No abstract

Cyhalofop-butyl-resistant Echinochloa crus-galli (L.) Beauv. has become widespread , so rapid diagnosis of herbicide resistance in E. crus-galli at various growth stages is crucial for timely and effective management of herbicide resistant E. crus-galli throughout the season. This study was thus conducted to diagnose cyhalofop-butyl resistance in E. crus-galli at various stages of growth using rapid diagnostic test methods. Growth pouch, trimmed seedling, and stem node tests were conducted on E. crus-galli at seed germination, juvenile, and heading stages, respectively, and the diagnostic results were then compared with the conventional whole plant test. All rapid diagnostic tests discriminated resistant and susceptible biotypes on the basis of R/S ratios (the ratio of GR 50 values of resistant and susceptible biotypes) within 7 d after herbicide treatment. The statistical agreement in R/S ratios between the rapid diagnostic tests (R/S ratios, 2.0-4.8) and the whole plant test (R/S ratio, 3.6) demonstrated that the rapid diagnostic tests could be reliably applied to diagnose cyhalofop-butyl resistance in E. crus-galli at various stages of growth with significant time and cost savings compared with conventional whole plant tests. In addition, the presented diagnostic results coupled with discrimination of herbicide-resistant weeds in previous studies suggest that the rapid diagnostic tests are capable of detecting herbicide resistance regardless of herbicide in many different weed species.

Akköprü A., Özaktan H. (2018): Identification of rhizobacteria that increase yield and plant tolerance to angular leaf spot disease in cucumber. Plant Protect. Sci., 54: 67-73.The biological control of angular leaf spot disease (ALS) of cucumbers (Cucumis sativus), caused by pseudomonas syringae pv. lachrymans (psl), using promising rhizobacteria (RB) and to compare RB efficacy to that of acibenzolar-S-methyl (ASM) was investigated. Effects of ASM and RB isolate pseudomonas putida AA11/1 that was isolated from the healthy cucumber root surface on disease severity and plant growth were evaluated using ALS-susceptible and tolerant cucumber cultivars in a growth chamber and a soilless growing system. ASM and AA11/1 significantly reduced average disease severity of ALS by 69 and 34% in the susceptible cultivar and 92 and 21% in the tolerant cultivar, respectively. ASM treatment significantly reduced psl populations, but AA11/1 did not inhibit psl growth in either cultivar. In the soilless system, disease severity was limited by either ASM or AA11/1, whereas only AA11/1 treatments significantly increased cucumber yield by 68 and 33% in the susceptible and tolerant cultivar, respectively.