A study was carried out to investigate the incidence and severity of fungal rot of tomato in different districts of Kashmir Valley. It was observed that in tomato fruits in storage are attacked by different fungal diseases such as Fusarium rot caused by Fusarium oxysporum, Mucor rot caused by Mucor plumbeus, and Rhizopus rot caused by Rhizopus stolonifer in all the districts surveyed. The incidence and severity of these diseases showed lot of variation during 2008–2010 in district Srinagar, Budgam and Anantnag. The severity of fungal rot was highest in Budgam followed by Anantnag and Srinagar districts, respectively. This varation in the incidence and severity in different districts may be due to different climatic and nutritional conditions.

Symptoms of a bacterial disease caused by Xanthomonas campestris pv. vesicatoria were observed on tomato plants growing in Al-Kharj area of Saudi Arabia. Symptoms included irregular yellow-necrotic areas on tomato leaves and spotting on the stem. Five bacterial isolates were isolated from the infected tomato seedlings. The pathogen identity was confirmed biochemically, and physiologically, hypersensitive reaction occurred in tobacco plants and pathogenicity test was conducted. All concentrations tested of salicylic acid (SA) had inhibitory effects against X. c. pv. vesicatoria under laboratory conditions. Application of SA at 1.5 ppm reduced severity of bacterial leaf spot of tomato.

A bacterial strain CH-67 which exhibits antagonism towards several plant pathogenic fungi such as Botrytis cinerea, Fulvia fulva, Rhizoctonia solani, Sclerotinia sclerotiorum, Colletotrichum sp. and Phytophthora sp. was isolated from forest soil by a chitin-baiting method. This strain was identified as Burkholderia cepacia complex (Bcc) and belonging to genomovar Ⅸ (Burkholderia pyrrocinia) by colony morphology, biochemical traits and molecular method like 16S rRNA and recA gene analysis. This strain was used to develop a bio-fungicide for the control of tomato leaf mold caused by Fulvia fulva. Various formulations of B. pyrrocinia CH-67 were prepared using fermentation cultures of the bacterium in rice oil medium. The result of pot experiments led to selection of the wettable powder formulation CH67-C containing modified starch as the best formulation for the control of tomato leaf mold. CH67-C, at 100-fold dilution, showed a control value of 85% against tomato leaf mold. Its disease control efficacy was not significantly different from that of the chemical fungicide tri-flumidazole. B. pyrrocinia CH-67 was also effective in controlling damping-off caused by Rhizoctonia solani PY-1 in crisphead lettuce and tomato plants. CH67-C formulation was recognized as a cell-free formulation since B. pyrrocinia CH-67 was all lethal during formulation process. This study provides an effective biocontrol formulation of biofungicide using B. pyrrocinia CH-67 to control tomato leaf mold and damping-off crisphead lettuce and tomato.

This study includes the investigation of chemical properties such as nitrosomyoglobin content, lycopene content, and the oxidation level, and the sensorial properties of frankfurters which have been produced by both reducing the nitrite level and adding tomato powder. All samples have been vacuum packed and stored at +4 °C for 60 days. The pH of the frankfurters produced with tomato powder was reduced, when compared to the samples which did not contain tomato powder. This effect was due to the acidic characteristics of tomato. As the level of nitrite was reduced, the oxidation level of the frankfurters was increased significantly. Addition of 2 g/100 g of tomato powder decreased the level of oxidation; however, 4 g/100 g of tomato powder caused a slight increase when compared to the samples which did not contain tomato powder. According to this result it can be stated that tomato powder retards the oxidation reaction. According to sensorial evaluations, tomato powder improved the consumer acceptability as well. Addition of tomato powder increased the internal and external colour scores, and frankfurters were found to be more acceptable by the panellists. Nitrosomyoglobin (NOMb) content of the samples was decreased along with the decreased level of nitrite, and this, in turn, contributed to the decreased level of redness (a*).

This is the first ICRISAT Information Bulletin that deals with a virus disease of groundnut. Attention is focused on bud necrosis disease, caused by tomato spotted wilt virus, because of its economic significance on three continents. Epidemics build up rapidly with little warning and cause serious losses to growers. Protocols for purification and identification of the virus are given in detail. The symptoms of the disease in groundnut are illustrated. Procedures for a simple enzyme-linked immunosorbent assay for the detection of the virus are given. The identification of the vector insects?species of Thysanoptera (thrips)?is difficult, and is still to be fully resolved. But a key is provided as an aid in identifying seven thrips species that have been implicated as vectors of tomato spotted wilt virus on groundnut. The current situation concerning management of bud necrosis disease is outlined. Suitable insecticides, cultural practices, biological control, and host-plant resistance are discussed to assist crop protection and extension workers in formulating integrated management systems appropriate to their particular situations | D V R Reddy et al., 'Bud Necrosis: A Disease of Groundnut Caused by Tomato Spotted Wilt Virus', International Crops Research Institute for the Semi-Arid Tropics, 2011

