Crop breeding is not only about publishing papers in journals. Considering the major number of papers in journals in the field of molecular genetics, it seems that this field has become a good strategy for publishing papers and books and not useful for farmers. Farmers still use varieties that improved by conventional breeding methods
Diallel crossing scheme would take lots of time and resources for developing varieties so half-allele scheme would be more relevant and efficient. Specifically, it is difficult for use diallel scheme if population size is large.
Dear Kumar, with advances in sciences, the publishing of results is becoming harder: I'm in the same situation like you, as many researchers worldwide. However, still important journals are publishing results of basic plant improvement methods. Check in Google Scholar.