scholarly journals Seed germination characteristics and control options for Noogoora bur (Xanthium strumarium) in commercial maize production

2016 ◽  
Vol 69 ◽  
pp. 270-277
Author(s):  
T.K. James ◽  
A. Rahman ◽  
M.R. Trolove ◽  
C.A. Dowsett

Noogoora bur (Xanthium strumarium) is a large herbaceous highly competitive annual weed of arable and horticultural crops which is subject to Regional Pest Management Plans in the Waikato and Bay of Plenty regions New Zealand A study with scarified burs showed that most plants emerged from 040 mm and none from 100 mm depth Plants emerged after 8 days from 030 mm after 14 days from 90 mm and continued to emerge over summer with some also germinating in the second year after initiation Cultivated fallow resulted in germination of similar numbers of seeds over two growing seasons with no new seed input Results from a field trial showed that dicamba and atrazine alone or in combination with other products as well as topramezone provided good control of this weed in maize crop

Author(s):  
Amanda Cecato Favorito ◽  
Edleusa Pereira Seidel ◽  
Taís Regina Kohler ◽  
William Ribeiro de Carvalho ◽  
Renan Pan ◽  
...  

The objective of the present study was to verify the effect of two doses of the biofertilizer ‘Supermagro’ applied in cover, in the presence and absence of cured bovine urine in the maize crop, and in the soil penetration resistance, as well as the effect in the application of biofertilizer ‘Fert Bokashi’. The experimental design used was of randomized blocks with four replicates. The treatments constituted of cover application of ‘Supermagro’ in the dose of 6% (recommended dose) (T1); cover application of ‘Supermagro’ in the dose of 12% (T2); cover application of ‘Supermagro’ in the dose of 6% + cured bovine urine 3% (T3); cover application of ‘Supermagro’ in the dose of 12% + cured bovine urine 3% (T4); cover application of cured bovine urine 3% (T5); use of the biofertilizer ‘Fert Bokashi’ in the dose of 0,5% of dilution) (T6); and control (T7). The results obtained were tabulated and submitted to analysis of variance and the comparison of means by the Dunnett test at 5% of probability, with the aid of the statistical analysis software SAS. For the parameters: thousand grain mass, the treatment ‘Fert Bokashi’ alone presented the highest thousand grain mass (375,00 g) being it superior to the control (p<0,05) with 360,94 g. For the yield parameter, the treatments ‘Supermagro’ 12% + urine, bovine urine alone and ‘Fert Bokashi’ presented the highest averages, (5961 kg ha-1, 5512 kg ha-1 and 5808 kg ha-1, respectively) which differed statistically from the control (5500 kg ha-1) (p<0,05). The biofertilizers are an alternative to increase the yield of maize in the organic system with an average increase of 20% in the maize production in relation to the area without application. The biofertilizer ‘Fer Bokashi’ is an alternative to increase maize yield in the organic production system. The application of biofertilizers did not influence in the soil penetration resistance.


1966 ◽  
Vol 56 (3) ◽  
pp. 417-444 ◽  
Author(s):  
M. Bigger

Many crops in southern Tanganyika are attacked by termites, especially those grown in the miombo woodland (Brachystegia-Pseudoberlinia), which covers much of the southern and western parts of the country. The termites chiefly concerned are Microtermes albopartitus (Sjöst.), M. redenianus (Sjöst.), Ancistrotermes latinotus (Hlmgr.) and Allodontermes tenax (Silv.). A pit dug to investigate their nest systems showed that M. albopartitus was the most numerous, 425 occupied cells being recovered from an area 50 × 24 ft. excavated to a depth of 6 ft. Cells of the other species included 166 of M. redenianus, 54 of Ancistrotermes latinotus and 49 of Allodontermes tenax. The cells of Ancistrotermes latinotus were aggregated into small clusters connected by long runways; those of the other species were more or less randomly scattered. The greatest concentration of cells of all species was within the top 2 ft. of the soil, but a number of cells were found at greater depths and it is certain that 6 ft. is not the maximum nesting depth. Descriptions of the nest systems and fungus combs are given.Observations at Nachingwea in 1959–63 showed that loss of maize stands from termite attack averaged 27 per cent, over the five years, and that of soya 33 per cent. The damage was often great on individual plots, as much as 90 per cent, being recorded from one plot of maize. Plant-population counts over three growing seasons showed that maize is lost mainly towards the end of the season, whereas soya may be attacked any time after planting, increased losses occurring during dry spells and at the end of the season.Control was achieved by the use of aldrin or dieldrin applied as dusts to the soil before planting or used in seed dressings. It was found in a series of field trials that good control of termites was afforded by aldrin worked into the soil along the planting ridges at a rate of 1 lb. active ingredient per acre, but that in practice ½ lb. per acre gave nearly as good results when measured by yields. In spite of the considerable losses, it was considered uneconomic to use aldrin to protect soya from termite attack, but the increased yields of 200–400 lb. maize per acre justified the expenditure on insecticide. The aldrin dust protected both crops for at least one further year after application, the effects on yield being of the same order as before.A seed dressing of 75 per cent, dieldrin gave excellent control and was considerably cheaper than soil application of aldrin. The cost was only a few shillings an acre when the dressing was used at the rate of 0·1 oz. per 1 lb. seed, and the effect was to raise yields of maize by 330–500 lb. and of soya by 110–180 lb. per acre.Trenches were dug to investigate the effects of soil treatment with aldrin on the nest systems of the termites. There was little effect on cell density eight months after application, but after 20 months there were signs of a reduction, especially in the top 9 in. of the soil.


