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  • Spectral analysis of stress symptoms caused by apple powdery mildew (Podosphaera leucotricha
    83-88
    Views:
    156

    An orchard can be examined on the basis of spectral data, using methods with which the reflected radiation can be divided into a large number of (several hundreds) small spectral channel (some nm). Calculated on the basis of such hyperspectral data from different index numbers the water supply of foliage conditions can be well characterized.

    The research site is an intensive apple orchard, which located in University of Debrecen, Agricultural Sciences Centre, Farm and Regional Research Institute at Pallag. During my experiments the preliminary evaluation of spectral, non-invasive measurement method are carried out for detecting stress symptoms caused by Podosphaera leucotricha.

    Based on the results narrow band greenness indices (NDVI705, mNDVI705, mSR705 and REP) can be used for determination of diseased canopy and for the detection of stress symptoms of Podosphaera leucotricha,. These statements can be utilized in precision plant protection systems, since it can be a basis for such integrated active sensors with LED or laser light source, measuring reflectance at the certain spectral range, which can facilitate real time status assessment of orchards and can control precision fungicide utilization.

  • Applicability of precision weed detection technologies
    163-168
    Views:
    156

    In an agricultural field or horticultural plantation, weeds compete with cultivated plants for water and nutrients. The transpirated water by the weeds is needed to be replaced, which saddles surplus costs on the farmer, which could reduce the profitability of crop production. The aim of the precision plant protection system is to protect cultivated plants by applying site-specific technologies and optimized herbicides combination and methods, without environmental damage. The first step of precision weed control is the scouting for weeds. Traditional and modern (passive and active remote sensing) weed surveying technologies are available to detect weeds. The examination was carried out in an intensive apple orchard with drip irrigation system, protected by hail net of the Study and Regional Research Farm of the University of Debrecen near Pallag. The spectral-based weed detection was worked out by the Tetracam ADC broadband multispectral camera and the GreenSeeker 505 vegetation indexmeter. A strong correlation observed between vegetation indices and weed coverage. Based on the collected data, weed maps are created in appropriate software environment, thus the spatial distributions of the weeds are determined. The species level discrimination and the recognition of weed structural parameters were executed based on the 3D point cloud data by Leica ScanStation C10 laser scanner.

  • Analysis of the plant physiological effects of late, artificial corn smut infestation using remote sensing methods
    31-35
    Views:
    109

    In Hungary, corn is also infected by several important pathogens. In this experiment, we analysed the plant physiological effects of artificial late cron smut infestation using remote sensing methods under field conditions We examined the experimental area from which the data comes from with a DJI Phantom 4 Multispectral Drone NDVI and NDRE indices were calculated and analyzed in GIS programs. Individuals treated with a higher dose remained much greener than the untreated control. They also showed significant differences within the indices used.

  • The phosphate state and biochemical mobilization of phosphorus compounds in arboreal plants’ soils
    95-98
    Views:
    78

    Some indices of the phosphoric fractions of primery degraded soils, which are formed separate areas of technogenic landscapes, on a spoil-bank of iron-ore mine in the near of Kryvyi Rig, under act of lignosa, which are used for biological recultivation of degraded soils are investigated. Maintenance of mineral phosphates and features of organic phosphorus accumulation are set in soil under arboreal planting. Nutrient supply of plants is enhanced by mobile phosphates and their dynamics during vegetation period. Activity of alkaline and acid phosphatase enzymes are concerned also. On the basis of the soil enzymes activity information it is stated, that under the 35-years-old plantage of Robinia pseudoacacia L. the biochemical mineralization of organic phosphorus compounds passes considerably more actively than under Pinus pallasiana D.Don.