Search

Automation continues to play a greater role in agricultural production with commercial systems now available for machine vision identification of weeds and other pests, autonomous weed control, and robotic harvesters for fruits and vegetables. The growing availability of autonomous machines in agriculture indicates that there are opportunities to increase automation in cotton production. This article considers how current and future advances in automation has, could, or will impact cotton production practices. The results are organized to follow the cotton production process from land preparation to planting to within season management through harvesting and ginning. For each step, current and potential opportunities to automate processes are discussed. Specific examples include advances in automated weed control and progress made in the use of robotic systems for cotton harvesting.

Anaerobic digester development on dairy, poultry, and swine confined animal feeding operations (CAFOs) reduce manure storage, produce energy and are poised to supply a variety of nutrient-rich mate...

Technology fees associated with modern cotton cultivars have increased seed costs considerably, giving producers the impetus to reduce plant population density, where possible. Most recent studies on cotton population density, conducted across diverse environments, report similar patterns of crop response: decreases in lint yield only at very low densities, with generally consistent yield across all higher densities. But no work had been done to bring the literature together, quantitively synthesizing the yield data collectively, to better pinpoint a population density threshold. And, notably, little had been reported on the effects of population density in lower-yielding dryland environments. Quantitatively synthesizing population density datasets from the literature, including our own dryland data, was the objective of this research. The dryland data showed that lint yield and biomass partitioning were not affected by population density, similar to higher-yielding environments over the same range in density. Following normalization of all lint yield data (literature and dryland datasets), a breakpoint in population density at 35,000 plants ha−1 was identified, which can be interpreted as the minimum plant density at which yield may be optimized. This rate is lower than the common density recommendation of 81,000 plants ha−1 and substantially lower than the risk-averse rates at which many producers plant (129,000 seeds ha−1 or greater). The analysis showed that yield will decline precipitously below 35,000 plants ha−1, exposing the enormous risk to cotton producers in approaching this low density, particularly if significant seed or plant loss is expected. However, the analysis suggests that excessive over-seeding may be occurring in many cases, resulting in economic losses to producers. The analysis also provides guidance on a threshold for producers facing replanting decisions.

Land use efficiency can be maximized if an intercropping system is utilized to produce switchgrass ( Panicum virgatum L.) biomass within the alleys between hybrid poplar trees ( Populus spp.). Information is limited on switchgrass production and intercropping system in the Pacific Northwest of U.S. The objectives of this study were to evaluate the effects of hybrid poplar trees on switchgrass yield and forage quality and to determine the land use efficiency in an intercropping system under irrigation. Three cultivars of switchgrass (‘Kanlow’, ‘Blackwell’, and ‘Trailblazer’) were planted in the alleys between hybrid poplar trees (Clones: OP367 and PC4) at the Greenwood Resources, Boardman, OR in 2011. Switchgrass growth was negatively influenced by hybrid poplar trees with mean leaf area index, tiller density, and switchgrass dry matter (DM) yield in the monoculture and intercropped plots equal to 4.9 and 1.7, 383 and 69 tillers m −2 , and 15 and 4 Mg ha −1 , respectively, in the third year of this study. The 3-year cumulative switchgrass monoculture, switchgrass intercropping, and tree yield was 47.7, 21.5, and 58.5 Mg ha −1 . As a result, cumulative land equivalent ratio during the three years of the study was 1.45 in intercropped compared to 1.0 in monoculture plots. This indicates that 45% more land would be required in monoculture system to produce the same amount of DM produced in the intercropping system. This study revealed that, despite the reduced switchgrass growth under hybrid poplar trees, intercropping hybrid poplar and switchgrass can improve land use efficiency for biomass production.

