2.43 million ha. The sugarcane aphid, Melanaphis sacchari (Zehntner), was discovered in damaging numbers in grain sorghum in Texas and Louisiana in 2013. The sugarcane aphid can be very damaging to sorghum grown for grain and forage and is capable of explosive population growth. An objective sampling plan based on knowledge of spatial distribution of the aphid in sorghum would be useful for pest management decision making. We sampled 94 commercial grain sorghum fields in five southern states during 2 years to obtain data that were used to assess several aspects of sugarcane aphid distribution within and among sorghum plants in commercial grain sorghum fields. There were frequently significant differences in number of aphids among upper and lower leaves in fields in each state. However, there were no consistent patterns as to whether the upper or lower leaf had more sugarcane aphids. Autocorrelation coefficients were calculated for consecutive plants and for plants separated by one and two intervening plants. Numbers of sugarcane aphids on adjacent plants and plants separated by intervening plants were not autocorrelated, indicating that there was no, or only slight, correlation in numbers of sugarcane aphids among plants in close proximity to one another. Taylor's power law parameters for linear regression models relating the variance to the mean of numbers of sugarcane aphids on sorghum plants differed significantly for fields sampled in different states, but not for fields in vegetative versus reproductive growth stages, fields with markedly different planting dates (early or late), or fields sampled in different years.
Favetto P.H.,Veterinarian |
Hoar B.R.,University of California at Davis |
Myers D.M.,Research and Extension Center |
Tindall J.,Research and Extension Center
California Agriculture | Year: 2010
The accurate determination of pubertal status in yearling beef heifers, possibly combined with the use of exogenous progesterone, allows females to produce the maximum number of calves over their lifetimes. This study aimed to determine the reliability of a reproductive tract scoring (RTS) system that combines manual palpation with ultrasound as a measure of pubertal status, and whether the treatment of heifers with progesterone-containing vaginal inserts - followed by breeding on the second estrus after removal of the insert - could result in increased conception rates compared to untreated heifers. Over 2 years, we found that RTS predicted pubertal status reasonably accurately. Progesterone-treated heifers were more likely to exhibit estrus than control heifers, but their overall breeding efficiency was not affected by progesterone treatment. Inadequate nutrition associated with increased pasture stocking density during both breeding seasons likely had a negative effect on the results of our study.
Griffin J.L.,Louisiana State University |
Bauerle M.J.,Louisiana State University |
Stephenson III D.O.,Research and Extension Center |
Miller D.K.,Northeast Research Station |
Boudreaux J.M.,Louisiana State University
Weed Technology | Year: 2013
Availability of soybean with dicamba resistance will provide an alternative weed management option, but risk of dicamba injury to sensitive crops from off-target movement and spray tank contamination is of concern. Research conducted at multiple locations and years evaluated soybean injury and yield response to POST applications of the diglycolamine salt of dicamba. Dicamba was applied at the two to three trifoliate stage (V3/V4) at 4.4, 8.8, 17.5, 35, 70, 140, and 280 g ae ha-1 (1/128 to 1/2 of the recommended use rate of 560 g ae ha-1). Soybean injury 7 d after application was 20% following dicamba at 4.4 g ha-1 and increased to 89% at 280 g ha -1. At 14 d after application, injury for the same rates increased from 39 to 97%. In a separate study, dicamba was applied at first flower (R1) at 1.1, 2.2, 4.4, 8.8, 17.5, 35, and 70 g ha-1 (1/512 to 1/8 of use rate). Soybean injury 7 d following dicamba application was 19% at 1.1 g ha -1 and increased to 64% at 70 g ha-1. For the same rates of dicamba, injury from 7 to 14 d after application increased no more than 4 percentage points. For dicamba rates in common for the timing studies, soybean injury 14 d after treatment was greatest for application at V3/V4, but the negative effect on mature soybean height and yield was greatest for application at R1. For dicamba at 4.4 g ha-1 (1/128th of use rate), soybean yield was reduced 4% when applied at V3/V4 and 10% when applied at R1. For 17.5 g ha-1 dicamba (1/32 of use rate), yield was reduced 15% at V3/V4 and 36% at R1. Based on yield reductions for 4.4 and 17.5 g ha-1 dicamba, soybean at flowering was around 2.5 times more sensitive compared with vegetative exposure.
