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Influence of Temperature on Growth and Metabolism of Ryegrass Seedlings. I. Seedling Growth and Yield Components 1
Author(s) -
Beevers Leonard,
Cooper J. P.
Publication year - 1964
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1964.0011183x000400020004x
Subject(s) - welsh , seedling , crop , yield (engineering) , biology , horticulture , agronomy , history , archaeology , materials science , metallurgy
-I-anTcHE effects of extreme temperatures on plant growth be readily demonstrated. Thus, growth usually ceases above 50° C. and below 0° C. Within these extremes, however, considerable variation in growth rate can occur depending upon the temperature. While this effect of temperature on growth is generally recognized less is known of the manner in which this influence of temperature is exerted. Blackman (6) in discussing plant growth likened the increase in dry weight of a plant growing without competition to a system of continuous compound interest. Thus, the increment in dry weight produced in any interval added to the capital for growth in the subsequent period. Although this concept has undergone various modifications throughout the years, it follows, as Watson (19) points out, that dry weight yield will be dependent upon (a) the initial capital, (b) the relative growth rate, and (c) length of the growth period. Gregory (10) further suggested that dry weight yield would be determined by the efficiency of the plant which could be measured in terms of dry matter production per unit leaf area in unit time. This measurement is termed net assimilation rate, N.A.R. As well as being determined by this photosynthetic efficiency, however, the dry matter production will depend on the relative proportion of photosynthetic to nonphotosynthetic tissue. The ratio of leaf surface (photosynthetic area) to total plant weight gives an indication of the proportion of photosynthetic surface and is usually termed leaf area ratio, L.A.R. The relative growth rate (R.G.R.) can be assessed as the product of N.A.R. and LA.R. In the present experiments controlled environmental facilities were used to study the influence of temperature regime on the vegetative growth, leaf and tiller development, and metabolism of ryegrass This paper presents data on the vegetative growth of ryegrass in three temperature regimes and the results are examined in terms of classical growth analysis.