Descriptor: Russian Wheat Aphid Chlorosis (RUSSAPHID)



 
Definition:
Reaction to the Russian Wheat Aphid (Diuraphis noxia). Amount of chlorosis. See RWA Leafroll descriptor, also.
Crop:
BARLEY
Category:
Insect descriptors
Status:
Crop Germplasm Committee approved
Data Type:
Alpha/numeric descriptor
Maximum Length:
3
Responsible Site:
National Small Grains Collection (NSGC)

Distribution of Values for Russian Wheat Aphid Chlorosis (RUSSAPHID)

CodeDefinitionNumber of Accessions
1PLANTS APPEAR HEALTHY, MAY HAVE SMALL ISOLATED CHLOROTIC SPOTS4
25% LEAF CHLOROTIC, CHLOROTIC SPOTS BECOME MORE NOTICEABLE14
315% LEAF CHLOROTIC, CHLOROTIC SPOTS ARE LARGER AND MORE NUMEROUS.29
425% LEAF CHLOROTIC - SOME STREAKING MAY BECOME APPARENT, ESPECIALLY ALONG TH EMIDRIB.53
540% LEAF CHLOROTIC, CHLOROTIC SPOTS BEGIN TO COALESCE OR DEFINITE STREAKING OCCURS.83
655% LEAF CHLOROTIC, LARGER CHLOROTIC SPOTS COALESCE. LEAVES START TO "DIE-BACK" FROM TIPS.154
770% LEAF CHLOROTIC, FURTHER SYMPTOMS DEVELOP.344
885% LEAF CHLOROTIC, EXTENSIVE CHLOROSIS AND NECROSIS.3445
9PLANT DEATH OR NO RECOVERY POSSIBLE23064
MIXMIXED FOR RESISTANCE TO RUSSIAN WHEAT APHID1