Agriculture Commons^™

Robots For Weed Control In Eden?, Stephen L. Young

West Central Research and Extension Center, North Platte

In the Biblical account, weeds were the result of the curse for Adam’s sin. In the 21st century, we are still toiling by the sweat of our brow to control weeds. What Adam and the rest of mankind have endured for thousands of years, may soon be controlled by a robot, similar to the ones that vacuum your floor, protect your car and entertain your kids.

Spatio-Temporal Relationship Between Water Depletion And Root Distribution Patterns Of Centaurea Solstitialis And Two Native Perennials, Stephen L. Young, Guy B. Kyser, Jacob N. Barney, Victor P. Claassen, Joseph M. Ditomaso

West Central Research and Extension Center, North Platte

In a 2-year field study, we quantified lateral root growth patterns and soil water depletion dynamics in the invasive annual Centaurea solstitialis and two native perennials, Elymus glaucus and Grindelia camporum. Centaurea solstitialis produced lateral roots most actively from early April to mid-June, during the late rosette to spiny seedhead stage while both root growth and water depletion were completed before flowering. In the wet year, roots were evenly distributed throughout the soil profile to 180 cm deep. Lack of deep soil moisture recharge in the second year restricted root distribution to shallow soil depths (< 60 cm). In contrast to C. solstitialis, …

Tree Fruits As Annual Crops?, Stephen L. Young

West Central Research and Extension Center, North Platte

Orchard systems have gone through dynamic changes over the past 50 years. High-density plantings and dwarfing rootstocks have allowed growers to make changes in production practices more quickly as markets have expanded and become more volatile. Will these changes in woody perennial crops in the past five decades be equaled or surpassed in the next?

From this research, it is clear that with breeding and genetics, intensive orchard systems can come into full production at a faster rate than those of the pre-twentieth century era. Future research will provide clues as to how even faster production capacity can be achieved …

Performance Of Solid-State Sensors For Continuous, Real-Time Measurement Of Soil Co2 Concentrations, Stephen L. Young, Francis J. Pierce, Jason D. Streubel, Harold D. Collins

West Central Research and Extension Center, North Platte

Recent advances in sensor technology provide a robust capability for continuous measurement of soil gases. The performance of solid-state CO₂ sensors (Model GMM220 series, Vaisala, Inc., Helsinki, Finland) was evaluated in laboratory, greenhouse, and irrigated winter wheat (Triticum aestivum L.). In ambient CO₂ concentration, the GMM222 sensor averaged 427 ± 8.3 μL L⁻¹. Under variable CO₂ concentrations, the sensor was slightly lower than concentrations measured with an infrared gas analyzer (IRGA). In greenhouse pots planted with triticale (Triticale hexaploide Lart.) and an agricultural field of irrigated winter wheat, soil CO₂ concentration exceeded …

Quantification Of Bt-Endotoxin Exposure Pathways In Carabid Food Webs Across Multiple Transgenic Events, Julie A. Peterson, John J. Obrycki, James D. Harwood

West Central Research and Extension Center, North Platte

Despite the reported specificity of Bacillus thuringiensis proteins against target pests, a number of studies have indicated that the uptake of Bt-endotoxins from bioengineered crops could have negative effects on natural enemies. It is therefore essential to quantify exposure pathways in non-target arthropod food webs across multiple transgenic events. Adult ground beetles (Coleoptera: Carabidae) were collected from transgenic corn fields expressing lepidopteran-specific Cry1Ab, coleopteran-specific Cry3Bb1, and both Cry1Ab and Cry3Bb1 (stacked event), as well as a non-transgenic isoline. Carabid gut-contents were screened for Cry1Ab Bt-endotoxin using enzyme-linked immunosorbent assay. Significant numbers of carabids tested positive for Cry1Ab from the lepidopteran-specific …

The Effect Of Delaying Initial Feedlot Implant On Body Weight, Average Daily Gain, And Carcass Characteristics Of Calf-Fed Steers, W. Griffin, D. C. Adams, R. N. Funston

West Central Research and Extension Center, North Platte

Two experiments were conducted to determine the effect of delaying initial feedlot implant on BW, ADG, and carcass characteristics. At receiving, steers were assigned to 1 of 2 treatments: 1) implant at feedlot entry (NORM) or 2) implant 30 d after feedlot entry (DELAY). In Exp. 1, steers (n = 200) were not implanted until feedlot entry; however, in Exp. 2 steers (n = 209) were implanted at approximately 50 d of age. In Exp. 1, there was a tendency (P = 0.11) for BW at d 30 to be heavier (10 kg) for NORM compared with DELAY; however, all …

Post Weaning Management Of Heifer Calves Impacts Average Daily Gain And Feed Efficiency As Pregnant Heifers, D. M. Larson, Tonya L. Meyer, L. A. Stalker, Richard N. Funston

West Central Research and Extension Center, North Platte

Three experiments evaluated replacement heifer development systems and subsequent effects on gain and efficiency of pregnant heifers. In Exp. 1 and 2, were developed grazing corn residue (CR; 422 ± 5 kg) or fed in a dry lot (DL; 446 ± 5 kg) prior to breeding. In Exp. 1, a subset of pregnant heifers (n = 40) were individually fed a diet composed of 90% grass hay (11.7 % CP; DM basis) and 10% of a wet distillers grains plus solubles/straw mixture (21.8 % CP; DM basis) during late gestation. In Exp. 2, 55 pregnant …

