We must treat the soil before going for the planting. The most effective soil conditioning is done by cold pressed neem cake, pongamia cake, castor cake in a ratio of 1:1:1. Apply these cakes and irrigate the soil. Keep the land for a week before planting.
Also, there are granular products available to control the soil borne pathogens. These products are bentonite granule based. You may use them.
We are working on the use of a soil strain of Trichoderma harzianum that enhances root growth and controls soil pathogens. Applied as a seed treatment, this strain is an endophyte so it colonizes the roots in the intercellular spaces and gives protection for the life of the crop. It is cheap to apply as a seed treatment, about US$5 per ha.
I suggest that the organic supplements recommended by Dr Maran will be doing a similar thing: enhancing rhizosphere microbial activity in order to suppress the Macrophomina phaseolina.
Since Macrophomina is a fungus that attacks when the soybean is under stress I would suggest that varieties could be screened for heat/drought tolerance and this may correlate with better tolerance to Macrophomina.
Since we are likely to encounter a hotter and drier world as time progresses the ability to identify characteristics that enhance defensive response to these characters might be well worthwhile.
In terms of probiotics Trichoderma, Bacillus and Pseudomonas are mentioned. The T. harzianum 382 is now know to turn on defense biochemical pathways. The investigation of consortia or mixtures of these might be interesting for testing compared to individual treatments.
Since one of the main side effects of Roundup Ready genes has been poorer rooting and enhanced Sudden Death it would fruitful to test if in Charcoal rot pathosystem the normal germplasm could give a better reaction than isoline with commercial roundup ready transformation.
Finally the use of organic material and high temperature can be used to highlight the potential use of solarization for effective control of soybean charcoal rot. The accumulation of organic material and its covering by clear plastic can be monitored and tested for the reduction of the inoculum potential and correlated with improved cropping suggest.
The ability to apply targeted drip irrigation maybe a useful control of charcoal rot and a way to greatly increase water use efficiency while stimulating a high yield environment under difficult conditions.
Hope these thoughts are useful for your brainstorming.
Under the right supervision and follow through these might make a nice dissertation project.
The best controls are resistant soybean varieties and cultural practices as indicated in the two attached PDF files (agriculture extension-type publications).
we need integrated disease management strategy. sowing date is important. plant density should be proper. irrigation in special time of plant growth stage help for disease management. rotation also is important. soil floating or rotation with rice is helpful for destroying fungus microsclerotia. nutrition is also an other factor that should be take in consideration. every decision should be taken according to the geographical location and climate condition.