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Phytopathological aspects of precision agriculture
135-139Views:104This paper illustrates the efforts based on the results obtained in the funding of precision agriculture, during more than two decades of cooperation between University of Debrecen and University of Oradea, within the framework of joint, EU co-financed projects, and put into practice on both sides of the border. Common plant-health databases, interactive Web pages, consultation activities, professional publications, professional training activities, laboratory infrastructure improvements, common research themes proves the progress made to date and create conditions for further development of joint research activities.
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Effect of Ozone Exposure on Phytopathogenic Microorganisms on Stored Apples
9-13Views:113The aim of our study was to clarify the effect of ozone exposure on several phytopathogenic fungi on stored apple fruits under different storage conditions. The study was conducted at Bistrita, Romania, in the storehouse of an experimental apple orchard in 2002 and 2003. Two widely grown apple cultivars (‘Jonathan’ and ‘Golden Delicious’) were used. General microbial examination of the fruits was made during storage in order to identify the most important storage pathogens. Efficacy of six ozone treatments was evaluted on fruit decay caused by phytopathogenic fungi. Monthly observations (January, February, March and April) were made of the degree of decay and three measurements were assessed (disease frequency, disease intensity and degree of attack). Our results showed that the most important phytopathogenic fungi during storage was blue mold, caused by species of Penicillium. Disease frequency of apple fruits was very high on cv. ‘Jonathan’, much higher than on cv. ‘Golden delicious’. Ozone treatments (25 ppm ozone for 0.5 and 1.5 hours in November) caused significantly lower disease incidence on stored apple than all other ozone treatments. For longer storage, it seems that additional ozone treatments in February increased treatment efficacy. Cv. ‘Golden delicious’ seemed to be more resistant to storage diseases than cv. ‘Jonathan’ both on the untreated and treated fruits. The effect of the ozone treatments was also the most effective when 25 ppm ozone was applied for 0.5 and 1.5 hours in November.
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The effect of crop rotation and fertilization on wheat and maize in the pedoclimatic conditions of the Banat Plain
14-18Views:85The simplification of the plant cultures range and the yields in the last 10-15 years brings into the actuality the role of crop rotation and
of fertilization on the yield level and stability for wheat and maize even on the soils with a high natural fertility. The results of the researches
performed between the years 2006 – 2009 on a cambic low gleyed chernozem from the Banat Plain showed that the wheat cultivated in
monoculture gives productions with 59-81% lower than that cultivated in crop rotation with other plants during 2-4 years. In maize, the yield
obtained in monoculture is situated behind that obtained in crop rotation with 11-21%. The most favorable crop rotations for wheat were
rape-wheat in a 4 years rotation and soybean-wheat in simple rotation of 2 years. In maize, the most favorable was the 2 years rotation
(wheat-maize). The mineral fertilization was very efficient both in wheat (11-36%) and maize (9-31%). The organic fertilization with manure
was very efficient for maize, the yields being superior with a mean value by 34% for a 60 t/ha dose and with 16% for 30t/ha. The fertilization
compensates the negative effect expressed by the monocultivation only in a small measure -
Tulip bulbs preparation by heat treatment for forced culture in green house
70-72Views:97Tulip can be grown in parks as ornamental plant and cut flowers, or possibly in protected areas for cut flowers during winter and early
spring.
An important condition for the successful cultivation of tulips is the quality of the bulbs that are going to be planted and their
biological preparation.
Under the quality aspect bulbs have to be uniform and large, preferably with circumference greater than 11 cm and must have good
phytosanitarical status.
Preparation of organic bulbs for ensuring the continuation of the differentiation process of germs (floral), is made during the storage.
It is known that the preparation of organic bulbs are made in interaction with environmental factors, among which temperature plays an
important role. At the beginning and throughout the process of biological preparation, temperature is maintained at a higher level then the
temperature must be low until planting.
The temperature level and the duration of treatment varies by followed objective respectively early or late flowering and staggered
flowers production over a longer period of time. -
Grain yield and quality of maize hybrids in different FAO maturity groups
126-131Views:81An improvement in the quality of maize grain by increasing the level of components responsible for its biological value is possible
by using genetic means. However, a change in the genotype, together with improving the nutrient properties of the grain, also has some
adverse consequences connected with a fall in yield and in resistance to diseases.
Field experiments were conducted during three years (2003, 2004and 2005) to evaluate environmental effects on grain yield and
quality responses of maize hybrids. Twenty one hybrids of various maturity groups (FAO 150-400) were planted to achieve an optimum
(60-70 000 plants per hectare) plant populations and grown under the medium-N (80 kg N ha-1) fertilization. Environmental conditions
significantly affected maize hybrid responses for grain yield, starch, oil and protein contents, and consequently, starch, oil and protein
yields per hectare. Hybrids of flint type, which have a short vegetation period, had high protein and oil content but the yield averages
were low due to the slower rate of starch incorporation. Hybrids of the dent type have a longer growing season and more intense
carbohydrate accumulation, but low protein and oil contents. In wet years there was a higher rate of starch accumulation, while dry
years are favorable for protein and oil accumulation. Positive correlation existed between starch content and grain yield and 1000-
weight as well as between oil content and volumetric weight among tested hybrids. Negatively correlation existed between grain oil and
starch content as well as between oil content and grain yield and 1000-weight. Thus, end-users that require high quality maize may need
to provide incentives to growers to off set the negative correlation of grain yield with oil and protein content. -
Theoretical and comparative study regarding the Galerkin-Vlasov method use for study the free vibrations of wood flat plate
223-228Views:79As for the historic record of the problem related to the study of flat plates, the first results were out for publishing at the end of the 18th century, the beginning of the 19th century, having Chladni E, Strehlke, Konig, R, Tanaka S, Rayleigh L, Ritz W and later on Gontkevich V, Timoshenko S, Leissa as pioneers. Each of the above mentioned authors have had significant contributions regarding the development of methods in order to solve the plates and establish some rigurous solutions of their differential equations of equilibrium.
The making of constructions, machines and different high-perfomance appliances, whose functioning should take place in safety conditions, have required theoretical studies of rich complexity, as well as practical experiments, within which the problem of their free and forced vibrations represent an important category in the respective theme of research.