Mersin is the second most intensive tomato-producing city in Turkey, with a harvest of 470,239 tons of tomatoes. Tomato is produced in plastic greenhouses in coastal areas of Mersin in winter, and open fields on the plateau are used for summer growth. In 2015, plastic greenhouses and open fields in Mersin city were surveyed to screen for tomato bacterial diseases. From surveys carried out in April-August 2015, it was determined that bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmm) was the most destructive tomato bacterial disease in open fields. However, typical symptoms of bacterial speck caused by Pseudomonas syringae pv. tomato (Pto), stem soft rot caused by Pectobacterium caratovorum (Pca), pith necrosis caused by Pseudomonas viridiflava (Pvir) and bacterial canker caused by Cmm were observed in plastic greenhouses between September 2014 and May 2015. Bacterial speck disease was widespread in plastic greenhouses. In total, 63 bacterial strains were isolated from diseased plant material, and all strains were pathogenic on tomato 'Alsancak'. The strains were identified as Cmm, Pto, Pca and Pvir according to morphological and biochemical properties by using LOPAT tests (L, levan production; O, oxidase reaction; P, pectolytic activity on potato slices; A, arginine dihydrolase activity; T, hypersensitive reaction on tobacco), fatty acid methyl ester (FAME) analysis and PCR with species-specific primers (except for Pvir). Visits to open fields and plastic greenhouses in Mersin are under way in further production season of tomatoes.

International audience | In spring 2016, severe spots were observed on nearly all tomato plants cvs. Amal, Kaouther and Malinche grown in several greenhouses in the region of Teboulba, on the eastern coast of Tunisia. Affected plants presented 1 to 5 mm, angular, necrotic spots surrounded by a yellow halo on young and older leaves (Fig. 1). When numerous lesions occurred on a single leaflet, they coalesced and a portion or the entire leaflet turned necrotic and died. Necrotic lesions were also observed on petioles, peduncles and stems of diseased plants. In some cases, a brown-black colouration was observed along the entire stem (Fig. 2). Similar necrotic symptoms were observed during spring 2017 on tomato seedlings grown in nurseries in the Kairouan governorate, in the centre of Tunisia.

In spring 2016, severe spots were observed on nearly all tomato plants cvs. Amal, Kaouther and Malinche grown in several greenhouses in the region of Teboulba, on the eastern coast of Tunisia. Affected plants presented 1 to 5 mm, angular, necrotic spots surrounded by a yellow halo on young and older leaves (Fig. 1). When numerous lesions occurred on a single leaflet, they coalesced and a portion or the entire leaflet turned necrotic and died. Necrotic lesions were also observed on petioles, peduncles and stems of diseased plants. In some cases, a brown-black colouration was observed along the entire stem (Fig. 2). Similar necrotic symptoms were observed during spring 2017 on tomato seedlings grown in nurseries in the Kairouan governorate, in the centre of Tunisia.

The mirid Engytatus varians (Distant) is a promising biological control agent of the tomato borer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), one of the most destructive pests of tomato (Solanum lycopersicum L.). The effects of five insecticides commonly used on tomato crops in Brazil were evaluated on E. varians in laboratory and semifield conditions. Glass Petri dish with residues of chlorfenapyr, thiamethoxam, and abamectin caused ˃90% mortality in both stages of the predator 72 h post-treatment, except imidacloprid that caused 78% of nymphs mortality. Teflubenzuron caused 24 and 66% mortality on adults and nymphs, respectively. The offspring of females derived from treated nymphs with teflubenzuron was significantly lower than the control but not when females were treated as adults. Longevity of males derived from nymphs treated with teflubenzuron was significantly reduced, but no effects were observed on females. When males and females were treated as adults with teflubenzuron there were no effects on their longevity. In the greenhouse-aged tomato plants, the 2 h-old residues of thiamethoxam, chlorfenapyr, and abamectin caused more than 70% of mortality of third instar of E. varians at 72 h post-treatment, 12 day-old residues of all three compounds caused a mortality lower than 30%. These data suggest that teflubenzuron can be associated with releases of E. varians adults, while the use of other evaluated pesticides should be avoided in this situation. Although, the low persistence of these products indicate that their spraying and later releases of E. varians adults on tomato crops are a possible strategy to control T. absoluta.

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a serious threat to tomato production in the world. Due to serious issues with insecticide resistance, there is a dire need for alternative control methods. Entomopathogenic nematodes (EPN) have potential for the biological control of T. absoluta. In the laboratory, we examined the effect of temperature, soil type, and exposure time on the efficacy of the EPN species Steinernema carpocapsae (Nematoda: Steinernematidae) and Heterorhabditis bacteriophora (Nematoda: Heterorhabditidae) against last-instar T. absoluta larvae. Both species caused high mortality in loamy sand (89%) and coco peat (93%) but not in sandy loam (17%). H. bacteriophora caused 92−96% mortality at 19, 25, and 31°C; S. carpocapsae caused 89−91% mortality at 25 and 31°C but only 76% at 19°C. Both species caused similar mortality levels after 65-min exposure; thereafter, mortality increased only with S. carpocapsae reaching high levels even at a low concentration. Both species infected larvae within leaf galleries. When applied to whole large tomato plants in the greenhouse, both species provided similar control levels (48−51%) at high pest densities. Both species could be incorporated as an effective alternative to synthetic insecticides into T. absoluta management programs in greenhouse tomato production.

In spring 2016, severe spots were observed on nearly all tomato plants cvs. Amal, Kaouther and Malinche grown in several greenhouses in the region of Teboulba, on the eastern coast of Tunisia. Affected plants presented 1 to 5 mm, angular, necrotic spots surrounded by a yellow halo on young and older leaves (Fig. 1). When numerous lesions occurred on a single leaflet, they coalesced and a portion or the entire leaflet turned necrotic and died. Necrotic lesions were also observed on petioles, peduncles and stems of diseased plants. In some cases, a brown-black colouration was observed along the entire stem (Fig. 2). Similar necrotic symptoms were observed during spring 2017 on tomato seedlings grown in nurseries in the Kairouan governorate, in the centre of Tunisia.

Bacterial canker caused by Clavibacter michiganensis is considered to be one of the most serious diseases, leading to economic damage to tomato worldwide. Diagnosis of the bacterial canker on tomato is known to be difficult because the causal pathogen is slow-growing on artificial media as well as causes latent infection in tomato. In this study, as a less time-consuming method, a specific primer set was newly designed for rapid detection of C. michiganensis. The method presented here is so simple, easy, and fast that it can be useful and practical in direct detection of the bacterial canker pathogen from tomato plants.