Aneja, D.R.Bishnoi, Rekha2017-03-022017-03-022016http://krishikosh.egranth.ac.in/handle/1/5810003617The objective of present investigation is to give an exhaustive review of work done on incomplete block designs for diallel and partial diallel crosses. Confounded diallel crosses for Methods I and III of Griffing (1956) given by Agarwal (1974, 75) are useful when the experimenter is interested in the estimation of all components i.e. g.c.a, s.c.a, maternal and maternal interaction effects of diallel crosses. The loss of information of different effects and interactions has also been given. N-ary designs using triangular PBIB designs given by Divecha and Ghosh (1994) for estimation of g.c.a, s.c.a, reciprocal effects for all four complete diallel crosses can be used. Efficiency of these designs is a matter of investigation. Optimal complete diallel crosses using Nested (Gupta and Kageyama, 1994) & PBIB designs (Dey and Midha, 1996) and efficient designs for complete diallel crosses through Latin square designs (Sharma et al., 2011) & balanced lattice designs (Sharma, 2005) have been also described in the present manuscript. These designs are efficient/optimal for g.c.a effects only. Catalogue of all such designs for number of inbred lines upto 20 have been also given which will be useful for the experimenter in the selection of appropriate blocked diallel cross design as per his requirement. Optimal complete diallel crosses designs given by Chai and Mukherjee (1999) are optimal for both g.c.a as well as s.c.a comparisons. Method of constructing Incomplete Block Designs for Partial Diallel Crosses using n-ary designs given by Agarwal & Das (1990) and Divecha & Ghosh (1997) have been illustrated through examples also. In these methods, two designs have to be considered; one for construction and another for evaluation of Partial Diallel Crosses. When the list of all such BIB and PBIB designs is not available, Mating Environment designs using circular designs (Sharma, 1998) are useful because these are available for any combination of number of treatments and block sizes. Catalogues of such designs have been provided in in tabular form. Construction method of optimal partial diallel crosses by Mukerjee (1997) & Das et al. (1998) available in literature have been also described.enThesis