scholarly journals Factors Influencing Phytophthora infestans Mont. de Bary Attack Degree in Potato

Author(s):  
Cristian IEDERAN ◽  
Ioan OROIAN ◽  
Ioan BRASOVEAN ◽  
Camelia TODORAN ◽  
Cristian MÄ‚LINAȘ

The strong relationship between the late blight and climatic factors (namely temperature and rainfall)  has  important  consequences  on  potato  crops.  In  Romania,  in  early  spring  and  early  fall  the attack  degree  of  the  Phytophthora infestans  Mont.  de  Bary,  late  blight  pathogen,  is  low  because  in European  climate  average  temperature  is  not  more  than  10 0C,  and  usually  the  rainfall  supply  is reduced;  it  increases  in  late  spring  and  summer  when  average  temperatures  are  around  20 0C  and rainfall average more that 65 mm/month. The aim of this paper is to describe the relationship between temperature, rainfall regimen and late blight attack degree in potato cultures. The research was carried on  during  two  years,  2009  and  2010,  in  three  experimental  fields  from  Transylvania:  Răhău,  Alba; Maieru,  BistriÅ£a-Năsăud;  Draguș,  Brașov.  Classical  methodology  was  used  for  monitoring.  The  data were statistically processed using STATISTICA  v. 7.0 programme. The interrelation attack degree - abiotic  factors  reflects  a  maximum  intensity  of  the Phytophthora infestans  Mont.  de  Bary  attack degree by the entire year 2009 around 42 % recorded when the rainfall average values begin with 110 mm  and  thermic  conditions  correspondent  to  values  bigger  than  20 0C.  In  the  year  2010  the multiregression  analyze  of  the  monitored  interactions,  led  to  a  very  strong  multiple  correlation coefficient  of  0.938  representative  in  share  of  87.90%.  In  2010,  by  the  entire  monitored  period,  the rainfall supply had a bigger influence on the attack degree compared to thermic conditions. In 2009, the predicted biggest recorded attack degree of Phytophthora infestans de Bary was of 44% while in 2010 it was of 40 %, correspondent to rainfall and temperature regimens.

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Andreea Maria Iordache ◽  
Constantin Nechita ◽  
Cezara Voica ◽  
Tomáš Pluháček ◽  
Kevin A. Schug

AbstractThe relationship between metal levels in the Olt River ecosystem in southern Romania (measured during 2018‒2019, with 1064 sediment and water samples) and daily climate data were explored to assess the need for targeted source identification and mitigation strategies. In 2018, there was a strong relationship between the sediment Pb, As, Cd, and Hg contents and temperature (r > 0.8, p < 0.001). Mercury in sediments had a positive correlation with precipitation, and Hg in the water correlated with minimum temperature in May 2018 (p < 0.01). In July 2019, heavy metals were positively correlated with precipitation and negatively correlated with temperature. According to nonsymmetrical correspondence analysis, the four climate parameters analyzed were linearly correlated with the frequency of metal detection (p < 0.001) in both years. The statistical analysis showed strong relationships between heavy metal levels and climatic factors and attributed the discrepancies in elemental concentrations between 2018 and 2019 to climate warming.


2013 ◽  
Vol 42 (1-2) ◽  
pp. 63-76
Author(s):  
Elżbieta Horodecka

The purpose of the studies carried out in 1983-1985 was to determine the relationships between the degree of susceptibility of green tomato fruit to late blight and several of the anatomical and morphological features of these fruits. It was found that in the studied material representing a wide range of susceptibility (from various degrees of resistance to susceptible) the extent of infection was dependent on the covering layer thickness (with cuticle) and number of hairs on the skin.


2020 ◽  
Author(s):  
endang naryono

This study examines the influence of receivables on liquidity at PT. Graha Tumarima. Sukabumi City for 5 years, with a sampling technique using a purposive sample in the form of financial statement data from 2010 to 2014 using a table of trade receivables and company liquidity. In this study, researchers refer to the theory of Bambang Riyanto (2008: 94) as the connecting theory of the title. This study aims to determine whether there is a relationship and influence between receivables and liquidity at PT. Graha Tumarima. The research design uses the method of exposing the facto, the method of data collection aims to test the hypothesis by using correlation analysis, determination, regression and hypothesis testing with t-test. The results of this study show the influence of receivables on liquidity is shown by the value of r = 0.888, meaning that receivables have a very strong relationship to liquidity. The nature of the relationship is positive, meaning that if the value of cooperative credit is higher the liquidity will be higher. Conversely, if the value of receivables decreases, liquidity will decrease. The magnitude of the influence of receivables on liquidity is shown by the value of R Square / Determination Coefficient of 0.789 or 78.9% thus the receivables have an effect of 78.9% on cooperative liquidity. Hypothesis testing uses the t test, that t arithmetic = 3.347 while t table = 3.182 means t arithmetic&gt; t table. Means that Ho is rejected and Ha is accepted. There is an influence between the receivables on liquidity at PT. Graha Tumarima, Sukabumi City


