An experimental trial of nine rice genotypes was conducted in the Agronomy field of the Institute of Agriculture and Animal Science (IAAS) Paklihawa Campus under a randomized block design layout with three replications from July to November of 2022. The aim was to study genetic variability and analyze the character association of yield and yield-attributing components in rice genotypes and their direct and indirect effect on grain yield under reproductive drought stress conditions. Observations on days to flowering (50%), plant height, panicle length, panicle weight, number of grains/panicles, effective panicle/m², grain yield, and 1000 kernel weight were recorded. Grain yield showed a highly positive significant correlation with effective panicle/m² (0.713**), followed by plant height (0.347) and panicle length (0.289). The path coefficient analysis of different traits revealed the highest positive direct effect of the effective panicle per m² (0.748963), followed by panicle length (0.24145) and plant height (0.227505). The highest negative direct effect was shown by the number of grains per panicle (-0.31218). The experimental results revealed that the selection of trait-effective panicle per square meter would be most beneficial for the improvement of yield in rice genotypes facilitating selection and plant breeding programs.

The rise in Earth’s temperature is one of the most alarming climatic issues in the field of agriculture and food production, in the present context. The increase in temperature leads to heat stress, major abiotic stress responsible for a huge decline in the production of crops. Wheat (Triticum aestivum), among many crops, also experiences a significant decline in yield and overall productivity due to extreme heat stress. But Wheat has also developed natural tolerance mechanisms to defend itself from heat damage. The selection of cultivars with a higher degree of tolerance mechanism protects against thermal stress, which minimizes the risk of poor productivity to a greater extent. In this review, we discuss the current works of literature concerning the heat stress tolerance mechanism in wheat plants and also highlight the strategic approaches that improve their heat stress tolerance at the molecular level. The success of these approaches depends on a better understanding of heat tolerance traits, their genomic composition, and molecular responses.

Tamarind (Tamarindus indica) belongs to the family Leguminosae. It is commonly growing in tropical and subtropical regions now and is one of the most important plant resources as cuisine materials. Antioxidative activity of tamarind seeds was investigated. An ethanol extract prepared from the seed coat contained antioxidative activity as measured by the thiocyanate and thiobarbituric acid (TBA) method. Essential oils are highly odorous droplets found in minimal quantities in the flowers, stems, leaves, roots and barks of aromatic plants. They are not recognized as true oils as the vegetable oils, but highly fluid and volatile. Experts recognize an essential oil by its aroma and test the oil characteristics such as vaporization and crystallization point using Differential Scanning Calorimetry (DSC). DSC has emerged as a powerful experimental technique for determining thermodynamic properties of biomacromolecules. Volatile components of tamarind leaves and seed locally grown will be isolated by Microwave Assisted Extraction (MAE). The presence of essential oil as the volatile components will be investigated to determine whether this method is effective or not to extract the oil from tamarind leaves and seed. The parameters that will be measured are the time for the oil droplets formation and the optimum temperature for the extraction of oil. At the end of the extraction, amber color oil was obtained. Results showed that the time for the oil droplets formation increasing with the increasing weight of sample for both tamarind leaves and seed samples. The optimum temperature for the extraction obtained was 125ºC with the yield of 1.2 mL of seed oil. The vaporization and crystallization point of oil are presented in the DSC curve and the specific heat capacity of the oil are calculated.

In many regions of world, maize is one of the most significant crops grown for staple foods. To increase the effectiveness of breeding programs using the right selection indices, it is very important to be aware of the correlations between grain yield and its numerous causal (contributory) components. This article presents the results of many studies that were carried out to ascertain the nature of relationships between grain yield and its contributing factors and to pinpoint those factors with significant effects on yield with the goal of using them as selection criteria by using path coefficient analysis (PCA). The direct and indirect impacts of cause factors on effect variables are displayed through path analysis. This approach divides the components of the correlation coefficient between two traits into those that assess the direct and indirect effects. Plant height, number of kernels per row, ear per pant, ear height, leaf width, days to 50% silking, tasseling, ear diameter, ear length, thousand kernel weight, days to physiological maturity, tassel length, and ear weight may have significant (or non-significant) influence on grain yield, either positively or negatively. The present review of different studies might be useful to the breeders to select the potential parental materials for maize improvement program in Nepal as well as region with similar geographical topography.

Heat stress is the major constraint for wheat production causing significant drops in the yield and potential productivity making it difficult to achieve the target yield by 2030, increasing food insecurity in Nepal. The main aim of the study is to help plant breeders to select appropriate heat stress-tolerant indices for increasing wheat yield by coping with the major problem of heat stress. The experiment holds the study for three years at the Institute of Agriculture and Animal Science (IAAS), Paklihawa campus. The experimental trial was of alpha-lattice design with 5 blocks and 4 plots. There were in total of 2 replications each of 20 genotypes. MP (Mean Productivity) had the highest strong correlation with the stress tolerance indices followed by STI (Stress Tolerance Index) for all three years, whereas YSI (Yield Stability Index) had the lowest tolerance index with a negative correlation for the years 2019 and 2021. The selection of MP and STI is encouraged for the production of heat-stress-tolerant varieties for high-yielding with tolerance.