scholarly journals Level of inoculum suitable for studies on the relationship of coffee seedlings and Rhizoctonia solani or Myrothecium roridum

1969 ◽  
Vol 83 (3-4) ◽  
pp. 181-188
Author(s):  
Wanda I. Mercado ◽  
Rocío del P. Rodríguez
Keyword(s):  
Rhizoctonia Solani ◽  
Disease Incidence ◽  
Dry Weight ◽  
Seedling Mortality ◽  
Inoculum Level ◽  
Inoculum Concentration ◽  
Myrothecium Roridum ◽  
Relationship Of ◽  
The Relationship ◽  
Coffea Arabica L

Suitable levels of inoculum of Rhizoctonia solani and Myrothecium roridum for the induction of symptoms in coffee (Coffea arabica L.) seedlings were determined in greenhouse tests based on the percentage of seedling mortality and disease incidence. Best inoculum level for R. solani and M. roridum was 15 and 10%, respectively. Myrothecium roridum was more virulent than R. solani, and thus caused higher mortality of coffee seedlings. For both pathogens, as the inoculum concentration increased, the dry weight of plants decreased. A direct positive relation between incidence of the disease and concentration of the inoculum was detected, it was found that R. solani is more persistent than M. roridum in the inoculated soil.

Population variation in Sorghum halepense, Johnson grass, at the northern limits of its range

1984 ◽  
Vol 62 (9) ◽  
pp. 1781-1790 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black
Keyword(s):  
New York ◽  
Dry Weight ◽  
Population Variation ◽  
Sorghum Halepense ◽  
Johnson Grass ◽  
Allocation Patterns ◽  
Cultivated Species ◽  
Relationship Of ◽  
The Relationship ◽  
Enzyme Patterns

Thirteen populations of Sorghum halepense, Johnson grass, were sampled from fields in Ontario, Canada, and Ohio and New York, United States. Only four of these populations were reported to overwinter as rhizomes. The morphology, phenology, resource allocation patterns, and growth of seedling and mature plants of the overwintering and the non-overwintering populations were compared. Field-collected specimens from the nonoverwintering populations had wider culms and leaves and larger seeds and inflorescences. Analysis of material grown in a 5-month greenhouse trial indicated similar differences. Greenhouse plants from the nonoverwintering populations were also characterized by greater percent emergence, larger and faster growing seedlings, earlier flowering, larger culms and seeds, greater reproductive dry weight per plant, and about 1/10th the rhizome dry weight of overwintering plants. Differences between populations within a biotype were evident for both biotypes, although there was little within-population variation, except in rhizome production, where certain individuals of some nonoverwintering populations did not produce extended rhizomes. Among the five enzymes which were examined electrophoretically, only one, phosphoglucomutase (PGM), showed variable isozyme patterns. No differences in enzyme patterns were apparent between the overwintering and the nonoverwintering biotypes. The relationship of the nonoverwintering populations to the cultivated species, Sorghum bicolor and S. almum, an introgressant between S. halepense and S. bicolor, is discussed.

Relationship of Rhizoctonia solani inoculum density to incidence of hypocotyl rot and damping-off in dry beans

1989 ◽  
Vol 35 (12) ◽  
pp. 1132-1140 ◽  
Author(s):  
A. J. L. Phillips
Keyword(s):  
Phaseolus Vulgaris ◽  
Linear Regression ◽  
Rhizoctonia Solani ◽  
Disease Incidence ◽  
Inoculum Density ◽  
Damping Off ◽  
Dry Beans ◽  
Site Model ◽  
Relationship Of

The effect of inoculum density on preemergence disease incidence was described by linear regression. Variations in virulence among 10 isolates formed a continuum. The effect of inoculum density on hypocotyl disease incidence was described by a limiting site model and variations in virulence among the isolates also formed a continuum. The ability of an isolate to cause preemergence disease was not necessarily related to its ability to cause hypocotyl disease. Both saprophytic colonization and preemergence infection arose from propagules in the spermosphere, while depending on the isolate, infection of hypocotyls was from propagules in either the rhizosphere or the rhizoplane. The observed number of hypocotyl lesions was greater than that estimated from the percentage of plants infected. This effect was more pronounced when seeds were sown at 4 than at 1 cm depth.Key words: beans, epidemiology, Phaseolus vulgaris, Rhizoctonia solani.

scholarly journals Temperature Affects Leaf Unfolding Rate and Flowering of Cyclamen

HortScience ◽  
2001 ◽  
Vol 36 (2) ◽  
pp. 292-294 ◽  
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Dry Weight ◽  
Similar Rate ◽  
Flower Number ◽  
Flower Buds ◽  
Open Flower ◽  
Leaf Unfolding ◽  
Response To Temperature ◽  
Relationship Of ◽  
The Relationship ◽  
Large Flower

