Rice Science ›› 2024, Vol. 31 ›› Issue (6): 751-760.DOI: 10.1016/j.rsci.2024.08.007

• Research Papers • Previous Articles    

Applying Boron Fertilizer at Different Growth Stages Promotes Boron Uptake and Productivity in Rice

Sitthikorn Bodeerath1, Jeeraporn Veeradittakit1, Sansanee Jamjod1,2(), Chanakan Prom-U-Thai1,2()   

  1. 1Agronomy Division, Department of Plant and Soil Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand
    2Lanna Rice Research Center, Chiang Mai University, Chiang Mai 50200, Thailand
  • Received:2024-03-20 Accepted:2024-08-26 Online:2024-11-28 Published:2024-12-10
  • Contact: Chanakan Prom-U-Thai (chanakan.p@cmu.ac.th); Sansanee Jamjod (sansanee.j@cmu.ac.th)

Abstract:

Boron (B) is an essential micronutrient for plant growth and yield. We investigated the optimal growth stage for B fertilizer application to improve rice production. The study was conducted using a 2 × 4 factorial design in a randomized complete block during the rainy season of 2022. We utilized two premium Thai rice varieties Khao Dawk Mali 105 (KDML105) and Pathum Thani 1 (PTT1), and four soil B fertilizer treatments: a control (no B application), B application at the tillering stage, B application at the flowering stage, and B application at both the tillering and flowering stages. The results showed that the application of B fertilizer at the flowering stage and at both the tillering and flowering stages increased grain yield of KDML105 by 25.0% and 34.0%, respectively. In contrast, the grain yield of PTT1 showed no response to B application. The increased grain yield of KDML105 was attributed to an increased number of panicles per plant and a higher filled grain rate, which was due to the elevated B concentration in all plant parts and the total B uptake, particularly when B was applied at the flowering and tillering stages. Notably, B application increased the fertilized grain rates and reduced the proportion of unfertilized grains, a phenomenon that corresponded with the increased B concentration across all plant parts. The total B uptake ranged from 5.11 to 15.85 mg/m2 in KDML105 and from 8.37 to 24.26 mg/m2 in PTT1, with the highest total B uptake observed when B was applied at both the tillering and flowering stages for both rice varieties.

Key words: biofortification, boron, rice cultivation, filled grain, unfertilized grain