HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Figures Only Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Bednarz, C. W. Articles by Roberts, P. M. Search for Related Content PubMed Articles by Bednarz, C. W. Articles by Roberts, P. M. Agricola Articles by Bednarz, C. W. Articles by Roberts, P. M. Related Collections Best Management Practices Cotton Pest Management Systems Production Agriculture

CROP PHYSIOLOGY & METABOLISM

Spatial Yield Distribution in Cotton Following Early-Season Floral Bud Removal

^a Univ. of Georgia, Coastal Plain Experiment Station, P.O. Box 748, Tifton, GA 31793
^b Univ. of Georgia, Rural Development Center, P.O. Box 1209, Tifton, GA 31793

* Corresponding author (cbednarz{at}tifton.cpes.peachnet.edu)

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
A better understanding of cotton (Gossypium hirsutum L.) compensatory growth after loss of early-season floral buds requires an assessment of the actual patterns of spatial yield distribution in damaged and undamaged plants. This study was conducted to determine if spatial yield distribution or yield components are altered in cotton in response to removal of early-season floral buds. Beginning with the second week of squaring, floral buds were removed by hand for one, two, or three consecutive weeks. At 90 d after planting, plant height, leaf area index, main stem node number, fruit present, total fruiting positions, and dry weights were measured. The contribution to total yield from each fruiting position was determined at crop maturity. Results from this study show the lowest level of floral bud removal resulted in no differences in spatial yield distribution. As the intensity of early-season floral bud removal increased, however, the probability of harvesting a mature boll decreased in the lower canopy but increased in the upper canopy. Removal of floral buds resulted in fewer first sympodial position fruit but more third sympodial position fruit at harvest. Thus, early-season removal of floral buds resulted in additional seed cotton production on more apical and distal fruiting positions. These modifications in spatial yield distribution adequately replaced those floral buds removed early in the season because total seed cotton yield was not different among the treatments at crop maturity.

Abbreviations: Bt, Bacillus thuringiensis • CPES, Coastal Plain Experiment Station • CPES'99, 1999 study at the Coastal Plain Experiment Station Ponder Farm • IPM, integrated pest management • LAI, leaf area index • NACB, nodes above cracked boll • RDC'98, 1998 study at the Coastal Plain Experiment Station Rural Development Center Farm • RDC'99, 1999 study at the Coastal Plain Experiment Station Rural Development Center Farm

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
ACROSS MUCH OF THE U.S. COTTON BELT, broad-spectrum insecticides are applied early in the growing season to protect fruiting forms from insect pests such as the boll weevil (Anthonomus grandis grandis Boheman) and the tobacco budworm [Heliothis virescens (Fabricius)] (Mann et al., 1997). These applications not only increase production costs and environmental contamination, but also increase the likelihood of insecticide resistance development (Plapp et al., 1990) and decrease the populations of beneficial arthropods (House et al., 1985). In the southeastern region of the U.S. Cotton Belt, the Boll Weevil Eradication Program has virtually eliminated A. grandis as an economic insect pest. In addition, cotton cultivars that contain genes for expression of the delta-endotoxin of Bacillus thuringiensis (Bt) are becoming widely accepted. These technological advances have resulted in a decline in insecticide use against A. grandis and H. virescens (Mann et al., 1997). Boll weevil eradication and Bt cotton are cornerstones of current integrated pest management (IPM) systems for cotton. One addition that may strengthen cotton IPM systems and lessen the dependence on insecticides is potential for compensatory growth following early-season floral bud loss due to insects.

In cotton, economic thresholds in pest control decisions are based on several factors, including insect densities, cultivar/technology utilization, weather, equipment, and farm size (Mi et al., 1998). Economic thresholds, however, rarely consider plant compensation for loss of early-season floral buds as part of the model. Inclusion of plant compensation in economic injury levels would raise treatment thresholds, thereby reducing insecticide applications and the costs, contamination, and resistance development related to them. Prior to inclusion in an economic injury level, however, the ability of cotton to compensate for loss of early-season floral buds must be fully documented.

