Cotton Emergence Force as Affected by Soil Temperature, Moisture, and Compression

Abstract

Emergence force of a seedling is a major factor influencing the ability of the seedling to emerge through a surface soil crust. This study was conducted to evaluate effects of soil physical conditions on the maximum emergence force of cotton [Gossypium hirsutum L.]. Effects of soil temperature and moisture on the emergence force were studied when the seedling was supported laterally to prevent buckling. The effect of compression of the top soil was investigated using a plate on the soil surface to simulate a crust. Measured emergence forces when the seedlings were laterally supported were greater than previously reported for cotton. Maximum emergence force varied quadratically with increases in soil temperature and moisture. The highest force was 11.4 N for a temperature of 28.5 °C and a soil water potential of −10 J kg−1. Maximum emergence force increased linearly with the hypocotyl cross‐sectional area, while calculated turgor potentials of hypocotyl cells were 768, 756, and 518 J kg−1 at soil water potentials of −10, −30, and −300 J kg−1, respectively. The emergence force was greatly reduced when lateral support was not provided. A compression pressure of 13.8 kPa on the top soil increased emergence force from 0.9 N at zero compression to 2.2 N, only ≈20% of the maximum force observed with adequate lateral support.

Tillage, Cover Cropping, and Poultry Litter Effects on Cotton: II. Growth and Yield Parameters

“…The faster rate of growth and development and the 15% higher lint yield of the cotton crop of 1998 compared with 1997 can be explained by more heat units received by the crop in 1998 (Fig. 1) Research on temperature effects on cotton growth and development has shown that rates of cotton seedling germination and emergence, rates of floral initiation, square development, and boll maturation in cotton increase with temperature up to about 32°C (Chu et al, 1991; Reddy et al, 1993; Hodges et al, 1993).…”

Morphological Characters Related to Varietal Differences in Tolerance to Deep Sowing in Wheat

“…These results were consistent with a previous report of Arndt ( 1965) who showed that soil resistance increased in proportion to cross section area of the penetrating object. Since dicotyledonous crops push soil up with the hook for seedling emergence, thicker hypocotyl was attributed to the elongation force of seedling (Chu et al, 1991;Inouye and Jin, 1981). By contrast, gramineous crops have to penetrate the soil with their coleoptile tip.…”

“…5, al., 1965Nayyar and Josum, 1978;Matsui, 1998;Sunderman, 1964) . However, the magnitude of soil resistance to the elongating plumule might depend on the shape of the plumule, mainly the cross-section area of plumule, as indicated in reports by Chu et al ( 1991), Inouye and Jin (1981) and Arndt (1965). These investigations suggested that the tolerance of a plant to deep sowing is associated with elongation force, coleoptile length and plumule shape.…”

The impact of mechanical impedance on the emergence of carrot and onion seedlings

“…The maximum axial growth pressure (σ max ) of shoots was measured using a method based on that of Chu et al (1991). In this approach, a shoot is allowed to grow against a balance until elongation stops and the axial growth force reaches a maximum (F max ).…”

“…Clark and Barraclough (1999) found that for a wide range of plant species, the σ max of seedling roots did not vary greatly and had a mean value of about 0.4 MPa. There are few estimates of maximum shoot growth pressure available in the literature, but Chu et al (1991) found that cotton shoots could generate 0.77 MPa at a soil water potential of −0.01 MPa.…”