2019 ◽  
Author(s):  
Chem Int

Mathematical model was developed and evaluated to monitor and predict the groundwater characteristics of Trans-amadi region in Port Harcourt City. In this research three major components were considered such as chloride, total iron and nitrate concentration as well as the polynomial expression on the behavious on the concentration of each component was determined in terms of the equation of the best fit as well as the square root of the curve. The relationship between nitrate and distance traveled by Nitrate concentration by the model is given as Pc = 0.003x2 - 0.451x + 14.91with coefficient of determination, R² = 0.947, Chloride given as Pc = 0.000x2 - 0.071x + 2.343, R² = 0.951while that of Total Iron is given as Pc = 2E-05x2 - 0.003x + 0.110, R² = 0.930. All these show a strong relationship as established by Polynomial Regression Model. The finite element techniques are found useful in monitoring, predicting and simulating groundwater characteristics of Trans-amadi as well as the prediction on the variation on the parameters of groundwater with variation in time.


2020 ◽  
Vol 3 (1) ◽  

The aim of this study is to investigate the relationship between extrinsic and intrinsic reward on retention among Gen Y employees in Malaysian manufacturing companies. The data was collected from 113 respondents worked in manufacturing companies located in Seri Kembangan, Selangor using questionnaires. Multiple regression analysis was conducted to test the hypotheses. The results showed both extrinsic and intrinsic reward are the factors influencing retaining Gen Y in manufacturing companies. The discussion on the analysis, limitation of the study, recommendation for future research and conclusion were discussed at the end of this study. In a nutshell, it was proven extrinsic reward and intrinsic reward has contributed to the retention of Gen Y employees.


2018 ◽  
Vol 34 (6) ◽  
pp. 4-11
Author(s):  
V.K. Chizhik ◽  
◽  
E.A. Sokolova ◽  
V.V. Martynov ◽  
M.A. Kuznetsova ◽  
...  

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 878
Author(s):  
Chang-Hyun Park ◽  
Ui-Cheon Lee ◽  
Soo-Chul Kim ◽  
Kwang-Hee Lee

To analyze the relationship between climatic factors (monthly mean temperature and total precipitation) and tree-ring growths of Pinus densiflora from the central region of the Republic of Korea, more than 20 trees were sampled from three national parks. The tree-ring chronology of Mt. Bukhan covering the period of 1917–2016 was assessed, as well as that of Mt. Seorak across 1687–2017 and Mt. Worak across 1777–2017. After cross-dating, each ring-width series was double-standardized by first fitting a logarithmic curve and then a 50 year cubic spline. Climate-growth relationships were computed with bootstrap correlation functions. The result of the analysis showed a positive response from the current March temperature and May precipitations for tree-ring growth of Pinus densiflora. It indicates that a higher temperature supply during early spring season and precipitation during cambium activity are important for radial growths of Pinus densiflora from the central region in the Republic of Korea.


2021 ◽  
Vol 13 (2) ◽  
pp. 313
Author(s):  
Yongfang Xu ◽  
Zhaohui Lin ◽  
Chenglai Wu

Central Asia is prone to wildfires, but the relationship between wildfires and climatic factors in this area is still not clear. In this study, the spatiotemporal variation in wildfire activities across Central Asia during 1997–2016 in terms of the burned area (BA) was investigated with Global Fire Emission Database version 4s (GFED4s). The relationship between BA and climatic factors in the region was also analyzed. The results reveal that more than 90% of the BA across Central Asia is located in Kazakhstan. The peak BA occurs from June to September, and remarkable interannual variation in wildfire activities occurs in western central Kazakhstan (WCKZ). At the interannual scale, the BA is negatively correlated with precipitation (correlation coefficient r = −0.66), soil moisture (r = −0.68), and relative humidity (r = −0.65), while it is positively correlated with the frequency of hot days (r = 0.37) during the burning season (from June to September). Composite analysis suggests that the years in which the BA is higher are generally associated with positive geopotential height anomalies at 500 hPa over the WCKZ region, which lead to the strengthening of the downdraft at 500 hPa and the weakening of westerlies at 850 hPa over the region. The weakened westerlies suppress the transport of water vapor from the Atlantic Ocean to the WCKZ region, resulting in decreased precipitation, soil moisture, and relative humidity in the lower atmosphere over the WCKZ region; these conditions promote an increase in BA throughout the region. Moreover, the westerly circulation index is positively correlated (r = 0.53) with precipitation anomalies and negatively correlated (r = −0.37) with BA anomalies in the WCKZ region during the burning season, which further underscores that wildfires associated with atmospheric circulation systems are becoming an increasingly important component of the relationship between climate and wildfire.


2021 ◽  
Vol 74 (1) ◽  
pp. 181-187
Author(s):  
Mehi Lal ◽  
Sorabh Chaudhary ◽  
Sanjay Rawal ◽  
Sanjeev Sharma ◽  
Manoj Kumar ◽  
...  

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