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 Google Scholar Google Scholar Articles by Dat, T. V. Articles by Rutger, J. N. Search for Related Content PubMed Articles by Dat, T. V. Articles by Rutger, J. N. Agricola Articles by Dat, T. V. Articles by Rutger, J. N.

Performance of Rice Composites Dimorphic for Plant Height and for Pubescence¹

The effects on yield of two contrasting rice (Oryza sativa L.) plant characteristics (tall vs. short, pubescent vs. glabrous) were studied. These plant types were developed from a cross between a pubescent short cultivar and a glabrous tall one with related parentage. Four plant types, glabrous short, glabrous tall, pubescent short, and pubescent tall, were selected in the F₂ and increased in panicle rows in the F₃. These panicle rows were composited and evaluated in broadcast plots in the F₄.

The two short types produced grain yields about 10% greater than the two tall types at optimum N fertility levels. Differences were attributed to a combination of factors including greatly reduced lodging of short types, production of significantly more panicles per unit area, more grains per panicle, and a higher percentage of fertile florets (filled grains). The 100-grain weight was similar for short and tall types.

The pubescent and glabrous leaf and hull characteristics did not affect grain yields significantly but number of grains per panicle and percent of sterile florets were significantly less in the pubescent than in the glabrous types. The four plant types were evaluated at six N fertility levels applied as urea. Rates of application were from 33.5 to 201 kg/ha with 33.5 kg increments. Optimum yields were obtained at 167.5 kg/ha. A progressive increase, in internode length occurred with N rate increments. The lower internodes (fourth and fifth from the top) elongated relatively more than upper ones with increased nitrogen fertilizer applications. Internodes of tall types elongated more than short types with increased N rates.

Key Words: Oryza sativa L. • Lodging resistance • Internode lengths • N response • loret sterility percentage • N-plant type interaction

² Research assistant and professor of agronomy, Univ. of California, and research geneticist, ARS, USDA, Dep. of Agronomy and Range Science, Univ. of California, Davis, CA 95616.

Received for publication April 22, 1977.