Many studies have investigated the ability of cotton to compensate for loss of fruiting forms with results that have ranged from small increases to large decreases in final lint yield (Sadras, 1995). In a review of the literature, Sadras (1995) indicated a better understanding of compensatory growth after loss of floral buds requires characterization of the actual patterns of spatial yield distribution in damaged and undamaged plants. Until now, no study has been conducted to determine if spatial yield distribution in cotton is altered by loss of early-season floral buds. Spatial distribution analyses of final lint yield will more fully determine if and how cotton plants may compensate for loss of early-season floral buds.

In describing plant compensation to loss of floral buds, Sadras (1995) further developed four types of responses that were originally defined by Hearn and Room (1979), Kletter and Wallach (1982), and Brook et al. (1992). First is a passive and instantaneous response in which reproductive structures that are damaged by insects would have shed physiologically anyway, resulting in no observable change in the spatial distribution of lint yield. Second is a passive and time-dependent response in which other reproductive structures that would have shed physiologically are retained, replacing those lost to insect damage. Third is an active and instantaneous response in which resources that would have been partitioned into damaged structures are partitioned into undamaged ones, resulting in increased boll weight. Fourth is an active and time-dependant response in which resources that would have been partitioned into damaged structures are partitioned into the production of additional fruiting sites, resulting in delayed crop maturity. The method in which cotton may compensate for loss of early-season floral buds, however, may be a combination of all possible responses.

The objectives of this investigation were to determine (i) if spatial distribution of lint yield is altered in cotton in response to loss of early-season floral buds, and (ii) which of the mechanisms outlined by Sadras (1995) are utilized in the redistribution of lint yield. We propose redistribution of lint yield in response to loss of early-season floral buds is possible and the mechanism of redistribution is most likely a combination of those proposed by Sadras (1995).

	MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
Cultural Practices
Studies were conducted at one location in 1998, and two locations in 1999. The 1998 study was conducted at the Coastal Plain Experiment Station (CPES) Rural Development Center Farm (RDC'98). The study was repeated in 1999 at the CPES Rural Development Center Farm (RDC'99) and the CPES Ponder Farm (CPES '99). Both locations are in Tift County, GA, on a Tifton loamy sand (Fine-loamy, kaolinitic, thermic Plinthic Kandiudults).

Cotton, ‘DeltaPine 33b’ was planted on 30 April (RDC'98) 1998, and 3 May (RDC'99) and 10 May (CPES'99) 1999 with a Monosem air planter (Lenexa, KS) on 91-cm row widths at a seeding rate of 10.8 seeds m^-2. While planting, 5.7 kg ha^-1 Aldicarb [2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl)oxime] was applied in furrow for insect control. Fertility, weed control, and insect scouting and control measures in all studies were in accordance with the University of Georgia Cooperative Extension Service guidelines (Brown et al., 1998). Water stress was minimized with sprinkler irrigation in all studies. Harvest aids were applied (2.3 L ha^-1 of ethephon plus cyclanilide and 0.07 kg ai ha^-1 of thidiazuron) in mid-September in all studies. The experimental design used in all studies was a randomized block design with three (RDC'98 and RDC'99) or four (CPES'99) replicates. Each plot was 4 rows wide and 15 m long.

Treatment Establishment
Hand removal of floral buds began early during the second week of squaring (43 d after planting) in each study. Only floral buds that were match-head size or larger (i.e., 3 mm) were removed in order to prevent damage to meristematic regions. During removal, floral buds that met the size criteria were grasped between the index finger and thumb and twisted until the peduncle snapped and the floral bud became disjoined. The treatments were as follows: (i) 50% floral bud removal for 1 wk, (ii) 100% floral bud removal for 1 wk, (iii) 50% floral bud removal for two consecutive weeks, (iv) 100% floral bud removal for two consecutive weeks, (v) 50% floral bud removal for three consecutive weeks, (vi) 100% floral bud removal for three consecutive weeks, and (vii) untreated. All floral buds on a sympodial branch that met the size criteria, regardless of position, were considered for removal. For the 50% floral bud removal treatments, all floral buds that met the size criteria were counted on a single plant, and one-half of these floral buds were removed at random. During the first week of removal, floral buds were removed from the first two-to-three sympodial branches. Most of the floral buds that were removed during this week were from first sympodial positions, as floral buds from second sympodial positions had not met the size criteria. Sympodial positions greater than two were not present at this time. During the second week of removal, floral buds were removed from the first four-to-five sympodial branches. Most of the floral buds that were removed during this week were from first and second sympodial positions, as floral buds from third sympodial positions had not met the size criteria. During the third week of removal, floral buds were removed from the first six-to-seven sympodial branches. Most of the floral buds that were removed during this week were also from first and second sympodial positions, as floral buds from third sympodial positions that met the size criteria had only been produced on the first one or two sympodial branches. During each week of floral bud removal, an additional one-to-two sympodial branches were noted in the apex of each plant. Floral buds were not removed from these branches, as they had not met the size criteria. One of the two center rows of each plot was randomly chosen for hand removal of floral buds. Floral buds were removed from the entire 15 m of the chosen row in each plot.

