Search

Search Results

• Spectral analysis of stress symptoms caused by apple powdery mildew (Podosphaera leucotricha

  83-88

  Attila Nagy

  Péter Riczu

  János Tamás

  Views:

  187

  An orchard can be examined on the basis of spectral data, using methods with which the reflected radiation can be divided into a large number of (several hundreds) small spectral channel (some nm). Calculated on the basis of such hyperspectral data from different index numbers the water supply of foliage conditions can be well characterized.

  The research site is an intensive apple orchard, which located in University of Debrecen, Agricultural Sciences Centre, Farm and Regional Research Institute at Pallag. During my experiments the preliminary evaluation of spectral, non-invasive measurement method are carried out for detecting stress symptoms caused by Podosphaera leucotricha.

  Based on the results narrow band greenness indices (NDVI705, mNDVI705, mSR705 and REP) can be used for determination of diseased canopy and for the detection of stress symptoms of Podosphaera leucotricha,. These statements can be utilized in precision plant protection systems, since it can be a basis for such integrated active sensors with LED or laser light source, measuring reflectance at the certain spectral range, which can facilitate real time status assessment of orchards and can control precision fungicide utilization.

• The effect of different shading net on the Quantum Efficiency of PS II in chilli pepper cultivar ‘Star Flame’

  21-23

  Stella Agyemang Duah

  Zsuzsa Nagy

  Lajos Helyes

  Views:

  361

  The study was undertaken to identify the effect of different shading net on the quantum efficiency of PS II on ‘Star Flame’ chilli pepper (Capsicum annuum) over a period of time cultivated under plastic house environment. ‘Star Flame’ pepper was grown under red shading net and samples without shading were used as control. Analysis of photosynthetic activity revealed a significant difference (p<0.05) between Fv/Fm values in control and red shading at the end of July (p = 0.031) after the first harvest. Chlorophyll fluorescence parameter Fv/Fm reflects the maximum quantum efficiency of photosystem II (PS II) used in the detection of early stress in plants.

   

• Identification of cow’s and buffalo’s milk and dairy product using a DNA-based method

  279-282

  Beáta Soltész

  Gabriella Gulyás

  Ádám Csikós

  Gábor Koncsos

  Nóra Vass

  János Oláh

  András Jávor

  Levente Czeglédi

  Views:

  173

  Aim of our study was the optimization of a DNA method, that is appropriate for reliable, low cost identification of animal species in milk and dairy product (cheese) and to determine the ratio of species. Mitochondrial DNA was used in our work to analyse buffalo/cow milk mixtures contained different ratio of bovine milk such as 0.1%, 0.5%, 1%, 1.5%, 2%, 5%, 10%, 15% (v/v%). Buffalo cheese were produced using buffalo and cows milk (0%, 2%, 5%, 10%, 15% – v/v% cows milk in buffalo milk). In case of milk mixtures, using species specific primers, the PCR assay showed a 0.5 v/v% detection limit. Cattle, in the buffalo/cows milk 99.9/0.1 v/v% mixture, was not detectable. The identification of buffalo and cows DNA in cheese was successful. The intensity of eletroforetic PCR fragment indicated the increase of cow milk ratio in milk and cheese samples as well.

• Yearly change of Wheat dwarf virus infection rate during 1996-2010 in winter barley

  22-28

  Emil Pocsai

  István Murányi

  Views:

  99

  Yearly change of the infection of Wheat dwarf virus was studied in winter barley during 1996-2010. Surveys were carried out at Kompolt (Rudolf Fleischmann Research Institute, Róbert Károly College), in winter barley breeding lines showing leaf yellowing and stunting symptoms. In 1996, 250 winter barley samples were tested. During the period of 1997–2005, 100 samples were collected in each year. In 2006, 490 winter barley samples were tested. In 2007 and 2008 the number of samples collected was 500 from winter barley. In 2009 year 100, and in 2010 year 100 winter barley samples were collected for virus testing. Virus diagnosis was carried out using DASELISA for the detection of Wheat dwarf virus (WDV), Barley yellow dwarf viruses (BYDV-MAV, BYDV-PAV, BYDV-RMV, BYDV-SGV), and Cereal yellow dwarf virus (CYDV-RPV). During the ten of the last fifteen years, the occurrence of Wheat dwarf virus in infected samples exceeded those of other viruses causing leaf yellowing and dwarfing symptoms. There were years (1997, 2002, 2004, 2007, 2009 and 2010) when only the Wheat dwarf virus played the main role in development of yirus symtoms. A contrasting tendency can be observed between the degrees of infection of WDV and BYDV. With a rise of infection in the WDV, the proportion of BYDV decreased and vice-versa.