Thesis (BS Arg (Agron) - Mariano Marcos State University

ABSTRACT

TABANGAY, ARIANNE JOY D. 2019. Growth and Yield Response of
Rice (Oryza sativa L.) Varieties to Varying Rates of Carrageenan Plant Growth
Regulator Under Rainfed Lowland Condition. Undergraduate Thesis. College of
Agriculture, Food and Sustainable Development Mariano Marcos State University.
City of Batac 2906 Ilocos Norte 100 pp.
Adviser: Ms. Joanna P. Crosby
Co-adviser: Dr. Dionisio S. Bucao

A field experiment was conducted at the experimental farm of the Mariano
Marcos State University (MMSU), City of Batac, Ilocos Norte, from July to November
2018, to evaluate the performance of different rice varieties to varying rates of
carrageenan plant growth regulator (CPGR) under rainfed lowland condition.
Specifically, the study aimed to: 1) compare the growth and yield performance of
different rice varieties under rainfed lowland condition; 2) determine the effect of
varying rates of CPGR on the growth and yield of rice under rainfed lowland condition;
3) identify the best rice variety and rate of CPGR that could give the highest yield under
rainfed lowland condition, and 4) determine the profitability and productivity of rice
varieties applied with CPGR at varying rates.
The experiment was arranged in a Strip-plot in Randomized Complete Block
Design with three replications. Three varieties were tested, PSB Rc82 (Peñaranda),
NSIC Rc282 (Sahod Ulan 7) and NSIC Rc286 (Sahod Ulan 9) which were assigned as
the vertical factor while the three CPGR rates (61 ba'!, 91 ha' and 12 I ha') including the untreated plants (control) were assigned as the horizontal factor. The experimental
unit plot size used was 24 m. A total land area of 1129.2 m' was used in the study.
Significant interaction effect between variety and CPGR rate was revealed on
the growth parameters of rice including tiller count, leaf area index (LAT) and above-
ground biomass (AGB). Moreover, significant interaction effect was found on percent
filled grains. However, these did not result to a significant interaction effect on grain
yield.
The rice varieties tested significantly differ in growth performance particularly
in terms of plant height, tiller count, AGB, heading and maturity. Among the varieties
evaluated, NSIC Rc282 had the heaviest panicle. On the other hand, the highest yield
was obtained in PSB Rc82 with 5.49 t ha' followed by NSIC Rc282 with 4.96 t ha-
The growth performance of rice also differs significantly with the application of
CPGR in terms of plant height, tiller count, leaf color, AGB, and heading. The yield
and yield components of rice including productive tillers and panicle weight also differ
significantly with CPGR application. Higher grain yield was obtained in plants applied
with CPGR. Moreover, the application of 12 1 ha- CPGR produced the highest yield
among the application rates.
Among the varieties, PSB Rc82 and NSIC Rc282 surpassed the average yield
of rainfed rice in Ilocos region at 3.78 t ha-' to 4.05 t ha- (2013-2017 period). Moreover,
PSB Rc82 generated the highest net income (Php 72,690.70-Php 86,350.00) and retum
on investment (ROI) with 2.01-2.30. Among the varieties, increase in net return (25.84
to 45.94%) with the application of CPGR was highest in NSIC Rc282.