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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Pettigrew, W. T. Search for Related Content PubMed Articles by Pettigrew, W. T. Agricola Articles by Pettigrew, W. T. Related Collections Crop Growth and Development Cotton Plant and Environment Interactions

The Effect of Higher Temperatures on Cotton Lint Yield Production and Fiber Quality

USDA-ARS, Crop Genetics and Production Research Unit, P.O. Box 345, Stoneville, MS 38776. Trade names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product or service, and the use of the name by USDA implies no approval of the product or service to the exclusion of others that may also be suitable

^* Corresponding author (bill.pettigrew{at}ars.usda.gov).

	ABSTRACT

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
An optimal temperature range exists for cotton (Gossypium hirsutum L.). When Mississippi Delta cotton experiences temperatures above the upper threshold, as can occur during the summer, it is not entirely clear what growth parameters are affected by the heat. The objectives of this study were to document differences in agronomic and physiological performance for two cotton genotypes (SureGrow 125 and SureGrow 125BR) when grown under an ambient temperature control and a warm temperature regime (about 1°C warmer). Field studies were conducted from 2003 through 2005. White bloom counts, nodes above white bloom (NAWB) data, dry matter partitioning data, lint yield, yield components, and fiber quality data were collected. Genotypes responded similarly to the temperature regimes. Warmer temperatures resulted in lower NAWB data, indicating a slightly advanced crop maturity. In two out of three years, the lint yield from the warm regime was 10% lower than that of the control. This reduction was primarily caused by a 6% smaller boll mass, with 7% fewer seed produced per boll in the warm regime. Fiber produced in the warm temperature regime was consistently 3% stronger than fiber in the control treatment. When temperatures become too hot, ovule fertilization may be compromised, leading to fewer seeds produced per boll, smaller boll masses, and ultimately, lint yield reductions.

Abbreviations: AFIS, Advanced Fiber Information System • Chl, chlorophyll • DAP, days after planting • F_v/F_m, variable Chl fluorescence/maximum fluorescence ratio • LAI, leaf area index • NAWB, nodes above white bloom • PPFD, photosynthetic photon flux density

	NOTES

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

Received for publication May 8, 2007.

The Effect of Higher Temperatures on Cotton Lint Yield Production and Fiber Quality

USDA-ARS, Crop Genetics and Production Research Unit, P.O. Box 345, Stoneville, MS 38776. Trade names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product or service, and the use of the name by USDA implies no approval of the product or service to the exclusion of others that may also be suitable

^* Corresponding author (bill.pettigrew{at}ars.usda.gov).

An optimal temperature range exists for cotton (Gossypium hirsutum L.). When Mississippi Delta cotton experiences temperatures above the upper threshold, as can occur during the summer, it is not entirely clear what growth parameters are affected by the heat. The objectives of this study were to document differences in agronomic and physiological performance for two cotton genotypes (SureGrow 125 and SureGrow 125BR) when grown under an ambient temperature control and a warm temperature regime (about 1°C warmer). Field studies were conducted from 2003 through 2005. White bloom counts, nodes above white bloom (NAWB) data, dry matter partitioning data, lint yield, yield components, and fiber quality data were collected. Genotypes responded similarly to the temperature regimes. Warmer temperatures resulted in lower NAWB data, indicating a slightly advanced crop maturity. In two out of three years, the lint yield from the warm regime was 10% lower than that of the control. This reduction was primarily caused by a 6% smaller boll mass, with 7% fewer seed produced per boll in the warm regime. Fiber produced in the warm temperature regime was consistently 3% stronger than fiber in the control treatment. When temperatures become too hot, ovule fertilization may be compromised, leading to fewer seeds produced per boll, smaller boll masses, and ultimately, lint yield reductions.

Abbreviations: AFIS, Advanced Fiber Information System • Chl, chlorophyll • DAP, days after planting • F_v/F_m, variable Chl fluorescence/maximum fluorescence ratio • LAI, leaf area index • NAWB, nodes above white bloom • PPFD, photosynthetic photon flux density