Lee D.-J.,Brigham Young University |
Xiong G.,Beijing Institute of Technology |
Lane R.M.,Research and Extension Center |
Zhang D.,Sun Yat Sen University
2012 12th International Conference on Control, Automation, Robotics and Vision, ICARCV 2012 | Year: 2012
Two grading criteria used in determining shrimp product quality and value by the shrimp industry are: 1. Presence or percentage of black spot, measured as a percentage of the total body surface. 2. Shape quality referring to whole shrimp and broken pieces. Black spots (melanoma) on the shrimp surface are evidence of aging shrimp and are considered defects that must be removed from the main production line. Shape quality is measured as the size and the completeness of the body. Broken shrimp pieces are considered a product defect and also must be removed from the main production line. Black spot detection is a simple task for a well-designed machine vision system, which provides consistent and controlled lighting. Shape analysis, on the other hand, is a challenging task because it involves contour extraction and shape analysis. In this paper, a simple, fast, and accurate shape analysis method using Turn Angle Cross-correlation is developed for shrimp quality evaluation. Our analysis results validate that the performance of the proposed shape analysis method is suitable for real-time inspection for commercial applications. © 2012 IEEE.
Richmond O.M.W.,University of California at Berkeley |
Chen S.K.,Olofson Environmental |
Risk B.B.,University of California at Berkeley |
Tecklin J.,Research and Extension Center |
Beissinger S.R.,University of California at Berkeley
California Agriculture | Year: 2010
After California black rails were discovered at the UC Sierra Foothill Research and Extension Center in 1994, an extensive population of this rare, secretive marsh bird was found inhabiting palustrine emergent persistent (PEM1) wetlands throughout the northern Sierra Nevada foothills. We inventoried a variety of PEM1 wetlands to determine which habitats would likely support black rails. Black rails were positively associated with larger PEM1 wetlands that had flowing water, dense vegetation and irrigation water as a primary source; they were negatively associated with fringe wetlands and seasonal water regimes. Recommendations for managing black rail habitat in the northern Sierra foothills include prioritizing the conservation of PEM1 wetlands with permanently or semipermanently flooded water regimes and shallow water zones (less than 1.2 inches), especially those that are greater than 0.25 acres in size; avoiding wetland vegetation removal or overgrazing, especially during the black rail breeding season (approximately March through July); maintaining and improving wetland connectivity; ensuring that impacts to black rails are considered in the environmental review process for development projects; and integrating management guidelines for black rails into existing wetland conservation programs.
News Article | January 29, 2016
So far, they've verified a common belief that there is a boost in production when growing produce in high tunnels, a low-cost alternative to a traditional greenhouse. But a newer finding is that shelf life is affected when produce is grown in high tunnels compared to an open field. A longer shelf life makes the products more marketable and can dramatically add to the grower's profits. Kansas State University's work is part of a $1 million grant shared with the University of Florida. Researchers have been comparing two model crops—tomatoes and spinach—grown in high tunnels and in open fields. High tunnels are prevalent among small-acreage growers in the Midwest and are becoming more popular across the country. In Florida, high tunnels help protect vegetables from heavy rains, while Kansas growers use them to protect from high winds and damaging storms. "People have known for a while that you can improve production by growing in high tunnels," said Cary Rivard, director of Kansas State University's Horticultural Research and Extension Center in Olathe. "Our findings that produce grown in high tunnels has a longer storage life and shelf life are something that have never been reported in the scientific literature. "If we're getting a few more days of storage for tomatoes grown in high tunnels compared to open fields, that's going to make an impact on the availability of those products," he said. Eleni Pliakoni, a Kansas State University assistant professor of horticulture who specializes in urban food production and postharvest handling, said that as much as 40 percent of fresh produce is lost in the food chain due to spills, spoilage and other losses. "Proper cold storage facilities for vegetables are very expensive and many of the new and first-generation farmers in our area don't have the equipment they need to store produce at the optimum temperatures," Pliakoni said. "Through our research, we are trying to develop tools that they can use to extend storage life even with limited storage facilities." The researchers also have found a new challenge. "It appears that the light spectrum available to the crop plants inside a high tunnel can affect the production of certain phytochemicals, such as antioxidants," said Rivard, who along with Pliakoni will begin a new project in 2016 to investigate the role of light in phytochemical production and evaluate new plastic films and light-emitting diode, or LED, technology. "Our goal is to increase the nutritional quality of crops grown in the high tunnel," Rivard said. The researchers also are working to adapt postharvest handling technologies used by farmers in California and Florida to help small-acreage growers support local food systems. "As extension educators, our job is to take the work done in the lab and help our farmers implement these systems," Rivard said. "We hope we can help local growers scale up to meet the needs of institutional markets like schools, hospitals, and other wholesale buyers." In addition to field trials with tomatoes and spinach, researchers at the University of Florida are testing the use of hot water treatments and chemical washes that can be used by certified organic growers to reduce postharvest losses. Pliakoni is leading work to test modified atmosphere packaging, similar to what is used for packaged mixed greens in the grocery store. She said that combined with physical or chemical washes, this could extend the shelf life of produce. The researchers also are working with a software development consultant to create a smartphone application for growers. The app will help growers track losses and understand why those losses occurred.
