Selection of isoresponsive genotypes in toria (Brassica campestris L.) based on the pattern of response to environmental variations: a proposed method.

Thirty-one toria genotypes were compared with three well-established cultivars, 'Ludhiana Composite-2', 'K-1' and 'TCSU-2' (standard testers). The genotypes, which were almost identical to a standard tester in response to environmental variations and which also had other desirable characteristics, were considered to be acceptable for commercial cultivation. Using this criterion, 'TCSU-7', 'TH-5' and 'TH-4' were found to be acceptable for commercial cultivation. 'TH-4' and 'TCSU-7' were found superior to 'TH-5' if r(2) can be considered as a measure of the agronomical manipulations expected in environmental variations.