	INTRODUCTION

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
COTTON (Gossypium hirsutum L.) is of subtropical, semiarid origin and is accustomed to warm, dry conditions (Lee, 1984). As with all plant species, an optimum temperature range exists for cotton growth, above and below which growth is depressed. Burke et al. (1988) defined the optimal temperature range or "thermal kinetic window" based on enzyme kinetics for cotton as between 23.5 and 32°C. They found a linear relationship between biomass production and the length of time the foliage temperature was within that optimum range. However, it is not uncommon for ambient air temperatures to exceed that upper threshold during the afternoon hours of July and August in the Mississippi Delta (Boykin et al., 1995). Most previous research on cotton response to higher temperatures has consisted primarily of artificial growth environment studies (growth chambers and greenhouses) (Reddy et al., 1991, 1992, 1999) or studies correlating cotton growth across multiple locations and years with the local weather data (Krieg, 2002; Meredith, 2002, 2005). In these artificial growth environments, Reddy et al. (1992) reported decreased reproductive dry matter as temperatures increased above 30°C and reduced flower retention with increased exposure to 40°C. Boll maturation period and boll size also decreased with higher temperatures, and fiber length was reduced (Reddy et al., 1999). Krieg (2002) reported that warmer night temperatures increased the fiber micronaire, and Meredith (2005) found that higher temperatures resulted in shorter fibers. While useful, these studies do not provide complete insight into how cotton's growth will respond to periods of higher temperatures because cotton grown in artificial environments sometimes does not behave like field-grown cotton (Carmi and Shalhevet, 1983), and the correlative studies do not completely isolate the temperature effect from other factors. For instance, higher temperatures often coincide with periods of high sunlight and/or periods of low precipitation (Boykin et al., 1995).

Gipson and Joham (1968a,b, 1969), using chambers equipped with either gas fired furnaces or air conditioners in the Texas Southern High Plains, investigated the influence night temperatures in the range of 5 to 25°C have on cotton production under field conditions. Night temperatures are often easier to associate with crop productivity because high night temperatures can sometimes be separated from periods of high sunlight. They found that boll development slowed and the rate and amount of cellulose synthesis was reduced as night temperatures decreased (Gipson and Joham, 1968a,b). Maximum fiber elongation rates were also obtained with night temperatures 21.1°C (Gipson and Joham, 1969). A concern with the chambers used in these studies, however, is how gas flow and exchange within the canopies would be affected by the chamber walls relative to that in a natural field environment.

Hence, uncertainty remains as to how completely information from these studies will translate into field performance in the southeastern and mid-southern parts of the U.S. cotton production belt, which are more humid environments than that of the semiarid Texas Southern High Plains. The increased humidity impacts the plants ability to cool itself through evapotranspiration and could potentially alter a temperature response. Therefore, the objectives of this study were to compare the agronomic and physiological field performance of two cotton cultivars under both the ambient temperature regime and a temperature regime a few degrees warmer than ambient. Using a transgenic cotton cultivar paired with its conventional recurrent parent cultivar will also provide insight into whether transgenic lines behave differently than conventional lines to different temperature regimes.

	MATERIALS AND METHODS

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
Field studies were conducted near Stoneville, MS, during the 2003–2005 growing seasons to test the effect warmer temperatures have on the agronomic and physiological traits determining lint yield and fiber quality. Field plots were established on a highly productive Bosket fine sandy loam (fine-loamy, mixed, active, thermic Mollic Hapludalf) soil in a randomized complete block design with two temperature regimes and two cotton cultivars arranged factorially. Five replications were used. The two temperatures regimes were the ambient air temperature (Ambient) and a regime that was approximately 1°C warmer than ambient (Warm). Genotypes used in this study were ‘SureGrow 125’ and its transgenic counterpart ‘SureGrow 125BR’ (SG 125 and SG 125BR; Delta and Pine Land Co., Scott, MS). SG 125BR contains both the Bt gene that produces an endotoxin (Cry1Ac) lethal to certain lepidopteran insects and a gene that conveys resistance to the herbicide glyphosate.

The plots were planted on 21 Apr. 2003, 22 Apr. 2004, and 18 Apr. 2005 and consisted of four rows 7.62 m long with a 1-m row spacing. Initially, the plots were overseeded and subsequently hand thinned to a uniform population density of 9 plants m^–1 of row or approximately 97,000 plants ha^–1 when the plants were at the second or third true leaf stage. The experimental area received 112 kg ha^–1 N in a preplant application each year. It was furrowed irrigated as needed each year to minimize moisture stress. Recommended insect and weed control were used throughout each growing season as needed.

