We established a multifactoral long-term field experiment at the Látókép experimental site of the University of Debrecen (Debrecen, Hungary), on mid-heavy calcareous chernozem soil in 1984, using experimental data from 17 years (1990-2008). We examined the extent to which soil fertility affects maize yield under natural conditions (without fertilisation). We analysed the effect of precipitation in the winter period (from the harvest of the previous crop (maize) until sowing (i.e. October-March)) and the growing season (i.e. April-September) on yield and we evaluated yield per FAO group. We examined the joint effect of crop year and hybrid maturity groups on maize yield; then we evaluated how hybrid maturity groups per crop year and wet and dry years per ripening group affected maize yield. It was shown that the pH value of soil significantly affected yield and also that there was a strong positive correlation between pH value and yield (r = 0.81) at a 1% significance level. The correlation between the two variables is described by a linear regression line. The slope shows that a 0.1 soil pH increase results in a 510 kg ha-1 maize yield increase on average. The correlation between the amount of precipitation during the growing season and maize yield is average, positive (r = 0.718) and linear. Based on the parameters of the estimated regression line - within non-fertilised conditions - 1 mm increase of precipitation resulted in a 9 kg ha-1 increase in yield. The analysis of the joint effect of hybrid maturity groups and crop year on yield showed that crop year determines standard deviation six times more than hybrid maturity groups, whereas the effect their interaction was not significant. and Práca bsahuje výsledky multifaktorového, dlhodobého pokusu na experimentálnej ploche Látókép, Univerzity v Debrecíne (Debrecen, Maďarsko). Experiment prebiehal od roku 1984, v tejto práci boli použité údaje z experimentu získané počas 17tich rokov (1990-2008). Pôda je stredne ťažká černozem. Bol skúmaný vplyv pôdnej úrodnosti na úrodu kukurice v prirodzených podmienkach, bez hnojenia. Študoval sa predovšetkým vplyv zrážok počas zimného obdobia (od zberu úrody kukurice až po nasledujúcu sejbu, t.j. od októbra do marca) a vplyv zrážok počas vegetačného obdobia (apríl -september) na úrodu kukurice. Okrem toho sa študoval vplyv ''sezóny'' a skupín skorosti hybridov na úrodu kukurice. Bolo vyhodnotený tiež vplyv skupiny skorosti hybridov počas suchých a mokrých rokov na úrodu kukurice. Bolo preukázané, že hodnota pH pôdy významne ovplyvňuje úrodu; súčiniteľ lineárnej korelácie medzi pH a úrodou na úrovni významnosti 1% bol r = 0,81. Z tejto korelácie vyplýva, že zvýšenie pH o 0,1 spôsobuje zvýšenie úrody kukurice priemerne o 510 kg ha-1. Korelácia medzi úrnom zrážok počas vegetačného obdobia kukurice a úrodou je pozitívna a lineárna (r = 0,718), z analýzy vyplýva, že zvýšenie úhrnu zrážok o 1 mm spôsobí priemerné zvýšenie úrody kukurice o 9 kg ha-1. Z výsledkov analýzy spoločného vplyvu skupín skorosti hybridov a sezóny vyplýva, že konkrétna sezóna ovplyvňuje tvorbu úrod 6-krát významnejšie, ako skupina skorosti hybridov; interakcia medzi skupinami skorosti hybridov a vlastnosťami sezóny nie je významná.