2008 ◽  
Vol 61 ◽  
pp. 287-291 ◽  
Author(s):  
A. Rahman ◽  
T.K. James ◽  
M.R. Trolove

Three field trials were conducted over two growing seasons to evaluate the efficacy of potential selective postemergence herbicides against dicamba resistant fathen (Chenopodium album) Results confirmed the presence of the biotype which tolerated dicamba up to 2400 g/ha eight times the recommended field rate Postemergence applications of bromoxynil pyridate nicosulfuron and mesotrione all showed equally good efficacy on both susceptible and resistant biotypes Flumetsulam provided good control in one of the three trials Nicosulfuron and mesotrione provided long term residual control in all trials with nicosulfuron also being more effective on grass weeds The 2400 g/ha rate of dicamba severely damaged the maize crop resulting in increased weed cover and reduced grain yield Numbers of viable fathen seeds in the soil at the end of the growing season remained similar to those recorded before planting except in plots that provided good control of fathen where numbers had dropped considerably


2020 ◽  
Vol 5 (1) ◽  
pp. 74-89
Author(s):  
Hugh Crago

In a seminal 1973 paper, Robert Clark described the very different “cultures” of the first and second year students in a four year clinical psychology PhD programme. The author applies Clark’s template to his own experiences as trainee or trainer in five different counsellor education programmes, one in the US and four in Australia. Each of the programmes, to varying degrees, demonstrates key features of the pattern identified by Clark, where the first year is “therapeutic” and other-oriented, the second is “professional” and self-focused. The author concludes that all the surveyed programmes exhibited some level of “second year crisis”, in which a significant number of students felt abandoned, dissatisfied, or rebellious. The author extends and refines Clark’s developmental analogy (first year = childhood; second year = adolescence) to reflect recent neurological research, in particular, the shift from a right hemisphere-dominant first year of life, prioritising affiliative needs, to a left hemisphere-dominant second year, prioritising autonomy and control. This shift is paralleled later by a more gradual move from a protective, supportive childhood to necessary, but sometimes conflictual, individuation in adolescence. The first two years of a counsellor training programme broadly echo this process, a process exacerbated by the second year internship/placement, in which students must “leave home” and adjust to unfamiliar, potentially less nurturing, authority figures. Finally, the author suggests introducing more rigorous “academic holding” into the first year, and greater attention to “therapeutic holding” of dissident students in the second, hopefully decreasing student dropout, and achieving a better balanced training experience.


Author(s):  
Veronika N. And Lince Sihombing

This study focused on finding out the effect of applying RAP (Read, Ask,Paraphrase) Strategy on students’ reading comprehension in reading analyticalexposition text. This study was conducted in experimental design. The populationof this research was the second year of students in SMA Swasta Katolik BudiMurni 2 Medan. There were seventy students of the second year senior highschool students as the sample of the research. This study was conducted with tworandomized groups namely Experimental Group and Control Group. Theexperimental group was taught by applying RAP Strategy, while the control groupwas taught by applying conventional strategy. The instrument of collecting thedata was multiple choice tests which consisted of 25 items. The data wereanalyzed by using t-test formula. The calculation shown that t-observed (5.36)was higher than t-table (1.994) at the level of significance (α) 0.05 with the degreeof freedom (df) 68. It means that there was a significant effect of applying RAPStrategy on students’ reading comprehension in reading analytical exposition text.


2016 ◽  
Vol 6 (1) ◽  
pp. 905-913
Author(s):  
Bahram Majd Nassiry ◽  
Neda Mohammadi

    One of the effects of reducing water content on soil is reduction of growth and development of seedlings and variation of field development. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stresses. The objectives of this research were to evaluate the effects of osmo-priming on germination characteristics and changes of proline, protein and catalase activity of Ocimum basilicum seeds. Results showed that drought stress reduced the germination characteristics and drought stress in -8 bar was the critical stress.  Priming treatments were include KNO3, PEG and NaCl by 0, -4 and -8 bar concentrations. The seeds were primed with those materials for 8 and 16 hours. The highest germination characteristics were obtained from nitrate potassium in -8 bar for 16 hours priming. Therefore the best seed treatment under drought stress during germination was obtained from the osmo-primed with -8 bar nitrate potassium for 16 hours. The drought stress increased proline and catalase activity but reduced total protein. Priming treatment increases proline, total protein and catalase activity under drought and control conditions. It is concluded that priming results in improvement in germination components of Ocimum basilicum in drought stress conditions and increases the resistance to drought stress with improvement of proline, protein and catalase activity in germination phase.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qinglong Zhao ◽  
Yao Wang ◽  
Meng Yang ◽  
Meina Li ◽  
Zeyu Zhao ◽  
...  

