http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.137.6506&rep=rep1&type=pdf

this journal might help....

WinRhizo is a suitable software for studying  the root morphology and architecture, incl. parameters mentioned by you: http://www.regentinstruments.com/assets/winrhizo_about.html

Look for this article, too:

http://www.sciencedirect.com/science/article/pii/S1872203209000213

Yes. Meine van Noordwijk, ICRAF Science Advisor and Part-time Professor Waginingen University, Netherlands has published widely in this area though not specifically on tomato. Also see Catherine Muturi. Am sure with these you can build a good bibliography. I hope it helps. All the best. Thomas

I 'm not biolygist but try to commande the non leneair system like the green house.specialy fuzzy logic controller...

Hi there, I don't  know much about your question but found this paper [https://js-soilphysics.com/data/pdf/095003.pdf] that might help you. You could make contact with one of the authors and adapt their methodology for your project. Good luck! 

Try WinRhizo software, just you need to scan the roots after deep cleaning and washing . Some technical practice are needed also ..

Hi Jeyavanan,  I found 3 papers that might help.  I am attaching the pdf version of two of them, and the web address for the third one.  Good luck!

Morgan L. 2013 Root Restriction in Hydroponics http://www.greenleafgardencenter.com/indoor_gardening/articles/Root_Restriction.htm

There are many ways to study root development, root density and the size of the root zone, none of them are easy. We have worked mainly with rhizotron based methods and studied root growth of various annual crops as described in the four papers listed below. We are right now working on a paper where we use similar methods to study the development of the root zone of plants during early growth. WinRhizo can be used with other methods than we have used, but I do not see it as easy as more or less indicated in some of the answers. Before using WinRhizo there is a lot of work on sampling and cleaning roots, the actual WinRhizo Work is just a small part of it all. I hope you can find some method that is useful for you!

Andersen SN, Dresbøll, DB and Thorup-Kristensen K (2014) Root interactions between intercropped legumes and non-legumes - a competition study of red clover and red beet at different nitrogen levels. Plant and Soil, 378, 59-72 (DOI 10.1007/s11104-013-2014-4)

Dresbøll DB, Thorup-Kristensen K, McKenzie BM, Dupuy LX and Bengough AG (2013) Timelapse scanning reveals spatial variation in tomato (Solanum lycopersicum L.) root elongation rates during partial water logging. Plant Soil 369, 467-477 (DOI: 10.1007/s11104-013-1592-5)

Thorup-Kristensen, K. (2006) Root growth and nitrogen uptake by carrot, early cabbage, onion and lettuce following a range of green manures. Soil Use and Management, 22, 29-38

Thorup-Kristensen, K and Van den Boogaard, R. 1998 Temporal and spatial root development of cauliflower (Brassica oleracea L. var. botrytis L.), Plant and Soil 201: 37-47

All the best

Kristian

Thanking you All and I have surprised and had a lot of information from all you. It is good collaboration. Thanks to all....

Methodologies for root drought studies in rice

H.E. Shashidhar, Amelia Henry, Bill Hardy IRRI 2012

Have a view at this resource from IRRI. Very informative chapters.

http://irri.org/resources/publications/books/methodologies-for-root-drought-studies-in-rice

In the attached paper you can find an approach you could adopt.

Cherubino

Plantstress is a great resource go through in detail http://www.plantstress.com/

There is a PhD work done in Portuguese, by Prof. Dr. Carlos Portas, on the root system of tomato. It dates from the 70s of last Century. If you are interested I can look for this work (Prof C. Portas is retired and lives in Elvas, Portugal).