7-9.Vol 20No 1-22014
An orchard can be examined on the basis of spectral data, using such methods with which the reflected radiation can be divided into a large number of (several hundreds) small spectral channel (some nm). Based on the spectral characteristics of the canopy, or the different index numbers calculated from hyperspectral data the water supply conditions... of foliage can be well characterized. The research site is an intensive apple orchard, which located in Debrecen University, Centre for Agricultural and Applied Economic Sciences, Farm and Regional Research Institute at Pallag. During our experiments the evaluation of spectral, non-invasive measurement method are carried out for detecting stress symptoms caused by drought. Furthermore, MODIS NDVI time series data were analyzed for orchards situated in North-Eastern part of Hungary in drought effected and wet years in order to detect differences. Significant differences in NDVI values were detected after the end of June.
29-32.Vol 17No 1-22011
Our investigation was carried out at an micro-irrigated intensive apple orchard in Debrecen-Pallag in 2010. The aims of the study were to monitor the effect of a compacted layer on soil water regime by tensiometers and supporting the water management of the orchard. The results suggest that the physical characteristic of the examined soil is sandy... soil with low capillarity and total available water content. The soil water tensions were varied between pF 0 and 2.5 due to the extreme precipitation circumstances in 2010. Tensiometers in 40 cm depth resulted fast (few hours) and significant respond to precipitation than in the 70 cm soil layer. Based on daily measurements, the soils possess a daily fluctuation of soil moisture, however the changes become more moderate in deeper layers. In accordance with all of the results, the amount of drainable water regime was about 20.6 V/V% at 40 cm depth and 18.6 V/V% at 70 cm mainly. The harmful surplus water can be infiltrated by loosening of the compacted soil layer in 50–70 cm depth or led off by vertical drainage.
Sunburn assessment: A critical appraisal of methods and techniques for characterizing the damage to apple fruit
7-14.Vol 16No 42010
Many methods and techniques have been introduced for measuring alterations in the fruit and in its surrounding environment related to sunburn incidence. The research objectives, fruit materials and the environment to be evaluated dictate the methods to follow. These procedures are either non-destructive and involve techniques that allow us to trac...k the course of sunburn development and related environmental parameters, or destructive and involve the removal of fruit from the tree for field/laboratory measurements. Techniques employed can be used for pre-symptomatic monitoring (before symptoms become visible) or characterizing the symptoms already present. The principles behind the measurements and their usefulness for sunburn assessments are discussed and critically evaluated in this review paper. Descriptions and evaluations of the methods and techniques were made in the following groups: 1. Thermal measurements; 2. Visual assessments; 3. Fruit quality measurements; 4. Measurements of physiological and biochemical alterations; and 5. Practical evaluation of sunburn damage. Thermal measurements involve methods tracking the ambient temperature and fruit surface temperature, and their relation to sunburn formation. Visual assessments cover all measuring techniques (skin color, chlorophyll fluorescence, radiation reflection, electron microscopy) that are able to detect changes on/in the fruit skin related to sunburn formation. Fruit quality measurements are used to point out differences in qualities (soluble solids, firmness, titratable acidity, and water content) between unaffected and sunburned areas of the fruit. The measurements of physiological and biochemical alterations (gas exchange, pigment analysis, enzyme activity, gene expression) give us a better insight to the mechanism of sunburn formation. Practical evaluations involve many procedures that are used by scientists to characterize the susceptibility of cultivars, evaluate protection technology, etc. For this purpose, the following methods are in use: expressing the percentage of the total fruit surface area affected by sunburn or the percentage of the total number of fruits damaged on the tree, or even a scale based on the severity of the symptoms occurred. All assessing methods and techniques described here have their pros and cons as well as their specific applicability, therefore any of these cannot be favored to use exclusively for assessing sunburn incidence. The combination of these techniques will be the best choice to meet a given research objective perfectly.
65-73.Vol 15No 1-22009
The plantation of intensive growing orchards and steady increase in yield is essential to return the growing cost by sale. Seasonal crop fluctuation of pear is increased by the frequently occurrence of drought and climatic changes. This study reviews genetic and growing factors determined the alternancy of pear and present the new knowledge concer...ning on water saving irrigation techniques. Use of dwarfing rootstocks, root pruning, branches pruning and new water saving irrigation make the changes in vegetative and generative growth that successfully improve the alternancy of pear growing. According to publications BA 29 of clonal quince rootstocks exhibited the best protection mechanism against to drought. Regulated deficit irrigation (RDI) applied during rapid shoot growth and slowly fruit growth result a decrease in shoot growth and 60% of water saving in pear orchard while there was no influence on harvested yield. Partial rootzone drying (PRD) microjet irrigation applied in pear orchard result 23-52% of decrease in water use, however concerning explorations are contradictory. Further investigations need to improve the efficiency of new irrigation technology adapted pear varieties based on monitoring of soil water status and measurement of stem water potential as stress indicators of plants.