In the Pacific Northwest, commercial hybrid poplar (Populus generosa Henry × Populus canadensis Moench.) is managed at low stocking densities under irrigation for high-value timber production. The objectives of this study were to measure greenhouse gas emissions (CH4, CO₂, and N₂O) during intercropping of switchgrass (Panicum virgatum L.) with hybrid poplar; estimate losses of fertilizer-N as N₂O, and estimate global warming potentials (GWP) of the intercrop. Cumulative above-ground biomass-C of the poplar monoculture (PM) closely matched the four year growing season (GS) soil CO₂–C emissions, where aboveground biomass of the switchgrass monoculture (SM) and intercrop (IC) exceeded GS CO₂–C emissions by 14.1 Mg C ha⁻¹. Soil CH₄–C uptake was not significantly different between treatments, while GS N₂O-N emissions for PM were ∼80% lower than both IC and SM. N₂O emissions factors averaged 0.7% of the applied N-fertilizer. Cumulative contributions of CO₂ emissions to GWP were offset by biomass-C resulting in a near zero balance (−5.1 Mg CO₂ₑq ha ⁻¹) for the PM, where, IC and SM sequestered significantly more CO₂ resulting in a net GWP of −42.5 and –32.2 Mg CO₂ₑq ha⁻¹, respectively. Intercropping with switchgrass can improve the net greenhouse gas balance of hybrid poplar. Continued research is needed on the effects of irrigated bioenergy production on GHG emissions in intercropped systems as they will become increasingly important as agricultural water use, water availability and quality are challenged by climate change.

Switchgrass (Panicum virgatum) has been identified as an important source of cellulosic biomass to produce biofuels and improve soil carbon storage. The natural 13C abundance of soils was used to calculate the quantity and turnover of C in a hybrid poplar (Populus x generosa and P. x canadensis) plantation intercropped with switchgrass. Levels of intercrop were grass cultivars inter-planted with poplar trees (IC), monoculture switchgrass (SM) and monoculture hybrid poplar (PM). Four years of intercropping increased soil organic carbon (SOC) 18% in the surface 60 cm for switchgrass. Surface soil was enriched 1.5‰ δ13C cropped to switchgrass compared to the poplar monoculture. On average, 14% of SOC in SM was derived from switchgrass and 9% in IC. SOC accrual rates were 0.32 Mg C ha−1yr−1 for the poplar monoculture; 1.3 Mg C ha−1yr−1 for switchgrass monocultures and 1.0 Mg C ha−1yr−1 for intercrop. The CO2 evolved during laboratory incubations was used to determine the size and turnover of the functional C pools of SOC. SOC was divided into three functional pools: an active, slow and resistant pool; where the size and turnover rates were estimated by curve fitting using a three-component first-order model. The resistant C pool was 62%, slow (Cs) 34% and active (Ca) 4% of SOC. The Cs increased 31% in the 0–15 cm horizon of SM and IC compared to PM. Field mean resident times of Ca and Cs cropped to switchgrass were 50d and 15yr for surface soil, respectively, compared to 41d and 9yr for PM. Switchgrass intercropped with hybrid poplar increased SOC compared to poplar alone.

Water is the limiting factor for crop production within the southern US Great Plains and it has become a critical resource for multiple stakeholders. Hence, efficient irrigation and cropping systems are of paramount importance to conserve water resources. The objective of this study was to determine the effect of irrigation timing and quantity, cover crop use and tillage on cotton production in an established conservation tillage system. Evaluated tillage systems included: 1) conventional tillage (CT); 2) strip-tillage (ST); 3) no-till (NT); and 4) NT with a terminated wheat cover crop (NT-W). Irrigation treatments included 1) 5.08-6.35 mm d−1 initiated mid-season (LOW); 2) 6.35-8.38 mm d−1 initiated mid-season (MED); and 3) 5.08-6.35 mm d−1 initiated early-season (HIGH). No significant differences in lint yield or irrigation water use efficiency (IWUE) were observed between MED and HIGH. Although HIGH resulted in 12 % greater lint yields than LOW, HIGH resulted in 67 % greater irrigation water applications. LOW resulted in significantly greater IWUE than MED and HIGH. No-till systems, with and without a cover crop, had significantly greater lint yields and IWUE than CT. Furthermore, inclusion of wheat in NT increased yields and IWUE compared with ST. Applying irrigation water at a critical growth stage proved to be more water efficient than early season irrigation that was used to bank moisture in the soil profile. Delaying irrigation application until critical growth stages and using cover crops should be considered as best management approaches to conserve water resources while sustaining cotton production in the Southern Great Plains.

