scholarly journals Mustard and Other Cover Crop Effects Vary on Lettuce Drop Caused by Sclerotinia minor and on Weeds

Plant Disease ◽  
2009 ◽  
Vol 93 (10) ◽  
pp. 1019-1027 ◽  
Author(s):  
Tiffany A. Bensen ◽  
Richard F. Smith ◽  
Krishna V. Subbarao ◽  
Steven T. Koike ◽  
Steven A. Fennimore ◽  
...  
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Seed Viability ◽  
Weed Seed ◽  
Short Term ◽  
Sclerotinia Minor ◽  
Cover Cropping ◽  
Long Term Study ◽  
Lettuce Drop

Mustard cover crops have been suggested as a potential biofumigant for managing soilborne agricultural pests and weeds. We conducted several experiments in commercial lettuce fields in the Salinas Valley, CA, to evaluate the effects of mustard cover crops on lettuce drop caused by Sclerotinia minor and on weed density and seed viability. In a long-term study, we measured the effects of white and Indian mustard cover crops on the density of S. minor sclerotia in soil, lettuce drop incidence, weed densities, weed seed viability, and crop yield in head lettuce. We also tested broccoli and rye cover crop treatments and a fallow control. Across several short-term studies, we evaluated the density of S. minor sclerotia in soil, lettuce drop incidence, weed densities, and weed seed viability following cover cropping with a mustard species blend. Numbers of sclerotia in soil were low in most experimental locations and were not affected by cover cropping. Mustard cover crops did not reduce disease incidence in the long-term experiment but the incidence of lettuce drop was lower in mustard-cover-cropped plots across the short-term experiments. With the exception of common purslane and hairy nightshade, weed densities and weed seed viability were not significantly reduced by cover cropping with mustard. Head lettuce yield was significantly higher in mustard-cover-cropped plots compared with a fallow control. Glucosinolate content in the two mustard species was similar to those measured in other studies but, when converted to an equivalent of a commercial fumigant, the concentrations were much lower than the labeled rate for lettuce production. Although mustard cover cropping resulted in yield benefits in this study, there was little to no disease or weed suppression.

scholarly journals Effects of Long-Term Cover Cropping on Weed Seedbanks

2020 ◽  
Vol 2 ◽  
Author(s):  
Virginia Nichols ◽  
Lydia English ◽  
Sarah Carlson ◽  
Stefan Gailans ◽  
Matt Liebman
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Production Systems ◽  
Early Spring ◽  
Weed Suppression ◽  
Winter Rye ◽  
Maize Crop ◽  
Cover Cropping ◽  
Crop Biomass

Cool-season cover crops have been shown to reduce soil erosion and nutrient discharge from maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] production systems. However, their effects on long-term weed dynamics are not well-understood. We utilized five long-term research trials in Iowa to quantify germinable weed seedbank densities and compositions after 10+ years of cover cropping treatments. All five trials consisted of zero-tillage maize-soybean rotations managed with and without the inclusion of a yearly winter rye (Secale cereal L.) cover crop. Seedbank sampling was conducted in the early spring before crop planting at all locations, with three of the five trials having grown a soybean crop the preceding year, and two a maize crop. Two of the trials (both previously soybean) showed significant and biologically relevant decreases (4,070 and 927 seeds m−2, respectively) in seedbank densities in cover crop treatments compared to controls. In another two trials, one previously maize and one previously soybean, no difference was detected in seedbank densities. In the fifth trial (previously maize), there was a significant, but biologically unimportant increase of 349 seeds m−2. All five trials' weed communities were dominated by common waterhemp [Amaranthus tuberculatus (Moq.)], and changes in seedbank composition from cover-cropping were driven by changes in this species. Although previous studies have shown that increases in cover crop biomass are strongly correlated with weed suppression, in our study we did not find a relationship between seedbank changes and the mean amount of cover crop biomass produced over a 10-years period (experiment means ranging from 0.5 to 2.0 Mg ha−1 yr−1), the stability of the cover crop biomass production, nor the amount produced going into the previous crop's growing season. We conclude that long-term use of a winter rye cover crop in a maize-soybean system has the potential to meaningfully reduce the size of weed seedbanks compared to winter fallows. However, identifying the mechanisms by which this occurs requires further research into processes such as seed predation and seed decay in cover cropped systems.

