|Cartwright, Bob - OKLAHOMA STATE UNIVERSITY|
Submitted to: Subtropical Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 1995
Publication Date: N/A
Interpretive Summary: Yellow vine is a serious vine decline disease of cucurbit crops grown in Oklahoma and Texas. We studied the potential relationships of soil-borne organisms as causal agents and insects as vectors of yellow vine in a series of experiments conducted at Lane, Oklahoma from 1989-1990. We found that soil fumigation had no effect on the incidence of yellow vine in squash indicating that soil borne organisms were not factors related to disease occurrence. Also, the disease occurred more often when squash was grown on plastic mulch compared to when grown on bare ground. Normally, reflective mulches repel insects which would, in turn reduce disease incidence. Insecticide usage resulted in lower incidence of yellow vine suggesting that unknown insect species play a role in disease transmission and/or development. Results did not indicate that squash bugs, cucumber beetles, or aphids were vectors of the causal organism of yellow vine.
Technical Abstract: In 1988, a distinctly different disease was observed in squash and pumpkin grown in Oklahoma. The disease has been designated as yellow vine, however, the causal agent of this disease is as yet unidentified. Symptoms include wilting, plant yellowing, phloem discoloration in the primary root and crown, and plant death. Preliminary observations suggested that squash bug (Anasa tristis) populations and melon aphid (Aphis gossypii) were associated with the occurrence of yellow vine. A series of field studies were conducted to determine if a relationship between insect populations and yellow vine was present and to document the nature of this relationship. Yellow vine incidence was significantly greater on plants with aluminum and black plastic mulch as compared to squash plants with white paint mulch and on bare ground. In squash grown under insecticide-sprayed and no-insecticide regimes, the occurrence of yellow vine symptoms was significantly reduced when an insecticide program was followed, regardless of mulch. Soil fumigation provided strong evidence that yellow vine was not soil-borne. Evidence suggests that insects are directly or indirectly involved with yellow vine, perhaps acting as a vector of the disease.