Philippine Journal of Science
152 (1): 419-431, February 2023
ISSN 0031 – 7683
Date Received: 23 Sep 2022

Agronomic, Yield, and Yield-related Traits
of Lowland Rice (Oryza sativa L.) to the
Regeneration Plasticity of Ratoon Crop

Cielo Luz C. Mondejar* and Gerald E. Bello

Philippine Rice Research Institute–Negros Branch Station (PhilRice Negros),
Murcia, Negros Occidental 6129 Philippines

*Corresponding author:
clcmondejar@philrice.gov.ph; cieloluzmondejar@gmail.com

[Download]
Mondejar CL, Bello G. 2023. Agronomic, Yield, and Yield-related Traits of Lowland Rice (Oryza
sativa L.) to the Regeneration Plasticity of Ratoon Crop. Philipp J Sci 152(1): 419–431.
https://doi.org/10.56899/152.01.34

 

 

ABSTRACT

Grain yield is a complex trait that is determined by direct and indirect traits. To improve grain yield, it is important to determine the relationships between these traits. To further explain the source-sink concept, fifteen genotypes were evaluated to explore not only the variation and association of primary and secondary traits of the main crop but also of the ratoon crop. Aboveground parts are cut at harvest leaving only stubbles and roots as sources of assimilates for the growth and development of ratoon crops. Results of this study indicated significant interactions in the grain yield and dry matter production between the main crop and ratoon crop with opposing tendencies of associations. This information is very useful in developing varieties with the breeding objective of increasing the grain yield potential of the ratoon crop. This may include advancing the grain partitioning in ratoon rice since the low grain yield of the ratoon crop was not the result of limited biomass production but rather a poor translocation and partitioning of assimilates into grains. The ratoon crop yield potential of genotypes identified with good ratooning ability in this study ranged from 1.8–2.4 tons/ha. Halay Palawan, Cuevas, and NSIC Rc216 were identified to have significantly higher ratoon grain yield than the other genotypes evaluated. However, NSIC Rc216, NSIC Rc222, and NSIC Rc480 were the best genotypes if the selection criteria should include shorter crop growth duration. If cultivars with good ratooning ability have similar crop duration and yield potential with the long-maturing varieties, the use of long-maturing varieties may be more practical in taking advantage of the residual water in areas with moisture and climate limitations instead of increasing crop intensity using ratoon strategy.