scholarly journals Influence of Short-term Maize–Green Manure Cover Crop Rotations on Germinable Weed Seed Bank under Conservation Agriculture

2021 ◽  
Vol 11 (1) ◽  
pp. 139-155
Author(s):  
Rugare Joyful Tatenda ◽  
Pieterse Petrus Jacobus ◽  
Mabasa Stanford
Keyword(s):  
Seed Bank ◽  
Cover Crops ◽  
Cover Crop ◽  
Seedling Emergence ◽  
Crop Rotations ◽  
Second Phase ◽  
Weed Seed ◽  
Weed Species ◽  
Short Term ◽  
Bidens Pilosa

The effects of one- and two-year maize-cover crop rotations on weed seed bank density and species composition were evaluated in fields at the University of Zimbabwe (UZ) and the International Maize and Wheat Improvement Center (CIMMYT, Harare) between 2014 and 2017. Nine cover crops were rotated, and maize and weed seed bank analyses were done using the seedling emergence method. Maize was used as the control. The results indicated that weed seed density was not significantly (p > 0.05) affected by cover crop mulch type across the seasons. There was a significant (p < 0.05) decline in weed density in the second maize phase of the rotation in UZ Field A. Bidens pilosa, Galinsoga parviflora, Amaranthus hybridus and Eleusine indica were the dominant weeds. B. pilosa density significantly decreased in the second season in UZ Field A but did not vary significantly among cover crops. Significant changes in weed species richness, evenness, and diversity were observed only in the second phase of the rotation in UZ Field A. The results suggest that maize-cover crop rotations could be effective in reducing seed bank size in the short term but have no short-term effect on weed species community composition.

Hematologic and Bone Marrow Changes after Short- and Long-term Administration of Two Recombinant Bovine Granulocyte Colony-stimulating Factors

1992 ◽  
Vol 29 (6) ◽  
pp. 521-527 ◽  
Author(s):  
J. S. Cullor ◽  
W. Smith ◽  
J. G. Zinkl ◽  
J. D. Dellinger ◽  
T. Boone
Keyword(s):  
Bone Marrow ◽  
Specific Response ◽  
Short Term ◽  
Term Study ◽  
Colony Stimulating Factors ◽  
Long Term Study ◽  
Short Term Study ◽  
Term Administration ◽  
A Cell

Colony-stimulating factors are a category of glycoproteins that are instrumental in the regulation of hematopoiesis and inflammation. This investigation documented the clinical bone marrow and peripheral blood responses to short-term and long-term administration of a recombinant bovine granulocyte colony-stimulating factor (rb-GCSF) and an analog, where the cysteine at position 17 was substituted with a serine (rb-GCSF ser17). The colony-stimulating factors produced the expected changes in the hematologic findings of the bovine subjects in the study, and there was a cell-specific response to the compounds. The sustained neutrophilia in the long-term study indicates that the bovine species can tolerate the administration of recombinant forms of bovine GCSF for extended periods of time without detectable adverse side effects. The neutrophils from the short-term study revealed no apparent fluctuation, either as enhanced or reduced capability to reduce nitro blue tetrazolium as compared to pretreatment neutrophils. The administration of both recombinant forms of GCSF produced large increases in the bone marrow myeloid: erythroid (M:E) ratio concomitantly with the neutrophilias. This is the first preliminary report documenting the bone marrow response of cattle to the native and recombinant (rb-GCSF ser17) forms of bovine GCSF.

scholarly journals Mustard Cover Crop Growth and Weed Suppression in Organic, Strawberry Furrows in California

