Studies conducted in root boxes showed that the potential root systems in terms of length, volume, weight and thickness were greater in Lalnakanda 41, Mtu 17 (talls) and Rasi while IR 20 had a relatively shallow system. Root volume, dry weight and number of thick roots were more in ‘A’ zone (0–30 cm depth) which gradually decreased as depth increased till 100 cm irrespective of the stature of the plant. The dry matter in ‘C’ zone (60–90 cm depth) was 2–3 times more in talls than in dwarfs. Dwarf plants concentrated much in ‘A’ zone while the proportion of distribution was relatively balanced in tall typts. Under sub-soil compacted conditions (high bulk density 1.8 g/cc), root length, volume and weight decreased in black soil conditions irrespective of plants type. However, Rasi showed its superiority over Lalnakanda 41. Plant types with low potential root system in red soil suffered comparatively less in Mack clay soils. Evaluation with five more traditional had shown that Bala and N 22 were fairly efficient in several characteristics. Further, it had become clear that for evaluations or screening purposes, different type of soils should be considered for eliciting behavioural pattern of the newly developing varieties.
