Bangladesh J. Environ. Sci., Vol. 28, 133-136, 2015 @ BAED ISSN 1561-9206 EFFECT OF SPACING ON MUSTARD YIELD AT SHIBGANJ AND SADAR UPAZILA OF BOGRA DISTRICT M. J. Alam 1 , K. S. Ahmed 2 , M. R. A. Mollah 3 , M. Z. Tareq 4 and M. M. I. Chowdhury 3 1 Dept. of Seed Science and Technology, Bangladesh Agricultural University, Mymensingh, Bangladesh; 2 Department of Entomology, Bangladesh Agricultural University, Mymensingh, Bangladesh; 3 On-Farm Research Division, Bangladesh Agricultural Research Institute, Bogra, Bangladesh; 4 Basic and Applied Research on Jute Project, BJRI, Rangpur, Bangladesh. ABSTRACT The experiment was conducted at Shibganj and Sadar upazila under Bogra district during October, 2014 to January, 2015 to observe the effect of row spacing on the yield of mustard. There were four row to row spacing such as 20 cm, 25 cm, 30 cm and 35 cm considered as a treatment. In both of the locations, significant variations due to different row to row spacing were observed in plant height, no. of branches plant - 1 , no. of filled siliqua plant -1 , no. of seed siliqua -1 , 1000 seed wt., yield plot -1 and yield ha -1 of mustard. Results also showed that the highest seed yield was 1.50 t ha -1 obtained from 30 cm row spacing in Shibganj upazila and 1.53 t ha -1 obtained from same spacing of row in Sadar upazila under bogra district. The lowest seed yield was 1.2 t ha -1 obtained from 20 cm row spacing. Key words: Row spacing; yield; mustard seed. Introduction Mustard (Brassica spp.) is one of the most important oil crop of the world. The genus Brassica belongs to the family Brassicaceae (formally Cruciferae). Rapeseed (Brassica campestris L.) commonly known as mustard in Bangladesh. It is a cool season crop. It is also a thermo sensitive as well as photosensitive crop (Ghosh and Chatterjee, 1988). It is popular edible oil in rural area of Bangladesh and is considered important for improving the taste of a number of food items. It also serves as an important raw material for industrial uses such as in soap, paints, varnishes, hair oils, lubricants, textile auxiliaries, pharmaceuticals, etc. The seed contains 40-45% oil and 20-25% protein. About 13.2% of the annual world edible oil supply comes from this crop (FAO, 2007). It is extensively grown traditionally as a pure crop as well as intercrop or mixed crop in marginal and sub-marginal soils in the eastern, northern and north western district of Bangladesh. However, the seed yield of mustard in Bangladesh is about 760 kg ha -1 which is very low in comparison to other developed countries (2400 kg ha -¹ ) (FAO, 2007). The low yield is due to lack of high yielding varieties and improper agronomic practices. Important physiological attributes such as planting dates, row to row spacing, plant density, planting method, seed rate, application of fertilizer, plant height, number of leaves plant -1 , number of filled siliqua plant -1 , number of seed siliqua -1 , 1000 seed weight plot -1 and yield plot -1 , leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR) and specific leaf weight (SLW) can address various constraints of a variety for increasing its’ productivity (Tandale and Ubale, 2007). There is a great scope of increasing yield of mustard by selecting high yielding varieties and improving management practices. Row spacing is one of the very important practice for mustard production (Mondal et al., 1999). Improved varieties of mustard or hybrids are capable of higher yields when grown under optimum row spacing and fertility level. The seed yield and maturity of mustard plants are greatly influenced by environmental conditi ons regardless of proper row spacing’s. Different row spacing’s provide variable environmental conditions within the same location for growth & development of crop and yield stability (Pandey et al., 1981). Row spacing is an important determinant of crop yield. It depends on the onset of significant rainfall, temperature and humidity of a region. Decreasing crop yield in improper spacing has been reported by many workers (Degenhardt & Kondra, 1981 and McDonald et al., 1983). The improper row spacing of mustard decreased seed yield through synchronization of silique filling period with high temperatures, the decrease in assimilates production, drought stress occurrence, shortened silique filling period and acceleration of plant maturity (Mendham et al., 1981). However, the information on yield dynamics of mustard with respect to row spacing is still lacking in Bangladesh. Therefore, the present study was undertaken to find out the suitable row to row spacing for mustard seed production in the northern part of Bangladesh. 133