The rate of leaf unfolding for Cyclamen persicum Mill. was determined at 8 to 24 °C. Temperature treatments started 9 weeks from seeding and after 8 weeks all plants were moved to 16 °C. The cultivars Miracle Salmon, Miracle Scarlet, and Miracle White produced leaves at a similar rate. The relationship of (leaves/d) = - 0.01727 - 0.02284 * °C + 0.005238 * (°C)2 - 0.000162 * (°C)3 (R2 = 0.99) best described the leaf unfolding rate in response to temperature. The maximum leaf unfolding rate was estimated to 0.329 leaves/day at 19.1 °C. Flower buds (2 mm diameter) developed within 60 days from the start of temperature treatments except at 8 °C. Thirty-five additional days at 16 °C were required for cyclamen initially grown at 8 °C for 8 weeks to produce flower buds. Despite similar conditions during bud development, flowering was delayed 14 to 18 days for plants initially grown at 24 °C compared to those grown at 12 to 20 °C. Plants initially at 8 °C did not flower within 70 days at 16 °C. Leaf and flower numbers at first open flower increased as initial temperature increased from 12 to 24 °C while dry weight and height only increased to 20 °C. No correlation between leaf unfolding and rate of flowering or flower number was detected. Recommendations for 20 °C during early cyclamen growth can be expected to support rapid rates of leaf unfolding and development, and large flower numbers.

scholarly journals Flooding Reduces Gas Exchange and Growth in Snap Bean

HortScience ◽  
1991 ◽  
Vol 26 (4) ◽  
pp. 372-373 ◽  
Author(s):  
Bharat P. Singh ◽  
Kevin A. Tucker ◽  
James D. Sutton ◽  
Harbans L. Bhardwaj
Keyword(s):  
Gas Exchange ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Quadratic Model ◽  
Snap Bean ◽  
Blue Lake ◽  
Relationship Of ◽  
The Relationship ◽  
Best Fit ◽  
Prior Stress

This study was conducted to determine the effect of various flooding durations on the growth, water relations, and photosynthesis of the snap bean (Phaseolus vulgaris L.). Greenhouse-grown plants of cv. Blue Lake 274 were flooded for 0 (control), 1, 3, 5, or 7 days. Leaf water potential (ψ), stomatal conductance (gs), transpiration (E), and net photosynthesis (Pn) were measured at the completion of the flooding period and after recovery for 7 days. Root, stem, and leaf dry weights were recorded after plants were allowed to recover from the flooding stress for 7 days. The values for ψ, gs, E, and Pn decreased quadratically with the increase in the duration of flooding. The Pn of plants flooded for 1 day was 17% lower than that of the control and it reached near zero in plants flooded for 7 days. The decrease in Pn after 1 day of flooding was not associated with ψ or gs; however, for longer duration of flooding, Pn decline coincided with the decline in gs. A week after the cessation of flooding, the level of recovery in ψ, E, and Pn was linear and that in gs quadratic to the duration of prior stress experienced by the plant. However, after recovering for 7 days, none of the flooded plants regained gas exchange activities at par with the control. The relationship of stem dry weight to duration of flooding was linear, while a quadratic model provided the best fit for the regression of root and leaf dry weight on the number of days of flooding. Overall, even 1 day of flooding reduces photosynthesis in snap bean and causes a decrease in dry weight of the plant. the extent of decrease in both increasing with the duration of flooding.

scholarly journals Reaction of the native Greek tomato varieties ‘Chondrokatsari Messinias’ and ‘Katsari Santorinis’ to Fusarium oxysporum f. sp. lycopersici and Rhizoctonia solani infection

2017 ◽  
Vol 10 (2) ◽  
pp. 70-79
Author(s):  
A.I. Darras ◽  
A. Kotsiras ◽  
C. Delis ◽  
K. Nifakos ◽  
E. Pavlakos ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Infectious Diseases ◽  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Biomass Production ◽  
Disease Incidence ◽  
Dry Weight ◽  
Disease Symptoms ◽  
Biotic Stresses