Data Collection
Growth analyses were conducted 90 d after planting in each study (during the boll-filling stage). For each growth analysis, all plants from 1 m of row in each plot were cut at the soil level, hand defoliated, and total leaf area was determined with an area meter (model LI-3100, LI-COR, Lincoln, NE). Plant height and total number of main stem nodes were then determined on each plant following leaf area determination. Next, the total number of squares, bolls, and missing positions were counted. Finally, dry weights of stems, leaves, squares, and bolls from each plot were determined after drying to uniformity at 60°C.

During the 3 wk prior to crop maturity in 1999, nodes above cracked boll (NACB) were counted on 6 different d in both studies. For this determination, the number of main stem nodes from the uppermost first sympodial position cracked boll to the uppermost harvestable boll were counted on ten plants in each plot. A harvestable boll was defined as a boll that had achieved full size (i.e., at least 3 wk old).

At harvest, 3 m of row in each plot were hand harvested as described by Jenkins et al. (1990a). Seedcotton, boll number, and boll weight at each fruiting site was documented. Thus, the contribution to total yield was determined for each fruiting position. All cotton on monopodial branches was harvested as one position. The only change in the Jenkins et al. (1990a) methodology was the cotyledonary node was counted as Node 0. In this investigation, every effort was made to establish the treatments accurately as outlined in the protocol. When the protocol required 100% floral bud removal, we attempted to remove precisely 100% of the floral buds that met the size criteria. Hand-harvest data collected at season's end, however, indicated that we were 85 to 90% efficient in our attempts to remove floral buds.

Statistical Analyses
Analysis of the Data Collected During the In-Season Growth Analyses and Data Collected from Monopodial Fruiting Positions at Harvest
A split plot in time (Steel and Torrie, 1980) was used to analyze the data. Study areas were considered main plots (two fields that were spatially separated were used in the two study years), blocks within study area as subplots, and treatments as sub-subplots. The Proc Mixed procedure (Littell et al., 1996) was used to analyze the data. The initial model considered study area and blocks within study area as random effects, while treatments were fixed effects. The second model analyzed six of the seven treatments as a two-by-three factorial consisting of two rates of floral bud removal and three times. A third analysis examined the linear and quadratic effects of time within levels of floral bud removal.

Analysis of the Data Collected from Sympodial Fruiting Positions at Harvest
The same model as before was used for analysis of these data, with the addition of nodes as sub-sub-subplots. Additional random error terms were blocks by treatments within study areas and blocks by nodes within study areas. Additional fixed effects were nodes and treatment by node interactions. The second model used six of the treatments as a two-by-three factorial as previously described. The third model examined the linear and quadratic effects of time and their interactions with level of floral bud removal and node.

Analysis of the Nodes Above Cracked Boll Data Collected Immediately Prior to Harvest
The same model as before was used for analysis of these data with the addition of dates as sub-sub-subplots and data from ten plants sampled at random as within sampling units. Additional random error terms were blocks by treatments within study areas, blocks by dates within study areas, and blocks by treatments by dates within study areas. Additional fixed effects were dates and treatment by date interactions. The second model used six of the treatments as a two-by-three factorial, as previously described. The third model examined the linear and quadratic effects of time and date and their interactions and interactions with level of floral bud removal.

