TY  - BOOK
AU  - Sumesh K V
AU  - Annamalainathan K
AU  - Jacob J
AU  - Sonam S K
TI  - Physiological comparison of root trainer and polybag plants of rubber
PB  - PLACROSYM XXI. International Symposium on Plantation Crops, 10-12 December 2014, Kozhikode, India, pp. 100. Abstracts.
KW  - Polybag plants
KW  - Root trainer nursery
N2  - The root trainer nursery technique is a cost-effective, eco-friendly and labour-saving propagation technique which is gaining popularity among rubber (Hevea brasiliensis) growing countries these days. This technique ensures well developed taproot and lateral root systems, helping better anchorage, moisture exploration and nutrient supply for young plants in the field. Root trainer plants constantly experience mild stress due to the self-pruning of tap root, the tip of which is in contact with air, leading to the emergence of numerous lateral roots into the well-aerated potting medium. A study on the physiology of root  trainer rubber plants in comparison to polybag plants was done using two popular clones, RRII 105 and RRII 430. Physiological parameters like water potential, relative water content, chlorophyll content, PS II activity and photosynthetic efficiency were studied in root trainer and polybag plants. The growth of root trainer plants was always less compared to polybag plants, due to the restriction of root growth to the small container. Water relations in the leaf showed little variation among polybag and root trainer plants indicating that the water status in the plants did not vary much irrespective of the container type. Total chlorophyll content and chlorophyll a/b ratio were higher in polybag plants than root trainer plants of both clones. Polybag plants showed higher light saturation point from the light response curves and at higher light intensities root trainer plants of RRII 105 showed more excess electrons compared to other treatments, though there was no variation in effective quantum yield. Photosystem II activity and photosynthetic carbon assimilation rates were less in root trainer plants. Reduced photosynthetic efficiency of root trainer plants can be attributed to the accumulation of starch or other non-structural carbohydrates in the leaves as a result of root restriction, which are to be explored further. The results indicated that the stress generated by root restriction and air-pruning of tap roots in root trainer plants has significant effect on physiology of these plants as long as they remain in the container, which may help the plants to better adapt in the field under harsh environments as a result of printing
ER  -