Background: Groundnut, Arachis hypogaea is a leguminous crop grown in tropical and subtropical regions of the world. Meloidogyne spp., is considered to be nematode pest of economic importance for the groundnut throughout the world. Plant metabolites with nematicidal property have been in use for a long time for nematode control that offer many environmental advantages. Methods: The nematicidal activity of methanolic leaf extract of Simarouba glauca on eggs and juveniles (Js) of root-knot nematode, Meloidogyne incognita infesting vegetables was evaluated at three concentrations in vitro (100%, 50%, 25%) with control at three exposure times. Result: Results revealed that at 100% concentration, the methanolic leaf extract of S. glauca showed the least number of eggs hatched (7.85, 12.63, 16.30/egg mass) and the highest mortality (60.58, 70.23, 92.58/100 juveniles) at the exposure times of 24 hrs, 48 hrs, 72 hrs, respectively. The phytochemical compounds viz., Hexadecanoic acid-methyl ester, Isopropyl palmitate, Octadecanoic acid and Methyl stearate detected through GC-MS profiling of methanolic extract of S. glauca were found to inhibit the nematode activity. Pot and field studies proved that soil application of Simarouba leaf powder @ 10 g/plant and 5 kg/ha reduced the nematode infestation. This study implies that use of Simarouba leaf powder produces nematicidal effect against plant parasitic nematodes and reduced the nematode infestation in groundnut and is more suitable candidate in the context of biological control.

Background: Black gram is the important pulses crop, grown throughout the country; gives low seed yield mainly due to poor management and low soil fertility. Development of suitable technology is essential to enhance productivity. Seed priming is one such effective technology which enhance rapid and uniform emergence to achieve high vigour, leading to better stand establishment and yield. The current research aimed to study micronutrient seed priming and rhizobium coating on seed germination, seedling vigour, crop growth and seed yield in black gram. Methods: Blackgram seeds were primed with 10 different micronutrient solutions with different concentrations and evaluated for its quality parameters to find out suitable seed priming technique. Seeds from two best priming treatments were coated with rhizobium @ 30g/kg of seed and evaluated for its production potential and resultant seed quality under field condition. Result: Seed priming with 0.5% ZnSO4 at 1/3rd seed to solution ratio for 3 hours recorded higher germination (96%) and vigour index (3811) than control which recorded 84% seed germination and 2528 of vigour index under laboratory experiment. Field experiments revealed that, seeds primed with 0.5% ZnSO4 and coated with rhizobium @ 30g per kg of seeds improved seed yield by 13.2% over control.

A fruit crop of significant economic importance, papayas are often propagated from seeds. Based on their freezing injury even at low moisture content, papaya seeds are classified as "intermediate seeds"; and rapid loss of viability in storage is assumed to be the primary cause of poor germination; thus, the development of appropriate technology is necessary to prolong the storability of papaya seeds. One such effective technology for prolonged seed storability is cryo-storage. The purpose of the current study was to investigate how cryostorage affects papaya seed storability. For this investigation, TNAU Papaya variety CO 8 seeds were utilised. Five distinct treatments were applied to the seeds, which were then kept for approximately six months at liquid nitrogen's vapour phase (-140°C). The biochemical parameters such as protein content, free amino acid, total carbohydrates, free sugars, total lipids, and dehydrogenase activity were measured on a monthly basis along with seed germination and seedling vigour in the cryopreserved papaya seeds. Results indicated that papaya seeds that had been vitrified (seeds with a 10% moisture content that had been soaked in loading solution for 20 minutes, then immersed in Plant Vitrification Solution 2 (PVS2) for another 20 minutes, packed in cryovials and kept in cryo-storage at -140°C) compared to papaya seeds that were packed in cloth bags and stored in ambient conditions had higher seed germination, dry matter production and vigour index at six months after storage. In comparison to fresh seeds, the results also showed that, after six months of cryo-storage, biochemical proximate, protein content, total carbohydrate content, total lipid content, and dehydrogenase activity were maintained in the aforementioned treatment with minimum reduction, while electrical conductivity, free amino acid content, and free sugar content gradually increased with the storage period at minimum rate. In crux, vitrified papaya seeds packaged in cryovials and kept in cryo-storage at -140°C preserved their quality for six months, meeting Indian Minimum Seed Certification Standards. This could be useful for storing papaya seeds for longer periods of time. Keywords: Papaya, vitrification, differential scanning calorimetry, liquid nitrogen, cryo-storage