Grow the plants (experiment + controls) > inoculate with fungal spores > evaluate the infection profile > compare it with control plants

The pathogenicity testing of Rhizoctonia solani, Fusarium lycopersici and Sclerotium rolfsii can be tested pot inoculation tests under greenhouse or growth chambers depending on your facilities. You need to establish a noninoculated control. I would suggest treatments be the individual fungi alone and a combined treatment of all three. Start your tomatoes from disease free clean seeds in let them grow 3 to 4 weeks. The test fungi can be grown on sterilized sorghum or millet seeds and the infected seeds mixed with growth medium to create the infection court. The healthy seedlings are transplanted in inoculated treatments and allowed to growth for 3 to 6 weeks taking periodic readling on the symptoms and issues.

Paul Reed Hepperly should i use sterilized tap water or just regular tap water to water the plants?

Tap water might be chlorinated which might confound the experiment. I would use sterilized water in your experimentation to avoid the chlorination issue related to the inoculum potential. It might not important but I would avoid the unsterilized water source. If you have a laboratory source distilled water which is sterilized is often used.

Paul Reed Hepperly, thank you very much, i highly appreciate it. i would like to add one more question, im running a nodulation test of a Rhizobium sp on chickpea, after 15 days the eadges of the leaves started turning yellow and wilting (the test was run in pots filled with a sterilized mixture of 1/3 sand + 1/3 field soil + 1/3 compost, watered with sterilized tap water) what could possibly be the reason?

PS: the weather has gotten unusually hoter around 35°C

Heat could be involved in the issues with plant yellowing the excess temperature may be affecting the rhizobia, the plant and their interaction. When testing for rhizobia reaction you will want to use a mixture without compost. The compost often rich in Nitrogen can inhibit the chemical signals between host plant and rhizobia. Some workers prefer a Leonard Jar culture where the nutrient feeder solution has all nutrient minus Nitrogen. Sand and vermiculite would give a more inert medium and low Nitrogen would allow the best Rhizobia reactions to be seen more clearly. Your strain efficacy can be measured based on both plant growth response and the number and weight of the nodules.

Paul Reed Hepperly , thank you very much, can i use perlite instead of vermiculite as it is unavailable?

Sand and perlite will work it is low nitrogen. The nutrient solution used is a hoaglund solution without the nitrogen. This creates an environment where the comparative biological nitrogen fixation capacity is more apparent and visible. The number and weight of the nodules will correlate very well with biological nitrogen fixation capacity.

إذا ظهرت إصابة بأعفان الجذور فى الحقل يتم استخدام إستحدام مبيد يساعد على تهوية التربه مثل مبيد كرانش 10%SP تسقيه حول النباتات المصابه إذا أمكن ذلك أو إستخدامه مع ماء الرى بمعدل 500 جم / فدان.

يمكن عمل خليط من 100 جم فيتافاكس + 100 جم ريزولكس + 100 جم توبسين أو سومى أيت أو بنليت / 100 لتر ماء مع ماء الرى.

If root infestation occurs in the field, a pesticide that helps to soil the soil, such as a 10% Cranche pesticide, can be applied to the infected plants if possible, or used with irrigation water at a rate of 500 g / fed. A mixture of 100 g of Vitafax + 100 g of Resulks + 100 g Tubsin, Sumy Ait or Penlit / 100 L of water with irrigation water.

Paul Reed Hepperly Thank you very much

following

I learned from Paul Reed Hepperly's response from

We have a recommendation of a mixture of fungicides to help deal with the damping-off and root rot.

For a nonchemical approach I would recommend using the natural probiotic approach of using a seed and substrate treatment with Trichoderma.

This probiotic fungus is not toxic nor a health hazard and not known to fail over time because of pest resistance to it.

The fungus also has been found to stimulate the plant defenisve systems and aidin evnronments of stress. \\