Thermal investigations using infrared (IR) thermometry and false colour
thermography were carried out on flowering plants in the Botanical Garden
of Berlin and in a private garden. Special interest went to phototropic plants
that orient their blossoms towards a light source (mainly the sun) and within
this group to solar trackers (heliotropism) that follow the path of the sun
during the day. Best known among the latter is the sunflower. Bowl shaped
flowers comparable to satellite disks focus the solar radiation effectively
on their centre, resulting in a warming of the female organs at that point.
Temperature differences above ambient can be as high as 10.7 K with a mean
value of 6.0 K. Pollinating insects were often observed sun-basking in the
bowls or on the flower disks attracted by energetic rewards in form of nectar
A new method is
introduced to agricultural practice for measuring the living active root of the
plants. The measured root capacitance is interpreted in electro-chemical
principles. In addition to the electrochemical interpretation of the
measurements we aimed to find a non-wounding electrode instead of the needle
plant electrode. Another reason for dealing with the tweezer plant electrode
was to decrease the relatively high standard deviation of the root capacitance
readings due to the relatively high uncertainty of hitting the xylem with the
needle plant electrode. To improve and standardize the contact between the
tweezer plant electrode and the stem a high electrical conductivity gel
(UNIGEL) was applied on the stem before clipping the tweezers. Experiments for the root capacitance
measurements were made in temperature and light controlled climate chambers
(Conviron, Canada) in 2 litre plastic pots filled with 4:1 soil:sand mixture
and water culture. Comparison of the root
capacitances of five-week old sunflower plants measured with the needle and the
tweezer plant electrodes proved identical in water culture and capillary water
saturated soil. However, the applicability of the tweezer plant electrode needs
further study for other plants and environmental conditions. The effect of
measurement frequency on root capacitance and resistance with the HP4284A
impedance bridge was also studied to see the effectiveness of polarization
(Figure 1). From Figure 1 it can be seen
that root capacitance decreased at frequencies above 1 kHz, while it increased
up to the dielectric constant of water at lower frequencies. An interpretation
of measurable root capacitance in the soil-plant system is given using separate
measured plant tissue and soil capacitances. We established that root
capacitance in the soil-plant system approximates the capacitance of the root
tissue. Good correlation was found
between root capacitance and the calculated root surface area (RA) for
sunflower plants (Figure 2). The GW
LCR-814 was found suitable for making root capacitance measurements. Finally,
further experimental work is needed to collect information for the more general
and extended applicability of the method before it becomes a routine tool in
ecological and agricultural practice.
Authors:Adnan Eser, Hajnalka Kató, Laura Kempf and Márton Jolánkai
Water availability is one of the major physiological factors influencing plant growth and development. An assessment study has been done at the Szent István University, Gödöllő to evaluate and identify the water footprint of protein yield of field crop species. Twelve field crop species (Sugar beet Beta vulgaris, spring and winter barley Hordeum vulgare, winter wheat Triticum aestivum, maize Zea mays, sunflower Helianthus annuus, peas Pisum sativum, potato Solanum tuberosum, alfalfa Medicago sativa, oilseed rape Brassica napus, rye Secale cereale and oats Avena sativa) were involved in the study. Evapotranspiration patterns of the crops studied have been identified by the regular agroclimatology methodology and physiologically reliable protein ranges within crop yields were evaluated.
The results obtained suggest, that water footprint of cereals proved to be the lowest, however maize values were highly affected by the high variability of protein yield. Oilseed crops had considerably high protein yield with medium water efficiency. Alfalfa, potato and sugar beet water footprints were in accordance with their evapotranspiration patterns.
Protein based water footprint assessment seems to be more applicable in crop species evaluations than that of yield based methodologies.
