Abstract. Powdery mildew caused by Erysiphe graminis f. sp. tritici is one of the most harmful disease causing great losses in wheat yield. Currently, thermal spectral sensing of plant disease under different environmental conditions in field is a cutting-edge research. Objectives of this study were to assess thermal imaging of normal and infected leaves for early detection of powdery mildew in wheat after the artificial infection with Erysiphe graminis fungus in a pot experiment under greenhouse conditions. Pot experiment lasting for 30 days was conducted. Additionally, wheat seedlings were artificially infected with pathogen at 10 days from sowing. This is the first study in Egypt to use thermal imaging technique for early detection of powdery mildew disease on leaf using thermal signatures of artificial infected leaves as a reference images. Particularly, the variations in temperature between infected and healthy leaves of wheat and the variation between air and leaf-surface temperatures under greenhouse conditions were sensed for early detection of disease. Results revealed that infection with powdery mildew pathogen induced changes in leaf temperature (from 0.37• C after one hour from the infection to 0.78• C at 21 days after infection with the pathogen) and metabolism, contributing to a distinct thermal signature characterizing the early and late phases of the infection.

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Sugar beet (Beta vulgaris L.) is one of the most important sugar crops in the world, which considered the second important sugar crop in Egypt after sugar cane. In Egypt, sugar beet is attack by Cercospora leaf spot disease caused by pathogen Cercospora beticola fungal, which caused losses can reach to 40% of yield. In the present study, three plant extracts of Flower of Haloxylon spp, Cichorium spp, and the leaf of Capparis spp were used .Different concentration of the three plant extracts (10%,20%,30%,35% and 40%) previously were used in experiment in vitro to determine Antifungal activity on the linear growth of Cercospora beticola .While in vivo, the concentration which recorded highest effect against Cercospora beticola in vivo were tested. In vivo the experiment conducted in two treatments, the first one sprayed sugar beet plants by plant extracts before the inoculation and the second treatment sprayed plant extracts after the inoculation. Experimental result show under laboratory, all tested plant extracts at concentrations (30,35 and 40%) showed highly effective on mycelial growth of Cercospora beticola and inhibited fungal growth compared to the control treatment and (10 and 20%) concentration. While in vivo result show that the treated sugar beet plants with plant extracts before inoculated then by Cercospora beticola give the best result for reduction the disease severity of CLS disease comparing with the control .In addition to result revealed that the treated sugar beet plants with tested extracts after inoculated by Cercospora beticola gave the best result for value total of chlorophyll a and chlorophyll b which recorded the highest value comparing with the control treatment.

A total of 61 wheat genotypes were screened for powdery mildew disease under natural infection during two seasons

This paper aims to demonstrate the usefulness of factor analysis for managing barley trials. It shows whether the relationship between barley yield parameters and morphological characters were affected by genotype and environment. The objectives of this study were to determine whether or not the interrelationship between barley yield parameters (total plant yield, grain yield, straw yield and thousand grain weight), and the morphological characters (vegetative duration, plant height, length of growing season and leafiness) was stable in each hybrid (hybrid 1, hybrid 2 and hybrid 3) and each of two areas in Syria by using factor analysis. The study also aimed to ascertain whether the relationship between yield parameters and morphological characters was affected by genotype environment interaction. There were three hybrids in each of the two Syrian areas: Tel Hadya and Breda. Each hybrid had 102 families. Correlation and factor analysis indicated that the interrelationship for yield parameters, except TGW, was stable, while the interrelationship between morphological characters was not stable. Factor analysis was applied to barley breeding data to determine the relationships between yield parameters and morphological characters. The results demonstrate that this relationship was stable in Tal Hadya, but not stable in Breda. The genotype and the environment influenced the relationship between yield parameters and morphological characters. Consequently, the relationship between yield parameters and morphological characters will not be suitable for forecasting yield.