The warm temperature regime was generated by placing 30-cm x 6-m Redi-Heat propagation mats (Phytotronics, Inc., Earth City, MO) between the rows on 30-cm-tall x 30-cm-wide x 6-m-long wooden racks. Mounting the mats on the wooden racks positioned the mats closer to the reproductive structures and allowed for furrow irrigation in those rows. Four mats were used per plot. Power to the mats was controlled with Redi-Heat RFT4 thermostats (Phytotronics, Inc.) that operated through a temperature range of 4 to 38°C but were set so that power supplied to the mats would not cut off until 38°C. Sensors for the thermostats were mounted inside 30-cm-long, 5-cm-diam. open-ended white polyvinylchloride tubes, which were positioned 76 cm above the ground in the crop canopy and within a plot row. One thermostat and one thermostat sensor were used per plot. The wooden racks, propagation mats, and thermostats were placed in the plots during the first week of July each year. Electrical power was supplied to the mats from 3 July through 1 Sept. 2003, from 6 July through 10 Sept. 2004, and from 1 July through 5 Sept. 2005. The period during which power was supplied to the heating mats roughly corresponded to the stages of growth from early bloom through boll filling.

Canopy air temperatures were monitored in all plots of reps 1 through 3 using Hobo H8 Pro Temp (Onset Computer Corp., Bourne, MA) data loggers. These temperature sensor–equipped data loggers were mounted inside solar radiation shields (Onset Computer Corp.) and positioned in the crop canopy on metal poles approximately 1 m off the ground. Temperature measurements were collected every 30 min for the same period of time as for when the electricity was supplied to the heating mats.

Dry matter partitioning data were collected by harvesting the aboveground portion of plants from 0.3 m of row in each plot and separating the plants into the component parts of leaves, stems and petioles, squares, and blooms and bolls. Leaf area was determined by passing the leaves through a LI-3100 leaf area meter (LI-COR, Lincoln, NE), and the main stem nodes were counted. Plant part samples were dried for at least 48 h at 60°C and the dry weights recorded. Dry matter harvest were conducted at 72 and 112 d after planting (DAP) in 2003, 76, and 109 DAP in 2004, and 79 and 112 DAP in 2005. The early dry matter harvests approximately corresponded to an early bloom stage and were collected shortly before or immediately after initiation of the warm temperature regime. The second dry matter harvests roughly correspond to a cutout harvest date. Cutout refers to a period of slowing vegetative growth and flowering because of assimilate diversion to feed the demand of the existing boll load.

The number of white blooms (blooms at anthesis) per plot were counted on a weekly basis to document the blooming rate throughout the growing seasons. These counts were taken on one of the inner plot rows and were initiated shortly after the imposition of the temperature treatments and continued until the production of blooms had almost stopped. The number of main-stem nodes above a sympodial branch that had a white bloom at the first branch fruiting position (nodes above white bloom [NAWB]) were also counted weekly on three plants per plot to document the progressive reproductive development up the main stem as well as crop maturity.

Dark-adapted chlorophyll (Chl) variable fluorescence/maximal fluorescence (F_v/F_m) ratios were measured on two leaves per plot using a Hansatech Fluorescence Monitoring System (Hansatech Instruments Ltd. Norfolk, UK). The youngest fully expanded, disease-free, fully sunlit leaves in each plot were used and were allowed to dark adapt for at least 15 min before measurement. In 2003 and 2004, immediately after the dark-adapted Fv/Fm readings, the leaves were exposed and acclimated to 650 µmol m^–2 s^–1 photosynthetic photon flux density (PPFD) for 90 sec. After this period of acclimation, light-adapted Chl fluorescence (F_s, steady state fluorescence yield; and F_m', light-adapted fluorescence maximum) were measured at 650 µmol m^–2 s^–1 PPFD. A saturation pulse of 9,000 µmol m^–2 s^–1 PPFD was used to for all Chl fluorescence measurements. From these light-adapted values, the quantum efficiency of photosystem II and electron transport rate were determined. In 2005 gas exchange was measured on these leaves before any fluorescence measurements using a CI-310 portable photosynthesis system (CID, Inc., Camas, WA). All measurements were taken with the leaves oriented perpendicular to the sun with the PPFD reaching the leaf surface 1600 µmol m^–2 s^–1. Light-acclimated fluorescence was measured on these leaves at 1600 µmol m^–2 s^–1 PPFD immediately following the gas exchange readings using the Chl fluorescence module on the CI-310. Leaves were then dark adapted for the 15-min period followed by dark-adapted F_v/F_m measurements as in the previous years.

