this research was carried out to investigate allelopathic effect of peganum harmala on seed germination of bromus tectorum. aboveground and underground tissues of peganum harmala in addition to its seeds were collected from bijar rangelands. collected materials of root, leaves, stem, seeds and a complex of mentioned parts were dried and powder. the research was performed at the greenhouse condi...

density-gradient centrifugation. ISCO fractionator scanning patterns indicated a high degree of purity but serological results revealed the presence of some host contaminates. The yield of virus was abeut 2mgfleOg of bro'ad bean leaves. The titer of the antiserum against isolate No. 30 was 1!2048 by ring precipitin tests. Although the iutact virus particles could n6t diffuse in agar gel plates,...

Beni Tal* and David J. Robeson A RCO Plant Cell Research Institute, 6560 Trinity Court, Dublin, CA 94568—2685, USA Z. Naturforsch. 41c, 1032—1036 (1986); received July 16/August 12. 1986 Pyrenocine A, Phytotoxin, Fungal M etabolite, Alternaria, Helianthus tuberosus A previously undescribed species of Alternaria was isolated from the leaves of Helianthus tuberosus bearing necrotic lesions. W hen...

Colour-thresholding digital imaging methods are generally accurate for measuring the percentage of foliar area affected by disease or pests (severity), but they perform poorly when scene illumination and background not uniform. In this study, six convolutional neural network (CNN) architectures were trained semantic segmentation in images individual leaves exhibiting necrotic lesions and/or yel...

n order to investigate the effect of nitrogen fertilizer rates and top dressed on nitrogen remobilization in different rice cultivars, a field experiment was conducted in the rice research institute of iran (amol) during 2006. a split split experiment in the basis of randomized complete block design with 3 replications and 3 factors were used in which fertilizer rates in 3 levels (including 46,...

In 2010, disease symptoms, including necrotic lesions on stems and leaves with circular yellow-brown or irregular brown color patches, were observed on cool-season turfgrass at golf courses (OHCC) and the Daegu University research farm in Gyeongbuk, Korea. We isolated the causal agent and identified it as Waitea circinata var. zeae by morphological characterization and molecular analysis. To th...

one of the main problems in the mass production of pepper transplant is the stickiness of seed coat to the cotyledony leaves that can lead to no emergence or having poor emergence of pepper seedlings. therefore, in order to evaluate the effects of different sowing depths and soil compactions on emergence and early seedlings growth of pepper, a greenhouse experiment was conducted in the faculty ...

In additioll to momilactone, phytocassanes A through E (diterpene phytoalexins) were detected in rice leaves in fields suffering from rice blast. Furthermore, phytocassane accumulation was mest abundant at the edges of necrotic lesions, indicating that the phytoalexins prevent subsequent spread of the fungus from the infected site. In pot experiments the pattern of phytocassane accumulation in ...