Crop Science Journal of Natural Resources and Life Sciences Education
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (5)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Pfeiffer, T.W.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Pfeiffer, T.W.
Agricola
Right arrow Articles by Pfeiffer, T.W.
Crop Science 40:387-390 (2000)
© 2000 Crop Science Society of America

CROP BREEDING, GENETICS & CYTOLOGY

Selecting Soybean for Adaptation to Double Cropping on the Basis of Full Season Plant Height

T.W. Pfeiffera

a Dep. of Agronomy, Univ. of Kentucky, Lexington, KY 40546-0091 USA

tpfeiffe{at}ca.uky.edu


   ABSTRACT
TOP
 NOTES
 ABSTRACT
INTRODUCTION
 Materials and methods
 Results and discussion
 Conclusion
 REFERENCES
 
Double-cropping soybean [Glycine max (L.) Merr.] shortens the growing season and reduces vegetative mass and seed yield. Soybean genotypes which produce greater vegetative mass may be better adapted to the double-crop system. This study was conducted to determine if tall soybean lines selected from full season plantings were better adapted to double-crop plantings than lines chosen from the same populations without regard to plant height. Four sets of soybean lines, with a tall and random height group in each set, were compared at Lexington, KY, in full season wide row and late planted narrow row (simulated double crop) cropping systems to determine the interaction between plant height and yield in the two different cropping systems. Soybean grown in the full season cropping system yielded an average of 32% more than when grown in the double-crop system. The height groups differed in yield in only one of the four sets. The cropping system x height group source of variation was not significant for yield in any set. Six of the eight lines ranked one or two for full season yield in each of the four sets were from the random height groups. Likewise, six of the eight lines ranked one or two for double-crop yield were also from the random height groups. Greater plant height did not consistently increase yield in the lower yielding double-crop environments. The selection of tall soybean lines did not provide improved adaptation to the double-crop cropping system.


   INTRODUCTION
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
Materials and methods
 Results and discussion
 Conclusion
 REFERENCES
 
WHEN A SPECIFIC CROPPING SYSTEM

imposes a unique set of environmental factors on a crop, plant breeders will evaluate the usefulness of conducting a separate selection program to produce genotypes specifically adapted to the cropping system. Soybean double cropped after wheat (Triticum aestivum L.) has been one such cropping system (Pfeiffer, 1987a, b; Panter and Allen, 1989). Double cropping delays soybean planting, and because planting soybean after a critical date reduces yield (Tanner and Hume, 1978), the productivity of double-cropped soybean is reduced. Thus, breeding soybean for double cropping may be considered breeding for marginal or low-yield environments.

Suggestions for improving adaptation of soybean to double-crop environments usually involve increasing vegetative growth (Cooper, 1989; Caviness, 1989). Experimentally, total dry matter at R5 had the greatest correlation with late-planted yield, and total dry matter at R7 was also significantly correlated with late-planted yield (Board et al., 1996). A vegetative mass of 500 g m-2 at beginning pod fill was suggested as a critical minimum to achieve maximum yield in late planting (Egli et al., 1987). While measuring vegetative mass is time consuming, measuring plant height is easy, and plant height measurements have ranked vegetative growth similarly to measurements of vegetative mass (Pfeiffer and Harris, 1990). Thus soybean breeders could use and have used plant height as an indicator of vegetative growth.

Adaptation to double cropping by specific cultivars has been attributed to increased plant height. Walker and Cooper (1982) conducted a regression analysis of 10 maturity group II lines grown in 43 environments. The cultivar Amcor had the highest mean yield and a regression coefficient for yield which was significantly less than one. Thus, Amcor was better adapted to low yield environments and was noted to have performed well in late plantings and in double cropping. They attributed this adaptation to low yield environments to Amcor's 12% taller height (108 cm). The maturity group VII cultivar Duocrop, with a tall indeterminate plant type, was developed specifically for delayed plantings where lack of vegetative growth of the commonly grown determinate plant types reduced yield (Boerma et al., 1982). Selection of soybean genotypes that produce larger plants was suggested as a useful approach for developing cultivars for double cropping (Boerma, 1978).