Yield was determined by hand harvesting the 4.6-m center section of row from one of the two inner plot rows. The number of bolls harvested per plot was counted each year. Boll mass was determined by dividing the total seed cotton harvested per plot by the total number of bolls harvested per plot. Lint yield and lint percentage were determined by ginning the seed cotton on a ten-saw laboratory gin. Average seed mass was determined from 100 non-delinted seeds per plot. The number of seed per bolls was calculated from the total seed weight per plot after ginning the seed cotton, the seed mass, and the number of bolls harvested per plot. One sample of the resulting lint from each plot was then sent to Starlab (Knoxville, TN) for fiber quality analyses. Fiber strength was determined by stelometer. Span lengths were measured with a digital fibrograph. Fiber maturity, wall thickness, and perimeter were calculated from arealometer measurements. Length uniformity, Rd (reflectance %), and +b (yellowness) were determined by high volume instrumentation (HVI) classification. In 2004 and 2005, a second lint sample was also tested for fiber quality traits using the Advanced Fiber Information System (AFIS) (Zellweger Uster Inc., Knoxville, TN).

Statistical analyses were performed by analysis of variance (PROC MIXED; SAS Institute, 1996). For traits where year interacted with treatments and the environmental effects associated with year were identified, the results were presented by year. When the treatment or genotype differences for a trait were consistent across years, the treatment or genotype means were averaged across years, and the year interactions with treatment or genotype were considered a random source of error. When statistically significant and meaningful interactions were not detected, treatment means were averaged across genotypes, and genotype means were averaged across treatments. Means were separated using a protected LSD at the P 0.05 level.

	RESULTS AND DISCUSSION

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
The years 2003 through 2005 offered three distinctive years in terms of weather for conducting the research (Table 1 ). Both 2003 and 2004 tended to have milder temperatures with more precipitation during the first half of the growing season. The growing season was warmer from June through September in 2005, with greater August and September precipitation due to two tropical systems (Hurricane Katrina in late August and Hurricane Rita in mid-September).

View this table: [in this window] [in a new window]   Table 1. Monthly weather summary for 2003 to 2005 at Stoneville, MS.

View larger version (20K): [in this window] [in a new window]   Figure 1. Number of main-stem nodes of cotton above a sympodial branch with a first-position white bloom (bloom at anthesis) at various times throughout the 2003 and 2005 growing seasons in plots of two different temperature regimes. These temperature regimes means were averaged across two cotton cultivars (SureGrow 125 and SureGrow 125BR). Vertical bars denote LSD values at the 0.05 level and are present only when the differences between temperature regimes are statistically significant at the 0.05 level.

Lint yield reductions because of smaller boll masses produced when the cotton was grown under the warm temperature regime (Table 5) are consistent with the findings of Reddy et al. (1999), who also reported decreased boll weights as temperature increased. Few seeds produced per boll under the warm temperature regime led to the reduced boll mass and indicates that one of the primary detrimental influences that higher temperature has on lint production may be through a disruption of ovule fertilization. Supporting this conclusion is the work of Meyer (1969), who reported that viability of cotton pollen can decrease as temperatures increase.

Few fiber quality traits were altered by the elevated temperatures. The lack of a temperature effect on fiber length contrasts with the finding of both Reddy et al. (1999) and Meredith (2005), who reported that higher temperatures produced shorter fiber lengths. A larger temperature differential than could be produced by the methodology used in this study may be necessary to generate observable differences in fiber length. Although warmer temperatures did not produce statistically greater fiber micronaire as had been previously reported by Krieg (2002), lint from the warm temperature regime did have statistically higher fiber maturity. Because fiber maturity is a component of micronaire, this increased fiber maturity tends to support the findings of increased micronaire with higher temperatures (Krieg, 2002). The slightly stronger fiber produced by the warm temperature regime appears to be new information. Because fewer seeds were produced per boll, the source-to-sink ratio for each ovule in the warm regime may have been altered such that more assimilate was available for the developing fibers on each individual ovule. Previous research has demonstrated that greater fiber strength is produced under growth conditions that enriched the potential amount of photosynthetic assimilates available to the developing boll load (Pettigrew, 1995, 2001).

In conclusion, whenever air temperatures become excessively high during the blooming and boll-filling periods, a loss in lint yield can be sustained. The loss initially manifests itself as a reduction in boll size because of fewer seeds per boll. The tradeoff is that the fiber produced is stronger. However, this minor improvement in fiber strength is not be sufficient to elicit a price premium and therefore could not offset the economic loss sustained from the loss in lint production.

All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher.

Received for publication May 8, 2007.