SummaryPlants have to cope with a number of biotic stresses among which, infectious diseases. The present study was conducted to investigate the reaction of two native Greek tomato vars, ‘Chondrokatsari Messinias’ and ‘Katsari Santorinis’, to infection by Fusarium oxysporum f. sp. lycopersici and Rhizoctonia solani. Disease symptoms, disease incidence and severity were recorded and the effects of infection on the number of flowers, the biomass production (fresh and dry weight), CO2assimilation, stomatal conductance and transpiration were also evaluated. Both tomato varieties were susceptible to F. oxysporum f. sp. lycopersici and R. solani infection. However, ‘Chondrokatsari Messinias’ was found to be less susceptible to F. oxysporum f. sp. lycopersici compared to ‘Katsari Santorinis’. Both pathogens negatively affected biomass production of var. ‘Chondrokatsari Messinias’ but not that of ‘Katsari Santorinis’. The number of fl owers produced by ‘Chondrokatsari Messinias’ was negatively affected by R. solani but not by F. oxysporum f. sp. lycopersici. Infection of both varieties by R. solani also caused reduction in the CO2assimilation, stomatal conductance and transpiration.

scholarly journals HUBUNGAN SANITASI RUMAH DENGAN KEJADIAN PENYAKIT TUBERKULOSIS (TB) DI KECAMATAN KUTA

2017 ◽  
Vol 11 (1) ◽  
pp. 55
Author(s):  
I Made Mudana ◽  
Nyoman Adiputra ◽  
I.B.G. Pujaastawa
Keyword(s):  
Disease Incidence ◽  
Control Group ◽  
Case Group ◽  
Residential Density ◽  
Independent Variables ◽  
Regression Test ◽  
House Floor ◽  
Relationship Of ◽  
The Relationship ◽  
Logistic Regression Test

RELATIONSHIP HOUSING SANITATION WITH TUBERCULOSIS DISEASES (TB) INCIDENCE IN KUTA DISTRICTOne of the endemic infectious diseases occured in the community is tuberculosis (TB). The World Health Organization (WHO) estimated about one third of the world's population has been infected by the bacteria mycobacterium tuberculosis. Badung regency as one of the districts in the province of Bali also having cases of tuberculosis. From the report Badung Health Agency in 2015 was recorded 275 TB patients. From 6 districts in Badung district, subdistrict of Kuta occupy the highest number of cases recorded 100 patients. tuberculosis is closely related to homes sanitation that do not meet health requirements. The purpose of this study was to determine the relationship of home sanitation with disease incidence of tuberculosis in the district of Kuta. Based on the type of research is observational analytic, design research is a case control studies linking ie risk factors. (Home sanitation) with TB disease events, by comparing the case group and the control group. The population in this study are patients with TB BTA (+) were treated working area Puskesmas Kuta I and Puskesmas Kuta II sanitation as well as his home. The number of samples in this study was 60 consisting of the case group and the control group. How sampling is the total population of TB patients in the last 3 months of 2015 as well as sanitary home. Data collected from interviews, observations and measurements and then analyzed using chi square and followed by multiple logistic regression test. From the statistic test bivariate home sanitation  with tuberculosis disease incidence 6 variables showed that: (1) lighting p = 0,00 (p< 0,05) OR = 21, (2) humidity p = 0,00 (p< 0,05) OR = 21,36 , (3) ventilation p = 0,00 (p< 0,05)OR = 11, (4) the walls of the house p = 0,00 (p< 0,05) OR = 8,64, (5) density residential home p = 0,00 (p<0,05) OR = 16,43 and (6) house floor p = 0,22 (p>0,05) OR = 2,143. To determine the relationship of all independent variables simultaneously multivariate analysis with multiple logistic regression test. Based on the results obtained that there are three independent variables significantly related (p<0,05) with the dependent variable is the humidity (OR = 19,158, 95% CI 3,171 –115,751), ventilation (OR = 6,408, 95% CI = 1,199 to 34,236), residential density (OR = 13,342, 95% CI = 2,261 – 78,733). Probability of people who occupy the house with sanitation (Humidity, Ventilation and Residential density) in the district of Kuta to contract tuberculosis (TB) is 97,08%. Based on these results, we can conclude that from the test bivariate (6 variables) are: lighting, humidity, ventilation, walls of houses, residential density and house floor associated with the incidence of tuberculosis in the district of Kuta. While the advice may be given to: (1). people who live in the district of Kuta in order to build or occupy a dwelling house to take into account the standard of sanitation and healthy home. (2). Government / agencies in order to provide guidance to the public in order to build houses of spatial attention and care homes that meet health requirements so that people who lived in the house to feel safe, comfortable, and avoid the disease especially those stemming from poor sanitation home.

