Maize, along with rice and wheat, is a popular staple food crop worldwide, and the most widely produced cereal crop. It is a versatile crop that may be utilized as a source of raw materials for human and animal fodders. Low agricultural yield and rapid population expansion significantly threaten future food security. Maize production is hampered by biotic and abiotic causes, with abiotic factors being the most critical limitation to agricultural output worldwide. Soil salinity is a key abiotic factor that reduces agricultural production by imposing negative impacts at several life cycle phases, including germination, seedling, vegetative, and reproductive development. Maize plants experience many physiological changes due to osmotic stress, toxicity of particular ions, and nutritional imbalance induced by salt stress. The degree and duration of stress, crop growth phases, genetic characteristics, and soil conditions influence yield reduction. Maize plants can tolerate salt stress involving a complex mechanism by changing their physiological, biochemical, and metabolic activities like stomatal functioning, photosynthesis, respiration, transpiration, hormone regulation, enzymes, metabolite generation, etc. After studying the salt tolerance mechanisms of maize plants under stress, integrated management techniques should be developed for maize agriculture in saline settings. Therefore, the study of plant responses to salt stress, stress tolerance mechanisms, and management strategies is one of the most imperative research fields in plant biology, and the study will focus on the effects of salt stress in different growth stages, plant tolerance mechanisms, and agronomic management practices for successful maize production all over the world.

The rapidly increasing human population is an alarming issue and would need more food production under changing climate. Abiotic stresses like heat stress and temperature fluctuation are becoming key issues to be addressed for boosting crop production. Maize growth and productivity are sensitive to temperature fluctuations. Grain yield losses in maize from heat stress are expected to increase owing to higher temperatures during the growing season. This situation demands the development of maize hybrids tolerant to heat and drought stresses without compromising grain yield under stress conditions. The chapter aimed to assess the updates on the influence of high-temperature stress (HTS) on the physio-biochemical processes in plants and to draw an association between yield components and heat stress on maize. Moreover, exogenous applications of protectants, antioxidants, and signaling molecules induce HTS tolerance in maize plants and could help the plants cope with HTS by scavenging reactive oxygen species, upregulation of antioxidant enzymes, and protection of cellular membranes by the accrual of compatible osmolytes. It is expected that a better thought of the physiological basis of HTS tolerance in maize plants will help to develop HTS maize cultivars. Developing HTS-tolerant maize varieties may ensure crops production sustainability along with promoting food and feed security under changing climate.

Maize is a very important cereal all over the world and generally cultivated in irrigated agricultural areas. Salinity affects adversely maize productivity in these areas. Maize is known as a salt sensitive species. The salt tolerance level identification in the large genetic resources and breeding populations is an important research topic for solving the salinity problem. The effects of NaCl stress on germination and seedling growth of fifteen maize genotypes were investigated in this study. Electrical conductivity (EC) values of the NaCl were settled 0 (distilled water), 4, 6, 8, 10 and 12 dS m-1. This investigation was performed as factorial arrangement of completely randomized design with four replications. Analysis of variance (ANOVA) showed that genotypes, salinity levels and interaction between genotype x salinity were significant for all the investigated treatments emergence index (EI), root dry weight (RDW), shoot dry weight (SDW), root length (RL), shoot length (SL), and salt tolerance indexes (STI). Results also revealed that the highest reduction in emergence index (59.7%) were obtained in the highest level (12 dS m-1) of salinity. The results further revealed that the cultivars named DKC 6589, PR31G98, and PR31A34 were the most tolerant genotypes than the others under NaCI stress.

The application of near-infrared reflectance spectroscopy (NIRS) and multivariate analysis for determining the seed germination rate of corn genotypes was assessed. Seed samples about 90 gr belong to commercial and local corn varieties at various ages were scanned with FT-NIRS on the reflectance mode from 1000 to 2500 nm wavelength. Filter paper technique showed the seed germination rates varied between 18-100% depending on the genotypes after 7 days at ±25°C. Partial least squares regression (PLSR) was applied to the reference values corresponding to the spectra. The best statistical results obtained from the pre-treatment combinations of Smooth Savitzky-Golay 9 Points (sg9), MSC full and normalization to unit length (nle). The regression coefficient of calibration (R2C) and prediction (R2P) of the created NIRS calibration via chemometric software NIRCal are realized 0.97 and 0.98 respectively for the property of corn germination rate. The standard error of both calibration (SEC) and prediction (SEP) were almost overlapping (4.17%, 4.61% respectively). The prediction accuracy of the final NIRS model was quite reasonable with the acceptable root mean standard error of prediction (RMSEP) as 8.88%. According to the residual predictive deviation (RPD) index (4.18), the accuracy of the NIRS model regarded as in the best category. Therefore, the NIRS model developed here is sufficient to predict the corn seed germination rate very fast and non-destructively without using any regents.

The grain yield of rice is far below from its potential yield due low organic matter and micronutrients in the soil. Application of cow dung and zinc fertilizer increases grain yield and quality. A field experiment was, therefore, conducted to evaluate the effect of zinc fertilization and well decomposed cow dung on the spikelet sterility, yield, zinc concentration in grains and plants of aromatic rice (cv. Tulsimala). In this experiment,two levels of well decomposed cowdung (CD) of 0, 10 tha-1, and fourdoses of zinc fertilization viz. 0, 2.16, 4.32, 6.48 kg ha-1 of zinc were used followingeight treatment combinations. The experiment was laid out in a factorial randomized complete block design (RCBD) with replication thrice. The data revealed that zinc fertilization remarkably increased the grain yield of Tulshimala by reducing the spikelet sterility percentages in both conditions of CD and the efficiency of zinc fertilization was superior in manuring (CD) condition to non-manuring condition. However, zinc fertilization at the rate of 4.32 kg ha-1 of zinc produced the maximum grainyields under manuring and non-manuring conditions. Zinc fertilization increased the concentration of Zn in the rice plants and grains without and with CD. The strong linear relationship between the grain yield and zinc concentration in the rice plants and grains was found with in this study. Zinc fertilization increased grain yield and quality by decreasing sterility percentage under CD. Hence, for increasing productivity towards food security in future generation, integrated use organic and inorganic fertilizers should be used.