Deprecation warning in rails 2.3.11

I am using Rails 2.3.11. I am getting a lot of deprecation warning like

DEPRECATION WARNING: Rake tasks in vendor/plugins/delayed_job/tasks, 
vendor/plugins/fckeditor/tasks, 
vendor/plugins/jrails/tasks, 
vendor/plugins/que开发者_JAVA百科ry_reviewer/tasks, 
vendor/plugins/thinking-sphinx/tasks, 
vendor/plugins/tiny_mce/tasks, vendor/plugins/tolk/tasks,
 and vendor/plugins/xss_terminate/tasks are deprecated. 
Use lib/tasks instead. (called from /usr/lib/ruby/gems/1.8/gems/rails-2.3.11/lib/tasks/rails.rb:10)

Give suggestions to avoid these warnings

Move tasks into lib/tasks… No, actually, start using bundler. If an upgrade to Rails 3.x is too much work, at least move over to bundler and move all those dependencies into your Gemfile. It works fine with Rails 2.3.