Soil water repellency causes at least temporal changes in the hydrological properties of a soil which result in, among other things, suboptimal growing conditions and increased irrigation requirements. Water repellency in soil is more widespread than previously thought and has been identified in many soil types under a wide array of climatic conditions worldwide. Consequences of soil water repellency include loss of wettability, increased runoff and preferential flow, reduced access to water for plants, reduced irrigation efficiency, increased requirement for water and other inputs, and increased potential for non-point source pollution. Research indicates that certain soil surfactants can be used to manage soil water repellency by modifying the flow dynamics of water and restoring soil wettability. This results in improved hydrological behavior of those soils. Consequently, the plant growth environment is also improved and significant water conservation is possible through more efficient functioning of the soil. and Vodoodpudivosť pôdy spôsobuje prinajmenšom dočasné zmeny v hydrologických vlastnostiach pôdy, ktoré okrem iného môžu viesť k suboptimálnym podmienkam rastu rastlín a k zvýšenej potrebe závlah. Vodoodpudivosť pôdy je rozšírenejší jav, ako sa pôvodne predpokladalo; bola identifikovaná v mnohých pôdnych typoch a klimatických podmienkach na celom svete. Dôsledkom vodoodpudivosti pôdy je strata zmáčavosti, zvýšený povrchový odtok a preferenčné prúdenie, znížená dostupnosť vody a iných vstupov pre rastliny, znížený účinok závlah, zvýšené požiadavky na vodu a iné vstupy, ako aj zvýšené riziko plošného znečistenia. Výskum naznačuje, že niektoré povrchovo aktívne látky (soil surfactants) môžu upraviť vodoodpudivosť pôdy obnovením omáčania a modifikáciou dynamiky vody. Výsledkom je zlepšenie hydrologických vlastností pôdy. Podobne, výsledkom je zlepšenie prostredia pre rast rastlín, zvýšenie retencie vody v pôde a teda aj efektívnejšia funkcia pôdy.
Different sustainable systems of husbandry on soil with various protective technologies are frequently studied. Direct sowing without ploughing is one of the alternatives. This article presents results of the effect of conventional tillage (CT) and no-tillage system (NT) on soil bulk density, soil porosity, maximum capillary capacity and available water capacity of Gleyic Fluvisol in conditions of the East-Slovakian Lowland. Observed years 1999 - 2005 from point of wiev of annual sum of precipitation are valued as dry till humid and of annual average air temperature as normal or warm. The effect of used agrotechnical arrangements was statistically highly significant (α = 0.01) for porosity changes and statistically significant for soil bulk density (α = 0.05). Non-significant effect was found for maximum capillary capacity and available water capacity. In the soil layer 0 - 0.3 m during years 1999 - 2005 soil bulk density increased about 22 kg m-3 (1.54 %) at no-tillage system in comparison to conventional tillage. At no-tillage system average values of porosity decreased about 1.32 %, maximum capillary capacity and available water capacity non-significantly decreased about 0.32 % in comparison to conventional tillage. and V trvalo udržateľných sústavách hospodárenia na pôde sa do popredia dostávajú rôzne ochranné technológie obrábania pôdy, medzi ktoré patrí aj priama sejba bez orby. Predkladaný príspevok sa zaoberá vplyvom konvenčnej agrotechniky (CT) a bezorbového systému (NT) na objemovú hmotnosť, pórovitosť, maximálnu kapilárnu kapacitu a využiteľnú vodnú kapacitu fluvizeme glejovej v podmienkach Východoslovenskej nížiny. Sledované roky 1999 - 2005 sú z hľadiska ročných zrážkových úhrnov hodnotené ako suché až vlhké a z hľadiska priemerných ročných teplôt vzduchu ako normálne, resp. teplé. Vplyv použitých systémov agrotechnických opatrení sa štatisticky významne (α = 0,01) prejavil pri pórovitosti, štatisticky na hranici významnosti (α = 0,05) pri objemovej hmotnosti a štatisticky nevýznamne pri maximálnej kapilárnej kapacite a využiteľnej vodnej kapacite. V porovnaní s konvenčnou agrotechnikou sa pri bezorbovom systéme zvýšili priemerné hodnoty objemovej hmotnosti vo vrstve pôdneho profilu do 0 - 0,3 m za roky 1999 - 2005 o 22 kg m-3 (1,54 %); priemerné hodnoty pórovitosti sa znížili o 1,32 %, hodnoty maximálnej kapilárnej kapacity a využiteľnej vodnej kapacity o 0,32 %.