	RESULTS AND DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
Growth Analyses
Sadras (1995) indicated that fruit loss changes partitioning of plant resources in favor of vegetative structures. This shift in partitioning increases the ability of the crop to acquire carbon and nitrogen and potentially increases the crop compensation capacity. Several studies have shown increased plant height (Patterson et al., 1978; Kennedy et al., 1986, 1991; Pettigrew et al., 1992; Holman and Oosterhuis, 1999) and leaf area index (LAI; Kennedy et al., 1986; Jones et al., 1996b) as a result of fruit loss. Our data (Table 1) illustrate that plant height and LAI were as much as 6 and 9% greater, respectively, 90 d after planting when early-season floral buds were removed. Additionally, the number of main stem nodes per plant 90 d after planting increased with duration of floral bud removal in our studies (Table 1). These data are in agreement with Kennedy et al. (1986), who reported an increased number of sympodia per plant with floral bud removal.

Jones et al. (1996b) and Pettigrew et al. (1992) reported that fruit removal decreased the reproductive: vegetative ratio during the boll filling stage of crop development. Our data also show a decreased fruit:shoot ratio (fruit dry weight per unit shoot dry weight) 90 d after planting with floral bud removal (Table 1). This is primarily attributed to the greater number of floral buds present (relative to bolls) with floral bud removal when the sampling was conducted. The percentage of bolls [(total bolls present/total fruit present) x 100] 90 d after planting ranged from 75.0% in the untreated to 52.5% in the most severe floral bud removal treatment (Table 1). While these data were collected 90 d after planting, they indicate that a delay in crop maturity is likely.

Numerous studies have demonstrated delayed crop maturity in response to fruit removal (McCarty et al., 1986; Ungar et al., 1987; Kennedy et al., 1991; Brook et al., 1992; Pettigrew et al., 1992; Jones et al., 1996b; Mann et al., 1997; Holman and Oosterhuis, 1999). Brook et al. (1992) and Mann et al. (1997), however, reported that maturity was delayed only by the greatest levels of fruit loss. Mann et al. (1997) also reported that the levels of fruit loss that delayed maturity in their studies are seldom encountered in the field. Crop maturity in our studies, as determined by NACB counts, was not different during the 3-wk period prior to harvest-aid application (Table 2). If a cotton crop may be considered mature at NACB 5 (Brown et al., 1998), however, then crop maturity in the untreated control occurred at 127 d after planting, while crop maturity in the treated plots was delayed from 3 to 7 d (Table 2). Interestingly, in some treatments floral buds were removed for three consecutive weeks, but crop maturity in these treatments was delayed for only 1 wk. This discrepancy may be partially explained by the greater LAI at 90 d after planting in the treated plots (Table 1). The greater LAI may have increased the ability of the crop to acquire carbon (Sadras, 1995), resulting in an increased rate of boll development and small differences in crop maturity at the season's end. Also, Malik et al. (1981) reported that vegetative organs provide efficient storage for excess assimilates, resulting from the complete suppression of early-season fruiting activity. Given that the rate of canopy photosynthesis in cotton declines beginning at 80 d after planting (Peng and Krieg, 1991), storage of excess assimilates prior to anthesis may provide additional carbohydrates for boll filling later in the growing season.

View larger version (20K): [in this window] [in a new window]   Fig. 1. Probability of harvesting a mature first sympodial position boll at each mainstem node in fruit removal studies conducted at Tifton, GA, in 1998 and 1999. Only select treatments are shown for clarity. FR, fruit removal; UNTD, untreated.

Intercepts for the probability of harvesting a mature third sympodial position boll were least in the untreated and 50% floral bud removal for 1-wk treatment, and greatest in the most severely damaged plants (Table 5). These data illustrate that early-season floral bud removal resulted in increased percentage boll retention in the third sympodial position at the bottom of the plant canopy (Fig. 2) . In addition, the linear component was greatest in the 100% floral bud removal for two and three consecutive weeks treatments, indicating retention increased at a greater rate in the damaged plants. Finally, the quadratic component for the probability of harvesting a mature third position boll was lesser in the untreated than in the most severe floral bud removal treatments, indicating that percentage fruit set was greater at the top of the canopy in the floral bud removal treatments.

View larger version (18K): [in this window] [in a new window]   Fig. 2. Probability of harvesting a mature third sympodial position boll at each mainstem node in fruit removal studies conducted at Tifton, GA, in 1998 and 1999. Only select treatments are shown for clarity. FR, fruit removal; UNTD, untreated.

