2.4.2. Crown roots

2.4.2. Crown roots

 

  Crown roots develop from each nodal portion higher in position than the coleoptile node. And they come out in order from the lower to the higher node. Many crown or adventitious roots emerge almost simultaneously around the node. Therefore they are crown-shaped, so the name is crown. They are growing from the rooting band just above and below the node in the case of rice. Crown roots growing from higher nodes are larger in number, thicker and more vigorous. They grow longer than those from lower nodes. There are two types of crown roots : mat roots which are shallow, and ordinary roots. Mat roots develop when the air cotent of the soil is low, as in later growth stages. Traditional upland rices produce few mat type roots, even at later  growth stages.