The paper deals with the diagnosis through applying DAS-ELISA and indicator plants for detecting most widespread viruses in tomato and pepper agroecosystems for the period of 2012-2013. Tomato spotted wilt virus (TSWV) and Tomato mosaic virus (ToMV) were established as the most widespread viruses for tomato and pepper in field and greenhouses. Symptoms of individual and mixed infections caused by both viruses on tomato and pepper fruits were described and the influence of damages upon the yield was commented.

Five fungicides viz, chlrothalonil 75% WP, mancozeb 63% WP, iprodione + carbendazim 25+25 WP, metalaxyl + mancozeb 72% WP and carbendazim + mancozeb 12+63% WP were tested and of which carbendazim + mancozeb (91.1%) was most inhibitory for mycelial growth of Alternaria solani followed by mancozeb (85.5%) at 300 ppm. Management of early blight was better with increase in concentration of fungicides under field conditions. The minimum disease intensity was 8.2% with carbendazim + mancozeb @ 0.2% conc. followed by 11.4% with mancozeb @ 0.2%, 15.2% with iprodione + carbendazim 0.2%, 18.4% with metalaxyl + mancozeb 0.2% and 20.8% chlorothalonil 0.2% in field.

The effect of silicates on Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici, was evaluated in four trials using 'Cuore di bue' tomato plants, grown soilless. Silicon, as potassium silicate, was added at 100 mg L-1 to the nutrient solution at three levels of electrical conductivity: 1.5-1.6 (EC1), 3.0-3.2 (EC2) and 4-4.2 mS cm-1 (EC3). Pots containing tomato plants were inoculated with F. oxysporum f. sp. lycopersici (3×105 clamydospores L-1) 15-20 days before transplanting. Tomato plants were grown on benches in a glasshouse (20-28°C), at a density of five plants m-2. Physiological parameters, including chlorophyll content, transpiration and assimilation rates, and disease index were analyzed every 7 days. The addition of potassium silicate reduced Fusarium wilt in all trials, and it was primarily adsorbed at the root level while a lower difference in silicon content was observed in the shoots. No significant effect to plants physiology was observed. The increase of electrical conductivity of the nutrient solution showed no effects on the disease and caused a decrease of fresh weight and a reduction of physiological parameters of tomato plants.

Tomato (Lycopersicumesculentum) is one of the important horticultural commodity unfortunately the production is still low in quantity or quality. One of the important problems for the low productivity is the bacterial wilt disease caused by Ralstonia solanacearum. Some control methods have been developed but the disease still caused damages. One alternative control which can be prospective to be developed is the use of biocontrol agents. Among them the endophytic bacteria and Plant Growth Promoting Rhizobacteria (PGPR). The experiment was conducted to evaluate the viability of biocontrol agents, i.e. S.epidermidis BC4 and P. fluorescens RH4003 in the formula during storage and 3 the effectiveness of biopesticides formulation to control the bacterial wilt disease on tomato. Biopesticides were applied to the root during transplanting. Disease incidence and the height of the plant were calculated every week. Population of the bacteria in the formula was calculated at 0, 2, 4, and 8 weeks during storage. P. fluorescens RH4003 in granule formula applied into the soil caused disease suppression index up to 46.15%, which significantly lower compared with control, while S. epidermidis BC4 in liquid formulation with pH 5 caused disease suppression index up to 57.69%. Formula containing both of the bacteria did not affect the height growth of tomato plant. Population of the bacteria in the formula grew well at pH 5, 6, 7 and it was stable until 8 weeks of storage.

