Comparative response of Malaysian weedy rice (Oryza sativa) initial growth towards the allelopathic potential of Leucaena leucocephala (Lam.) de Wit and Dicranopteris linearis (Burm. f.) Underw

The infestation of weedy rice has becoming a threat which leads to competition between weedy rice and commercial rice for nutrient uptake. Weedy rice management is more dependent on the herbicides application that can contribute to various environmental problems. Thus, this study was conducted to assess the allelopathic potential of two invasive plants namely L. leucocephala and D. linearis in controlling the growth of weedy rice. The allelopathic potential was evaluated through laboratory bioassay namely the dish pack method, sandwich method and plant box method to determine the allelopathic potential on the seedling growth of two weedy rice variants collected in Peninsular Malaysia (designated as WRE and WRN) and MR220 CL2 rice variety. Highest concentration of L. leucocephala leaf litter (50 mg) inhibited the radicle elongation of MR220 CL2, WRN and WRE by 49 %, 51 % and 83 % compared to control, respectively. Through the dish pack method, the volatile compound from D. linearis leaf were found to disrupt the radicle growth of MR220 CL2, WRN and WRE by 21 %, 29 % and 25 % of the control at the nearest distance (41 mm) of the bioassay plants with the D. linearis leaf. Compared with D. linearis, the root exudate from L. leucocephala exhibited higher inhibitory effect towards the bioassay species. Overall, the findings from this study showed that the allelopathic potential of L. leucocephala was more preferable to be investigated further for sustainable weedy rice management in the future by infusing the biological approach.

China and India’s Comparative Response to the 2017 Rohingya Crisis in Bangladesh

The simultaneous rise of China and India has been creating significant re-orientation in the contemporary international system. Both the countries are trying to climb up in the global power hierarchy but for the first instance, they are competing with each other for the Pan-Asian leadership. As a result, their neighboring countries like Bangladesh and Myanmar are becoming hot spots for geostrategic power play between the two Asian powers. The Sino-Indian geostrategic competition intensified after 25 August 2017 when the military crackdown happened at the Rakhine state on Rohingya people. This paper illustrates the nature and dimensions of the response from New Delhi and Beijing on the 2017 Rohingya Refugee crisis. This paper adopted a qualitative method and data was analyzed based on secondary data. The findings argue that there was a qualitative difference between the responses from India and China in this crisis. India claimed to remain neutral in the crisis and provided limited humanitarian and economic assistance to Bangladesh and Myanmar. This paper also reviews why China and India back Myanmar and the international response to this crisis. Finally, this paper concludes with Bangladesh’s challenges from the Sino-Indian geostrategic interests in the Rakhine state.

Assessment of NaCl-Induced Stress in Tomato (Lycopersicon esculentum L.)

Comparative study about the salt-induced oxidative stress and lipid peroxidation has been realised in primary root tissues for Tomato (Lycopersicon esculantum L.) in order to evaluate their responses to salt stress. Salinity impacts in terms of root growth, H2O2 generation, lipid peroxidation and membrane destabilisation were more pronounced in roots. Salt treatment in form of NaCl was given to the roots of the tomato plants in hydroponics culture. Root length was measured by centimetre scale, H2O2 and lipid peroxidation was confirmed by spectrophotometer. Absorbance for H2O2 estimation was recorded at 480 nm whereas for Lipid peroxidation was done at 600nm. When the tomato plants were treated with different concentrations of NaCl, it was observed that as the concentration of NaCl was increasing, there was decreased root growth resulting in reduced root length and proportionate increase in the amount of H2O2 production level with increase in the concentrations of NaCl treatment upto 300mM Concentration and Significant increase in Lipid peroxidation was observed with the increase in NaCl concentrations upto 500mM Concentration. Comparative response may be helpful in developing a better understanding of tolerance mechanisms to salt stress in Tomato.

Response of guava var. Arka Amulya to branch bending during winter and summer in the Eastern tropical region of India

Aim: The study aimed to evaluate the comparative response of guava var. Arka Amulya to branch bending practice during winter and summer for controlling shoot vigour and improving flushing, yield, and quality of harvest under hot and humid climate of Odisha. Methodology: The experiment was laid out in a Randomized Block Design with five treatments consisting of branch bending during first week of January, February, May, June, and without branch bending as control. Each treatment was replicated four times and each replication unit had four plants. Observations were recorded on flushing, flowering, yield, and fruit quality parameters. Results: Branch bending technique was found effective for controlling the shoot vigour and enhancing flushing, flowering, and yield in guava, when practised during January, February, and May, however, effects were more pronounced when branch orientation was manipulated during winter months. January branch bending produced the shortest vegetative shoots (50.48 cm) and recorded the maximum value for flush count (28.91 shoots m-1 branch), flowering (57.91%), and fruit yield (38.46 kg per tree). Branch manipulation during winter resulted in higher yield gains (70.87-81.59%) over control (21.18 kg per tree) as compared to summer months (11.99-42.21%). All the treatments of branch bending caused a significant improvement in various fruit quality attributes, however, May and June treatments excelled in the performance. June bending produced the best quality fruit (TSS: 11.35ºB, Total sugar: 7.85%, Vitamin C: 197.39 mg 100 g-1 pulp, Total phenolic content: 117.29 mg GAE 100 g-1 FW, and total flavonoid: 52.74 mg QE 100 g-1 f. wt.), followed by May bending. Interpretation: In guava, canopy architecture manipulation through branch bending appears to hold immense potential for enhancing the quantum and quality of produce, if practised at suitable time. Practising this technique after May month would not give significant yield gain over the control plant.