Hello Md. Nuruzzaman re: Effect of indole acetic acid (IAA) on the germination and seedling growth of crop plants Your question is very open-ended. Can you focus your question and tell us more what you have already found and where you going with your query? Are you trying to get an answer to a study question or are your focusing your research ideas? Do you have access to GoogleScholar? Have you searched here on ResearchGate? [ hint: https://www.researchgate.net/search.Search.html?type=publication&query=indole%20acetic%20acid%20(IAA)%20germination%20seedling%20growth%20crop%20plants]
I am not a specialist in your field, so instead of posting citations here I have sent some suggestions [ResearchGate message] to get you started.