Soybean breeders will visually select in progeny rows against tall lines which lodge severely. W.J. Kenworthy (about 1984, personal communication) suggested selecting in conventionally planted progeny rows solely for the tallest lines, while ignoring lodging. The yield of these lines would then be assessed in double-crop plantings where growth would be reduced and lodging less problematical. This might result in retaining lines adapted to double cropping which would normally be discarded early in the selection process. The objective of this experiment was to determine whether selected tall soybean lines were more productive in late plantings than lines chosen randomly with regard to plant height.


   Materials and methods
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
 Materials and methods
Results and discussion
 Conclusion
 REFERENCES
 
All selections and evaluations were conducted at Lexington, KY (38° N latitude). The soil type in any particular year was either a Maury silt loam (fine, mixed, mesic Typic Paleudalf) or a Lanton silt loam (fine-silty, mixed, thermic Cumulic Haplaquoll). This experiment was conducted with four different sets of selections: A, B, C, and D. Each set of selections consisted of two groups of lines. Tall lines and random lines were chosen from unreplicated 3-m progeny rows (Sets A, B, and C) or replicated hill plots (Set D) of material being evaluated in a soybean cultivar development program. The initial pool of lines for each set consisted of approximately 1200 F4:5 lines. All lines were progenies of two-parent crosses. Plant height at maturity was measured for the tallest plant of all lines in the initial pools.

The progeny rows of Set A were grown in 1984. The 10 tallest lines were selected for the tall group. For each of these 10 lines the line from the nearest plot which had the same maturity date was chosen for the random group. The tall lines were progeny from four crosses, and the random lines were progeny from ten crosses. One cross contributed lines to each group. All tall and random lines had indeterminate growth habit. The progeny rows for Set B were grown in 1985. Eleven lines in each group were selected in the same manner as for Set A. The tall lines were progeny from eight crosses, and the random lines were progeny from nine crosses. Four crosses contributed lines to each group. All tall lines and four random lines had indeterminate growth habit. The other seven random lines had determinate growth habit. The progeny rows for Set C were grown in 1987. Ten lines in each group were selected similarly as above. The tall lines were progeny from eight crosses, and the random lines were progeny from nine crosses. Two crosses contributed lines to each group. All tall lines and seven random lines had indeterminate growth habit. The remaining three random lines had determinate growth habit. The progeny hills for Set D were grown in 1990. The 10 tall lines were selected as above. The 10 random lines were chosen as the line from the nearest plot with the same maturity date and from the same cross as a tall line. Each group consisted of progeny from five crosses. All tall lines and eight random lines had indeterminate growth habit.

The two groups in each set were evaluated for 2 yr (Set A, 1985 and 1986; Set B, 1987 and 1989; Set C, 1989 and 1990; Set D, 1992 and 1993) in a split-plot arrangement of a randomized complete block design with three replications. Whole plots were planting dates. Full season planting dates ranged from 10 May to 23 May, while double-crop planting dates ranged from 22 June to 8 July. Subplots were lines. A check cultivar was included with the evaluation of each set, `Douglas' with Set A and `Pennyrile' with the other three sets. The plots in the first year evaluation of Set A were two 3-m-long rows with a 0.76-m row spacing in the full season plots and four 3 m long rows with a 0.38 m row spacing in the double-crop plots. For all other evaluation tests, plots consisted of four 6-m-long rows with a 0.76-m row spacing in the full season plots and eight 6-m-long rows with a 0.38-m row spacing in the double-crop plots. Seeding rates were 33 seeds m-1 of row in the full season plots and 16 seeds m-1 of row in the double-crop plots. Double cropping was simulated by a delayed planting date and narrower row widths compared with the full season cropping system. However, because of equipment limitations, the double-crop plots were planted in a tilled seedbed. They were not planted no-till into wheat stubble.

Variables measured included date of maturity (R8) (Fehr and Caviness, 1977), plant height at maturity (cm), lodging (score 1–5, where 1 is all plants erect and 5 is all plants lodged), and seed yield (kg ha-1 adjusted to 130 g kg-1 moisture). After end-trimming at maturity, yield was determined by combine harvesting two rows in the full season plots and four rows in the double-crop plots.