To summarize, removal of early-season floral buds in our studies increased the probability of harvesting a mature boll in more apical and distal positions. These data are in agreement with Jones et al. (1996b), who removed flowers for several weeks after anthesis. Thus, depending on main stem node and sympodial fruiting position, our results both support and refute the hypothesis outlined by Sadras (1995) that cotton might compensate for loss of fruiting forms through increased fruit retention.

Seed cotton yields in the first sympodial position (Table 6) followed the boll set percentages discussed earlier (Table 4). Totaled across main stem nodes, first sympodial position seed cotton was greater in the untreated (2677 kg ha^-1) and the 50% floral bud removal for 1 wk treatment (2747 kg ha^-1) than all others. In the second sympodial position, only the 50% floral bud removal for two consecutive weeks treatment was different from the untreated. In the third sympodial position, however, the results were opposite those recorded in the first sympodial position. Totaled across main stem nodes, third sympodial position seed cotton was greatest in the 100% floral bud removal for 2 and 3 wk treatments (657 and 927 kg ha^-1, respectively) and the 50% floral bud removal for 3 wk treatment (694 kg ha^-1; Table 6). The third sympodial position seed cotton was least in the untreated and 50% floral bud removal for 1 wk treatment (305 and 375 kg ha^-1, respectively; Table 6). No treatment, however, was different from the untreated control in total seed cotton (Table 6).

Regression coefficients for first and third sympodial seed cotton are presented in Table 7. Few differences were observed in the second sympodial position data, and are therefore not presented. For this analysis, the intercept was again set at main stem Node 7 because the slope was generally greatest at this node in the data collected.

View this table: [in this window] [in a new window]   Table 7. Regression coefficients for first and third sympodial position seed cotton in fruit removal (FR) studies conducted at Tifton, GA, in 1998 and 1999.

View larger version (19K): [in this window] [in a new window]   Fig. 3. First sympodial position seedcotton at each mainstem node in fruit removal studies conducted at Tifton, GA, in 1998 and 1999. Only select treatments are shown for clarity. FR, fruit removal; UNTD, untreated.

View larger version (18K): [in this window] [in a new window]   Fig. 4. Third sympodial position seedcotton at each mainstem node in fruit removal studies conducted at Tifton, GA, in 1998 and 1999. Only select treatments are shown for clarity. FR, fruit removal; UNTD, untreated.

	CONCLUSIONS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
In this study, the lowest level of early-season floral bud removal (i.e., 50% removal for 1 wk) resulted in no observable changes in spatial yield distribution. These results support the hypothesis that those floral buds damaged early in the season would have shed physiologically anyway. The probability of harvesting a mature boll was reduced in the lower plant canopy and in the first sympodial position as a result of more intense early-season floral bud removal. More intense removal of early-season floral buds, however, increased the probability of harvesting a mature boll in the upper canopy and in the third sympodial position. Thus, these results support the hypothesis that reproductive structures that may have shed physiologically (in the upper canopy and in the third sympodial position) were retained, replacing those damaged earlier in the growing season. It is possible, however, that the increased probability of harvesting a mature boll in the upper canopy and in the third sympodial position was due in part to the production of additional fruiting sites. Regardless, these modifications in spatial yield distribution adequately replaced those floral buds removed early-season, as total seed cotton yield was not different among the treatments at crop maturity.

Floral bud removal also resulted in decreased boll weight in these studies, but only in the first sympodial position. We propose that this decrease was due to the fact that the heaviest fruit produced at the bottom of the canopy was removed as floral buds and was not included for boll weight determinations at harvest. Therefore, our data lead us to reject the hypothesis indicating resources that would have been partitioned into damaged structures are partitioned into undamaged ones.

Finally, growth analyses at 90 d after planting showed that removal of early-season floral buds resulted in an increase in the number of fruiting sites. These results support the hypothesis proposing resources that would have been partitioned into damaged structures are partitioned into the production of additional fruiting sites. The production of additional fruiting sites, however, did not result in a significant delay in crop maturity.