The Respiratory Physiology of the Marine Nematodes Enoplus Brevis (Bastian) and E. Communis (Bastian)

1973 ◽  
Vol 59 (1) ◽  
pp. 255-266
Author(s):  
H. J. ATKINSON
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Oxygen Tension ◽  
Dry Weight ◽  
Respiratory Physiology ◽  
Rate Of Oxygen Consumption ◽  
Oxygen Tensions ◽  
The Difference ◽  
Relationship Of ◽  
The Relationship

1. The rate of oxygen consumption of individual males of Enoplus brevis and E. communis was measured at 15 °C and at each of four oxygen tensions, 135, 75, 35, and 12 Torr, after at least 12 h experience of these conditions. 2. It was clearly demonstrated that the level of oxygen consumption of both species was reduced by each lowering of the imposed oxygen tension. 3. In all cases the oxygen consumption of each species fell with increasing body size. On a unit dry-weight basis the oxygen consumption of E. brevis is greater than that of the larger E. communis, but after allowing for the difference of body size the two species have more or less similar oxygen uptakes at all oxygen tensions. 4. In E. brevis oxygen tension influenced the relationship of body size and metabolism, the slope relating oxygen consumption and body weight becomes steeper with decreasing oxygen tension. This effect was not shown by E. communis. 5. Some general factors influencing the availability of oxygen to nematodes are considered.

scholarly journals Potential Role of Laccases in the Relationship of the Maize Late Wilt Causal Agent, Magnaporthiopsis maydis, and Its Host

2020 ◽  
Vol 6 (2) ◽  
pp. 63
Author(s):  
Ofir Degani ◽  
Yuval Goldblat
Keyword(s):  
Potential Role ◽  
Dry Weight ◽  
Maize Cultivars ◽  
Maize Plants ◽  
Relationship Of ◽  
The Relationship ◽  
Host Tissues ◽  
Adult Plants

Late wilt is a vascular disease of maize (Zea mays L.) caused by the soil-borne and seed-borne fungus Magnaporthiopsis maydis. The pathogen penetrates the roots of maize plants at the seedling stage, grows into the xylem vessels, and gradually spreads upwards. From the flowering stage to the kernel ripening, the fungal hyphae and secreted materials block the water supply in susceptible maize cultivars, leading to rapid dehydration and death. Laccase is an enzyme secreted by fungus for diverse purposes. The M. maydis laccase gene was identified in our laboratory, but under what conditions it is expressed and to what functions remain unknown. In the current study, we tested the influence of plant age and tissue source (roots or leaves) on M. maydis laccase secretion. The results show increasing laccase secretion as corn parts (as ground tissue) were added to the minimal medium (MM). Furthermore, roots stimulated laccase secretion more than leaves, and adult plants enhanced laccase secretion more than young plants. This implies the possibility that the richer lignin tissue of adult plants may cause increased secretion of the enzyme. In vitro pathogenicity assay proved the ability of M. maydis to develop inside detached roots of maize, barley, watermelon, and cotton but not peanut. Testing root powder from those plants in MM revealed a negative correlation between M. maydis growth (expressed as biomass) and laccase secretion. For example, while the addition of maize, barley, or cotton root powder led to increasing fungal dry weight, it also resulted in relatively lower laccase activity. Watermelon and peanut root powder led to opposite responses. These findings suggest a pivotal role of laccase in the ability of M. maydis to exploit and grow on different host tissues. The results encourage further examination and a deeper understanding of the laccase role in these interesting host–pathogen interactions.

scholarly journals Correlation between selected parameters of planting material and strawberry yield

2010 ◽  
Vol 22 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Marcin Bartczak ◽  
Jolanta Lisiecka ◽  
Mikołaj Knaflewski
Keyword(s):  
Correlation Coefficients ◽  
Dry Weight ◽  
Fresh Weight ◽  
Planting Material ◽  
Whole Plant ◽  
Different Types ◽  
Positive Correlation Coefficient ◽  
Relationship Of ◽  
The Relationship ◽  
Strawberry Cultivars

Abstract The aim of this study was to determine the effect of fresh and dry weight, as well as the number and length of roots and number of crowns of different types of plants, on the yield of strawberry grown for the spring and autumn harvests. Three different types of frigo strawberry plants (waiting bed plants, plug plants, A+ plants) and two strawberry cultivars (‘Honeoye’ and ‘Elsanta’) were compared in the experiment. The plants were grown in polypropylene bags in an unheated glasshouse in the years 2002-2005. The correlation coefficients were calculated to estimate the relationship of the strawberry plants’ parameters to the yield quantity. An analysis of regression for the plant parameters that most significantly correlated to the strawberry yield was carried out, which determined that the fresh and dry weight of the strawberry plants, crown number, as well as length of roots were positively correlated to the quantity of the strawberry yield. The highest positive correlation coefficient was found for the fresh weight of a whole plant and the lowest one for the number of roots.

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