Abstract Background Based on differences in populations and prevention and control measures, the spread of new coronary pneumonia in different countries and regions also differs. This study aimed to calculate the transmissibility of coronavirus disease 2019 (COVID-19), and to evaluate the effectiveness of measures to control the disease in Jilin Province, China. Methods The data of reported COVID-19 cases were collected, including imported and local cases from Jilin Province as of March 14, 2019. A Susceptible–Exposed–Infectious–Asymptomatic–Recovered/Removed (SEIAR) model was developed to fit the data, and the effective reproduction number (Reff) was calculated at different stages in the province. Finally, the effectiveness of the measures was assessed. Results A total of 97 COVID-19 infections were reported in Jilin Province, among which 45 were imported infections (including one asymptomatic infection) and 52 were local infections (including three asymptomatic infections). The model fit the reported data well (R2 = 0.593, P < 0.001). The Reff of COVID-19 before and after February 1, 2020 was 1.64 and 0.05, respectively. Without the intervention taken on February 1, 2020, the predicted cases would have reached a peak of 177,011 on October 22, 2020 (284 days from the first case). The projected number of cases until the end of the outbreak (on October 9, 2021) would have been 17,129,367, with a total attack rate of 63.66%. Based on the comparison between the predicted incidence of the model and the actual incidence, the comprehensive intervention measures implemented in Jilin Province on February 1 reduced the incidence of cases by 99.99%. Therefore, according to the current measures and implementation efforts, Jilin Province can achieve good control of the virus’s spread. Conclusions COVID-19 has a moderate transmissibility in Jilin Province, China. The interventions implemented in the province had proven effective; increasing social distancing and a rapid response by the prevention and control system will help control the spread of the disease.


2021 ◽  
Vol 13 (15) ◽  
pp. 2983
Author(s):  
Alberto López-Amoedo ◽  
Xana Álvarez ◽  
Henrique Lorenzo ◽  
Juan Luis Rodríguez

Land fragmentation and small plots are the main features of the rural environment of Galicia (NW Spain). Smallholding limits land use management, representing a drawback in local forest planning. This study analyzes the potential use of multitemporal Sentinel-2 images to detect and control forest cuts in very small pine and eucalyptus plots located in southern Galicia. The proposed approach is based on the analysis of Sentinel-2 NDVI time series in 4231 plots smaller than 3 ha (average 0.46 ha). The methodology allowed us to detect cuts, allocate cut dates and quantify plot areas due to different cutting cycles in an uneven-aged stand. An accuracy of approximately 95% was achieved when the whole plot was cut, with an 81% accuracy for partial cuts. The main difficulty in detecting and dating cuts was related to cloud cover, which affected the multitemporal analysis. In conclusion, the proposed methodology provides an accurate estimation of cutting date and area, helping to improve the monitoring system in sustainable forest certifications to ensure compliance with forest management plans.


2013 ◽  
Vol 464 ◽  
pp. 253-257
Author(s):  
Hui Fang Chen

This paper takes the automatic control system of controllable pitch propeller in a multipurpose ocean tug as an example to describe the application of the S7-200 series PLC in the control system of 4500 horse power controllable pitch propeller in detail. The principle of control system is addressed, as well as the hardware configuration, the design idea of the main software and control process. The system shows high reliability, accuracy and good control performance in practical in practical running.


1991 ◽  
Vol 67 (5) ◽  
pp. 528-531 ◽  
Author(s):  
Gary O. Fiddler ◽  
Philip M. McDonald

A study on alternatives for releasing young conifer plantations on National Forests in northern and central California was started in 1980, and enlarged to include State of California, Bureau of Land Management, and private industry lands. Forty studies involving chemical, manual, mechanical, mulch, and animal treatments have been established and their effect on the survival and growth of conifer seedlings is being quantified. Plant diversity and succession on both treated and untreated sites are being recorded. The oldest study has had 10 growing seasons since the first treatments were applied. To release conifer seedlings, a treatment radius of at least 1.5 meters is required; smaller radii do not provide enough site resources for acceptable growth. Diameter, rather than height, is the best indicator of release. Some non-phenoxy chemicals show promise for good control of competing vegetation. Mechanical release requires additional treatments to effectively control shrubs. Mulching has given limited results to date. Manual treatments, if applied to non-sprouting and nonrhizomatous plants soon after planting, and usually more than once, provide adequate control of competing vegetation, but are costly.


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