The physiological parameters mortality, mass, oxygen consumption and amylase activity, and microanatomical features of the digestive tract, mesenchym and reproductive organs were used to characterise starvation in Galumna elimata. The mites were reared in sterilised plastic vials containing moistened zeolite at 25°C and a 12:12 photoperiod. The control group was kept under the same conditions, but pieces of bark covered with the green bark alga, Desmococcus vulgaris (syn. Protococcus viridis), were added as food for the mites. The physiological parameters were recorded after 21 days, and the microanatomical after 21 and 42 days. The guts of the starved mites were empty or filled with mucoid substances, while the guts of control mites contained food boli formed from algal cells. The mortality was significantly higher in starved animals. The mortality after 42 days of starvation was higher in males than females. The fresh mass of starved individuals significantly decreased while the water proportion content of their body tissues increased. Oxygen consumption of the starved mites was lower. Starvation did not influence the activity of amylase. Glycogeneous granulae were characteristically absent, and mucoid substances present in the guts of mites starved for 21 days. The activity of mesenteral and caecal cells, proventricular glands and cells of salivary glands was reduced after 42 days of starvation. The cells of the seminal vesicles were reduced and contained no spermatic cells in males starved for 42 days. Starved females probably resorbed immature oocytes, but had eggs in their oviducts. Starvation induces ovovivipary or larvipary in Galumna elimata.
Perinatal hypoxic-ischemic insult (HII) is one of the main devastating causes of morbidity and mortality in newborns. HII induces brain injury which evolves to neurological sequelae later in life. Hypothermia is the only therapeutic approach available capable of diminishing brain impairment after HII. Finding a novel therapeutic method to reduce the severity of brain injury and its consequences is critical in neonatology. The present paper aimed to evaluate the effect of sulforaphane (SFN) pre-treatment on glucose metabolism, neurodegeneration, and functional outcome at the acute, sub-acute, and sub-chronic time intervals in the experimental model of perinatal hypoxic-ischemic insult in rats. To estimate the effect of SFN on brain glucose uptake we have performed 18F-deoxyglucose (FDG) μCT/PET. The activity of FDG was determined in the hippocampus and sensorimotor cortex. Neurodegeneration was assessed by histological analysis of Nissl-stained brain sections. To investigate functional outcomes a battery of behavioral tests was employed. We have shown that although SFN possesses a protective effect on glucose uptake in the ischemic hippocampus 24 h and 1 week after HII, no effect has been observed in the motor cortex. We have further shown that the ischemic hippocampal formation tends to be thinner in HIE and SFN treatment tends to reverse this pattern. We have observed subtle chronic movement deficit after HII detected by ladder rung walking test with no protective effect of SFN. SFN should be thus considered as a potent neuroprotective drug with the capability to interfere with pathophysiological processes triggered by perinatal hypoxicischemic insult.
