361 Original Article Biosci. J., Uberlândia, v. 32, n. 2, p. 361-370, Mar./Apr. 2016 EFFECT OF ORGANIC AMENDMENT ON STEM CANKER AND BLACK SCURF DISEASE OF POTATO (Solanum tuberosum) EFEITO DA ALTERAÇÃO ORGÂNICA SOBRE O CANCRO DA HASTE E DOENÇA DOS TUBERCULOS PRETOS DA BATATA (Solanum tuberosum) M. M. RAHMAN 1 ; M. A. ALI 2 , T. K. DEY 3 ; M.M. ISLAM 4 ; M. U. AHMAD 2 ; K. M. KHALEQUZZAMAN 5 1. Tuber Crops Research Sub-centre, BARI, Bogra, Bangladesh; 2. Department of Plant Pathology, BAU, Mymensingh, Bangladesh; 3Pulses Research Centre, BARI, Ishurdi, Pabna, Bangladesh; 4. Tuber Crops Research Centre, Bangladesh Agricultural Research Institute, Gazipur-1701, Bangladesh. monirupm.my@gmail.com; 5. Spices Research Centre, BARI, Shibganj, Bogra, Bangladesh ABSTRACT: An experiment was conducted at Tuber Crops Research Centre, BARI, Bogra during 2008-2009 to evaluate the organic amendment for controlling the stem canker and black scurf of potato. The different kinds of organic amendments were: T 1 =Poultry refuse (PR) at 4 t ha -1 , T 2 =PR at 5 t ha -1 , T 3 =PR at 6 t ha -1 , T 4 =Mustard oil cake (MOC) at 300kg ha -1 , T 5 =MOC at 500kg ha -1 , T 6 =Neem oil cake (NOC) at 300kg ha -1 , T 7 =NOC at 500kg ha -1 , T 8 =Sawdust burning and T 9 = Control. The experiment was laid out in a randomized complete block design (RCBD) with four replications. The organic amendment significantly influenced the disease incidence, yield attributes and yield of potato. The lowest disease incidence (17.5%) and per cent disease index (9.99) were found in T 3 (poultry waste at 6 t ha -1 ). The minimum russet, deformed and Sclerotia infected tubers were also recorded in poultry waste at 6 t ha -1 . The highest healthy tubers and tuber yield were found in the same treatment. Therefore, poultry manure 6 t ha -1 along with recommended dose of chemical fertilizer can be recommended to produce healthy tubers and maximum tuber yield of potato. KEYWORDS: Organic soil amendment. Stem canker. Black scurf. Solanum teberosum. INTRODUCTION Potato is a very important vegetable crop in Bangladesh (HASHEM, 1990). It is used as food and cash crop in cool countries. It can meet the vegetable demand and provide necessary nutrients for the people from low income group (ISLAM et al., 2009). The average fields of potato in Bangladesh is 18.25 t ha -1 , which is much lower than the other potato growing countries especially North America and Netherlands where potato is 41.3 t ha -1 (SWAMINATHAN, 2000). The major constraint of potato production in Bangladesh is prevalence of epidemic disease, the lack of quality supply of potato seed to the farmers (RAHMAN et al., 2014). In Bangladesh, a total of 39 diseases both biotic (fungi, bacteria, virus, nematode, actinomycetes, mycoplasma) and abiotic (nutritional, physiological, environmental) of potato tuber have been recorded (ALI; KHAN, 1990). One of the major diseases is stem canker and black scurf caused by Rhizoctonia solani (Khun). It is the most common and widespread disease throughout the country (ALI; DEY, 1994). Rhizoctonia solani is a soil-borne and tuber-borne fungus and causes `black scurf’ on potato tubers and canker on stems. Severe stem canker can kill shoots and delay crop emerge (RAHMAN et al., 2014). The canker is commonly known as black scurf. The pathogen is also involved in the early dying syndrome of potato (KOTCON et al., 1985). In winter, the pathogen usually lives as mycelium or sclerotia in the soil and in or on infected perennial plants or propagative material such as potato tubers. Sometimes, the fungus may be carried in the seed. The fungus is present in most soils and once established in a field, remains there indefinitely (AGRIOS, 2005). Organic amendment with poultry refuse (PR), poultry liter (PL), sawdust (SD) and mustard oil cake (MOC) was evaluated where poultry refuse was found to be effective in controlling stem canker and black scurf of potato and showed the maximum yield (DEY et al., 2005). Many researchers attempted to control black scurf and stem canker of potato Integration of different approaches has also been attempted in different countries (RAHMAN, 2011). However, there is no sufficient report for controlling the black scurf and stem canker of potato in Bangladesh (RAHMAN et al., 1996). Under this circumstance, developing a package for controlling the diseases is of prime need. Therefore, the present study was initiated to evaluate the organic amendment in soil for controlling stem canker and black scurf of potato. Received: 20/04/15 Accepted: 20/01/16