Authors:Carmen Solcan, Dorina Timofte, Viorel Floristean, Stuart Carter and Gheorghe Solcan
A study was conducted to evaluate the nephrotoxic effect of ochratoxin A (OTA) in broiler chickens. Forty Ross 308 broilers (6 days old) were divided into two groups: one group received daily, by gavage, ochratoxin A at a daily dose of 50 μg/kg body weight for up to 21 days, while the control group received only diluent (sunflower oil). After 21 days, the chickens were euthanised and the kidneys removed for analysis by histopathology and immunohistochemistry to detect an anti-apoptotic marker (Bcl-2), and by transmission electron microscopy. Macroscopically the kidneys were enlarged, showing degeneration and gout deposits. Histologically, glomerulonephrosis and tubulonephrosis were common lesions in all chicks. In two of the five chicks exposed to OTA for 21 days, focal tubular cell proliferation, multiple adenoma-like structures and Bcl-2-positive epithelial cells were identified in layers of the renal papilla and in convoluted tubules. Transmission electron microscopy of the proximal convoluted tubules identified abnormal forms of mitochondria. The nephrotoxic effect of ochratoxicosis in chickens is probably due to carcinogenic changes induced in the epithelial tissues.
Authors:J. Tarek-Tilistyák, J. Agócs, M. Lukács, M. Dobró-Tóth, M. Juhász-Román, Z. Dinya, J. Jekő and E. Máthé
The nutritive value, the microbiological safety of oilseed cake (OSC) obtained from naked pumpkin seed (PuC), sunflower seed (SC), yellow linseed (LC), and walnut (WnC), and their impact on wheat flour (WF) dough and bread sensory characteristics at 5% and 10% addition ratio were investigated. The OSCs had high protein (34–50%), fat (8–15%), total dietary fibre (23–36%) content and high energy value (383–444 kcal/100 g)). The OSC samples with a minimal exception fulfilled the requirements of feed legislation in force. An increased water absorption, dough development time, and reduced elasticity were observed probably due to the enhanced fiber and protein content. Dough stability increased with WnC, and decreased with PuC or SC addition. Enrichment provided the appearance of a brown bread for WnC, of a half-brown bread for LC. PuC gave an unusual look. The appearance of OSC fortified bread similar to daily bread, was an advantage resulting the 1st rank for 10% WnC bread and the 2nd one for 10% LC bread (P=0.05). The studied OSCs are suitable for food enrichment, however, in case of PuC and SC fortified flour blends, hydrocolloid application is recommended. Our data suggest that the newly developed fortified breads could be a valuable source for healthy nutrition.
Authors:J. Tarek-Tilistyák, M. Juhász-Román, J. Jekő and E. Máthé
We evaluated the microbiological safety, the short-term storability, and the macronutrients of oil seed cake (OSC) obtained from walnut (WnC), linseed (LC), and sunflower seed with hull (SC). The OSCs had 3.6–5.8% moisture content, 0.50–0.60 water activity (aw), 29.9–39.4% protein, 15.5–23.6% fat, and 36.6–48.0% dietary fibre content. The grinded OSCs could be stored in opaque plastic bags for 4 months at temperatures of 4 °C, 14 °C, and 25 °C. Total colony count of mesophilic microorganisms depending on oxygen demand and spore-forming ability, and faecal indicator microorganisms were determined during a 4-month storage term at 4 °C, 14 °C, and 25 °C using traditional culturing methods. The OSCs were free from sulphite-reducing Clostridia and coliforms, including Escherichia coli. Data were analyzed statistically by multifactor analysis of variance. Ascending order of the average contamination of the three products (log10 CFU g−1) was aerobic sporogenic bacteria (2.39), fungal count (2.51), total aerobic microbe count (3.00), anerobic sporogenic bacteria (3.75), and total anaerobic microbe count (4.23). As for the average microbial count, WnC was the least (2.73 log10 CFU g−1) and LC was the highest (3.53 log10 CFU g−1) contaminated material. Regarding the variation of microbial contamination during storage, temperature was indifferent (P=0.191), while storage time (P=0.0033) and the product type were influential (P=0.000).