Effect of Some Biochemical and Agricultural Treatments on the Control of Cucumber Root and Crown Rot Disease Caused by Rhizoctonia solani in Plastic Houses

Abstract

The study was conducted to evaluate the effect of root secretions, Bacillus subtilis HA-1 and chitosan on the growth rate of isolate Rs14 of R. solani in the laboratory, and to assess the potential of some biochemical and agricultural treatments on disease severity of cucumber hybrids infected with root and crown rot disease incited by R. solani Rs14 isolate, in addition to their effect on some growth parameters under plastic house conditions. The results obtained showed that grafting of hybrid cucumber on mountain honey gourd was the most effective in significantly reducing infection, followed by the PGC treatment in both hybrids. The grafting treatment also resulted in the highest biological weight for Captain F1 hybrid followed by the plant growth cleaner (PGC) treatment. Both treatments resulted in significant increase of biological plant yield; with the grafting treatment caused a 101.60% increase compared to the positive control treatment and a 15.16% increase compared to the negative control treatment, whereas the PGC treatment caused a 100.71% increase compared to positive control treatment and 14.64% compared to the negative control treatment. The specific enzymatic activity of the peroxidase enzyme increased more than two-fold in the combined treatment of the bacteria + Humzinc and three-fold in the activity of the polyphenol oxidase enzyme, and the PGC treatment was superior with an increase of approximately three-fold. There was a five-fold increase in the effectiveness of the chitinase enzyme in the grafting and PGC treatments compared to the other combinations in the Seegreen F1 hybrid cucumber.

Keywords:

Fungal diseases, soil-borne fungi, control factors, Cucumis sativus, Iraq.‎