RESUMO
Aim: Salt stress adversely affects plant growth and development. Various mitigating strategies have been employed to enhance the adaptability of plants to salt stress. The present study was conducted with the objective of evaluating the recently developed CO55 rice variety's ability to withstand salt-induced stress during seedling growth. This evaluation included foliar spraying of plant growth promoting substances like melatonin, salicylic acid, silicon, and selenium, along with the identification of effective plant growth-promoting substances that exhibit tolerance to salinity. This study is required to develop salt-tolerant varieties capable of withstanding salinity stress during the seedling stage. The seedling stage is more susceptible to salinity, and also to increase the growth and yield of rice, thereby satisfying the country's agricultural needs.Study Design: Completely randomized design.Place and Duration of Study: Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore; March-April 2023.Methodology: In the hydroponics experiment, the CO55 rice variety was subjected to foliar spraying of various plant growth promoting substances such as melatonin, salicylic acid, orthosilicic acid, and sodium selenate. Parameters like leaf drying score, osmotic potential, osmotic adjustment, sodium content, potassium content, and Na+/K+ ratio were assessed. One-way ANOVA was used to analyze the data.Results: Specific pairwise differences between means were assessed at the 0.05 significance level using Fisher's least significant difference (LSD) test. Among the treatments applied, salicylic acid recorded the highest potassium content (3.94%), and the lowest potassium content (2.60%) was found in orthosilicic acid. On the other hand, from the standard evaluation score, it was observed that CO55 rice variety seedlings were found to be tolerant when treated with salicylic acid, whereas it was susceptible under orthosilicic acid treatment.Conclusion: Observations indicated that foliar application of salicylic acid at the concentrations of 50µM and 100µM exhibited higher tolerance towards salinity during the seedling growth stages.
RESUMO
A field experiment to evaluate the performance of ten scented field roses in terms of growth and floral parameters under open field condition was carried out at Botanical Garden, Department of Floriculture and Landscape Architecture, Tamil Nadu Agricultural University, Coimbatore during the year 2022-2023. Since there is a major lacuna in variety of scented field roses for cultivation in farmer’s field, the present study was undertaken to assess suitable variety for commercial cultivation under Coimbatore condition. The field experiment was carried out using Randomized Block Design (RBD) with ten treatments (Arka Sukanya, Arka Parimala, Bourbon rose type 1, Bourbon Rose type 2, Pusa Alpana, Rose Sherbet, Scent Pink, Damask rose type 1, Damask rose type 2, Andhra Red) and three replications. Results indicate a significance difference between the varieties for growth, flowering and yield characters. Experimental data revealed that the maximum plant height (68.92 cm), maximum number of shoots per plant (8.21), maximum leaves per plant (410.50), stem girth (6.28 cm), Highest chlorophyll content (58.1), Least number days for flower bud initiation (31.05), Diameter of fully opened flower (5.89 cm) and fresh flower weight (3.59 g) were seen in Bourbon rose type 1. Bourbon rose type 2 recorded maximum number of flowers per plant (41.12) and Andhra red rose recorded maximum number of petals per flower (94.89) among the evaluated varieties.
RESUMO
The dragon fruit (Hylocereus costaricencis) is a new emerging fruit crop, there is very less information available on the spacing and fertilizer dose requirements of this crop so the present study was carried out to find the effect of fertilizer doses, spacings, and interaction effect of both on plant growth of dragon fruit (Hylocereus costaricencis) at the Orchard, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore. during the year 2022. The design of the experiment was a split plot with four main plots viz. M1 = 3.5 x 2.0 m2, M2 = 3.0 x 3.0 m2, M3 = 3.0 x 2.5 m2, M4 = 2.5 x 2.5 m2 and six sub plots viz. S1 = N540 P420 K360, S2 = N495 P385 K330, S3 = N450 P350 K300, S4 = N340 P260 K225, S5 = N225 P175 K150, S6 = N0 P0 K0 g per pillar was applied and replicate four times. A significant difference was observed in terms of vine length (m), cladode girth (cm), cladode length (cm), and cladode number when different doses of fertilizers were applied. The highest vine length (2.96), cladode girth (24.52), cladode length (67.21), and number of cladodes (67.48) were observed in S3 (N450 P350 K300). Similarly, the highest vine length (2.503) and cladode girth (19.78) were observed in M4 (2.5 x 2.5 m2). The highest cladode length (67.47) was observed in treatment combination M2S3. Hence, the application of fertilizer dose S3 (N450 P350 K300) and adoption of spacing M4 (2.5 x 2.5 m2) is good to enhance the vegetative growth characters of dragon fruit under Tamil Nadu conditions.
RESUMO
Aims: An experiment was conducted to examine the effect of various concentrations of melatonin on post harvest weight loss and shelf life of three traditional banana varieties viz. Ney Poovan, Nendran and Red Banana.Study Design: Completely Randomized Design.Place and Duration of Study: Post Graduate laboratory, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore during 2022.Methodology: Banana hands were dipped in 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mM melatonin for 15 minutes and were stored at ambient temperature. The hands dipped in water were treated as control. Observations on physiological weight loss and shelf life were recorded till the fruits remained marketable.Results: The results depicted that fruits immersed in 1.0 and 1.5 mM melatonin for 15 minutes recorded lower weight loss (31.56, 30.55 and 24.90%) on 11th, 11th and 12th day of storage and longer shelf life by 3, 2.67 and 2.67 days in Ney Poovan, Nendran and Red Banana respectively.Conclusion: The effects of melatonin were due to its efficiency in reducing transpiration and respiration and thereby lowering weight loss. The lowered metabolic activity not only mitigated weight loss but also maintained firmness and turgidity of the fruits and thereby prolonging the storability. It was evident from the results that melatonin treatment could be a good practice for extending postharvest life of banana by reducing the physiological loss in weight simultaneously maintaining the appearance.