An analysis of variance was conducted for each set using a fixed model and ignoring the data from the check cultivar. Sources of variation with calculated probability levels greater than 0.05 were considered nonsignificant. Correlation coefficients were calculated on an entry-mean basis within each year and cropping system for yield with plant height and yield with lodging. Within each set, rank correlation coefficients were calculated for a line's 2-yr full season mean yield rank with its 2-yr double-crop mean yield rank.


   Results and discussion
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
 Materials and methods
 Results and discussion
Conclusion
 REFERENCES
 
The cropping system x height group x year source of variation was not significant for yield in any set. Therefore, data from all sets are presented as 2-yr means (Table 1) , and sources of variation involving interactions with years are not shown.


View this table:
[in this window]
[in a new window]
  		Table 1 Height group means and (in parentheses) genotype within height group ranges for four sets of tall and random soybean lines each grown for two years in two cropping systems at Lexington, KY

 
In all sets, soybean grown in the full season cropping system yielded more than when grown in the double-crop system (Tables 1, 2, and 3) with the average double crop yield reduction ranging from 16% for Set A to 33% for Set B. The height groups were significantly different in yield only once (Table 2). Random lines (2460 kg ha-1) yielded more than tall lines (2370 kg ha-1) in Set A. More importantly, the cropping system x height group source of variation was never significant for yield (Table 2). In the double-crop system, the mean yield of the tall lines was never greater than the mean yield of the random lines, and only in Set A was the yield of the highest yielding tall line greater than the yield of the highest yielding random line (Table 1). For yield, the genotype (height group) and the genotype (height group) x cropping system sources of variation were significant in all sets (Table 2). So, measurable genetic differences were present, and lines within each height group changed ranks across cropping systems. However, when all lines in a set were ranked on the basis of full season and on double-crop yields, the rank correlations between cropping systems within sets ranged from r = 0.45 to r = 0.51. All rank correlations were significant (P = 0.05). The changes in line ranks in the two cropping systems were not based primarily on plant height.


View this table:
[in this window]
[in a new window]
  		Table 2 Significance levels for variables yield, plant height, and lodging for four different sets of tall and random soybean genotypes. Each set was grown at Lexington, KY, in two cropping systems for two years

 

View this table:
[in this window]
[in a new window]
  		Table 3 Yield levels and correlation coefficients for yield with plant height and lodging within each year and cropping system for four sets of tall and random soybean genotypes grown at Lexington, KY

 
Across all four sets six of the eight lines ranked one or two for full season yields were from the random groups and six of the eight lines ranked one or two for double-crop yields were also from the random groups. The six random lines which ranked first or second for yield in the double-crop environments had plant heights greater than or equal to the mean double-crop height of the random group. But, they were never the tallest random lines and were, in all cases, shorter than the mean double-crop height of the tall group. The two tall lines which ranked second for yield in the double-crop environments were shorter than the mean double-crop height of the tall group. On the other hand, six of the eight lines ranked last or next to last for the four sets for double-crop yield were random lines, and in Sets B and D these included the shortest line in that set.

In all sets, the height groups were significantly different in plant height (Table 2). However, selection of the tallest lines in the F4:5 progeny plots did not provide complete height separation between height groups as there was overlap in each set for the tallest line in the random group and the shortest line in the tall group (Table1). In all sets, there were significant height differences among genotypes within height groups (Table 2). Ranges in height were larger within the random groups than within the tall groups (Table 1) due in part to the inclusion of lines in the random group with determinate growth habit.

In all sets, height groups did not differ in maturity. Thus, greater height was not due to later maturity. Plant height was greater in the full season plantings than in the double-crop plantings in Sets A and B, greater in the double-crop planting than in the full season planting for Set C, while there was no height difference between cropping systems in Set D (Tables 1 and 2). The interaction between cropping system and height group was significant in each set for plant height (Table 2). This was because height differences between groups were accentuated in the full season plantings (26 cm difference) compared to the double-crop plantings (15 cm difference).

