Cocopeat: An alternative to soil medium for propagation of papaya (Carica papaya L)

The present study aimed to standardize soilless media mixtures for papaya propagation, focusing on stability, sustainability and environmental impact. A trial was conducted in the winter and summer seasons during 2023-2024 at TNAU, Coimbatore, to evaluate the properties of cocopeat mixtures and optimize the cocopeat media mixture for papaya seedling production. The trial employed a factorial randomized complete block design with two factors [cocopeat media mixture (Factor-T) and papaya varieties (CO7 and TNAU Papaya CO8, as factor-V] and with four replicates. Each treatment contains different proportions of cocopeat, inorganic fertilizers, bio-inoculants, biofertilizers and oil cakes. Commercially available cocopeat and potting mixture were used as absolute control and control, respectively. The findings showed that T2 (TNAU Mixture 2) consist of cocopeat (96.86%) + inorganic mixture (0.34%) + bioinoculant mixture (0.70%) + biofertilizer mixture (0.42%) + oil cakes mixture (0.42%) recorded increased seed vigour (96.86%), seedling survival (96.17%), seedling height (46.07 cm), leaf area/plant (28.50 cm²), leaf chlorophyll (26.05 SPAD units) and total nutrient (N-1.89%, P-0.89%, K-3.47%). The treatment T4 (commercially available cocopeat alone) had the highest germination (97.90%) and was on par with T2. Among the variety, V2 outperformed V1. In the treatment (T) and variety (V) interaction, the T2×V2 combination promoted significant seedling growth at the nursery. Cocopeat media mixtures showed good physical properties, like bulk density(g/cc), particle density (g/cc), porosity (%) and water holding capacity (%), promoting better seedling growth. The trial revealed that the treatment T2 is recommended as the best alternative soilless medium for papaya propagation

Effect of Bio sulphur granules (BSG) as fertilizer ingredient on different fractions of sulphur in calcareous soil cultivated with blackgram (Var.VBN-8)

The purpose of this study was to examine the various sulphur (S) fractions in experimental pot calcareous soil treated with Bio sulphur granules (BSG) in order to assess the impact of granular sulphur fertilization in S deficient calcareous soil using blackgram (Var. VBN-8) as a test crop.Factorial randomized block design with ten treatments (T1- Absolute control;T2-Recommended dose of NPK and S (Control);T3-Soil test based NPK; T4-T3 + S as Elemental Sulphur @ 40 kg S/ha; T5-T3 + S as BSGI@ 40 kg S/ha; T6-T3 + S as BSGII@ 40 kg S/ha;T7-T3 + Vermicompost @ 4 t ha-1; T8-T4  + Vermicompost @ 4 t ha-1;T9- T5 + Vermicompost @ 4 t ha-1; T10- T6+ Vermicompost @ 4 t ha-1 ) replicated thrice and 5 pots were maintained for each replication. The results of this study revealed that there was an upward trend in all S fractions in every treatment (T1 to T10), in the following order: organic > inorganic > water soluble > exchangeable S. The pot that received vermicompost coupled with BSG II (T10) (ES@ 40 kg ha-1 and MethylobacteriumthiocyanatumVRI7-A4 as S source) was found to have the greatest S-fraction and was higher than other treatments. Therefore, using BSG II in conjunction with vermicompost is necessary to preserve the availability of S nutrients in calcareous soil and increase the solubility of nutrients through S-oxidation

Performance of dual-purpose sorghum (Sorghum bicolor) under different sowing windows and crop geometry

India is one of the most vulnerable countries to climate change and its impact on agricultural production and livestock. Sorghum (Sorghum bicolor) is an important food crop of India cultivated in tropical and subtropical climates, especially the semiarid tropics; varying environmental attributes significantly affect its duration and yield. Therefore, the present research aimed to evaluate the potential of dual-purpose sorghum under varying sowing windows and crop geometry. The experiment was conducted in Eastern block farm of Tamil Nadu Agricultural University during the summer season- 2022. The experiment was laid out in strip plot design with three different dates of sowing in the main plot, i.e., D1 - First fortnight of February, D2 - First fortnight of March and D3 - First fortnight of April and six different crop geometries in the subplot viz., 45 x 15 cm (S1),45 x 10 cm(S2), 45 x 5 cm (S3), 30 x 15 cm (S4),30 x 10 cm (S5) and 30 x 5 cm (S6) and replicated thrice.The results revealed that sowing during the first fortnight (I FN)  of April with a spacing of 45x 15 cm resulted in maximum grain yield(2585 kg/ha) and for fodder yield, April I FN sowing with a crop geometry of 30x 5 cm resulted in maximum green biomass (43.6 t/ha) as well as dry matter production. So, spacing of 30x 5 cm helps in better utilization of resources along with maximum fodder yield

Assessing the genetic variability and trait interactions for nitrogen use efficiency in rice