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 432-440 ◽  
Author(s):  
Eric B. Brennan ◽  
Richard F. Smith
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Sinapis Alba ◽  
Weed Suppression ◽  
Shoot Biomass ◽  
Plastic Mulch ◽  
Seeding Rate ◽  
Crop Cover ◽  
Cover Cropping ◽  
Growing Seasons

Strawberry (Fragaria ×ananassa Duch.) production in California uses plastic mulch–covered beds that provide many benefits such as moisture conservation and weed control. Unfortunately, the mulch can also cause environmental problems by increasing runoff and soil erosion and reducing groundwater recharge. Planting cover crops in bare furrows between the plastic cover beds can help minimize these problems. Furrow cover cropping was evaluated during two growing seasons in organic strawberries in Salinas, CA, using a mustard (Sinapis alba L.) cover crop planted at two seeding rates (1× and 3×). Mustard was planted in November or December after strawberry transplanting and it resulted in average densities per meter of furrow of 54 and 162 mustard plants for the 1× and 3× rates, respectively. The mustard was mowed in February before it shaded the strawberry plants. Increasing the seeding rate increased mustard shoot biomass and height, and reduced the concentration of P in the mustard shoots. Compared with furrows with no cover crop, cover-cropped furrows reduced weed biomass by 29% and 40% in the 1× and 3× seeding rates, respectively, although weeds still accounted for at least 28% of the furrow biomass in the cover-cropped furrows. These results show that growing mustard cover crops in furrows without irrigating the furrows worked well even during years with relatively minimal precipitation. We conclude that 1) mustard densities of ≈150 plants/m furrow will likely provide the most benefits due to greater biomass production, N scavenging, and weed suppression; 2) mowing was an effective way to kill the mustard; and 3) high seeding rates of mustard alone are insufficient to provide adequate weed suppression in strawberry furrows.

scholarly journals Temporal Change of Soil Carbon on a Long-Term Experimental Site with Variable Crop Rotations and Tillage Systems

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 840 ◽  
Author(s):  
Ahmed Laamrani ◽  
Paul R. Voroney ◽  
Aaron A. Berg ◽  
Adam W. Gillespie ◽  
Michael March ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Soil Carbon ◽  
Cover Crops ◽  
Cover Crop ◽  
Red Clover ◽  
Conventional Tillage ◽  
Crop Rotations ◽  
Tillage Practices ◽  
No Till

The impacts of tillage practices and crop rotations are fundamental factors influencing changes in the soil carbon, and thus the sustainability of agricultural systems. The objective of this study was to compare soil carbon status and temporal changes in topsoil from different 4 year rotations and tillage treatments (i.e., no-till and conventional tillage). Rotation systems were primarily corn and soy-based and included cereal and alfalfa phases along with red clover cover crops. In 2018, soil samples were collected from a silty-loam topsoil (0–15 cm) from the 36 year long-term experiment site in southern Ontario, Canada. Total carbon (TC) contents of each sample were determined in the laboratory using combustion methods and comparisons were made between treatments using current and archived samples (i.e., 20 year and 9 year change, respectively) for selected crop rotations. Overall, TC concentrations were significantly higher for no-till compared with conventional tillage practices, regardless of the crop rotations employed. With regard to crop rotation, the highest TC concentrations were recorded in corn–corn–oats–barley (CCOB) rotations with red clover cover crop in both cereal phases. TC contents were, in descending order, found in corn–corn–alfalfa–alfalfa (CCAA), corn–corn–soybean–winter wheat (CCSW) with 1 year of seeded red clover, and corn–corn–corn–corn (CCCC). The lowest TC concentrations were observed in the corn–corn–soybean–soybean (CCSS) and corn–corn–oats–barley (CCOB) rotations without use of cover crops, and corn–corn–soybean–winter wheat (CCSW). We found that (i) crop rotation varieties that include two consecutive years of soybean had consistently lower TC concentrations compared with the remaining rotations; (ii) TC for all the investigated plots (no-till and/or tilled) increased over the 9 year and 20 year period; (iii) the no-tilled CCOB rotation with 2 years of cover crop showed the highest increase of TC content over the 20 year change period time; and (iv) interestingly, the no-till continuous corn (CCCC) rotation had higher TC than the soybean–soybean–corn–corn (SSCC) and corn–corn–soybean–winter wheat (CCSW). We concluded that conservation tillage (i.e., no-till) and incorporation of a cover crop into crop rotations had a positive effect in the accumulation of TC topsoil concentrations and could be suitable management practices to promote soil fertility and sustainability in our agricultural soils.

