How High Plant Density of Maize Affects Basal Internode Development and Strength Formation

Abstract

High plant density of maize (Zea mays L.) reduces the stalk quality of the basal internodes and increases stalk lodging. The objective of this experiment was to explore the mechanism by which plant density influences basal internodes. The morphological, mechanical, anatomical, and biochemical characteristics of the third basal internode were compared at three plant densities. High plant density increased internode length due to an increase in the rate of rapid elongation. High plant density decreased the duration of internode thickening and dry matter accumulation, causing the diameter and dry weight per unit length to decline. However, rind penetration strength (RPS) did not increase rapidly until after the termination of rapid morphological growth. The mid‐to‐late stage of dry matter accumulation was critical for RPS formation. The rapid increase in RPS was closely related to cellulose and lignin accumulation. High plant density reduced the rates of cellulose and lignin accumulation, which was adverse to the formation of cortex tissue and RPS. High plant density caused rapid elongation, thickening, and structural carbohydrate accumulation to begin and end earlier. These results indicate that measures should be implemented as early as possible in the growing season to increase lodging resistance at high plant density of maize. These measures need to reduce the rate of rapid internode elongation and increase the rate of rapid cellulose and lignin accumulation.

Stress equation for a cantilever beam: a model of lodging resistance in field pea

“…Agronomic factors such as sowing date, seeding rates, crop rotation, soil rolling, type of tillage system, type of irrigation system, nitrogen fertilization rate, timing of nitrogen fertilization, and phosphorus and potassium fertilization also play a role (Shah et al, 2017). It is well known that increasing plant density decreases stem diameter per plant, increases internode length, and decreases lodging resistance (Xue et al, 2016). However, Spies et al (2010) indicated that relatively high seeding rates are needed to optimize crop yield.…”

Evaluation of maize lodging resistance based on the critical wind speed of stalk breaking during the late growth stage

“…Several studies have indicated that the rind penetration strength (RPS), crushing strength (CS), and bending strength (three-point bending exural tests) are all signi cantly negatively correlated with the stalk lodging rate [13]. Stalk strength is signi cantly positively correlated with the contents of cellulose, hemicellulose, and lignin [8,14]. Furthermore, corn borers signi cantly increase the rate of stalk lodging by drilling into stalks [15], whereas maize stem rot weakens stalk tissue, which greatly increases the risk of stalk lodging [16].…”

“…Furthermore, corn borers signi cantly increase the rate of stalk lodging by drilling into stalks [15], whereas maize stem rot weakens stalk tissue, which greatly increases the risk of stalk lodging [16]. Moreover, as plant density increases, the length of the basal internode signi cantly increases and the diameter signi cantly decreases, the contents of cellulose, hemicellulose, and lignin, and the stalk mechanical strength decrease, and the risk of lodging increases [14]. Reasonable water and fertilizer management and the application of plant growth regulators can reduce the internode elongation rate, the ratio of length to diameter, the plant height, and the ear height, promote structural carbohydrate accumulation, and increase stalk mechanical strength and lodging resistance [17,18].…”

“…The Chinese national standard for mechanical maize grain harvesting (GB/T-21962-2008) suggests that the lodging rate should be less than 5% for such harvesting. In the past, maize harvesting in China was mainly performed by hand and via mechanical ear harvesting, and therefore research on maize lodging has mostly focused on the growth stage before physiological maturity [9,14,17,26,27]. After PM, the decomposition of stalk carbohydrate and the decrease of stalk moisture content causes the stalk mechanical strength to decrease.…”

Non-Structural Carbohydrate Metabolism, Growth, and Productivity of Maize by Increasing Plant Density

“…However, the understanding of how plant physiology works to perform those small increases is very important to drive new technologies for productivity enhancement. As a result, this issue has recently attracted the attention of many researchers in this area [11][12][13][14][15][16][17]. There are suggestions that even though carbohydrate reserves do not directly increase yield potential in maize plants under normal conditions for growth, they contribute to yield stability when plants are challenged by environmental or biotic stresses [2,6].…”