Sicklepod (Cassia obtusifolia) Control in Soybean (Glycine max) Grown in Rotations of 97- and 18-cm Row Spacings

Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 748-752 ◽  
Author(s):  
David R. Shaw ◽  
Clyde A. Smith ◽  
Charles E. Snipes

Various 3-yr rotation sequences of 97- and 18-cm row spacings, with appropriate sicklepod control treatments within each row spacing, were implemented to evaluate sicklepod population and soybean yield at two locations. Alachlor plus metribuzin applied preemergence followed by either a postemergence-directed spray of metribuzin plus 2,4-DB or hand hoeing in 97-cm rows consistently reduced sicklepod populations. Reductions with 97-cm rows and preemergence-applied herbicides coupled with cultivation were not as great. At one location, using a split application of metribuzin preplant incorporated followed by preemergence with 18-cm rows reduced sicklepod populations if effective control measures had been used in wide rows the previous year, but the narrow-row treatments did not reduce sicklepod numbers if 18-cm rows had been used previously. Soil-applied metribuzin was more effective under high soil pH conditions, and sicklepod populations were reduced substantially whether the previous row spacing was 18 or 97 cm. After the third year, all plots were planted in 97-cm rows with no herbicides. No differences were found among sicklepod populations with any previous row spacing or sicklepod control program, indicating that, even with 3 yr of effective control, subsequent sicklepod populations were not affected.

Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Otis W. Howe ◽  
Lawrence R. Oliver

The interference and seed production potential of pitted morningglory (Ipomoea lacunosaL. # IPOLA) with conventional-row (1 m) and narrow-row (20 cm) ‘Hill’ soybeans [Glycine max(L.) Merr.] was studied for 2 yr. Pitted morningglory densities were 3.3, 10, 20, and 40 plants/m2while soybean densities were 23 and 50 plants/m2in conventional and narrow rows, respectively. Pitted morningglory interfered with soybean growth earlier in conventional-row soybeans than in narrow-row soybeans due to its rapid increase in leaf area index (LAI) and biomass from 4 to 8 weeks after emergence. Soybeans were competitive with pitted morningglory until the soybean reproductive stage began at 7 weeks after emergence. Pitted morningglory reduced soybean yields 17% more in a dry year than in a wet year. Yield of narrow-row soybeans was equal or greater than yield of conventional-row soybeans at all pitted morningglory densities. Conventional-row soybean yields were reduced an average of 42 and 81% at pitted morningglory densities of 3.3 and 40/m2, respectively, but yield of narrow-row soybeans was reduced only 6 and 62% at equivalent densities. Pitted morningglory grown without soybean interference produced an average of 52.3 million seeds/ha. Total seed production of pitted morningglory growing in soybeans increased as pitted morningglory density increased and was greater in conventional rows than in narrow rows. Narrow rows reduced total seed production an average of 90 and 68% at pitted morningglory densities of 3.3 and 40/m2, respectively.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Kelly A. Nelson ◽  
Reid J. Smeda ◽  
Randall L. Smoot

Field research in 2002 and 2003 evaluated spring-interseeded winter rye (Secale cerealeL.) at 67, 134, or 200 kg ha−1at two soybean (Glycine max(L.) Merr.) row spacings (19- and 76-cm) on weed control, yield, and gross margins. Based on regression analysis, wide-row (76-cm) soybean grain yield and gross margins were greatest when winter rye was interseeded at 114 and 106 kg ha−1, respectively. Yields and gross margins for wide-row soybean were 8 to 55% greater than narrow-row (19-cm) soybean seeded at 494,000 or 742,000 seeds ha−1which was probably due to flexibility for implementing cultivation. As interseeded rye rates increased from 67 to 200 kg ha−1, yields and gross margins for narrow-rows decreased. Soybean row spacing had minimal impacts on specific weed species and total weed biomass or density. The use of wide-row soybean and spring-interseeded rye at 67 kg ha−1was more cost-effective compared to narrow rows.


