HPIPM:Crops/Dry Beans/Leaf Variegation

Author: Howard F. Schwartz, David H. Gent, Gary D. Franc and Robert M. Harveson

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Rosanae
Order	Fabales
Family	Fabaceae
Subfamily	Faboideae
Genus	Phaseolus

Scientific Name

Phaseolus vulgaris

Scientific Name Synonyms

Phaseolus vulgaris var. humilis

Common Name

common bean

Identification and Life Cycle

Leaf variegations are a condition determined by the genetic factors of the variety. Some varieties are more subject to the problem than others. Environmental factors such as low soil temperature (below 60° F) can increase the frequency of leaf variegations. Leaf variegations occur in very low frequencies in commercial varieties, and are of no practical significance.

Plant Response and Damage

Only a small portion of plants show leaf variegations. Leaf variegations appear as a patchwork pattern or mosaic of varying shades of green, yellow, and white tissue on one or more leaflets of trifoliolates. The size and intensity of these color patches usually varies between leaflets, and can occur on some or all leaves of a branch or entire plant. Completely yellow or white (albino) seedlings die within a few days after emergence. Leaf variegations are sometimes confused with other problems such as mosaic viruses, but the latter produce leaf cupping and a different pattern of color mosaics in the tissue surrounding leaf veins. Other genetic factors may cause small yellow spots of unifoliolate and some trifoliolate leaves, or cause leaf crippling and curling.

Biological Control

No biological control strategies have been developed for leaf variegation.

Cultural Control

No management procedure need be applied in commercial bean fields. Plant recommended varieties, most of which are free of this problem. Inspect registered and certified seed fields routinely, especially before row closure, and rogue variegated plants since this can be a heritable trait.

Chemical Control

No chemical controls are available.

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.