<div  id="Producers">

 <template  v-if="isInAddingMode"> 
  <select  v-model="selectedProducer" >
      <option value="" disabled selected>Производитель</option>
      <option v-for="producer in producers"
      v-bind:key="producer.id" 
      v-bind:value="producer.id" >{{producer.title}}</option>
    </select> 
</template>

<template v-else> 
    <input  v-model="newProducerName"
          id="newProducerName"
          type="text" >
      <label for="newProducerName">Производитель техники</label> 
</template>

 <button  class="waves-effect waves-light btn-small"  v-on:click="isInAddingMode=!isInAddingMode">+</button >
</div>