Leguminous Vegetable Cultivation and Seed Production S ...
Leguminous Vegetable Cultivation and Seed Production S ...
Leguminous Vegetable Cultivation and Seed Production S ...
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SEED PRODUCTION AND MANAGEMENT OF MUNGBEAN AND SOYBEAN 365<br />
been contradictory (Edwards <strong>and</strong> Hartwig 1971, Fontes <strong>and</strong> Ohlrogge 1972, Green<br />
et al 1965, Johnson <strong>and</strong> Luedders 1974, Ndunguru <strong>and</strong> Summerfield 1975). Some<br />
changes associated with seed deterioration are reduced protein synthesis, reduced<br />
ability to utilize labeled glucose, reduced respiration, <strong>and</strong> increased respiration<br />
quotient (A. Knapp, pers. comm.). Although small seeds are associated with better<br />
seed longevity, the reasons are not yet understood.<br />
<strong>Seed</strong> vigor is an elusive <strong>and</strong> complex concept.Vigorous seeds are "likely to .. .<br />
perform particularly well in the field, better than others which may be equally<br />
satisfactory in the laboratory test" (Heydecker 1972). Loss of seed vigor due to<br />
weathering precedes loss of seed viability. Assessing seed vigor is problematic for<br />
seedmen (Kuenernan 1982). The concept of seed vigor <strong>and</strong> its importance to seed<br />
production were described by Heydecker (1972) <strong>and</strong> Perry (1978). A modified<br />
accelerated aging <strong>and</strong> hot water stress test were used to screen for seed longevity <strong>and</strong><br />
vigor.<br />
In the accelerated aging stress test, seeds are kept at 42 °C <strong>and</strong> 100% relative<br />
humidity (RH) for 48 h, followed by a laboratory germination test (Byrd <strong>and</strong><br />
Delouche 1971). To distinguish cultivars with good <strong>and</strong> pOOr seed storability, Wien<br />
<strong>and</strong> Kueneman (1981) used a modified accelerated aging stress technique. After pods<br />
dried, they threshed the seeds <strong>and</strong> subjected them to 75% RH at 40 °C for 6 wk,<br />
followed by a laboratory germination test.<br />
Germination (%)<br />
100 -<br />
80<br />
60<br />
40<br />
0 AGS 2<br />
AGS 29<br />
V AGS 66<br />
V AGS 129<br />
0 Pb-l(check)<br />
Bragg (check)<br />
20<br />
1 Jan 1 Mar 1 Apr 1 May 15 May 1 Jun 15 Jun 1 Jul<br />
Date of germination test<br />
2. Germination percentage of 6 soybean varieties evaluated at different intervals after storage at ambient<br />
temperature. Bangladesh, 1985.
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