January 22, 2015

Yuccas will bounce back

In a recent post, I mentioned a wide-spread illness of yucca (Yucca glauca) in the Nebraska Sandhills.  The illness appeared as a yellowed leaf condition, and most individuals halted flowering at many sites that I observed, although pockets of 'normal' yuccas could be found.  The impact was felt by some UNL scientists who were trying to study yucca and pollinator interactions--it was hard to find flowering plants for their study.  That was odd and an unexpected problem.
Yucca in the north-central region of the Nebraska Sandhills
during the summer of 2014.  A yellow condition of the leaves
can be seen (photo by Larkin Powell).
Many people wondered--are we going to lose our yucca?

It appears the answer is no...they were just sick.  It has taken some time, but in December, a University plant pathologist has released a report on samples brought to the UNL West Central Research and Extension Center in North Platte, NE.

The report concluded that the plants from the sample provided were affected by a fungal disease called "Coniothyrium" or brown leaf spot.  A further explanation of the disease can be found, from a horticulture perspective, here.

Scientists from the UNL Center reflected that the spread of this disease was unusually widespread and severe.  As suggested previously, weather conditions and plant stress from the 2012 drought could be to blame. 

Although some plants did die, many yucca have already recovered.  Stop on the prairie next summer and take a look at the yucca you find.  Can you find new shoots or dead plants?  I'll bet if you look closely, you can find evidence of this disease.  But, it looks like yucca will be back to full strength in the Sandhills, and we can continue to appreciate them as a perching spot for grassland birds.  And, we can curse at them when we are stabbed by their leaves.

1 comment:

  1. Excellent news! It will be interesting to be able to document a return to flowering and health for some of the individuals Shivani has been following.