19-29.Vol 12No 22006
Fruit setting behaviour of fruit trees remains to be in the focus of plant breeders and growers. Realizing that most species (cherry, apple, pear etc.) are self-incompatible and certain cultivars are cross-incompatible, mutual fertility properties and their reliable determination are of great interest. This review gives a comprehensive description... of all known S-genotyping procedures, i.e. the classical fruit set analysis after open field test crosses; pollen tube growth monitoring with fluorescent microscopy; stylar ribonuclease electrophoresis (using different types of isoelectric focusing and 2-dimension polyacrilamide gel electrophoresis); as well as the most recent polymerase chain reaction based DNA-level analyses and DNA sequencing. The review presented not only gives a compilation of the bases of the methods described but also provides a critical evaluation and a comparative characterization of their applicability.
The KLP+ ("hat") trap, a non-sticky, attractant baited trap of novel design for catching the western corn rootworm (Diabrotiea v. virgifera) and cabbage flea beetles (Phyllotreta spp.) (Coleoptera: Chrysomelidae)
57-62.Vol 12No 12006
In the course of research aimed at the development of non-sticky, easy-to-use alternative trap designs for the capture of selected beetle pests, a newly designed "hat" trap, codenamed CSALOMON® KLP+, was compared with conventional trap designs. In the case of the western corn rootworm (WCR) Diabrotica v. virgifera (Coleoptera, Chrysomelidae) the ...new KLP+ traps baited with pheromonal or floral baits were equally sensitive as the former PAL or PALs sticky "cloak" designs, but the KLP+ traps catch capacity and selectivity was much higher. When baited with the floral WCR bait, the KLP+ trap proved to be more sensitive in capturing female \VCR, than the former sticky PALs trap design. In capturing cabbage flea beetles (Phyllotreta spp., Coleoptera, Chrysomelidae), the new KLP+ trap design baited with allyl isothiocyanate performed better than the previously used VARL+ funnel traps in all respects studied. In conclusion, the new KLP+ trap design, baited with the respective attractants, appears to be advantageous to use for the trapping of both WCR and cabbage flea beetles, and can be recommended for use as a trapping tool in plant protection practice in the detection and monitoring of these pest Coleoptera.
Study on the emergence of the raspberry cane midge (Resseliella theobaldi Barnes) on the basis of temperature data and catches of sex pheromone traps
23-26.Vol 14No 42008
Effective chemical protection against the raspberry cane midge (Resseliella theobaldi) should be based on the monitoring of the emergence of the pest. Before the application of sex pheromone traps, the results of several international studies carried out to determine the accumulated temperature needed by the larvae to become adults showed differen...ces in the calculated data. The aim of this paper was to give information on the time of cane midge emergence by using sex pheromone traps and different methods of accumulated temperature calculations. On the basis of three years' results, the use of accumulated soil temperatures turned out to be reliable for the prediction of cane midge flight, and the relative standard deviation was the smallest in the case of 0 °C compared with other values applied as supposed biological zero points. According to our studies, 665 day °C are required for the development of one generation of the raspberry cane midge during the vegetation period. The emergence of the first generation was found at 451 day °C.
Luminescence variations in cucumber (Cucumis sativus L.) leaves derived from different regeneration systems
50-52.Vol 5No 1-21999
Plants obtained from in vitro culture can show increased susceptibility to environmental stress conditions. In the process of their adaptation to natural conditions it requires monitoring of their physiological state. The methods used to check this phenomenon should estimate quickly and exactly the tolerance to suboptimal environmental factors. Su...ch requirements are satisfied by the methods of measuring chlorophyll luminescence in vivo, e.g. fluorescence induction and delayed luminescence. The objects of our studies were cucumber plants regenerated from cultures of callus and embryogenic cell suspension, as well as the plants obtained from seeds. The plants derived from in vitro cultures displayed a poor physiological condition at the early phase of adaptation characterised by higher susceptibility both to stress caused by increased density of the light flux and low temperature (4 °C) in comparison with the plants obtained from seeds.
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