Germination of seeds as influenced by matric potential and by area of contact between seed and soil water

Abstract

Experiments with Medicago tribuloides and Lactuca sativa confirm Sedgley's conclusion that the wetted area of contact is a factor controlling germination of the seed. The evidence suggests that this is of consequence at matric potentials near that of free water and is most important for germination of the last seeds in each population. Matric potential is shown to be an important factor in seed germination over and above its effect in controlling the wetted contact area of seed and medium. Prewetting the seed at matric potentials near that of free water for a few minutes increases the germination rate markedly and minimizes the normal effect of matric potential. The results and experimental conclusions are discussed and are shown to indicate the need for further investigation. They show that it is practicable to design experiments to distinguish the effects of the various facets of soil water energy on seed germination behaviour.

Factors Affecting Seed Germination and Seedling Establishment of Fen‐Meadow Species

“…Soil disturbance probably improved water uptake of the seeds. An undisturbed litter layer on the soil surface, as at the CM site, and a microtopographically uniform soil surface, as at the HJ site, likely reduced the contact between the seed and soil water and therewith a sufficient imbibition (Collis‐George & Hector 1966; Hadas & Russo 1974). Investigations on successional grassland have shown the strong adverse effect of a litter layer on seedling emergence and recruitment (Carson & Peterson 1990; Spackova et al 1998).…”

The effect of soil water potential on seed germination of some British plants

“…Consequently there is no lack of driving greater effect in delaying imbibition and germination potential, and some seeds can germinate in soils at or than a corresponding or greater decrease in i/rb elow the permanent wilting potential (Doneen & (McGinnies, 1960;Collis-George & Sands, 1962;MacGillivray, 1943;Manohar & Heydecker, 1964). Collis-George & Hector, 1966; Seed imbibition rates and the rate and level of Hadas & Stibbe, 1973; Hadas germination generally decrease as i/f^^^i decreases & Russo, 1974 a, b). Slight changes in ^^ are (Doneen & MacGillivray, 1943;Hunter & Erickson, accompanied by simultaneous changes in soil water 1952;Collis-George & Sands, 1959, 1962 Collis-conductivity and seed-soil contact area, whilst George & Hector, 1966;Williams & Shaykewich, changes in i/f^ per se are not (Sedgley, 1963;Collis-1971).…”

Assessing Maturity of Rotary Barrel Green Waste Composts for Use as Tomato and Sweet Pepper Seedling Starter and Transplant Growth Substrates

“…Additionally, water-soluble toxic compounds are present at a higher concentration in compost than in compost extracts. The presence of strong adhesive intermolecular forces between water and solid particles (matric potential) of growth substrates in in vivo investigations may have lessened imbibition of water by seed, resulting in lower germination rates (Collis-George and Hector, 1966;Kaufmann and Ross, 1970). Seedling survival in BLC and LCC may have been affected by high EC values, reported to reduce water and nutrient uptake (Grattan and Grieve, 1999).…”