	REFERENCES

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 

• Bednarz, C.W., and R.L. Nichols. 2005. Phenological and morphological components of cotton crop maturity. Crop Sci. 45:1497–1503.[Abstract/Free Full Text]
• Boykin, D.L., R.R. Carle, C.D. Ranney, and R. Shanklin. 1995. Weather data summary for 1964–1993, Stoneville, MS. Tech. Bull. 201. Mississippi Agric. and Forestry Exp. Stn., Mississippi State.
• Burke, J.J., J.R. Mahan, and J.L. Hatfield. 1988. Crop-specific thermal kinetic windows in relation to wheat and cotton biomass production. Agron. J. 80:553–556.[Abstract/Free Full Text]
• Carmi, A., and J. Shalhevet. 1983. Root effects on cotton growth and yield. Crop Sci. 23:875–878.[Abstract/Free Full Text]
• Gipson, J.R., and H.W. Joham. 1968a. Influence of night temperature on growth and development of cotton (Gossypium hirsutum L.): I. Fruiting and boll development. Agron. J. 60:292–295.[Abstract/Free Full Text]
• Gipson, J.R., and H.W. Joham. 1968b. Influence of night temperature on growth and development of cotton (Gossypium hirsutum L.): II. Fiber properties. Agron. J. 60:296–298.[Abstract/Free Full Text]
• Gipson, J.R., and H.W. Joham. 1969. Influence of night temperature on growth and development of cotton (Gossypium hirsutum L.): III. Fiber elongation. Crop Sci. 9:127–129.[Abstract/Free Full Text]
• Krieg, D.R. 2002. Cotton yield and quality, genetic vs. environmental affectors. In J. McRae and D.A. Richter (ed.) Proc. 2002 Beltwide Cotton Conferences, Atlanta, GA. 8–12 Jan. 2002. National Cotton Council of America, Memphis, TN.
• Lee, J.A. 1984. Cotton as a world crop. p. 1–25. In R.J. Kohel and C.F. Lewis (ed.) Cotton. ASA, CSSA, SSSA, Madison, WI.
• Meredith, W.R., Jr. 2002. Factors that contribute to lack of genetic progress. In J. McRae and D.A. Richter (ed.) Proc. 2002 Beltwide Cotton Conferences, Atlanta, GA. 8–12 Jan. 2002. National Cotton Council of America, Memphis, TN.
• Meredith, W.R., Jr. 2005. Influence of cotton breeding on yield and fiber quality problems. In Ch.H. Chewing (ed.) Proc. of the 18th Annual EFC Conf. 6–8 June 2005. Memphis, TN. Available at http://www.cottoninc.com/2005ConferencePresentations/GeorgiaCottonUpdateMeredith/GeorgiaCottonUpdateMeredith.pdf?CFID=1597964&CFTOKEN=75210149 (verified 28 Sept. 2007).
• Meyer, V.G. 1969. Some effects of genes, cytoplasm and environment on male sterility in cotton (Gossypium). Crop Sci. 9:237–242.[Abstract/Free Full Text]
• Perry, S.W., D.R. Krieg, and R.B. Hutmacher. 1983. Photosynthetic rate control in cotton: Photorespiration. Plant Physiol. 73:662–665.[Abstract/Free Full Text]
• Pettigrew, W.T. 1995. Source-to-sink manipulation effects on cotton fiber quality. Agron. J. 87:947–952.[Abstract/Free Full Text]
• Pettigrew, W.T. 2001. Environmental effects on cotton fiber carbohydrate concentration and quality. Crop Sci. 41:1108–1113.[Abstract/Free Full Text]
• Reddy, V.R., D.N. Baker, and H.F. Hodges. 1991. Temperature effects on cotton canopy growth, photosynthesis, and respiration. Agron. J. 83:699–704.[Abstract/Free Full Text]
• Reddy, K.R., H.F. Hodges, and V.R. Reddy. 1992. Temperature effects on cotton fruit retention. Agron. J. 84:26–30.[Abstract/Free Full Text]
• Reddy, K.R., G.H. Gavidonis, A.S. Johnson, and B.T. Vinyard. 1999. Temperature regime and carbon dioxide enrichment alter cotton boll development and fiber properties. Agron. J. 91:851–858.[Abstract/Free Full Text]
• SAS Institute. 1996. SAS system for mixed models. SAS Inst., Cary, NC.

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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Pettigrew, W. T. Search for Related Content PubMed Articles by Pettigrew, W. T. Agricola Articles by Pettigrew, W. T. Related Collections Crop Growth and Development Cotton Plant and Environment Interactions