African Journal of Agriculture

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 178–185

DOI: 10.46882/2026/AJA/000756

Article Type: Original Research Article

Title: Impact of Silicon Soil Amendments on Resistance to African Rice Gall Midge (Orseolia oryzivora) in Lowland Rice Varieties

Names of Authors: Chukwudi N. Eze¹, Blessing I. Udoh¹, Amara C. Nwosu²

Authors’ Affiliations: ¹National Cereals Research Institute (NCRI), Badeggi, Nigeria; ²Department of Crop Science, University of Nigeria, Nsukka, Nigeria

Abstract: The African rice gall midge (Orseolia oryzivora Harris) is a destructive insect pest that induces severe vegetative distortion and sterile galls ("onion shoots") in lowland rice ecosystems across West Africa. Silicon (Si) accumulation in grass tissues is known to enhance mechanical defense against chewing and sucking pests, but its efficacy under heavy gall midge pressure requires field verification. This 2-year field study evaluated the effect of four calcium silicate soil amendment rates (0, 50, 100, and 150 kg Si/ha) on the resistance and yield of three lowland rice varieties (FARO 44, FARO 52, and a susceptible local check). The field design utilized a split-plot layout with four replications. The results demonstrated that applying 150 kg Si/ha significantly reduced the percentage of onion shoots from 24.6% to 6.2% across all varieties (p < 0.01). Scanning electron microscopy confirmed a dense deposition of silica bodies in the epidermal cells of leaf sheaths, which mechanically disrupted larval boring activity. The silicon-amended plots maintained significantly higher productive tiller counts and leaf area indices. Variety FARO 52 treated with 100 kg Si/ha produced the highest grain yield (5.24 ± 0.28 t/ha), representing a 38.5% yield increase over the unamended control. This research highlights silicon application as a highly viable, eco-friendly component of integrated pest management for sustainable rice production.

Keywords: Orseolia oryzivora, Calcium silicate, Mechanical defense, Lowland rice, Onion shoots, Grain yield

Manuscript Timeline: Received: June 25, 2026; Revised: July 28, 2026; Accepted: August 16, 2026; Published: August 31, 2026

Citation: Eze, C. N., Udoh, I. I., & Nwosu, A. C. (2026). Impact of Silicon Soil Amendments on Resistance to African Rice Gall Midge (Orseolia oryzivora) in Lowland Rice Varieties. African Journal of Agriculture, 13(8), 178–185. DOI: 10.46882/2026/AJA/000756

Subscribe to read the full article: https://www.internationalscholarsjournals.org/subscribe-to-read