Switchgrass (Panicum virgatum L.) is a perennial warm-season grass identified as a model species for bioenergy feedstock production. Established switchgrass stands are very resilient to the environmental fluctuations; however, seed dormancy and weak seedling vigor make establishment difficult. Breaking seed dormancy of switchgrass is a first step to reduce risk of establishment failure and the costs associated with reseeding. Many studies have reported a myriad of methods to break seed dormancy of switchgrass, including chemical, mechanical, thermal, and hormonal seed treatments. Length of seed storage, storage conditions (e.g., temperature and humidity), and prior soil conditions (e.g., soil salinity and fertilizer rates) affect switchgrass seed dormancy. Strong interactions exist among germination, seedling emergence, and soil conditions; therefore, treated seeds tested in soil media will generate more accurate results following dormancy breaking techniques. This paper reviews the current methods used to break switchgrass seed dormancy.

Background N1,N12-diacetylspermine (DiAcSpm) is a recently identified tumor marker. Its concentration increases in the urine of cancer patients at early clinical stages. To utilize this characteristic feature and thus contribute to the early detection of cancer, we developed an immunochromatographic determination system for DiAcSpm. Methods We examined the factors that affect the performance and stability of our determination system, including antibody selection and the conditions for the formation of stably dispersed antibody-coated gold nanoparticles. We then tested the performance of the system by determining the DiAcSpm concentration in human urine samples. Results We constructed an immunochromatographic strip using anti-DiAcSpm antibody-coated gold nanoparticles in the conjugate pad and an acetylspermine–protein conjugate (a DiAcSpm mimic) immobilized on the analyzing membrane. The use of the immunochromatographic strip and an immunochromato-reader allowed for the quantitative determination of DiAcSpm in the range of 20 to 700 nM. The analytical values obtained by this method were well correlated with those determined by a colloidal gold aggregation procedure using an automatic biochemical analyzer. The immunochromatographic strip was stable for at least 8 weeks at 50°C. Conclusions A competitive immunochromatographic device for DiAcSpm determination was developed in this study. This simple device will contribute to increasing the opportunities for early cancer detection and timely care.

In man, circulating leptin levels are increased with obesity and are regulated by a complex of hormonal, feeding and body-weight changes. Accurate and precise methods to quantitate circulating serum free leptin (f-leptin) concentrations are needed for physiological and clinical studies. We developed a one-step enzyme immunoassay to measure human f-leptin in serum. The detection limit was 0.40 ng/ml. The recovery of leptin added to serum was 90.8-102.8%. The within-run and between-day coefficients of variation (C.V.) ranged from 2.8 to 7.7 and 5.7 to 9.7%, respectively, and the immunoassay had an overall recovery rate for serial dilution in the range of 94. 0-109.9%. Measured serum f-leptin concentrations in 201 adults correlated (r=0.449, P0.001) directly with body mass index (BMI kg/m(2)), particularly when results were separated by gender (r=0. 709 for male, P0.001; r=0.643 for female, P0.001). We conclude that this one-step enzyme immunoassay is accurate for measuring f-leptin in human serum.

Monoclonal antibodies (MAbs) were generated against human prostate specific antigen (PSA) to allow development of a sensitive free-PSA (f-PSA) assay. Of a total of 211, 12 could detect only f-PSA, the other 199 MAbs binding to both f-PSA and complex-PSA. In the present study, one MAb (no. 5C6) specific for f-PSA and another (no. 79) reacting with both forms were used to develop an enzyme-linked immunoassay (ELISA) for serum f-PSA. The detection limit was established as 0.008 microg/l (n = 20, mean of zero standard + 3 S.D.) and the average recovery of f-PSA was 93-102%. The within-run and between-day coefficient of variation (CV) varied from 5.4-7.4% and 4.8-6.5%, respectively. The cross-reactivity of the assay to PSA-alpha1-antichymotrypsin complex was determined to be < 0.4%.