Yield was positively correlated with height in three (Set B, 1987; Set B, 1989; Set D, 1992) of eight full season environments and two (Set A, 1986 and Set B, 1989) of eight double-crop environments (Table 3). These three full season environments were ranked first, fifth, and eighth for full season yield, and the two double-crop environments were ranked six and seventh for double-crop yield. The 1987 full season and 1987 double-crop environments would be considered low yield environments, with yields less than 1500 kg ha-1. In only one of these environments was height positively correlated with yield (Table 3). Taller plants did not automatically produce higher yields in the lowest yielding environments.

The tall group had significantly greater lodging in all sets (Tables 1 and 2), with an increase of approximately one-half lodging unit. Lodging for each set was significantly different between cropping systems. Greater lodging was usually observed in the full season plantings (Sets A, B, and C), but for Set D greater lodging occurred in the double-crop planting. Yield and lodging were positively correlated in one full season and one double-crop environment and negatively correlated in one double-crop environment (Table 3). Overall, lodging in this experiment was not a constraint on yield, and increased height was not deleterious in the highest yield environments. Yield in the most productive environment in this study was below 4000 kg ha-1, however, the level at which Cooper (1989) suggested a shorter plant type was needed to reduce the negative effect of lodging on yield.


   Conclusion
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
 Materials and methods
 Results and discussion
 Conclusion
REFERENCES
 
Increased height was not consistently beneficial for increasing yield in the double-crop environments. This is not to say that high yielding tall lines could not be developed for this cropping system, and these data do suggest that selection against plants with shorter than average heights may eliminate from testing some lines which will be poorly adapted to double cropping. There are, however, many other genetically controlled processes which contribute to a genotype's yield potential in double-crop environments. Selecting first for tall lines did not enhance the probability of finding these better genotypes. While this selection scheme, selecting lines to test in double-crop environments based on full season plant height, could be easily implemented, the results were no more encouraging as a method to improve adaptation to double cropping than those from previous research utilizing selection for altered flowering times to increase plant growth prior to flowering (Pfeiffer and Pilcher, 1987) or using specific alleles to increase plant growth (Raymer and Bernard, 1988; Pfeiffer and Harris, 1990). The best selection scheme I can currently recommend for improving soybean yield in double cropping is to select for mean productivity, the mean yield of a genotype tested in both full season and double-crop cropping systems (Rosielle and Hamblin, 1981; Pfeiffer, 1987b), and, whenever possible, to select for resistance to soybean mosaic virus (Ren et al., 1997).


   NOTES
TOP
 NOTES
ABSTRACT
 INTRODUCTION
 Materials and methods
 Results and discussion
 Conclusion
 REFERENCES
 
This paper (99-06-83) is published with approval of the director of the Kentucky Agric. Exp. Stn.

Received for publication June 28, 1999.


   REFERENCES
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
 Materials and methods
 Results and discussion
 Conclusion
 REFERENCES
 




This article has been cited by other articles:


Home page
 Agron. J.Home page
S. Kyei-Boahen and L. Zhang
Early-Maturing Soybean in a Wheat-Soybean Double-Crop System: Yield and Net Returns
Agron. J., February 7, 2006; 98(2): 295 - 301.
[Abstract] [Full Text] [PDF]

Home page
 Crop Sci.Home page
R. S. Taylor, D. B. Weaver, C. W. Wood, and E. van Santen
Nitrogen Application Increases Yield and Early Dry Matter Accumulation in Late-Planted Soybean
Crop Sci., March 28, 2005; 45(3): 854 - 858.
[Abstract] [Full Text] [PDF]

Home page
 Agron. J.Home page
J. E. Board
A Regression Model to Predict Soybean Cultivar Yield Performance at Late Planting Dates
Agron. J., May 1, 2002; 94(3): 483 - 492.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (5)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Pfeiffer, T.W.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Pfeiffer, T.W.
Agricola
Right arrow Articles by Pfeiffer, T.W.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
The SCI Journals Agronomy Journal Vadose Zone Journal
Journal of Natural Resources
and Life Sciences Education		 Soil Science Society of America Journal
Journal of Plant Registrations Journal of
Environmental Quality		 The Plant Genome