Image Number D4480-2
During biological indexing at the USDA-ARS-NCGRCD, horticulturist Robert Krueger inspects a "sour orange" indicator plant displaying symptoms of the disease Citrus vein enation. These symptoms are sometimes transient, so if the index is not observed for several months, all the previous work may be lost. Once the biological index is started, the plants continue to grow and must be observed until the test's completion.
Photo by Brittany Moreland.
640 pixels wide: (D4480-2.jpg)
Please visit our Image Gallery.