Spring Web Flow & Java Server Faces @ManagedProperty injection always null during flow

Question

I have succesfully integrated JSF with Spring WebFlow & PrimeFaces, but injection by @ManagedProperty is always NULL during my web flow but using @Autowired annotation injection works. I would like to know why @ManagedProperty does not work but @Autowired works.

My enviroment: Spring 3.2.1.RELEASE, JSF 2.2.4, PrimeFaces 3.0.

UserBean class:

     @ManagedBean
     public class UserBean implements Serializable {

         @ManagedProperty(value="#{messageBean}")
         private MessageBean messageBean;

         public MessageBean getMessageBean() {
           return messageBean;
         }

         public void setMessageBean(MessageBean messageBean) {
           this.messageBean = messageBean;
         }
     }

MessageBean class:

    @ManagedBean(name = "messageBean")
    public class MessageBean implements Serializable {
       public String getMessage(){
          return "Hello, " + name;
       }
    }

faces-config.xml:

<application>
    <el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
</application>

webflow.xml:

<!-- Executes flows: the central entry point into the Spring Web Flow system -->
<flow-executor id="flowExecutor">
    <flow-execution-listeners>
        <listener ref="facesContextListener"/>
    </flow-execution-listeners>
</flow-executor>

<!-- The registry of executable flow definitions -->
<flow-registry id="flowRegistry" flow-builder-services="flowBuilderServices" base-path="/WEB-INF/flows">
    <flow-location-pattern value="/**/flow.xml" />
    <flow-location id="parent-flow" path="parent-flow.xml"/>
</flow-registry>

<!-- Configures the Spring Web Flow JSF integration -->
<faces:flow-builder-services id="flowBuilderServices" development="true" />

<!-- A listener to create and release a FacesContext -->
<beans:bean id="facesContextListener" class="org.springframework.faces.webflow.FlowFacesContextLifecycleListener"/>

I have also file flow.xml and view.xhtml because I have integrated spring web flow with JSF using PrimeFaces.

WEB-INF/flows/ajax-jsf/flow.xml:

<var name="userBean"    class="org.springframework.samples.webflow.ajax.UserBean" />
<var name="messageBean" class="org.springframework.samples.webflow.ajax.jsf.MessageBean" />

<view-state id="view">
    <transition on="suggest" >
        <evaluate expression="userBean.createEmailSuggestion(flowRequestContext)"
            result="viewScope.emailSuggestion" />
    </transition>
</view-state>

Do you know why my @ManagedProperty injection fails? If I replace @ManagedProperty with @Autowired I can see that object is created but @ManagedProperty is always null.