Abstract
The effects of shading on growth and photosynthetic potential was analyzed with 8 cultivars with greengram (Vigna radiata (L.) Wilczek). Plants grown in 5 L pots were subjected to 2-week shading treatment and after 2-week recovery by removing a black-cheese cloth. Photosynthetic potential was evaluated by electron transport rate sealed on the both leaf surfaces by vaseline, which is close relationship to gross photosynthetic rate because CO 2 released by the reaction of photorespiration is recycled by stroma in chloroplast. Shading treatment reduced total dry weight of all cultivars. In particular, significant reduction in total dry weight was found in Nyangoo, Magwe and VC. Leaf specific area under shading treatment showed increment tendency and remarkable increase in this parameter was found in Nyangoo and VC, which cultivars decreased total dry weight under shading, indicating that shading treatment lead to thin of the leaf thickness. The ratio of plant height to diameter of stem was significantly decreased in R-288-8, Kanti and Yezin-5 by shading, indicating the restriction of succulent growth under shading condition and these cultivars are superior in lodging resistance to other cultivars. Photosynthetic rate as evaluated by electron transport rate sealed by vaseline was decreased by shading treatment. The extent of decrease in photosynthetic potential was found cultivaral difference. According to these results, Kanti is capable of applicable to the highest in resistance to shading and its recovery.
