الفهرس 
he importance of sugar beet and industryOnly 14 pages are availabe for public view
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Abstract
Sugar beet (Beta vulgaris var. saccharifera, L.) is one of the main economical sugar crops in Egypt its roots have a high concentration of sucrose and it used commercially for sugar production. Sugar beet cultivation has spread in Egypt in Lower and Upper Egypt governorates. Need to cultivate about 200,000 feddans for the factories of Kafr El-Sheikh, Dakahlia and Fayoum in Egypt to operate at full capacity, producing half a million tons of sugar. Cercospora leaf spot of sugar beet plants caused by Cercospora beticola Sacc. is one of the most serious and destructive foliar disease of sugar beet worldwide and in North Nile Delta of Egypt. Test sensitivity of some sugar beet cultivars to infect by Cercospora leaf spot disease was evaluated in open-field study under a heavy natural infection level. All evaluated sugar beet cultivars were susceptible to Cercospora leaf spot disease however, cultivar was Farida the most susceptible while Oscar Poly was the least once. The efficiency of four induced resistance chemicals (IRCs) alone at two concentrations i.e. zinc sulphate, ammonium molybdate, salicylic and calcium silicate and difenoconazole fungicide (Score 25% EC) beside untreated treatment (control) or in combination with potassium humate were tested on disease incidence (DI) and severity(DS) and quality (Sucrose, extractable sugar, purity and sucrose loss to molasses percentage), growth traits (Root length and diameter (cm)/ plant, root and top fresh weight (kg)/ plant) and productivity traits (Top yield (ton/fed) and percentage of harvest index and root and sugar yields (ton/fed.)) of sugar beet plants were tested under greenhouse conditions at faculty of agriculture farm, Fayoum and in the fields of El-Hamol County at Kafr El-Sheikh Governorate under natural infection, respectively. All the tested compounds showed different degrees of efficiency for the percentage of disease incidence and disease severity and quality, growth traits and chemicals productivity traits of sugar beet plants in comparison with the control treatment. The Score fungicide treatment with or without KH the best results compared to all the tested materials followed by potassium humate with Zinc Sulphate (12mM) and Ammonium molybdate (1.6 mM) with or without KH treatments, while the highest DS and DI was observed in untreated control plants. All tested materials showed different degrees of efficiency in disease incidence (DI) and severity (DS), quality, growth traits and productivity traits of sugar beet plants compared to the control treatment. The Score fungicide treatment with or without potassium humate recorded the best results compared to all tested treatments followed by potassium humate with zinc sulphate (12mM) and ammonium molybdate (1.6mM) with or without potassium humate treatment, while the highest incidence and severity of the disease were observed in control treatment. Some of the tested treatments did not record a significant effect on reducing disease measurements and improving the quality, growth and productivity traits of the crop compared to untreated plants under greenhouse and field conditions. Spectral assessment of Cercospora leaf spot disease in sugar beets planted at Kafr El-Sheikh Governorate, El-Hamol County, Egypt under the effect of combination between potassium humate treatment and some induced resistance chemicals was investigated under field conditions at different times during the growing season. Spectral analysis revealed that all indicators had significance with induced resistance chemicals, except for WI, MCARI, and BIG2 indices. Repeated spraying showed efficiency in all indices except NDVI, PSNDa, OSAVI, and BIG2. Time measurements showed that the third measurement had the highest efficiency of all indices except MCARI index. Accordingly, remote sensing can be considered a promising method for use in estimation different levels of disease density and severity in the field. Therefore, it can be used to determine the rate and timing of adding materials used in control and improves agricultural practices through establishment models that express the extent of infection with different diseases which leads to increased crop productivity.
Key Words: Sugar beet (Beta vulgaris L.), Cercospora leaf spot disease, Cercospora beticola, induce resistance chemicals, remote sensing, Quality, growth traits and chemicals productivity traits.