Developing functional relationships between sesame growth, development, and nitrogen nutrition during early season

Abstract

Plants, being sessile, are subjected to multiple environmental stresses of varying intensity throughout their life cycle. Among the stresses, low fertility, drought, salinity, and nonoptimal temperatures limit crop productivity worldwide. Functional relationships between leaf N and crop growth are prerequisites to developing management tools that optimize productivity in the field. An outdoor pot-culture experiment was conducted to determine the relationship between leaf N and sesame (Sesamum indicum L.) growth and development. Plants were grown in pots filled with fine sand and irrigated with full-strength Hoagland's nutrient solution until 10 d after sowing (DAS). Five N treatments were then imposed: one treatment of full-strength Hoagland's nutrient solution (control, 100% N), and four reformulations of Hoagland's nutrient solution containing reduced N at 60, 20, 10, and 0% of the control. Treatments were maintained until plants were harvested at 31 DAS. Growth, including several root traits, photosynthesis, and leaf N were measured at the end of the experiment. Maximum values were achieved at 5.3% leaf N in the leaves except for transpiration rate, stomatal conductance, and root/shoot ratio. Even though all growth rates declined with lower leaf N, the leaf area expansion among shoot and root volume among the root growth traits were most sensitive to leaf N. Among the root developmental traits, number of root tips was more sensitive to leaf N than other parameters. Among the plant dry components, leaf dry weight had the most considerable decrease. The root/shoot ratio increased under N deficiency. These N stress response indices and critical leaf N levels for various growth processes will help model and manage sesame crops in the field.

Analysing the SPAD dynamics of water-stressed vs. well-watered sesame (Sesamum indicum L.) accessions and establishing their relationship with seed yield

“…The results of the present study were also supported by Sehgal et al (2021) , who also suggested that management of sesame crops for optimal yields under varying growing conditions requires an understanding of the key levels of leaf N and the functional relationships between leaf N, growth and developmental processes. In their study, leaf photosynthesis declined at 31 DAS more than stomatal conductance and transpiration rates, indicating that both stomatal and non-stomatal mechanisms are involved in the decrease in photosynthesis in response to leaf N. In addition, Mehmood et al (2021) suggested that the nitrogen uptake or contents of sesame leaves were highest at the mid-bloom stage (65 DAS) and lowest at the physiological maturity stage.…”

Effects of fine grinding on mid-infrared spectroscopic analysis of plant leaf nutrient content

“…The leaf samples collected from different experiments were dried in a forced drier at 70 °C until a constant weight was reached. In brief, 12 plant types (Table 2) were grown under different climatic (UV-B, low and high temperatures, elevated CO 2 ) or soil variables (low nutrient, water logging, salt, and drought) using Soil Plant Atmosphere Research (SPAR) chambers [41][42][43][44] , outdoor pot culture 45 , and field conditions following www.nature.com/scientificreports/ the appropriate institutional guidelines. Leaf samples collected across experiments were coarsely ground using a tumbler grinding method.…”