Studies evaluating the correlation between endoscopic disease activity and noninvasive markers are scarce in inflammatory bowel disease (IBD). The aim of this study is to evaluate the accuracy of the fecal calprotectin (FC) assay as a marker of disease activity of IBD, as determined by an extensive endoscopic scoring system. Thirty-five children and adolescents with IBD [17 with ulcerative colitis (UC) and 18 with Crohn’s disease (CD)] and 28 healthy volunteers were enrolled. FC levels were determined by ELISA. The sum of Matts’ score for UC and the simple endoscopic score for Crohn’s disease (SES-CD) were used. The ileal lesions were evaluated by ultrasonography. In UC patients, there was a strong correlation between FC levels and the sum of Matts’ score (r = 0.838, p

Childhood systemic diseases are commonly treated with steroids. Consequently, steroid-induced osteoporosis is often observed as a side effect of steroid therapy. However, osteoporosis of tibia resulting from steroid therapy has not been reported yet. Herein we constructed a steroid-induced osteoporosis in tibia of the growing phase rats to examine internal structural changes of the bone and tried to find out the effect of bisphosphonates as a new and early treatment method. Biomechanical analysis was performed using two-dimensional microdensitometry and three-dimensional pQCT method. In addition, the following evaluations were carried out: noninvasive bone strength measurements in steroid-induced osteoporotic rat tibiae; comparing the effectiveness of single high-calcium diet versus combined treatment of high calcium and bisphosphonate for osteoporosis; and quantitative measurement of four elements (Ca, P, Mg, Zn) in bone matrix. Our data suggested that a combined treatment of high calcium and bisphosphonate was an effective new method to improve and treat steroid-induced osteoporosis in childhood.

Prostate specific antigen(PSA) is widely used as a marker for screening and monitoring prostate cancer. However, there are several assay methods, which often give different PSA values for the same patient sample. A possible cause of these discrepancies might be the varied immunoreactivity with free-PSA and complex-PSA among methods. This study revealed that pre-treatment of samples with anti-free-PSA monoclonal antibodies improved polyclonal antibodies-based non equimolar PSA assay to equimolar assay. This might be achieved by that the monoclonal antibodies bind to free-PSA and then change its reactivities with polyclonal antibodies to those similar to complex-PSA.

We have developed an enzyme-linked immunoassay (ELISA) for serum complexed-antigen (prostate-specific antigen; PSA)(c-PSA) with simultaneous blocking of free-antigen (PSA)(f-PSA). The assay utilizes three different monoclonal antibodies (MAbs) recognising three distinct PSA epitopes. The detection limit was established as 0.19 microg/l (n=20, mean of zero standard+2S.D.) and the average recovery of f-PSA was 98-100%. The within-run and between-day coefficients of variation (CV) ranged from 2.1% to 3.2% and 2.8% to 6.3%, respectively. There was a good correlation between serum c-PSA measured by the present ELISA and PSA-alpha(1)-antichymotrypsin complex (PSA-ACT) concentrations (r=0.991). This method should provide a better tool for discriminating between benign and malignant prostatic disease.

AIM: To investigate the association between Helicobacter pylori infection and serum pepsinogen (PG) 1 and 2 concentrations in various gastroduodenal diseases. METHODS: Serum PG1 and 2 concentrations and antibodies to H pylori were measured by enzyme linked immunosorbent assay (ELISA); gastric mucosal pH was assessed and urease activity in biopsy tissue was determined. A comparison of the ELISA and urease test results permitted division of the cases into positive, false positive, false negative and negative categories for control, gastritis, and ulcer groups. RESULTS: The gastric mucosal pH and serum PG2 in cases positive for H pylori were significantly increased in ulcer and gastritis cases compared with H pylori negative cases. Similar tendencies were observed for the false positive and false negative categories. CONCLUSIONS: A positive ELISA reaction for antibodies and an increased serum PG2 concentration are reliable indicators of H pylori infection.