Lodging is characterized by the reduction in plant canopy and the bending or fall over of mature plants with panicles on the soil or water resulting in yield and quality decline. It may be induced by variations in crop nutrition, water management, susceptible tall varieties and windy conditions. In all cases the plant stem base is unusually weak with a reduced diameter. This study evaluated the use of 2 plant growth regulators as Paclobutrazol (PP333) [(2RS, 3RS)-l-(4-chlorophenyl)-4,4-dimethyl-2-(1H-l,2,4-triazol-1-yl)pentan-3-ol], and Trinexapac-ethyl (cyclohexane carboxylate) which are synthetic plant growth regulators that showed reliable stem shortening and a reduction in lodging on two varieties of rice (Oryzica 2 and 3) at varying rates and time of applications. The studies were conducted in commercial fields over several growing seasons. The results indicate that Trinexapac-ethyl reduced plant height and the incidence of lodging in var Oryzica 3, and similarly improved yield over the control by 1.17 t.ha-1.
Key words: Trinexapac-ethyl, paclobutrazol, lodging, cytokinin, gibberellins.