A significant factor in the development of hypertension may be excessive vasoconstriction within the renal medulla. This study therefore investigated the role of superoxide dismutase (SOD) in the regulation of renal medullary and cortical blood perfusion (MBP and CBP, respectively) in both stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar rats. CBP and MBP were measured before and after intra-renal infusion of the SOD inhibitor, diethyldithio-carbamic acid (DETC). Under basal conditions, mean arterial pressure was significantly greater in SHRSP than Wistar rats, but both MBP and heart rate (HR) were significantly lower in SHRSP relative to Wistar rats (P<0.05, n=7 in both groups). Infusion of DETC (2 mg/kg/min) into the cortico-medullary border area of the kidney significantly decreased MBP in the SHRSPs (by 28±3 %, n=7, P<0.05), indicating a greater vasoconstriction within this vascular bed. However, DETC also significantly decreased MBP in Wistar rats to a similar extent (24±4 %, n=7, P<0.05). These results suggest that superoxide anions play a significant role in reducing renal vascular compliance within the renal medulla in both normotensive and hypertensive animals, although the responses are not greater in the hypertensive relative to the control animals., A. F. Ahmeda, M. G. Rae, L. M. Anweigi, M. F. Al Otaibi, A. A. Al-Masri, E. J. Johns., and Obsahuje bibliografii
Pine caterpillar, Dendrolimus tabulaeformis Tsai et Liu, is a major pine pest in North China. The larvae enter diapause in the third or fourth instar before winter. Supercooling points (SCP) and cold hardiness of the diapausing larvae were investigated and compared in non-acclimated, acclimated and de-acclimated larvae. A bimodal frequency distribution was observed with a break point of -14°C in the SCP. Larvae in the low group (LG, SCP <= -14°C) were more cold tolerant with lower lethal temperatures than those in the high group (HG, SCP > -14°C). This bimodality occurred in three patterns, LG (> 60% of individuals in LG), LG-HG (< 60% of individuals in LG and HG) and HG (> 60% of individuals in HG), in response to cold acclimation and de-acclimation. The cold hardiness was ranked as: LG > LG-HG > HG pattern. Cold hardiness was enhanced by an increase in concentrations of trehalose, galactose, glucose and mannose in the haemolymph as well as by decrease in metabolism after cold acclimation, but was lost after de-acclimation. Loss of cold hardiness was correlated with decrease in sugars and increase in metabolic rate. In conclusion, the species is a chill tolerant insect, adopting the strategy of depressing SCP through accumulation of low molecular weight sugars in the haemolymph, concomitant with metabolic depression.
Environmental degradation caused by climate change greatly affects the forest ecosystems of the Mediterranean region, in particular the sclerophyllous Quercus forests typical of central and southern Spain. An important pest that damages oak trees in this area is Coraebus florentinus (Herbst), a heliophilous and thermophilous insect whose survival could be favoured by the temperature increase associated with climate change. The main objective of this paper was to determine the effect of temperature on the duration and percentage survival of the preimaginal stage of C. florentinus and provide data for determining more precisely when to control for this pest by applying silvicultural techniques. The experiment included six treatments, with 25 branches infested with C. florentinus in each of the treatments, which were kept at different temperatures over the range 15–28°C. The results clearly support the hypothesis that higher temperatures affect the post-larval development of C. florentinus by increasing the percentage survival and shortening the developmental time. In fact, partial correlations confirm that the highest percentages of emergence and survival were recorded when the developmental times were shortest, which occurred at the highest temperatures used. Despite the clear influence of temperature on the development of the preimaginal stage of C. florentinus, additional trials are required to accurately determine future trends in C. florentinus populations. Accordingly, it is necessary to develop monitoring programs in zones affected by C. florentinus and to apply scheduled management techniques that ensure the control of this species., Ana M. Cárdenas, Patricia Gallardo., and Obsahuje seznam literatury
Gronotoma micromorpha is a solitary egg-pupal and larval-pupal parasitoid. In a previous study, the developmental time of this parasitoid decreased with the age of its leaf miner host, Liriomyza trifolii, being significantly longer when the host was 0-day old (= 0-24 h old egg) than when 4 days old (mature larva) at the time of parasitization at 25°C. In the present study, the suitability and acceptability of 0 and 4 day old L. trifolii as hosts for G. micromorpha, and the ovipositional preference of this parasitoid for these two developmental stages of the host were examined. No significant difference was found in the size of the parasitoid offspring that emerged from hosts parasitized at these two developmental stages. There was no significant difference in the acceptability of the two developmental stages of L. trifolii in no choice tests, but 4 day old larvae were preferred to 0 day old eggs in choice tests. Moreover, parasitization of eggs by G. micromorpha did not appear to result in more of the eggs dying before they hatched. Non-reproductive killing (host feeding and host stinging without oviposition) of host eggs by this parasitoid was also not detected.