News Article | March 11, 2016
"Warm and dry conditions have made it possible to get an early start on the grain sorghum crop, especially compared to 2015, but how might this year's conditions influence sugarcane aphid infestations?" asked Dr. Robert Bowling, an AgriLife Extension entomologist at the Texas A&M AgriLife Research and Extension Center at Corpus Christi. Left unchecked, the aphids suck sap from plant leaves and deposit "honeydew," a sticky waste that clogs harvesting equipment, Bowling said. They can also move into the grain head, slowing the ripening process thus reducing both quality and yield. Sugarcane aphid reproduction is favored by the weather conditions prevalent lately in the Coastal Bend and Lower Rio Grande Valley, he said. "We've seen evidence as far north as Hill County suggesting sugarcane aphids are maturing and producing offspring," Bowling said. "It is possible they will start moving from their overwintering sites to sorghum this early in the season. So, it's important to know the path forward to protect the crop from sugarcane aphid injury in 2016." First, know the aphid, Bowling said. "It's important that growers know how to accurately spot sugarcane aphids. Images can be viewed at ccag.tamu.edu/sorghum-insect-pests/ . Take a magnifying glass when looking for aphids because their characteristic structures are not visible to the naked eye." The sugarcane aphid has a tan to green body and dark cornicles, tailpipe-like structures at the rear of the body, and dark feet, he said. "Aphids are typically found on the underside of sorghum leaves," Bowling said. "If honeydew is observed on the top of a leaf, look at the underside of the leaf above the leaf with honeydew for the aphid. If they are found on Johnson grass or volunteer sorghum, start scouting sorghum shortly after plants have emerged." Danielle Sekula-Ortiz, the AgriLife Extension integrated pest management agent in Weslaco, said she recommends scouting early this season. "If the planting seed was treated with an insecticide seed treatment, the crop should be protected for 30-45 days," she said. "In that case, we recommend starting your scouting about 30 days after the sorghum has emerged." The first objective in scouting is detection, Sekula-Ortiz said. "This involves weekly scouting of field edges, about 25 feet into the field, and examining plants along 50 feet of row. Check all sides for presence of the aphid. If none are present, or if only a few wingless or winged aphids are found on the upper leaves, continue scouting once a week." While several hybrid sorghum varieties have been identified as "tolerant" to sugarcane aphid, that does not equate to immunity and all fields should be scouted for the insect, she said. If the current hot, dry weather conditions continue, these tolerant hybrids may require an insecticide application if sugarcane aphids reach treatment thresholds in South Texas. The U.S. Environmental Protection Agency has made no determination on the emergency use request for the insecticide Transform, which is still under review by the agency, Sekula-Ortiz said. "Insecticide options for managing sugarcane aphids are limited," she said. "But besides Transform, there are a few other products including Sivanto, Nufos and Lorsban, that are effective and safe to beneficial insects. We will update growers on any decision EPA makes about Transform." Other field practices, including proper insecticide coverage the first time, are important, Bowling said. But the most important point is to not be complacent. "Predicting the occurrence and severity of insect pests is an imperfect science," he said. "A slight change in environmental conditions may have a profound effect on their populations." This is especially true of sugarcane aphids. "Last year's wet conditions allowed for low populations, but we must not allow that experience to let our guard down," Bowling said. "Instead, remember how quickly populations increased in 2014 and even late last season when conditions returned to hot and dry. But sugarcane aphids are easily managed when fields are routinely scouted and management options are implemented in a timely manner." Explore further: Sugarcane aphids under control as South Texas grain sorghum harvest begins