A solution culture experiment was conducted to screen out a number of Bangladeshi tomato germplasms for salinity tolerance by exposed to control, 8, 12 dS/m NaCl (salt stress). Salinity tolerance of tomato germplasms were evaluated with respect to salinity tolerance index, shoot and root dry matter production, shoot Na+, K+, Ca2+ accumulation and their respective ratios. A tolerance index was calculated for every single germplasm in root, stem and leaf dry weights and in the K/Na and Ca/Na parameters of these organs. Tomato germplasms responded differently to salt tolerance. Based on the salinity tolerance index caused by the NaCl treatment “BT14 (BARI Tomato 14)” and “BHT5 (BARI Hybrid Tomato 5)” were found to be most tolerant germplasms to salinity with highest salinity tolerance index, root-shoot dry matter production, accumulation of K and Ca and exclusion of Na. Thus, “BT14” and “BHT5” can be regarded as a breeding material for development of new tomato varieties for tolerance to salinity.

Tomato (Lycopersicon esculentum Mill.) is one of the most important vegetable crops in China. In May 2011, root rot and plant wilt were observed on tomato plants (variety Jinguan No. 5 and Meina) in 26 commercial greenhouses in Huludao city, Liaoning Province, China. Disease incidence was 30 to 95%. At beginning of fruit set, symptoms were chlorosis of lower leaves and lack of turgidity in young leaves. Severely affected plants were wilted and stunted as fruit approached maturity. Primary and secondary roots became necrotic with few fine feeder roots. Symptomatic roots were collected and cut into small pieces, disinfested in 2% sodium hypochlorite for 2 min, rinsed with sterile water, and placed on potato dextrose agar. After incubation at 25°C for 5 days, 20 axenic cultures were obtained from single conidia. Colonies were buff or salmon pink, moist, and had appressed, slimy mycelium. Aerial mycelium was sparse with simple or branched conidiophores. Conidia were 4.0 to 8.9 × 2.0 to 4.0 (average 6.9 × 2.8) μm, aggregated in slimy heads, hyaline ellipsoidal and ovoid, smooth, and 0 to 1 septate. Conidia were borne on phialides that were 6.3 to 24.3 × 1.4 to 3.3 (average 15.9 × 2.2) μm. These characteristics are typical of Plectosphaerella cucumerina (Lindf.) W. Gams (1) (anamorph: Fusarium tabacinum) (3). The internal transcribed spacer (ITS) region of the 20 isolates was amplified using the primers ITS1/ITS4 and sequenced. Identical sequences were obtained from all 20 isolates, and the sequence of isolate HLDT15 was submitted to GenBank (Accession No. KC894931). BLAST analysis of the sequence showed 100% similarity to P. cucumerina (AB469880). Pathogenicity tests were conducted with tomato variety Jinguan No. 5. Six 12-liter pots were filled with sterilized potting mix (equal parts sand, peat, and soil) and 200 ml conidial suspension (1 × 10⁵ conidia ml–¹). The conidial suspension of the isolate of P. cucumerina was prepared from 7-day-old cultures grown in potato dextrose broth on a shaker (120 rpm) at 25 ± 1°C. Six control pots were filled with potting mix and 200 ml of sterilized potato dextrose broth. Each pot was sown with six surface-sterilized (2% sodium hypochlorite for 2 min) tomato seeds. All the pots were kept in a greenhouse at 23 to 28°C. Three to four weeks after seedling emergence, all inoculated plants were dwarfed and lower leaves were chlorotic. Roots were necrotic and produced fewer fibrous roots. All characteristics were similar to original observations on the host of origin. Control plants remained asymptomatic. The same results were obtained when pathogenicity tests were repeated twice. P. cucumerina was reisolated from inoculated plants and matched the morphological and molecular characteristics of the original isolates. P. cucumerina was reported as a pathogen of tomato in Italy (2) and Australia (4). To our knowledge, this is the first report of P. cucumerina causing tomato wilt in China. So far, we have observed the disease on tomatoes in commercial greenhouses of Pulandian and Panjin city, Liaoning Province, China. The spread of this disease may pose a threat to tomato production in China.References: (1) A. Carlucci et al. Persoonia 28:34, 2012. (2) A. Matta et al. Riv. Patol. Veg. 14:119, 1978. (3) M. E. Palm et al. Mycologia, 87:397, 1995. (4) I. G. Pascoe et al. Mycol. Soc. 83:343, 1984.