Growth and Anatomical Responses of Gogo Rice Plant (Oryza sativa L.) Var. Inpago Unsoed 1 to Paclobutrazol Application

Abstract

The improvement of gogo rice production in dryland is constrained by its extraordinary height, which leads to falling, and its long lifespan. The shorter gogo rice plant can be obtained through growth inhibition using paclobutrazol. Gogo rice plant var. Inpago Unsoed 1 was used during the study. An experimental study was performed using factorial completely randomized design. The main factor was four paclobutrazol concentrations (0,100, 200, and 300 ppm). The sub-main factor was paclobutrazol application time after planting (three, four, and five weeks). The results showed that the interaction between paclobutrazol concentration and application time was highly significantly affecting plant height. The most appropriate treatment resulting in optimum plant height was the combination of 100 ppm paclobutrazol applied four weeks after planting. Interaction between paclobutrazol concentration and application time also significantly affect stem diameter, leaf width, and stomata number in the lower leaf epidermis. However, there was no significant effect of paclobutrazol observed on stomata size. The significant result of the combination of paclobutrazol concentration and the application time was also supporting tissue thickness. The thickest tissue was obtained by 300 ppm of paclobutrazol applied five weeks after plantation.