الفهرس 
ACKNOWLEDGEMENT
Effect of Hirsutella rhossiliensis against T. semipenetransOnly 14 pages are availabe for public view
 |  | from | 133 |  |  |
| | | from | 133 | | |
Abstract
The present work was conducted to study the following main points:
1. Survey studies on citrus nematode associated with citrus orchards of certain areas of Assiut Governorate, under field conditions.
2. Host reaction of certain citrus rootstocks; Baladi orange (C. sinensis), Troyer citrange (C. sinensis x P. trifoliata), Mandarin (C. reticulta), Clemantine mandarin (C. reticulta) and Lime (C. aurantiflia) to infection by T. semipenetrans under greenhouse conditions.
3. Effect of Bacillus megaterium, Trichoderma album and Hirsutella rhossiliensis on T. semipenetrans infected Baladi orange and Lime under laboratory and greenhouse conditions.
4. Effect of plant extracts (Allium sativum, Capsicum frutescens, Foeniculum vulgare, Nerium oleander and Lantana camara) on T. semipenetrans under laboratory and greenhouse conditions.
Results of our study can be summarized in the following:
1- A total of 600 soil and root samples were collected from four counties; Sahel-Selim, El-Badary, Manfalout and El- Fath cultivated with C. sinensis and C. reticulata. Results showed that the citrus nematode is found with different population density and number of females in all the collected samples.
2- Studying the susceptibility of certain citrus rootstocks to the citrus nematode, showed that the citrus rootstocks differed in their susceptibility to the citrus nematode, Baladi orange and Lime were susceptible while, Troyer citrange and Mandarin were resistant.
3- The percentage of J2 mortality increased with increasing the rates of different bio-agentis (Bioarc and Biozeid) and exposure periods Whereas, B. megaterium and T. album gave the highest reduction in mobility the larvae of citrus nematode at the rate of 30g/l for a period of exposure 72 hours. Moreover, Bioarc exhibited higher mortality effect than Biozeid.
4- The fungus (H. rhossiliensis) has achieved significant decrease in the census nematodes after 30 days of treatment. The percentage of the colonized nematode by fungus increased with increasing the exposure periods.
5- All treatments gave significant increase in reducing the number of nematodes in both soil and roots of Baladi orange and Lime seedlings especially at the rate of 30g/l for both tested compounds.
6- There is a significant difference between concentrations use of the fungus in the experiment after 90 days of treatment also achieved a significant reduced in the census, compared with the control.
7- Data also revealed that most of the treatments recorded a significant improvement in plant growth from infected plants nematode only.
8- Laboratory results showed that, all plant extracts (Lantana, Garlic, Chile pepper, Oleander and Fennel) reduced the mobility of the larvae of T. semipenetrans, where, Lantana extract with (S) concentration gave the highest reduction in the mobility of larvae while, fennel extract gave the lowest reduction in the mobility of larvae.
9- The tested plant extracts reduced the population density of citrus nematode. Lantana camara gave the highest percentage of reduction.
10- Data also revealed that most of the treatments recorded a significant improvement in plant growth from infected plants nematode only.