Weed Science ◽  
1984 ◽  
Vol 32 (4) ◽  
pp. 498-501 ◽  
Author(s):  
C. S. Williams ◽  
Robert M. Hayes

Johnsongrass [Sorghum halepense(L.) Pers., ♯3SORHA] dry weight and johnsongrass culms/ha at harvest were more negatively correlated with soybean yield reductions than the number of johnsongrass plants/ha present at 4 to 6 weeks after planting. However, plant numbers can be determined in sufficient time to implement control measures to prevent yield reduction. Prediction equations for estimating soybean yield at various johnsongrass populations are Ŷ = 1776 + 424e-.023x2for 0.25-m row spacing and Ŷ = 1668 + 643e-.004x2for the 1-m row spacing, where Ŷ = estimated yield and x = the number of johnsongrass plants/10 m2. Full-season heavy johnsongrass competition reduced soybean yields from 59 to 88%. Soybeans in the 1-m row spacing were more competitive with low johnsongrass densities than in the 0.25-m row spacing. The johnsongrass-free requirement for soybeans was 4 weeks after planting and soybeans could not tolerate heavy infestations of johnsongrass for more than 5 weeks without loss in yield potential. Application of sethoxydim {2-[1-(ethoxyimino)-butyl]-5-[2-ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} at 3 or 4 weeks after planting was effective in controlling heavy infestations of johnsongrass and preventing yield reductions due to competition.


Author(s):  
N.A. Thomson

In a four year grazing trial with dairy cows the application of 5000 kg lime/ ha (applied in two applications of 2500 kg/ha in winter of the first two years) significantly increased annual pasture production in two of the four years and dairy production in one year. In three of the four years lime significantly increased pasture growth over summer/autumn with concurrent increases in milk production. In the last year of the trial lime had little effect on pasture growth but a relatively large increase in milkfat production resulted. A higher incidence of grass staggers was recorded on the limed farmlets in spring for each of the four years. In the second spring immediately following the second application of lime significant depressions in both pasture and plasma magnesium levels were recorded. By the third spring differences in plasma magnesium levels were negligible but small depressions in herbage magnesium resulting from lime continued to the end of the trial. Lime significantly raised soil pH, Ca and Mg levels but had no effect on either soil K or P. As pH levels of the unlimed paddocks were low (5.2-5.4) in each autumn and soil moisture levels were increased by liming, these factors may suggest possible causes for the seasonality of the pasture response to lime


The results of scientific research are presented, which made it possible to develop less labor-intensive methods for selecting flax plants to grow original (updated) seeds. Studies have shown that a positive selection of tall plants of flax, compared with the accepted counterpart (control), increased seed yield 1.7-1.9 times. Moreover, plant homogeneity according to the main characteristics (height and fiber content in the stem) characterizing the varietal quality of grown seeds turned out to be at the control level. A negative selection, involving the removal of atypical plants, provided an increase in the output volume of seeds compared to the control by 3.9-4.1 times. This selection method did not reduce the varietal quality of seed material compared to the accepted analogue. With both selection methods, after combining typical plants, seeds with the same high germination rates were obtained (96-99 %). The breeding efficiency of the grown flax seeds using narrow-row sowing methods is shown. Studies have established that narrow-row sowing of seeds with a row-spacing of 7.5 and 6.25 cm compared with sowing by a wide-row method significantly increased their yield by 2.8-3.0 and 2.3-3.0 kg / ha, respectively. The greatest influence on the formation of seed yield in narrow-row sowing (6.25 cm) was exerted by the method of sowing, the part of which was 76.1 %. As the length of seed propagation of flax in creased (up to the uterine elite 2 years) in narrow-row sowing (6.25 cm) compared to broad-row, there was no decrease in quality indicators - germination and seed strength.


2020 ◽  
Author(s):  
Lukman Olagoke ◽  
Ahmet E. Topcu

BACKGROUND COVID-19 represents a serious threat to both national health and economic systems. To curb this pandemic, the World Health Organization (WHO) issued a series of COVID-19 public safety guidelines. Different countries around the world initiated different measures in line with the WHO guidelines to mitigate and investigate the spread of COVID-19 in their territories. OBJECTIVE The aim of this paper is to quantitatively evaluate the effectiveness of these control measures using a data-centric approach. METHODS We begin with a simple text analysis of coronavirus-related articles and show that reports on similar outbreaks in the past strongly proposed similar control measures. This reaffirms the fact that these control measures are in order. Subsequently, we propose a simple performance statistic that quantifies general performance and performance under the different measures that were initiated. A density based clustering of based on performance statistic was carried out to group countries based on performance. RESULTS The performance statistic helps evaluate quantitatively the impact of COVID-19 control measures. Countries tend show variability in performance under different control measures. The performance statistic has negative correlation with cases of death which is a useful characteristics for COVID-19 control measure performance analysis. A web-based time-line visualization that enables comparison of performances and cases across continents and subregions is presented. CONCLUSIONS The performance metric is relevant for the analysis of the impact of COVID-19 control measures. This can help caregivers and policymakers identify effective control measures and reduce cases of death due to COVID-19. The interactive web visualizer provides easily digested and quick feedback to augment decision-making processes in the COVID-19 response measures evaluation. CLINICALTRIAL Not Applicable


