[RESEARCH NOTE]
Philippine Journal of Science
152 (2): 665-668, April 2023
ISSN 0031 – 7683
Date Received: 05 May 2022
Influence of Seeding Rate and Flooding Period
on Growth of Lowland Ecotype Cyperus rotundus L.
and Yield of Wet Direct-seeded Rice under Dual Culture
Dindo King M. Donayre*, Jessica Joyce L. Jimenez, Henesie G. Pascua,
and Edwin C. Martin
Crop Protection Division, Philippine Rice Research Institute Central Experiment Station,
Maligaya, Science City of Muñoz, 3119 Nueva Ecija, Philippines
*Corresponding author: dindoking08@gmail.com
[Download]
Donayre DK et al. 2023. Influence of Seeding Rate and Flooding Period on Growth
of Lowland Ecotype Cyperus rotundus L. and Yield of Wet Direct-seeded
Rice under Dual Culture. Philipp J Sci 152(2): 665–668.
https://doi.org/10.56899/152.02.11
ABSTRACT
A higher seeding rate and water management through flooding are proven effective against many weeds of wet direct-seeded rice. However, the efficacies of these techniques against the lowland ecotype Cyperus rotundus are not yet known. Two experiments were conducted each twice to determine the influence of seeding rate and flooding period on the growth of lowland ecotype C. rotundus and the yield of wet direct-seeded rice under dual culture. The first experiment involved two levels of weed pressure (without and with lowland ecotype C. rotundus) and four seeding rates of wet direct-seeded rice (60, 120, 180, and 240 kg ha–1); the second involved three flooding periods (7, 14, and 21 DAS) including the full saturated condition. The shoot biomass of the weed was heaviest at 60 kg ha–1; reduced by 10, 20, and 41% at 120, 180, and 240 kg ha–1. It only weighted 8% when flooding was applied at 7 DAS; 23 and 31% at 14 and 21 DAS, respectively. The grain yield of wet direct-seeded rice was not different at four seeding rates nor various flooding periods. Despite that, the grain yield was higher by 66% when flooding was done at 7 DAS; 39 and 40% at 14 and 21 DAS, respectively. The findings of this study demonstrated that using a higher seeding rate and early flooding had negative influences on the growth of lowland ecotype C. rotundus but not on the yield of wet direct-seeded rice.