It should be noted, however, that crop productivity in these studies was maintained at the highest possible level, resulting in an average seed cotton yield across all three studies of 4914 kg ha^-1. Compensatory growth after loss of floral buds has been shown to be restricted under conditions of low resource availability (i.e., low fertility, low temperature, and high plant density; Sadras, 1996). Therefore, the compensatory capacity of cotton in commercial production systems may be more variable due to local management practices and regional weather patterns.

It also should be noted that cotton in many production systems is managed to achieve the highest possible level of early-season floral bud retention (i.e., 90%). Early in the growing season (i.e., before anthesis) the majority of the floral buds present on a cotton crop are from first sympodial positions on the first seven sympodial branches. In these studies, the probability of harvesting a mature boll on any one of these positions in the untreated was never >70.7%. Therefore, even in the absence of plant compensatory growth as part of the economic injury level, economic thresholds should be developed to include spatial distribution of lint yield as part of the model.

	ACKNOWLEDGMENTS

 
The authors wish to thank Benjamin G. Mullinix, Jr. for assistance with statistical analyses, and Walter C. Harvey and T. Dudley Cook for technical support. The authors also wish to thank the Georgia Agricultural Commodity Commission for Cotton and Cotton Incorporated for financial support.

Received for publication April 24, 2000.

	REFERENCES

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 

• Brook, K.D., A.B. Hearn, and C.F. Kelly. 1992. Response of cotton, Gossypium hirsutum L., to damage by insect pests in Australia: manual simulation of damage. J. Econ. Entomol. 85:1368–1377.[ISI]
• Brown, S.M., M. Bader, R.E. Baird, G. Harris, P.M. Roberts, and W.D. Shurley. 1998. 1998 Cotton Production Guide. Cooperative Extension Service Publication CSS 97–01. Univ. of Georgia, Athens, GA.
• Hearn, A.B., and P.M. Room. 1979. Analysis of crop development for cotton pest management. Prot. Ecol. 1:265–277.
• Holman, E.M., and D.M. Oosterhuis. 1999. Cotton photosynthesis and carbon partitioning in response to floral bud loss due to insect damage. Crop Sci. 39:1347–1351.[Abstract/Free Full Text]
• House, G.J., J.N. All, K.T. Short, and S.E. Law. 1985. Impact of synthetic pyrethroids on beneficial insects from cotton grown in the Southern Piedmont. J. Agric. Entomol. 2:161–166.
• Jenkins, J.N., J.C. McCarty, Jr., and W.L. Parrott. 1990a. Effectiveness of fruiting sites in cotton: yield. Crop Sci. 30:365–369.
• Jenkins, J.N., J.C. McCarty, Jr., and W.L. Parrott. 1990b. Fruiting efficiency in cotton: boll size and boll set percentage. Crop Sci. 30: 857–860.[Abstract/Free Full Text]
• Jones, M.A., R. Wells, and D.S. Guthrie. 1996a. Cotton response to seasonal patterns of flower removal: I. yield and fiber quality. Crop Sci. 36:633–638.[Abstract/Free Full Text]
• Jones, M.A., R. Wells, and D.S. Guthrie. 1996b. Cotton response to seasonal patterns of flower removal: II. growth and dry matter allocation. Crop Sci. 36:639–645.[Abstract/Free Full Text]
• Kennedy, C.W., W.C. Smith, Jr., and J.E. Jones. 1991. Chemical efficacy of early square removal and subsequent productivity of superokra-leaf cotton. Crop Sci. 31:791–796.[Abstract/Free Full Text]
• Kennedy, C.W., W.C. Smith, Jr., and J.E. Jones. 1986. Effect of early season square removal on three leaf types of cotton. Crop Sci. 26: 139–145.[Abstract/Free Full Text]
• Kerby, T.A., and D.R. Buxton. 1981. Competition between adjacent fruiting forms in cotton. Agron. J. 73:867–871.[Abstract/Free Full Text]
• Kletter, E., and D. Wallach. 1982. Effects of fruiting form removal on cotton reproductive development. Field Crops Res. 5:69–84.
• Littell, R.C., G.A. Milliken, W.W. Stroup, and R.D. Wolfinger. 1996. SAS System for Mixed Models. SAS Institute, Cary, NC.
• Malik, M.N.A., D.G. Edwards, and J.P. Evenson. 1981. Effects of flower bud removal and nitrogen supply on growth and development of cotton (Gossypium hirsutum L.). Aust. J. Plant Physiol. 8:285–291.
• Mann, J.E., S.G. Turnipseed, M.J. Sullivan, P.H. Adler, J.A. Durant, and O.L. May. 1997. Effects of early-season loss of flower buds on yield, quality, and maturity of cotton in South Carolina. J. Econ. Entomol. 90:1324–1331.[ISI]
• McCarty, J.C., Jr., J.N. Jenkins, and W.L. Parrot. 1986. Yield response of two cotton cultivars to tobacco budworm infestation. Crop Sci. 26:136–139.[Abstract/Free Full Text]
• Mi, S., D.M. Danforth, N.P. Tugwell, M.J. Cochran. 1998. Plant-based economic injury level for assessing economic thresholds in early-season cotton. J. Cotton Sci. 2:35–52.
• Patterson, L.L., D.R. Buxton, and R.E. Briggs. 1978. Fruiting in cotton as affected by controlled boll set. Agron. J. 70:118–123.[Abstract/Free Full Text]
• Peng, S., and D.R. Krieg. 1991. Single leaf and canopy photosynthesis response to plant age in cotton. Agron. J. 83:704–708.[Abstract/Free Full Text]
• Pettigrew, W.T., J.J. Heitholt, and W.R. Meredith, Jr. 1992. Early season floral bud removal and cotton growth, yield, and fiber quality. Agron. J. 84:209–214.[Abstract/Free Full Text]
• Plapp, F.W., Jr., J.A. Jackman, C. Campanhola, R.E. Frisbie, J.B. Graves, R.G. Luttrell, W.F. Kitten, and M. Wall. 1990. Monitoring and management of pyrethroid resistance in the tobacco budworm (Lepidoptera: Noctuidae) in Texas, Mississippi, Louisiana, Arkansas, and Oklahoma. J. Econ. Entomol. 83:335–341.[ISI]
• Sadras, V.O. 1995. Compensatory growth in cotton after loss of reproductive organs. Field Crops Res. 40:1–18.
• Sadras, V.O. 1996. Cotton compensatory growth after loss of reproductive organs as affected by availability of resources and duration of recovery period. Oecologia 106:432–439.[ISI]
• Steel, R.G.D., and J.H. Torrie. 1980. Principles and procedures of statistics a biometrical approach. 2nd ed. McGraw Hill, New York.
• Ungar, E.D., D. Wallach, and E. Kletter. 1987. Cotton response to boll and bud removal. Agron. J. 79:491–497.[Abstract/Free Full Text]

