Effect of water deficit regimes on growth and flowering of marigold

The present research work was conducted to evaluate the two cultivars of marigold for the drought tolerance in a pot trial. Various treatments consisting of the application of the irrigation at different time intervals were applied to the both cultivars. The data was collected at the termination of the experiment and was subjected to analysis using statistical software. As a result of the treatment application variation in the performance was exhibited as the means values of the studied traits varied significantly. Data regarding various growth and physiological parameters after analysis showed variations in their performances. The effect of all the treatments on the plant height of both the cultivar was significant. The plant height of both the cultivars was maximum when the plants were irrigated after one day time period. The plant height gradually decreased as the irrigation interval increased. Maximum plant height (44.3 cm) was yielded by the cultivar Inca followed by the same cultivar for the treatment T2 (4 days interval). Over all the performance of the variety Inca for the plant height was better as compared to variety Bonanza for all treatments. It was also clear that root length also varied drastically against the influence of the drought. It was exhibited from the results that the maximum root length 6.5 cm was produced by the cultivar Inca when the water was applied after 1 day interval followed by the cultivar Bonanza yielding 6.1 cm of the root length against the same treatment. Similarly, the treatment T2 and T3 performed drastically and yielding 5.6 cm and 5.2 cm for the variety Inca and 5.2 and 4.8 for the variety Bonanza respectively. As the irrigation interval increased the shoot fresh weight dramatically decreased leading to the minimum value for the shoot fresh weight at the treatment T4 (Irrigation after 8 days). It is also clear that among all the treatments the treatment T0 yielded maximum cumulative value for shoot fresh weight (14.84 g) for both cultivars as compared to all other treatments. It was obvious from the comparison of means that both of the cultivars behaved differently for the root fresh weight. Maximum root fresh weight (5.953 g) was yielded against T1 in which irrigation was applied after 1 day interval. Similarly, the treatment T2 also showed much better results as it yielded 5.097 g of the root fresh weight. Poor performance with respect to root fresh weight (2.607 g) was exhibited by the treatment T4 (irrigation after eight days interval). Over all the performance of the variety Inca for the root dry weight was better as compared to variety Bonanza for all treatments. It was also clear from the results that maximum root-shoot ratio for fresh weight (5.2) was produced by the cultivar Inca when the water was applied after 4 day interval followed by the same cultivar against the treatment T0. Similarly, the treatment T3 and T4 performed drastically and yielding 4.9 and 4.7 for the variety Inca and 2.8 and 2.2 for the variety Bonanza respectively. The chlorophyll a contents gradually decreased as the irrigation interval increased. Maximum amount of chlorophyll a (2.7 mg g-1 FW) was yielded by the cultivar Inca followed by the cultivar Bonanza for the treatment for the same treatment (irrigation after 1 days interval). Over all the performance of the variety Inca for the Chlorophyll a was better as compared to variety Bonanza for all treatments. The comparison of the both cultivars for this biochemical attribute depicted that among both the cultivars the cv. Inca produced the maximum amount of chlorophyll b (1.43 mg g-1 FW) followed by the cultivar Bonanza (1.28 mg g-1 FW) for the treatment T0. It was obvious from the results that the chlorophyll b contents in the plants gradually decreased as the irrigation interval increased. The minimum values (0.58 mg g-1 FW) for the chlorophyll b were recorded in the cultivar Bonanza at the irrigation interval of 8 days. Maximum total chlorophyll contents (4.32 mg g-1 FW) was produced by the cultivar Inca when the water was applied after 1 day interval followed by the cultivar Bonanza yielding total chlorophyll contents 3.58 mg g-1 FW against the same treatment. Similarly, the treatment T2 and T3 performed drastically and yielding 3.2 mg g-1 FW and 2.2 mg g-1 FW total chlorophyll contents for the variety Inca and 2.58 mg g-1 FW and 2.16 mg g-1 FW total chlorophyll for the variety Bonanza respectively. Various levels of drought also affected the anatomical structure of the root, shoot and the leaves. However the best performance among both the cultivars were exhibited by the Cultivar Inca which behaved also good for most of the morphological, yield and anatomical attributed against all levels of irrigation intervals. It can be recommended for the landscape premises facing the scarcity of water.