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

This Article Full Text (PDF) 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Tewolde, H. Articles by Unruh, L. G. Search for Related Content PubMed Articles by Tewolde, H. Articles by Unruh, L. G., Jr. Agricola Articles by Tewolde, H. Articles by Unruh, L. G.

Critical Petiole Nitrate-Nitrogen for Lint Yield and Enhanced Maturity in Pima Cotton

Texas A&M Univ. Agric. Res. & Ext. Ctr., 1619 Garner Field Rd., Uvalde, TX 78801

Larry G. Unruh, Jr.

Texas A&M Univ. Soil and Crop Sciences Dep., College Station, TX 77843

^* Corresponding author (Email: h-tewolde{at}tamu.edu).

Petiole NO₃-N concentration (PNN) has been recommendaeds indicator of midseason N deficiency in upland cotton (Gossypium hirsatum L.). Its use in Pima cotton (G. barbadense L.) managemeenstp, ecially when early maturity is the goal, is not well documented. A 3-yr study evaluated PNN as an indicator of N status in Pima cotton in order to identify a critical minimum PNN level for yield and early maturity. Treatments were five preplant applied N rates of 0 to 180 kg ha^–1 in 1990 and 0 to 269 kg ha^–1 in 1991 and 1992. The PNN was measured throughout boll development, starting 2 wk before or at first flower. Applied N significantly(P 0.05) affected PNN in 1991 and 1992, when residual soil N was low, but not in 1990, when residual N was high; differences among treatments in 1991 and 1992 were largest during early flowering. PNN was a good indicator of plant.N status within but not across seasons. Based on early-flowering samples, the critical PNN level for lint yield was 3.84 g kg^–1 in 1991 and only 1.75 g kg^–1 in 1992; in 1990, residual soil N alone resulted in PNN much higher than the critical levels in the othery ears. PNN < 2 g kg^–1 in 1991 and < 1 g kg^–1 in 1992 resulted in earlier maturity, but also resulted in less lint yield. Pima cotton PNN did not exceed an average of 11 g kg^–1, in contrast to 24 to 30 g kg^–1 reported for upland cotton. Plant growth or petiole anatomical variables that cause year-to-year variation in PNN should be identified and the necessary normalization made before PNN can be used as a midseason diagnostic tool in Pima cotton.

Received for publication March 14, 1994.

This article has been cited by other articles:

				F. B. Fritschi, B. A. Roberts, D. W. Rains, R. L. Travis, and R. B. Hutmacher Recovery of Residual Fertilizer-N and Cotton Residue-N by Acala and Pima Cotton Soil Sci. Soc. Am. J., April 11, 2005; 69(3): 718 - 728. [Abstract] [Full Text] [PDF]

				F. B. Fritschi, B. A. Roberts, D. W. Rains, R. L. Travis, and R. B. Hutmacher Fate of Nitrogen-15 Applied to Irrigated Acala and Pima Cotton Agron. J., May 1, 2004; 96(3): 646 - 655. [Abstract] [Full Text] [PDF]

				F. B. Fritschi, B. A. Roberts, R. L. Travis, D. W. Rains, and R. B. Hutmacher Response of Irrigated Acala and Pima Cotton to Nitrogen Fertilization: Growth, Dry Matter Partitioning, and Yield Agron. J., January 1, 2003; 95(1): 133 - 146. [Abstract] [Full Text] [PDF]