scholarly journals 14 Long-term Efficacy of Brexpiprazole in Patients with Schizophrenia with Clinically Relevant Levels of Negative Symptoms

CNS Spectrums ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 180-180
Author(s):  
Catherine Weiss ◽  
Peter Zhang ◽  
Ross A Baker ◽  
Mary Hobart ◽  
Nanco Hefting ◽  
...  
Keyword(s):  
Negative Symptoms ◽  
Extension Study ◽  
Short Term ◽  
Open Label ◽  
Term Study ◽  
Post Hoc Analysis ◽  
Long Term Study ◽  
Open Label Extension ◽  
Post Hoc

AbstractBackgroundEffective treatments for patients with high levels of negative symptoms of schizophrenia are lacking. Brexpiprazole is a serotonin–dopamine activity modulator that is a partial agonist at 5-HT1A and dopamine D2 receptors, and an antagonist at 5-HT2A and noradrenaline alpha1B/2C receptors, all with subnanomolar potency. Long-term treatment with brexpiprazole demonstrated broad efficacy across all five Marder factor groupings, including positive, negative, disorganized thoughts, uncontrolled hostility/excitement, and anxiety/depression. This post-hoc analysis of long-term effects of brexpiprazole in patients with clinically relevant levels of negative symptoms of schizophrenia is based on data from two similarly designed short-term, placebo-controlled studies (Vector; NCT01396421 or Beacon; NCT01393613) for the brexpiprazole-treated patients who continued into an open-label extension study (Zenith; NCT01397786).MethodsIn the short-term studies, patients with acute schizophrenia were randomly assigned to fixed once-daily doses of brexpiprazole 0.25mg (Vector), 1mg (Beacon), 2mg , 4mg or placebo for 6weeks. The long-term study was an open-label, 52-week (amended to 26weeks), safety extension study with flexible-dose (1–4mg/day) brexpiprazole. The post-hoc analyses were performed on brexpiprazole-treated patients from the short-term studies who continued into the long-term study, and who had clinically relevant negative symptoms, defined as PANSS Factor Score for Negative Symptoms (PANSS-FSNS; N1, N2, N3, N4, G7, G16) of ≥24, and score of ≥4 on at least two of three core negative symptom PANSS items at randomization in the parent study. The outcome of the analysis included change from baseline to up to 58weeks in PANSS-FSNS, PANSS Total, and PSP. Safety was also assessed.ResultsA total of 187 patients with clinically relevant levels of negative symptoms in the parent study rolled-over into the open-label extension study and were available for analysis. Eighty-three of these patients remained in the studies for 58weeks. Due to the study amendment, not all patients had the opportunity of complete 52weeks of open-label treatment. Baseline PANSS Total score was 104.4, while baseline PANSS-FSNS was 27.6 and baseline PSP Total score was 41.3. Mean change (SD) from baseline in PANSS-FSNS was –10.9 (5.0), and –44.2 (17.5) for PANSS Total score at Week 58. Change from baseline (SD) to Week 58 for PSP Total score was 24.8 (12.9) with improvement in all domains (socially useful activities, personal and social relationship, self-care, and disturbing and aggressive behaviors). The TEAEs reported ≥5% were schizophrenia (18.9%), insomnia (8.6%), weight increased (5.9%) and akathisia (5.9%).ConclusionThis post-hoc analysis suggests that brexpiprazole has long-term effectiveness on negative symptoms and functioning in patients with schizophrenia and clinically relevant levels of negative symptoms.Funding Acknowledgements: The study was funded by Otsuka Pharmaceutical Development & Commercialization Inc. and H. Lundbeck A/S

scholarly journals Did the introduction and increased prescribing of antidepressants lead to changes in long-term trends of suicide rates?

