I use the water extraction of the root to make an organic, water soluble spray for fruit and vegetables.  See Little Medicine the video at www.herbvideos.com 

We spray our pears with Yucca root water in the spring.  The results are excellent.  Take about a cubic inch of root blend it in 2 cups water.  Strain, filter into sprayer.  Add another pint of water and spray directly on buds, flowers and young pears, apples.

Agave (Sisal) and yucca may be pounded and  combed to make fiber for cloth rope. (More on yucca)

Below: Yucca plant, Eagle Lake.