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Yearly change of Wheat dwarf virus infection rate during 1996-2010 in winter barley
22-28Views:96Yearly 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.
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Changes in the Diaporthe helianthi Infection of Sunflower Hybrids Between 1998 and 2002
214-233Views:65Plant protection, and especially the efficiency of protection against mycosis, is a very important production technological element concerning sunflower. The efficiency of production can be increased on the basis of a thorough pathological survey and its results carried out in a wide variety of hybrids, as the features of hybrids, the reactions of genetic bases to pathogens can be found out under domestic conditions.
The tests were carried out at variety-test lots of OMMI for hybrids used for food or oil and other sunflower varieties admitted by the state at the Experimental Site DTTI Látókép, Centre of Agricultural Sciences, University of Debrecen between 1998 and 2002. The number of the tested hybrids was 49 in 1998, 45 in 1999, 49 in 2000, 55 in 2001, and 44 in 2002.
Due to the infection source of high amounts remained from 1997 and the favourable weather conditions for the pathogens, an infection of high degree was experienced in the tested stands. The lowest infection index in the hybrids with a very short vegetative period was experienced with Beni hybrids. Comparing to the average of the hybridgroup with short vegetative period, a low infection index characterised the Baleno, Trident, IBH-166, Hysun 321, Resia, Alexandra, Cergold and Pixel hybrids. In 1999, among hybrids with medium vegetative period, Zoltán, Zsuzsa and Util hybrids could be highlighted because of their low infection index. In 1998, among confentionary hybrids, Marica-2 hybrid had the most favourable index values (2,55).
During our trials, the experienced infection dynamics were compared in the event of hybrids with higher and lower susceptibility under different sowing technological elements. The results call for the fact that when a hybrid with higher susceptibility is produced, production technological elements, such as the time of sowing, influence considerably the damage caused by the pathogen, therefore it must not be ignored when its determination takes place. In the event of hybrids with lower susceptibility the change of the tested production technological elements within the biological optimum does not lead to the increased risk of the damage caused by Diaporthe helianthi. -
Effect of two different cropyear and the agrotechnological factors on the agronomic characteristic of the winter weat in a lon-term experiment
143-149Views:109We studied the effects of crop rotation, fertilization and crop protection technologies on occurence of the major ear- and leaf-diseases (powdery mildew, helminthosporiosis, leaf rust, Fusarium wilt) and the degree of lodging in the winter wheat variety Mv Pálma in two very different years (2006/2007=dry; 2009/2010=rainy). The experiments were carried out at the Látókép Experimental Farm of the University of Debrecen CAAES in triculture (pea-wheat-maize) and biculture (wheat-maize) at five fertilization levels by applying three different crop protection technologies (extensive, average, intensive).
In the cropyear of 2006/2007, the disease severity of leaf diseases was higher than the average in both crop rotations in spite of the fact that the weather during the whole vegetation period was dry. Infection by powdery mildew, helminthosporiosis and leaf rust increased with increasing fertilization, the highest infection was measured at the highest fertilization level (N200+PK) in the extensive crop protection technology. According to the results, no infection of ears by Fusarium and no lodging occurred in either bi- or triculture due to the dry year. The extremely rainy weather in 2009/2010 was favourable not only for the vegetative development of the stand, but also increased the occurance of leaf-, stalk- and ear-diseases and a high degree of lodging was observed. The highest infection by powdery mildew was observed in the plots with the highest fertilizer dosage under an extensive crop protection technology. A much higher helminthosporiosis infection was measured than in the cropyear of 2006/2007. The wet weather and higher than average temperature promoted the occurence and spreading of leaf rust. Under an extensive crop protection technology, a leaf rust infection of 24% and 31% was detected after maize and pea as a forecrop, respectively, in the N200+PK treatment. As opposed to 2006/2007, the disease severity of Fusarium was 3–8% and 2–7% in the control after maize and pea as a forecrop, respectively. This value, similarly to that of other pathogens, increased with increasing fertilization levels. Due to the large vegetative mass, a significant lodging was observed in the wheat stands in both bi- and triculture (17–100%, 12–100%). -
The Effect of Forecrop and Plant Protection on the Pathology Parameters and Yields of Winter Wheat
84-89Views:88We carried out our experiment in the cropyears of 2000/2001, 2001/2002 and 2002/2003, on calcareous chernozem soil, at the experimental site of the Debrecen University Farm and Regional Research Institute, at Látókép. We examined the disease resistance and the yield quantity of Mv Magvas variety by adopting different forecrops and plant protection technologies, at 30+30 N level and at normal cereal row spacing. We applied two forecrops (wheat and pea) and two plant protection technologies (extensive and intensive). We measured the rate of infection by population survey in the first ten days of June.
In the course of our examinations, we found, that the rate of powdery mildew infection was higher in the thicker population sown after pea forecrop in all three years, as powdery mildew is not a typical cereal disease.
The infection rate of leaf mildew and DTR (Dreschlera tritici-repentis) was higher after wheat forecrop in all examined years, because these are typical wheat diseases and infection centres in the soil promote the spreading of these diseases. However, it was possible to parry the adverse effect of forecrops by intensive plant protection.
Due to the chernozem soil, wich has good water management features, and due to the good preparation of the seedbed, the effect of forecrops on yield quantity did not appear in the examined years. The quantity of the yield was only slightly larger after pea forecrop in the cropyears of 2000/2001 and 2002/2003 than after wheat. Nonetheless, the data of technical literatures state that the yield quantity can be larger, even by 15-20%, after pea forecrop.
In the course of intensive plant protection technology, we applied systemic pesticides, while in the course of environmentally sound technology, we used contact pesticides of sulphur content. In those populations that were treated with environmentally sound plant protection technology, infection rate was higher in all three years.
Yield quantities were somewhat lower in the course of applying extensive, environmentally sound technology, because diseases appeared in these populations to the higher degree. Powdery mildew does not, but leaf mildew and Dreschlera tritici-repentis have a significant yield decreasing effect. With appropriate, well-selected fungicides, we were able to keep every leaf diseases well in hand, and the rate of infection was almost independent of the influence of the breeding year. -
Describing Fusarium diseases on maize in 2013 using data from several production sites
60-64Views:137As in other parts of the world, the frequency of weather extremes has increased greatly in Hungary in recent years. This means that maize production is faced with greater risks from all aspects: nutrient replacement, irrigation, plant protection. This is especially true of fusarium diseases. In a continental climate, the pathogens causing the most serious problems are species belonging to the Fusarium genus. They infect the ears, which – besides reducing the yield – poses considerable risk to both human and animal health due to the mycotoxins produced by them. Depending on which Fusarium species are dominant at a given location, changes can be expected in the level of infection and in the quality deterioration caused by the mycotoxins they produce. Fusarium spp. not only damages the maize ears but when pathogen attacks the stalk, the plant dies earlier, reducing grain filling and resulting in small, light ears. In addition, the stalks break or lodge, resulting in further yield losses from ears that cannot be harvested. The degree of infection is fundamentally determined by the resistance traits of the maize hybrids, but also a great role in that region Fusarium species composition as well.