2020 ◽  
Author(s):  
Simone Amendola ◽  
Martin Plöderl ◽  
Michael P Hengartner
Keyword(s):  
General Pattern ◽  
Extended Period ◽  
Joinpoint Regression ◽  
Short Term ◽  
Term Study ◽  
Suicide Rates ◽  
Long Term Study ◽  
Prescription Rates ◽  
Long Term Trends

Abstract Background Ecological studies have explored associations between suicide rates and antidepressant prescriptions in the population, but most of them are limited as they analyzed short-term correlations that may be spurious. The aim of this long-term study was to examine whether trends in suicide rates changed in three European countries when the first antidepressants were introduced in 1960 and when prescription rates increased steeply after 1990 with the introduction of the serotonin reuptake inhibitors (SSRIs). Methods Data were extracted from the WHO Mortality Database. Suicide rates were calculated for people aged 10–89 years from 1951–2015 for Italy, 1955–2016 for Austria and 1951–2013 for Switzerland. Trends in suicide rates stratified by gender were analyzed using joinpoint regression models. Results There was a general pattern of long-term trends that was broadly consistent across all three countries. Suicide rates were stable or decreasing during the 1950s and 1960s, they rose during the 1970s, peaked in the early 1980s and thereafter they declined. There were a few notable exceptions to these general trends. In Italian men, suicide rates increased until 1997, then fell sharply until 2006 and increased again from 2006 to 2015. In women from all three countries, there was an extended period during the 2000s when suicide rates were stable. No trend changes occurred around 1960 or 1990. Conclusions The introduction of antidepressants around 1960 and the sharp increase in prescriptions after 1990 with the introduction of the SSRIs did not coincide with trend changes in suicide rates in Italy, Austria or Switzerland.

Efficacy and safety of percutaneous administration of dihydrotestosterone in children of different genetic backgrounds with micropenis

2017 ◽  
Vol 30 (12) ◽  
Author(s):  
Dan Xu ◽  
Liangsheng Lu ◽  
Li Xi ◽  
Ruoqian Cheng ◽  
Zhou Pei ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Side Effects ◽  
Low Doses ◽  
Efficacy And Safety ◽  
Short Term ◽  
Term Study ◽  
Long Term Study ◽  
Percutaneous Administration ◽  
Open Prospective Study

AbstractBackground:Exogenous androgen supplement is an optional treatment for micropenis; however, its use in childhood is controversial due to potential side effects.Methods:Twenty-three children (mean age: 4.07±3.4 years) with micropenis of unknown causes harboring the 46,XY karyotype were recruited in an open prospective study. Androgen receptor (Results:Two patients were found withConclusions:Short term and local application of DHT at low doses in patients with micropenis could accelerate penile growth effectively without evident side effects; however, precautions still need be taken due to the paucity of long term study and the lack of ideal DHT dosage.

scholarly journals Benefits of winter cover crops and no-tillage for microbial parameters in a Brazilian Oxisol: A long-term study

2014 ◽  
Vol 197 ◽  
pp. 31-40 ◽  
Author(s):  
Elcio L. Balota ◽  
Ademir Calegari ◽  
Andre S. Nakatani ◽  
Mark S. Coyne
Keyword(s):  
Cover Crops ◽  
No Tillage ◽  
Term Study ◽  
Long Term Study ◽  
Winter Cover ◽  
Winter Cover Crops
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