Symptoms of a bacterial disease caused by Xanthomonas campestris pv. vesicatoria were observed on tomato plants growing in Al-Kharj area of Saudi Arabia. Symptoms included irregular yellow-necrotic areas on tomato leaves and spotting on the stem. Five bacterial isolates were isolated from the infected tomato seedlings. The pathogen identified was confirmed biochemically and physiologically, hypersensitive reaction occurred in tobacco plants and pathogenicity tests were conducted. Significant variability was shown among the bacterial isolates. Isolates T2, T4 and T5 were the most pathogenic isolates as expressed by the disease severity index. The highest severity index (57.8%) was observed by isolate T5, followed by the two isolates T4 (55.3%) and T2 (43.1%) two weeks post inoculation. In an attempt to control this disease, Salicylic acid was used to study its ability to inhibit the growth of X. campestris pv. vesicatoria in vitro, and its potentiality in suppressing bacterial spot of tomato under artificial inoculation conditions. All concentrations tested had inhibitory effects against X. campestris pv. vesicatoria. The inhibition zone increased with increasing concentrations. SA at 1.5 ppm caused the largest inhibition zone (40 mm) followed by 1 ppm (33 mm). Application of SA at 1.5 ppm reduced the severity of bacterial leaf spot of tomato. Application as foliar treatment was more effective than seedling treatment. SA was the most effective at 1.5 ppm as foliar treatment where the number of lesions/leaf and disease severity were 1.8 and 14.1, respectively.

Black leaf mold caused by Pseudocercospora fuligena is an important fungal disease of tomato in Southeast Asia. The objective of this study was to evaluate the control of this disease using high manganese (Mn) applied to the root substrate and to evaluate the role of the leaf apoplast in plant response to fungal infection. In a nethouse experiment in Thailand, Mn above the optimum for plant growth but below toxicity increased resistance of tomato plants to black leaf mold. Enhanced resistance caused by Mn was also obtained when tomato plants were grown under controlled conditions in a mist chamber and artificially inoculated with the fungus. Manganese significantly increased plant peroxidases in the leaf apoplast. The highest peroxidase activity was measured when plants were inoculated with Pseudocercospora fuligena. Defense‐related proteins in the leaf apoplast increased when plants were inoculated with Pseudocercospora fuligena but not when treated with high Mn. It is concluded that Mn above the optimum level for plant growth can contribute to the control of Pseudocercospora fuligena in tomato. The Mn effect on disease resistance is associated with the activation of plant peroxidases in the leaf apoplast. A systemic response, possibly mediated by NADH peroxidase activity, also seems to trigger disease resistance in leaves with low Mn concentrations.

Several surveys were carried out during three consecutive years (2007-2009) on the major crops cultivated in different districts of Nepal, in order to verify the possible presence of diseases caused by bacteria. The monitoring was carried out twice a year, in spring and autumn. During the survey we observed a wide range of bacterial diseases of plants. Most of the diseases were observed for the first time while others had been reported previously. Among the bacterial diseases observed for the first time, the most important were olive knot, bacterial speck of tomato, crown gall of plum, soft rot of potato, bacterial spot of tomato, and bacterial spot of cucurbits. Outbreaks of black rot were observed in different Brassica fields. Among the other widespread diseases, the most important were bacterial leaf blight of rice, citrus canker, citrus greening, bacterial wilt of tomato, potato, pepper, and eggplant, halo blight of bean, and bacterial pustule and bacterial blight of soybean. Attempts to explore the source of introduction of these pathogens, their spread, and yield losses caused were made together with recommendations for control measures.

Bacterial wilt of tomato caused by Ralstonia solanacearum is one of the most devastating diseases of tomato (Solanum lycopersicum) on the Eastern Shore of Virginia (ESV). Four research trials were conducted on the ESV over three growing seasons to determine the temporal and spatial distribution of bacterial wilt throughout commercial tomato fields. Individual plants were assessed at 1-week intervals throughout the growing seasons with the incidence of bacterial wilt for each individual plant being recorded. Bacterial wilt increased gradually during each growing season. An increase in the clustered distribution of symptomatic plants was determined to exist within rows but not across rows. There were positive correlations between disease incidence and the percentage of rows exhibiting a significantly clustered distribution in every trial. These findings suggest that as bacterial wilt incidence increases in tomato fields by either the intimate contact between roots of adjacent tomato plants or the movement of the pathogen in surface irrigation water, symptomatic plants become more clustered within rows.

The tomato (Solanum lycopersicum L.) crop is highly susceptible to viruses, including the Tomato mosaic virus (ToMV), Tobamovirus. The symptoms vary from tiles, wrinkle, reduction and curvature of leaflets, and irregular ripening of fruits. This disease requires attention because of its easy dissemination by contact, cultural practices, or contaminated seed. Control is mainly based on the use of virus-free seeds. For detection of the pathogen, different methods may be used, including molecular or biological, and the use of indicator plants. However, these methods require appropriate facilities and are time consuming. Furthermore, the existence of strains of Tobacco mosaic virus (TMV), Tobamovirus, may cause symptoms similar to those caused by ToMV, making the biological test more complex. When it comes to establishing the health of a seed lot, the use of indicator plants may be replaced by the monoclonal-ELISA test. The DAS-ELISA is a relatively sensitive technique and is widely used for preliminary identification and quantification of viruses in plants. This study aimed to evaluate the efficiency of the ELISA test for detection of ToMV in tomato seeds, and to determine the ideal time for seed treatment by thermotherapy using dry heat (70°C). The DAS-ELISA test on tomato seeds was an efficient method for detection. Thermotherapy for 24 h was shown to be effective in eradicating the virus, and caused less damage to the seed physiological quality.