The Effects Of Corn Coproduct Supplementation On Primiparous Cow Reproduction And Calf Performance, D. M. Larson, R. N. Funston

West Central Research and Extension Center, North Platte

An experiment was replicated over 2 yr to determine the effect of additional RUP and dietary fat from dried distillers grains plus solubles (DDGS; n = 2) or wet corn gluten feed (WCGF; n = 2) before breeding on primiparous cow reproduction and calf production. Over 2 yr, 134 postpartum, primiparous cows (429 ± 5 kg initial BW) were fed 1 of 2 isocaloric, approximately isonitrogenous diets in 1 pen/yr (n = 4) providing varying levels of RUP and dietary fat. Treatments were initiated 21 (yr 1) and 60 d (yr 2) postpartum and continued for 56 (yr 1) or …

Penstemon ‘Sweet Joanne’, Dale T. Lindgren, Daniel Schaaf, Kim Todd

West Central Research and Extension Center, North Platte

Penstemon Mitch. (Plantaginaceae Juss. formerly Scrophulariaceae Juss.) is a diverse genus of ≈271 species that occur throughout the United States (except Hawaii), Canada, Mexico, and Guatemala (Lindgren and Wilde, 2003). Many cultivars have been named (Lindgren, 2006). Although selections from interspecific crosses are less common than intraspecific crosses, many European hybrids have been derived from intercrossing species and hybrids from Mexico with the large flowered P. cobaea Nutt. from the central United States. Most of these large and colorfully flowered European hybrids do not overwinter in the United States except in the milder climates.

Selections from intersectional crosses between the …

Effect Of Amount And Timing Of Subsurface Drip Irrigation On Corn Production, Simon Van Donk, James Petersen, Don Davison

West Central Research and Extension Center, North Platte

Subsurface drip irrigation (SDI) has the potential of being a more efficient irrigation system compared to systems such as center pivot and furrow irrigation. The objective of this study was to determine the effect of the amount and timing of irrigation, using SDI, on corn (Zea mays) production. A field study was conducted at North Platte, Nebraska in 2007 and 2008, using two SDI systems. The study was replicated eight times on the older SDI system (SDI1) and four times on the newer SDI system (SDI2). On SDI1, there were nine treatments to impose different irrigation regimes, ranging from dryland …

My View: Automated Weed Control In Organic Cropping Systems, Stephen L. Young

West Central Research and Extension Center, North Platte

In 2005, for the first time, all 50 states in the United States had some certified organic farmland (USDA 2007). Producers in the United States dedicated over 1.62 million hectares of farmland to organic production systems in 2005. The increase in the number of hectares of crops being grown organically has brought with it a growing need for more labor and nonconventional inputs for weed control. Currently, weed control is ranked as the number one production cost by organic and many conventional growers. Over the past 10 yr, development of machine-guided technologies for site-specific (precision) weed control has advanced rapidly, …

Functionally Similar Species Confer Greater Resistance To Invasion: Implications For Grassland Restoration, Stephen L. Young, Jacob N. Barney, Guy B. Kyser, Tracy S. Jones, Joseph M. Ditomaso

West Central Research and Extension Center, North Platte

Plant community functional composition can be manipulated in restored ecosystems to reduce the establishment potential of invading species. This study was designed to compare invasion resistance among communities with species functionally similar or dissimilar to yellow starthistle (Centaurea solstitialis), a late-season annual. A field experiment was conducted in the Central Valley of California with six experimental plant communities that included (1) six early-season native annual forbs (AF); (2) five late-season native perennials and one summer annual forb (NP); (3) a combination of three early-season native annual forbs and three late-season native perennials (FP); (4) six early-season non-native annual …

Penstemon ‘Dark Towers’, Dale T. Lindgren, Daniel Schaaf

West Central Research and Extension Center, North Platte

Penstemon Mitch. (Plantaginaceae Juss. formerly Scrophulariaceae Juss.) is a genus of plants with ≈ 271 species that can be found from low deserts to high alpine areas (Lindgren and Wilde, 2003; Wolfe et al., 2006). It is one of the largest genera of North American wildflowers. Some Penstemon are easy to grow; others are very challenging to maintain (Lindgren and Wilde, 2003). Numerous selections of Penstemon have been named and released (Lindgren, 2006) and many crosses between species have been attempted (Lindgren and Schaaf, 2007). New Penstemon selections are needed that combine valuable traits of multiple species and cultivars. Several …

The Effect Of Adjuvants, Pesticide Formulation, And Spray Nozzle Tips On Spray Droplet Size, Robert N. Klein, Jeffrey A. Golus, Kelli L. Nelms

West Central Research and Extension Center, North Platte

Many factors, including adjuvants, pesticide formulations, and nozzle tips, affect spray droplet size. It is important to understand these factors as spray droplet size affects both drift and efficacy of pesticides, which is a main concern with pesticide application. A laser particle analyzer was used to determine the spray droplet size and distributions of a range of formulations sprayed through several types of nozzle tips. Nozzles included were extended range flat fan sizes 11003 and 11005 (Spraying Systems XR), air induction flat fan sizes 11005 and 11004 (AI) air induction extended range flat fan size 11005 (AIXR), preorifice flat fan …