The researchers studied how different combinations of rice plants can produce higher grain yield. They used a method called line x tester analysis with four main lines and ten testers. They found that some crosses resulted in significant increases in grain yield, panicle length, grains per panicle, and amylose content. The crosses Krishna Kamod x IET-19389 and Krishna Kamod x GNR-2 showed the highest increase in grain yield. Overall, certain hybrid combinations like Krishna Kamod x GNR-2 and Acharmati x GR-11 were the most productive for grain yield due to more grains per panicle and panicles per plant.