Question

Of the many factors which influence the temperature response of seed germination, which do you think are most important and why?

Answer 1

The optimal temperature may be defined as the temperature giving the utmost percentage of germination in the unswerving time. The maximum temperature is governed by the temperature at which denaturation of proteins essential for germination occurs. The optimum temperature for most seeds is between 15 and 30^oC. The maximum temperature for most species is between 30 and 40^oC. Not only does germination have cardinal temperatures, but each stage has its own cardinal temperature; therefore, the temperature response may change throughout the germination period because of the complexity of the germination process. The response to temperature depends on a number of factors, including the species, variety, growing region, quality of the seed, and duration of time from harvest. It has been found that temperate-regions seeds require lower temperatures than do tropical region seeds, and wild species have lower temperature requirements than do domesticated plants. High-quality seeds are able to germinate under wider temperature ranges than low-quality seeds.

Out of these factors, Quality of seed (viability, dormancy, field emergence) plays a crucial role in temperature response to seed germination.

Seeds are the institution of agriculture. Technology has updated much of farming's day-to-day operations, but devoid of a steady supply of high-quality seed, yields and crop quality would be greatly decreased.

Seed quality plays an important role in the production of agronomic and horticultural crops. Characteristics such as trueness to variety, germination percentage, purity, vigor, and appearance are important to farmers planting crops and to homeowners establishing lawns and gardens. Achieving and maintaining high seed quality is the goal of every professional seed producer.

Germination is the emergence from the seed and development of those essential structures that under favorable conditions produce a normal plant.

Field Emergence is the elongation of the seedling axis resulting in protrusion of the seedling shoot from the soil.

Viability is the potential to germinate. A nonviable seed will not germinate under any conditions. Viable and a nonviable seeds may look exactly the same.

Dormancy is the state of non germination in viable seed. During this period, germination is blocked by conditions within the seed. Dormant seeds are often thought of as being in a resting state.