ISSN-1991-3036 (Online) & ISSN-2075-1621 (Optical) Int. J. Sustain. Crop Prod. 5(3):35-42 (August 2010) ECO-FRIENDLY SEED TREATMENTS IN CONTROLLING BLACK POINT (Bipolaris sorokiniana) OF WHEAT R. ZAMAN 1 , F.M. AMINUZZAMAN 2* , M.R. ISLAM 3 AND S.R. CHOWDHURY 4 1-4 Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh. Corresponding author & address: Dr. F.M. Aminuzzaman, E-mail: aminsaupp@yahoo.com Accepted for publication on 15 July 2010 ABSTRACT Zaman R, Aminuzzaman FM, Islam MR, Chowdhury SR (2010) Eco-friendly seed treatments in controlling black point (Bipolaris sorokiniana) of wheat. Int. J. Sustain. Crop Prod. 5(3), 35-42. Effect of different eco-friendly seed treatments against of black point of wheat under lab and field condition was studied during the period from December-2007 to March-2008 at the laboratory and farm of Sher-e-Bangla Agricultural University. Twelve treatments were explored in this experiment namely farmers saved seed ((T 1 ), apparently healthy seed (T 2 ), farmer’s saved seed treated with brine solution (T 3 ), apparently healthy seed treated with brine solution (T 4 ), sun drying of farmer’s saved seed (T 5 ), sun drying of apparently healthy seed (T 6 ), farmer’s saved seed treated with hot water (T 7 ), apparently healthy seed treated with hot water (T 8 ), polythene solarization of farmer’s saved seed (T 9 ), polythene solarization of apparently healthy seed (T 10 ), farmer’s saved seed treated with Bavistin 50WP (T 11 ) and Apparently healthy seed treated Bavistin 50WP (T 12 ).The experiment was laid out in the Randomized Complete Block Design (RCBD) with three replications. The highest reduction of incidence of black point (Bipolaris sorokiniana) was recorded in the treatment T 12. Among the eco-friendly treatments the highest reduction of incidence of seed infection over control was found in treatment T 8 (apparently healthy seed treated with hot water) in blotter test. Brine solution, sundrying and polythene solarized farmer’s and apparently healthy seeds also resulted significantly reduced black point severity over control. The treatments, T 6 also gave good result in reducing seed infection and increasing seed germination. Treatment T 4 and T 10 also increased seed germination and reduced the seed infection in field condition. Farmer’s saved seed treated with hot water, polythene solarization, brine solution and apparently healthy seeds showed moderate performances reducing black point severity over control (T 1 ). The treatment T 2 decreased 66.15% disease incidence though the maximum germination was increased up to 98.20% over untreated control under chemical seed treatment (T 12 ) where eco-friendly seed treatment (T 8 ) increased seed germination up to 90.67%. Key words: eco-friendly, seed treatment, black point (Bipolaris sorokiniana) wheat INTRODUCTION Wheat (Triticum aestivum L.) is the second food crop in Bangladesh due to its high nutritive value and low cost of production. But its yield is too low (1.85 t/ha) in compare to the world wheat production (2.54 t/ha). There are many constraints limiting the quality yield of wheat in Bangladesh. Among them use of poor quality or diseased seeds is one of the major constraints. Wheat plants at all growth stages prone to the attack of numerous diseases. Wheat suffers from as many as 26 seed borne pathogens causing 14 seed borne diseases. Among them leaf blight and black point caused by Bipolaris sorokiniana has become a serious concern in the recent years in Bangladesh (Fakir 1988). Bipolaris sorokiniana is reported highly seed transmitted causes seedling blight, Bipolaris leaf blight (BpLB) and black point in growing crop (Bazlur Rashid et al. 1994). General observations indicate that BpLB appears at the seedling stages & increased with increasing plant age and finally the pathogens attacks wheat grain causing black point (Alam et al. 1994). The fungi that causes black point are generally considered to be highly seed transmitted and considered a potential pathogenic threat to the subsequent crops produced from the infected seed but it’s practically impossible to obtain black point free seeds (Fakir 1999). The black point has in adverse effect on seed weight, germination and grain yield. The germination of black point affected seed was reduced to a great extent compared to the healthy grains (Khanum et al. 1987). Moreover, the reduction of germination was found in respect to the severity of black point infection (Dhurj 1991 and Chowdhury 2008). Since the black point disease of wheat causes significant yield loss, reduces the quality of the seed and has appeared as a potential threat for seed producer as well as to the farmers in Bangladesh. In controlling black point disease, several approaches have been practiced, such as use of resistant variety, cultural control, chemical control, biological control and use of plant extract etc. Cultivation of resistant variety is the most acceptable method for controlling this disease. But none of the wheat varieties in the country is found resistant against this disease (Hossain and Azad, 1992). The most acceptable method for controlling this disease is sowing of pathogen free seeds. Therefore along with routine seed health testing, seed treatment before sowing is necessary. Treatment of seed with seed-dressing fungicides was found to improve germination and decrease infection of seedling growth from the black pointed seeds. Indiscriminate uses of chemicals are creating health hazard and environmental pollution. Use of alternate methods instead of seed treating chemicals is of great concern now a day to save our environment. Int. J. Sustain. Crop Prod. 5(3): August 2010 35 Copyright© 2010 Green Global Foundation