Study on Radiation Interception and Use in Some Mustard Varieties

Aim: Solar radiation is the unique source of energy which drives the photosynthesis of green plants for producing biomass to living being. Use efficiency of solar radiation to produce biomass has been quantified for many crops in field condition but no study is undertaken for mustard although it is an important oil seed crop in the world as well as in Bangladesh. Therefore, the present study was undertaken to evaluate the radiation-use efficiency of mustard crop.

Study Design: The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replicates.

Place and Duration of Study: The experiment was conducted in the Crop Botany Field Laboratory, Bangladesh Agricultural University, Mymensingh during the winter season extended from November 2011 to March 2012.

Methodology: Treatments comprised six mustard varieties viz. BINAsarisha-3, BINAsarisha-4, BINAsarisha-5, BINAsarisha-6, BINAsarisha-7 and BINAsarisha-8 which were grown following standard cultivation techniques to optimize the growth and development. Radiation measurements along the growing season were carried out during solar noon on some sunny days with a Radiometer connected to a 1 m long Line Quantum Sensor.

Results: Mustard varieties showed wide variation in terms of plant height, branch number, leaf area index (LAI), dry matter (DM) accumulation, yield components and yield and radiation interception and use. BINAsarisha-6 showed better performance on the aforesaid traits followed by BINAsarisha-7 while lower performance was observed in BINAsarisha-3 and BINAsarisha-4. The higher seed yield (2.41 t ha-1) was obtained in the BINAsarisha-6, the variety also showed higher radiation-use efficiency, RUE (3.75 g MJ-1 PAR) whereas the lower seed yield (about 2.1 t ha-1) was observed in the BINAsarisha-3 or BINAsarisha-4, the varieties also showed the lower RUE (<3 g MJ-1 PAR) which indicate that the higher accumulation of DM in BINAsarisha-6 variety as influenced by higher utilization of solar radiation effectively constitute the seed yield. The temporal RUE showed much fluctuated pattern in all the varieties and higher RUEs were observed at the later part of the crop growth. The variety BINAsarisha-6 also showed the higher seasonal mean RUE whereas BINAsarisha-4 showed the lower.

Conclusion: Mustard varieties showed wide variation in growth, yield and radiation interception and use. Higher biomass production as well as higher seed yield is associated with higher utilization of solar radiation.