Abstract:

Yellow rust disease in wheat is one of the major fungal pressures threatening food security as a result of global outbreaks. In this work, spectral reflection values were employed to monitor the disease (Caused by; Puccinia striiformis f. sp. tritici) and indicate reaction variations in wheat over distinct phenological phases. The spectrum reflection values obtained as a consequence of the assessments done in the genotypes with and without the disease were apportioned within the scope of the study, and the development of the stress in different band gaps was tracked by reading the graphs created. As research plant material in the study carried out in the 2018-2019 growing season; Bayraktar 2000, Demir 2000, Eser and Kenanbey bread varieties and Çeşit-1252, Eminbey, Kızıltan 91 and Mirzabey 2000 durum varieties were used. All of the test material was sown by hand in 3 replications in rows 33-35 cm apart and 1 m long in October. Using essential mineral oil (Soltrol 170®), the newly collected disease spores were inoculated into the test material at doses of 0%, 25%, 50%, and 100%. Evaluations of disease’s reactions were made using the Modified Cobb scale between 25 May and 06, 15 and 23 June, and infection coefficients were derived using these results. As a result of the investigation, reflection curves for various phenological periods were constructed, accounting for reflection rates based on assessments of genotypes with and without illness. It was discovered that throughout the same developmental period, the spectral reflectance values of the disease-inoculated genotypes increased in the visible region and reduced in the near infrared area. The most effective disease dose to utilize in assessing the disease reaction was determined to be 50% for bread types and 25% for durum varieties. With effort, it was demonstrated that it was able to numerically analyses the correlations with the disease reaction through dynamic changes in the spectrum reflections of the canopy at various growth stages of wheat. Variations in these regions at various band ranges are assumed to be related to the extent of the pigments in mesophyll tissues as a result of the ageing process of leaves.

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