Chemosphere ◽  
2020 ◽  
pp. 128901
Author(s):  
Yin Liu ◽  
Qing Huang ◽  
Wen Hu ◽  
Jiemin Qin ◽  
Yingrui Zheng ◽  
...  

Author(s):  
Ting Wan Tan ◽  
Han Ling Tan ◽  
Man Na Chang ◽  
Wen Shu Lin ◽  
Chih Ming Chang

(1) Background: The implementation of effective control measures in a timely fashion is crucial to control the epidemic outbreak of COVID-19. In this study, we aimed to analyze the control measures implemented during the COVID-19 outbreak, as well as evaluating the responses and outcomes at different phases for epidemic control in Taiwan. (2) Methods: This case study reviewed responses to COVID-19 and the effectiveness of a range of control measures implemented for epidemic control in Taiwan and assessed all laboratory-confirmed cases between 11 January until 20 December 2020, inclusive of these dates. The confirmation of COVID-19 infection was defined as the positive result of a reverse-transcriptase–polymerase-chain-reaction test taken from a nasopharyngeal swab. Test results were reported by the Taiwan Centers for Disease Control. The incidence rate, mortality rate, and testing rate were compiled, and the risk ratio was provided to gain insights into the effectiveness of prevention measures. (3) Results and Discussion: This study presents retrospective data on the COVID-19 incidence rate in Taiwan, combined with the vital preventive control measures, in a timeline of the early stage of the epidemic that occurred in Taiwan. The implementation of multiple strategy control measures and the assistance of technologies to control the COVID-19 epidemic in Taiwan led to a relatively slower trend in the outbreak compared to the neighboring countries. In Taiwan, 766 confirmed patients were included, comprised of 88.1% imported cases and 7.2% local transmission cases, within the studied period. The incidence rate of COVID-19 in Taiwan during the studied period was 32 per million people, with a mortality rate of 0.3 per million people. Our analysis showed a significantly raised incidence risk ratio in the countries of interest in comparison to Taiwan during the study period; in the range of 1.9 to 947.5. The outbreak was brought under control through epidemic policies and hospital strategies implemented by the Taiwan Government. (4) Conclusion: Taiwan’s preventive strategies resulted in a drastically lower risk for Taiwan nationals of contracting COVID-19 when new pharmaceutical drug or vaccines were not yet available. The preventive strategies employed by Taiwan could serve as a guide and reference for future epidemic control strategies.


2020 ◽  
Vol 13 (1) ◽  
pp. 238
Author(s):  
Alice Giusti ◽  
Enrica Ricci ◽  
Laura Gasperetti ◽  
Marta Galgani ◽  
Luca Polidori ◽  
...  

Proper investment in mushroom production (farming and wild mushroom picking activities) may represent a winning strategy for many countries, including Italy, to better face the problems of food security and environmental impact, and to break away from imports, enhancing the local products. However, the risk related to the consumption of poisoning species requires governments to implement or reinforce effective control measures to protect consumers. Mushroom identification by phenotype observation is hardly applicable if morphologically-similar species, non-whole specimens, or clinical samples are involved. Genotypic analysis is a valid alternative. An ongoing research project involving the Experimental Zooprophylactic Institute of Lazio and Tuscany, the regional Mycological Inspectorate, the Tuscany Mycological Groups Association, and the Department of Veterinary Sciences of the University of Pisa aims to reinforce the collaboration among institutions for the management of mushroom poisoning. The core’s project aims to develop an internal genetic database to support the identification of wild and cultivated mushroom species in the Italian territory. The database will include Internal Transcribed Spacer (ITS) sequences retrieved from official databases (the NCBI GenBank and the BOLD system) which are considered to be reliable, after a proper selection process, and sequences from specimens collected directly and identified by expert mycologists. Once it is validated, the database will be available and further implementable by the official network of national laboratories.


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