In major cereals, excessive use of nitrogen fertilizers and low nitrogen use efficiency adversely affect land, water and food systems. Developing nitrogen-efficient cereal varieties reduces fertilizer dependence, lowers costs and minimizes environmental pollution while maintaining yield stability. These varieties enhance nitrogen uptake and assimilation, ensuring sustainable food production in low-nitrogen soils. The study aimed to assess the genetic variability for nitrogen use efficiency among 160 rice genotypes by evaluating their performance under three different nitrogen levels -N0 (0N), N50 (50% recommended dose of nitrogen (RDN) and N100 (100% RDN), during rabi season. The physiological and yield traits were recorded at the active tillering and flowering stages. The results indicated that the application of different nitrogen levels significantly affected the physiological traits such as chlorophyll index (SPAD value), leaf greenness index (NDVI), light-adapted PSII quantum yield (Fv'/Fm'), photosynthetic rate at both the stages. Also, there was a significant variation observed in yield traits such as the number of productive tillers, spikelets per panicle, 100-grain weight, spikelet fertility and grain yield among the rice genotypes under different N levels. Correlation analysis showed a significant positive relationship between Fv'/Fm' and photosynthetic rate with grain yield under N50 and N100 levels. Hierarchical clustering analysis identified the five high-yielding genotypes such as IRG91, IRG140, IRG302, IRG374 and IRG375, that performed significantly well under N50 in terms of physiological and yield traits compared to the N0 level and the reduction in yield was significantly less over N100. Future research should focus on identifying the key genes and pathways associated with NUE in rice

Responses of cereals to nitrogen deficiency: Adaptations on morphological, physiological, biochemical, hormonal and genetic basis

Nitrogen (N) is a primary macronutrient essential for plant growth and development. Global nitrogen fertilizer consumption is approximately 120 million tons, with nitrogen use efficiency (NUE) ranging between 25 % and 50 %. Excessive use of nitrogen fertilizer poses significant risks to the envi ronment and living organisms, highlighting the need to reduce fertilizer ap plication, improve NUE, and sustain crop productivity. Sustainable agricul tural practices emphasize minimizing fertilizer usage. Therefore, developing high-NUE crop varieties capable of maintaining yields under reduced nitro gen input is critical for ensuring food security and protecting ecosystem. A promising strategy involves investigating plant responses to varying nitro gen levels, particularly under low-nitrogen conditions. This review explores the morphological, physiological, biochemical, hormonal, and genetic changes in cereals subjected to low-nitrogen conditions. Morphological adaptations include alterations in root and shoot architecture, while physi ological responses involve enhanced chlorophyll content, leaf nitrogen lev els, and photosynthetic efficiency. Biochemical changes are characterized by increased activity of nitrogen uptake and assimilation enzymes, accom panied by hormonal shifts such as elevated auxin levels in roots. These traits provide a foundation for developing nitrogen-efficient crop varieties. Future research should prioritize breeding crops with enhanced tolerance to low-nitrogen conditions to improve NUE, grain quality, and yield potential

Harnessing volcanic ash for benzene mitigation and maize seed enhancement

The presence of Benzene in aqueous solution is a great concern for the health-related issues of the living things that consume the same. Among various removal methods, the adsorption method with volcanic ash is a less laborious and eco-friendly process. With this notion, the seeds and grains of maize COH (M) 8 were coated with volcanic ash and they are utilized in this study as a biological entity to remove the benzene from the aqueous solution. Volcanic ash was characterized using FTIR, XRD, and FE-SEM-EDAX analyses, revealing key structural features, including sulfoxide functional groups, a crystalline size of 179.06 nm, and particle sizes ranging from 36.24 to 234.60 nm. Batch experiments were conducted to optimize adsorption and degradation efficiencies under different conditions. A maximum degradation efficiency of 80.62 % was achieved at a benzene concentration of 10 µg/mL within 1 hr. The efficiency increased to 87.96 % with a higher catalyst dosage at a benzene concentration of 50 µg/mL over 5 hr. Acidic conditions (pH 3) further enhanced the efficiency to 81.43 % over 5 hr. Under sunlight irradiation, a maximum degradation efficiency of 83.54 % was achieved within 1 hr. These findings establish volcanic ash as a promising, eco-friendly material for benzene adsorption in aqueous solutions, with the added advantage of enhancing seed germination and growth parameters. Its abundant availability and cost-effectiveness make it a sustainable solution for environmental remediation and agricultural applications.

Thresholds, sensitive stages and genetic variability of finger millet to high temperature stress

Finger millet [Eleusine coracana (L.) Gaertn.] is an important coarse cereal crop grown in the arid and semi‐arid regions and often experiences high temperature (HT) stress. The objectives of this research were (i) to quantify effects of season‐long HT stress on physiological and yield traits, (ii) to identify the developmental stages most sensitive to HT stress and (iii) to quantify the genetic variability for HT stress tolerance in finger millet. Research was conducted in controlled environment conditions. HT stress decreased the chlorophyll index, photosystem II activity, grain yield and harvest index. Maximum decrease in number of seeds per panicle and grain yield per plant was observed when stress was imposed during booting, panicle emergence or flowering stages. Maximum genotypic variation was explained by panicle width and number of seeds per panicle at optimum temperature (OT) and grain yield per plant at HT and number of seeds at HT. Based on the stress response and grain yield, tolerant or susceptible genotypes were identified. Finger millet is sensitive to HT stress during reproductive stages, and there was genotypic variability among the finger millet genotypes for number of seeds per panicle and grain yield under HT, which can be exploited to enhance stress tolerance