PPDL Picture of the Week
March 7, 2016
Healthy transplants: Healthy beginning
Dan Egel, Extension Plant Pathologist, Southwest Purdue
The photo that accompanies this article shows a tray of
watermelon seedlings that are ready to be transplanted into a field or garden.
Every effort should be made to plant only healthy
seedlings to avoid the unwanted introduction of diseases and insects.
These seedlings should be inspected for leaf
spots and other symptoms that may indicate a disease or insect pest.
Overall, the leaves of the watermelon seedlings in this
photo seem pretty healthy. However,
there appears to be something wrong with a few of the seedlings. Several of the seedlings are smaller and wilting. Does this indicate a disease?
We are all familiar with plants that wilt due to lack of
water, however the soilless mix in the tray used does not appear to be
dry. Since some diseases and feeding
from insect damage also cause plants to wilt, samples could be sent to the Purdue Plant and Pest
Diagnostic Laboratory for diagnosis.
Isolation from the stems of these plants would identify Fusarium wilt as
the cause of the wilt.
In a few weeks, retail garden stores will start to sell
vegetable seedlings for home gardens.
In addition to avoiding seedlings with leaf spots, buyers should also
avoid wilted plants. The cause may be
more serious than lack of water.