Journal of Kerbala for Agricultural Sciences

This study was conducted to isolate and identify three isolates of the pathogenic fungus Pythium aphanidermatum causing seed rot and seedlings death in cucumber plants (Cucumis sativus L.) collected from three different regions, namely Abbasiya, Um-Abbasiyat and Qazwainiya in the province of Najaf.  Pathogenicity test on cucumber seeds showed that all isolates from the three regions were  pathogenic and caused seed rot. Isolate P. aphanidermatum from Al-Abbasiya region was the most aggressive isolate followed by the isolates obtained from Um-Abbasiyat and Qazwainiya regions that caused cucumber seed rot of 90, 74 and 72%, respectively; whereas no seed rot was seen in the control treatment.
 
Results obtained from the polymerase chain reaction (P.C.R) of  two most pathogenic isolates (P.a1 and P.a2) on cucumber seeds showed that it was possible to amplify 700-800 bp sized products. Results of the sequence analysis of nitrogen bases generated from the PCR-amplified products using BLAST showed that both isolates are belonging to the fungus P. aphanidermatum. The P.a2  was 100% identical to the globally isolated fungus that deposited at the National Center for Biotechnology Information (NCBI). The BLAST results showed that P.a1 had similarity of 98-998% with the isolates recoded at NCBI; therefore this isolate was registered in NCBI as a new isolate under the GenBank accession no. MF347709.

magnetized water(MW), the fungus Aspergillus spp. the herbicide Granestar on wheat growth. In a preliminary experiment, magnetized water at three magnetic density levels (1600, 3200, 4800) Gauss was tested to determine the better intensity for seed germination and plant growth of wheat and the wild radish weed. The aim of the study was to control the wild radish in the wheat fields by developing an integrated program to reduce the use of chemical pesticides by using environmentally friendly agents including the bio-agent fungus Aspergillus spp., magnetized water as a physical agent and the Granstar herbicide.




solani and Aspergillus spp. were isolated from wheat and wild radish seedlings and pathogenically tested on both host plants. Results showed that both R. solani and Aspergillus sp. increased germination and seedlings growth of the wheat and inhibited germination and growth of the wild radish. Aspergillus spp. had no negative effects on seed germination and seedlings growth where tested on different plant families seeds including cow pea, cucumber, radish, barley, melon, garden cress and green mung beans.




      Seed germination percentage and seedlings length of wheat and wild radish were affected by magnetic intensity levels after 21 days of planting. The 1600 G was the best treatment for seed germination and seedlings length of wheat, and at the same time this intensity level  negatively affected the wild radish seeds and seedlings resulted in the lowest values of  germination and seedlings length. However, the highest intensity level 4800 G  did support highest seed germination percentage and seedlings length of the wild radish, but this intensity had negative effects on wheat seeds germination and seedlings length. 
 
     The main field experiment was conducted during the winter growing season of 2016 in one of Al-Hirah wheat field  in the province of Najaf. The experiment was factorial with two factors, MW as main factor and the fungus Aspergillus spp. and the herbicide Granstar at half and full of recommended dose based on RCBD design with three replicates.
 
    The treatment of MW (1600 G) significantly increased all plant growth parameters tested (Weight of spike, weight of 1000 seeds, and total yield) compared to the control (RW). All treatments combinations that included the bio-agent Aspergillus spp. Resulted in enhancing all growth and yield parameters tested with total yield of 5.505 ton.h-1 compared to 2.778 ton.h-1from the plants not treated with the fungus.