This article has been cited by other articles:

				C. I. Mills, C. W. Bednarz, G. L. Ritchie, and J. R. Whitaker Yield, Quality, and Fruit Distribution in Bollgard/Roundup Ready and Bollgard II/Roundup Ready Flex Cottons Agron. J., January 11, 2008; 100(1): 35 - 41. [Abstract] [Full Text] [PDF]

				G. Wu, F.-J. Chen, Y.-C. Sun, and F. Ge Response of Cotton to Early-Season Square Abscission under Elevated CO2 Agron. J., May 11, 2007; 99(3): 791 - 796. [Abstract] [Full Text] [PDF]

				D. Dumka, C. W. Bednarz, and B. W. Maw Delayed Initiation of Fruiting as a Mechanism of Improved Drought Avoidance in Cotton Crop Sci., March 1, 2004; 44(2): 528 - 534. [Abstract] [Full Text] [PDF]

				O. L. May, A. S. Culpepper, R. E. Cerny, C. B. Coots, C. B. Corkern, J. T. Cothren, K. A. Croon, K. L. Ferreira, J. L. Hart, R. M. Hayes, et al. Transgenic Cotton with Improved Resistance to Glyphosate Herbicide Crop Sci., January 1, 2004; 44(1): 234 - 240. [Abstract] [Full Text] [PDF]

This Article Abstract Figures Only Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Bednarz, C. W. Articles by Roberts, P. M. Search for Related Content PubMed Articles by Bednarz, C. W. Articles by Roberts, P. M. Agricola Articles by Bednarz, C. W. Articles by Roberts, P. M. Related Collections Best Management Practices Cotton Pest Management Systems Production Agriculture