Dr Kumar developed several protocols and suitable technologies for tissue culture and genetic transformation of crop species such as Brinjal, Tomato, Cabbage, Chickpea and Pigeonpea. In addition, codon-modified genes were constructed for hyperexpression of insecticidal protein genes of Bacillus thuringiensis (Bt) in plant tissues. Such genes include cry1Fa1, cry1Ac-F and cry2Aa. The genes were patented and licensed to several private research companies. The genes were also provided to scientists working in public research institutions and universities.

Technologies such as tissue-specific expression of foreign genes in plants and hyper-expression of Bt genes in bacteria were developed and standardized. Several plant promoters were isolated and characterized such as Shoot-specific promoter (Sorghum), light-inducible promoter (Pigeonpea), Boll-specific promoters (Cotton) and stress-inducible promoters (Cotton).