Global demand for food is outpacing gains from conventional plant breeding. Scientists have turned to molecular crop breeding techniques to increase crop output and mitigate global hunger; however, a common setback in this process is the pleiotropic effects of target genes. We need to develop strategies to specifically modulate desired traits without incurring undesired penalties. Natural evolution frequently balances such tradeoffs through extensive regulation, which we can leverage to produce more specific results. Reproductive development is an important target of breeding efforts due to its direct effect on yield. Rice, a major staple food crop for half the world’s population, is a model organism due to its well-annotated genome and genetic tractability, making it an ideal candidate for molecular study. Small RNAs (sRNAs) are an important and widespread mechanism of regulation in plants, and sRNA pathways have expanded over time. To study the sRNA landscape during anther development of rice, we created sRNA and expression atlases of anther development in Kitaake rice and discovered new compositionally and temporally distinct clusters of 21- and 24- x nt phasiRNAs. Though there are thousands of sRNAs, there are only 19 Argonaute (AGO) proteins in rice, which load sRNAs and carry out gene repression, making them attractive candidates for breeding efforts. We studied the functional diversification of the four rice AGO1 proteins, since AtAgo1 is known to play a role in plant development and stress response, thus making AGO1 a good candidate for study regarding regulation for specificity. We studied different potential mechanisms of differentiation and found evidence of neofunctionalization based on spatiotemporal expression and subcellular localization. Furthermore, we found an erect panicle mutant phenotype of the osago1b single mutant. These findings provide us with potential molecular mechanisms driving specific functions among paralogs, which we can leverage to uncouple plieotropic effects in crop breeding efforts.