Abstract

Comparison of growth on 8 commercial oil palm in 9 years old in acid sulfate soil in the central region with extremely acidic soil. (Rangsit Soil Series). The experimental field trial was established since February 2010 in the area of oil palm plantation of the Department of Agronomy, Faculty of Agriculture, Kasetsart University, located at Nong Mu Subdistrict, Wihan Daeng District, Saraburi Province. The field study was arranged in a randomized complete block design (RCBD), consisting of 3 repetitions of 8 varieties with spacing 9x9x9 m. The planting materials were Surat Thani 2 varieties (ST2), Surat Thani 3 varieties (ST3), Surat Thani 4 varieties (ST4), Surat Thani 5 varieties (ST5), Surat Thani 6 varieties (ST6), UTI, Univanich (UNI) and Golden Tenera (GT). Data collection of plant growth consists of rachis length, frond production, leaf area, leaf width, leaf length, petiole cross section and trunk height. The analysis of variance showed that ST5 had the highest number of newly created leaves per year, with the average value of 24.30. UTI had the highest petiole cross-section at 39.76 square centimeters. ST2 had the highest leaf width with a value of 6.26 centimeters. The highest leaf length was 114.03 cm. and ST6 had the highest rachis length at 595.12 cm. The highest average leaf number was 348.89 leaves. The highest leaf area was 11.72 square meters and the highest average height was 304.53 cm. There was no significant difference in the analysis of the variance of the yield. The average value of all varieties is 92.22 kilograms per plant per year. The highest sex ratio was 64.56 percent in ST2 variety.