Interactive Effects of Abiotic Stress and Bacterial Treatments on the Severity of Viral Infection in Greenhouse-Grown Cucumbers: A Case Study from Erbil, Iraq and Syria, Raqqa

Abstract

Viral diseases and climate change are the most significant challenges facing cucumber cultivation in greenhouses. This study aims to study the impact of Pseudomonas fluorescens, Bacillus subtilis, water, and heat stress on viral infection cultivars in three commercial cucumber cultivars (Master, CODE11, and AYOUBI) in Erbil and Raqqa, within greenhouses conditions. In Erbil, the efficacy rate was 100% during W1,W2 and W3. Moreover, the reduced rate for Bacillus was (100 to 16.32)% from W1 to W7 respectively. The Master cultivar showed a high response to both types of bacteria compared to the other cultivars. In Raqqa, the effectiveness of Pseudomonas bacteria ranged from 81.52% in W1 to 15.91% in W7, while the effectiveness of Bacillus ranged from 36.95% to 6.57% from W1 to W7. Meanwhile, the CODE11 cultivar showed a greater response to both types of bacteria, with a rate of 52.21% for Pseudomonas and 0.94% for Bacillus.
The effect of water and heat stress was clear in W5 in Erbil and in W4 in Raqqa. In Erbil, the percentage increase in infection severity in W5 was 25.92% due to water stress and 15.22% due to heat stress. In Raqqa, the infection rate increased in the Master cultivar more than in the other cultivars, which the infection percentage was 16% of water stress. Furthermore, the highest effect of the time was noticed in W 4, which the percentage of infection severity in W4 was 21.00% due to water stress and 9.58% due to heat stress.