Shade Tolerance of 20 Genotypes of Tomato (Lycopersicon esculentum Mill.).

Abstract

Tomato is one of the major vegetable that has been cultivated in Indonesia. Decrease of harvest area of tomato affect decreasing in production, so it requires an effort to improve tomato production. The efforts to improve tomato production were use the land under trees, agroforestry, or intercropping system. Low light intensityis a limiting factor in the cultivation of intercropping. Aim of this study was to evaluate the production, morphosiology, and fruit quality of 20 tomato genotypes under shade. This studywas conducted at Cikabayan (experimental station-University Farm of IPB) from January to April 2013. The research was arranged by nested design with 3 replicates. The main plot was shade consisted of four levels, i.e., 0, 25, 50, and 75%, while sub plot was 20 genotypes of tomato i.e. Intan (T1), GIK (T3), SSH 3 (T6), Karina (T13), Roma (T21), Rempai (T23), Apel (T30), SSH 9 (T33), SSH 20 (T34), M4HH (T43), Bogor (T53), Medan 4 (T57), Kediri 1 (T60), Papua 2 (T64), Montero (T80), Fatma (T82), Ratna (T83), Delana (T84), Palupi (T85), dan Mawar (T86). Results of this study showed that most of the tested genotypes increased the production per plant under 25% shade, while under 50% shade showed a high diversity among genotypes. Based on relative yield under 50% shade, genotypes can be grouped into three, there are : sensitive (Intan, Rempai and Delana), tolerant (GIK, Roma, SSH 9, SSH 10, Bogor, Kediri 1, Montero, Ratna, and Mawar), dan shade-like (SSH 3, Karina, Apel, M4HH, Medan 4, Papua 2, Fatma, and Palupi). Production per plants affected by the yield component, mainly number of fruit per plant. 50% shade significantly affected some morphologicsl characters ie plant height, and leaf area. 50% shade increase significantly up to 68% on plant height and 45% on leaf area. More over on physiological character, 50% shade significantly affect leaf thickness, chlorophyll a and b, and the ratio of chlorophyll a/b. 50 % shade significantly reduced tomato leaf thickness up to 25 %. Chlorophyll a and b increased by level of shade, while the ratio of chlorophyll a/b decreases. Shade also affects the quality of tomato fruits. Tomato diameter increase significantly by 7 % on shade-like genotype in 50 % shade. 50% shade not significant on firmness, otherwise decrease significantly on total solid soluble but increasing total titration acid on shade-like genotype.