SUMMARY

The study on controlling black leaf mold on tomato (Lycopersicon esculentum Mill) in the rainy season at Cho Gao district, Tien Giang province was conducted in Cho Gao district and the Lab of Nong Lam university from April to November 2009. The study’s contents consisted of (i) investigating the prevalence and progress of black leaf mold on tomato in the rainy season; (ii) examining some of morphological and biological characteristics of P. fuligena; and (iii) managemant of black leaf mold on tomato.

The study results were followed:

- Black leaf mold on tomato occurs commonly on all investigated fields of tomato in Binh Ninh, Binh Phuc Nhut, and Hoa Dinh commune of Cho Gao district with the disease incidence from 21.6 to 49.7% and the disease severity from 13.9 to 40.8% at the period 65-70 DAT (Days After Transplanting). The disease began to appear at 27-30 DAT, developed slowly to the period 50 DAT and then increased quickly from 50 DAT to the final harvest period.

- Conidia did not germinate at 10⁰C and 36⁰C temperatures after 10 hours. In the free water, the spore of P. fuligena germinated to 95% and the length of germ tube got 8.73 μm at temperature 28⁰C after 4 hours. Conidia germinated from 84.5% relative humidity, 19.16% germinated at 93.5% relative humidity after 4 hours and 11.85% germinated at 84.5% relative humidity after 10 hours. Conidia did not germinate at 80% relative humidity after 10 hours.

- Effective dosage 50% of germination of P. fuligena spore by fungicide Daconil 75WP, Trineb 80WP, Dithane M-45 80WP, and Antracol zinc was 31.01 mg ai/L, and 36.43 mg ai/L, 38.84 mg ai/L, and 393.18 mg ai/L respectively.

- The efficacy of the treatment with Olicide 9DD and Trineb 80WP was 77.7% and 54.4% in the period 37 and 80 DAT, increased 100% of the fresh fruit yield of tomato and the profit of 91.26 million VND per hectare compared with the untreated control.

- Application of integrated disease management procedure for controlling of black leaf mold on tomato reduced 70kg N/ha and 200kg P₂O₅/ha and two spraying times of chemical fungicides, but tomato yield was not lower than farmer’s field.