| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
The magnitude of a seed yield increase that occurs when soybeans [Glycine max (L.) Merr.] are irrigated depends upon the phenologic timing of the irrigation in relation to the temporal sequence with which the components of seed yield are established and fixed. Eight soybean cultivars, varying in stem growth habit and maturity, were irrigated according to a factorial treatment design in which either no irrigation or one irrigation was applied at three reproductive stages: R1 to R2 flowering (F), R3 to R4 pod elongation (P), or R5 to R6 enlargement (S). An F irrigation increased the numbers of pods/plant (+ 2.8) and seeds/plant (+ 5.8), but an offsetting decrease occurred 100-seed weight (-0.9 g), resulting in little change in seed yield. P irrigation had no effect on 100-seed weight, but increased the numbers of pods/plant (+3.4) and seeds/plant (+7.9) resulting in a large increase in seed yield. An S irrigation resulted in only slight increases in the numbers of pods/plant (+1.0) and seeds/plant (+3.3), but greatly increased 100-seed weight (+1.4 g), again leading to a large seed yield increase. These observations suggested that irrigation early in reproductive ontogeny greatly reduced flower and pod abortion, whereas irrigation later in ontogeny reduced ovule abortion within developing pods. The cultivar ‘Harcor’ possessed unusually high numbers of oneand two-seed pods, while ‘Elf’ had substantially fewer numbers of three-seed pods, and ‘Woodworth’ possessed larger numbers of fourseed pods. Irrigation timing differentially influenced the frequencies of the various pod classes relative to their contribution to the increase in total pods/plant, primarily because of effects on ovule abortion within developing pods. The effects of irrigation timing on number of seeds/plant and 100-seed weight were thus consistent with the effects on seed yield reported earlier.
Key Words: Glycine max (L.) Merr. • Soil moisture • Water stress • Growth stage • Cultivars • Seed number • Seed size
2 Graduate student, associate professor, and professors, Dep. of Agronomy, Univ. of Nebraska, Lincoln, NE 68583.
Received for publication September 1, 1982.
This article has been cited by other articles:
|
|
 |
|
  P. Pedersen and J. G. Lauer Soybean Growth and Development in Various Management Systems and Planting Dates Crop Sci., March 1, 2004; 44(2): 508 - 515. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. d. Sousa-Majer, N. C. Turner, D. C. Hardie, R. L. Morton, B. Lamont, and T. J. V. Higgins Response to water deficit and high temperature of transgenic peas (Pisum sativum L.) containing a seed-specific {alpha}-amylase inhibitor and the subsequent effects on pea weevil (Bruchus pisorum L.) survival J. Exp. Bot., February 1, 2004; 55(396): 497 - 505. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. E. Brevedan and D. B. Egli Short Periods of Water Stress during Seed Filling, Leaf Senescence, and Yield of Soybean Crop Sci., November 1, 2003; 43(6): 2083 - 2088. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. W. Sweeney, J. H. Long, and M. B. Kirkham A Single Irrigation to Improve Early Maturing Soybean Yield and Quality Soil Sci. Soc. Am. J., January 1, 2003; 67(1): 235 - 240. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Desclaux, T.-T. Huynh, and P. Roumet Identification of Soybean Plant Characteristics That Indicate the Timing of Drought Stress Crop Sci., May 1, 2000; 40(3): 716 - 722. [Abstract] [Full Text]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Vadose Zone Journal | |||
| Journal of Plant Registrations | Soil Science Society of America Journal | ||||
| Journal of Natural Resources and Life Sciences Education |
Journal of Environmental Quality |
||||
