Influence of Specific Gravity Grading Using Floatation Technique on seed and Seedling Quality Characteristics in Amaranthus CV. PLR 1

Study was undergone to evaluate the efficacy of floatation grading on the seeds of Amaranthus Cv. PLR 1 using organic solvents in Department of Seed Science and Technology, TNAU, Coimbatore during March 2023.The experiment was laid out in Completely Randomized Design with four replications in each five treatments. We considered four organic solvents viz., Acetone, Methanol, Dichloromethane and Petroleum Ether along with water and observed the seed recovery percentage, germination percentage, root length, shoot length and vigour index of all the treatments. The results showed that sinker fraction regardless of organic solvent and water performed better than floater fraction. The grading ability of Dichloromethane was greater among the assessed organic solvents. The sinkers seed recovery percent of dichloromethane (93%) was higher than sinkers recovered by water (63%). Also, the sinkers of dichloromethane recorded higher germination percent(77%) and vigour index(304) than the sinkers of water whose germination percent is 55% and vigour index is 272.This specific gravity grading using dichloromethane can be adopted to segregate well filled and ill filled seeds in a seed lot of Amaranthus. This method of floatation grading is a good substitute for sieve grading which requires skilled labour and availability of specific size sieve to properly segregate seeds. So, this can be used as an alternate method for grading Amaranthus seeds.

CaO Nanoparticles Seed Invigoration on Germination and Seedling Growth of Rice var. TRY 3

Rice (Oryza sativa L.), a vital cereal and staple food crop in South East Asia. It faces significant challenges in cultivation worldwide, due to soil salinity. Seed enhancement techniques like priming have shown resilience against salt stress. In this study, the potential of nano-priming with calcium oxide nanoparticles (CaO NPs) to enhance rice seed germination and growth was investigated. CaO NPs were synthesized from organic waste (eggshells) using a sol-gel technique and characterized using Raman and UV-Vis spectroscopy. Paddy seeds were primed with varying concentrations of CaO NPs, and their germination and seedling growth were assessed. The results showed that nano-priming with 40 ppm of CaO NPs significantly improved germination, root and shoot length, dry matter production, and seedling vigour as compared to the control. However, higher concentrations of CaO NPs had a detrimental effect on germination. The study suggests that CaO NP seed priming has the potential to enhance rice germination and seedling development.

Effect of pH on the Mycelial Growth of Aspergillus niger and Aspergillus flavus

Aspergillus fungus is well-known for causing a number of secondary plant and food rots that can result in the buildup of mycotoxins, despite their significant economic contribution to the fermentation industries. In the past, even the most fundamental influences on the development and inhibition of significant mycotoxigenic fungi were only partially understood. To overcome this issue, an investigation on the impact of pH on the mycelial development of Aspergillus species was conducted. A. niger and A. flavus were inoculated in PDA medium with a range of pH values from 4.0 to 9.0 under in vitro conditions and then cultured for 7 days at room temperature. Results revealed that, the mycelial growth of A. niger and A. flavus was increased with increase in pH level up to 6 and then became static up to pH level 9 and there was no mycelial growth in pH 4. Hence, it was concluded that the use of alkaline compounds as a way of preventing their proliferation and reproductive processes may be used to inhibit the development and spore production of A. niger and A. flavus, which can affect the crops.