Correlation, path coefficient analysis and heritability for agronomic characters of oil palm (Elaeis guineensis Jacq.)

A study of correlation, path coefficient analysis and heritablity for some agronomic characters of oil palm was investigated during February 1998 to January 2002. The oil palm population used in this experiment was derived from F1 tenera hybrids which were collected from various oil palm plantations in Southern Thailand. One good performance bunch (i.e., big bunch, thin shell) was selected from each plantation and four to six seeds per selected bunch were used for cultivation. One thousand thirty eight plants were grown at Klong Hoi Khong Research Station, Faculty of Natural Resources, Prince of Songkla University, Songkhla, in 1989. Forty five palms consisted of Dura, Tenera and Pisifera types with 18, 18 and 9 plants respectively, were selected by randomization and tagged for investigation. The oil palm bunch yield and yield component characters were observed from individual palm for 4 years (February 1998 to January 2002). The bunch composition characters were analysed from a single bunch of each palm, sampled between June to October 1999. The results showed that in F2 plants of oil palm, the correlation and the path coefficient between characters relating to oil yield and %oil/bunch varied according to oil palm types (Dura, Tenera and Pisifera). In Dura and Tenera palms, the characters which gave highly positive correlation with a large direct and indirect positive effects on oil yield and %oil/bunch were total bunch weight, %oil/bunch, %fruit/bunch and %oil/fruit. In case of Pisifera palms, the characters which gave highly positive correlation with a large direct and indirect positive effects on oil yield and %oil/bunch were total bunch weight, number of bunches, single bunch weight, %oil/bunch and %fruit/bunch. However, from all investigated characters in F2 plants, only %mesocarp/fruit, %oil/fruit and %fruit/bunch showed the high values of broad sense heritabilities

Genetic variation and phylogenetic relationships in oil palm (Elaeis guineensis Jacq.) based on RAPD analysis

The genetic variability and phylogenetic relationships in oil palm (Elaeis guineensis Jacq.) were studied using RAPD (Random Amplified Polymorphic DNA). Leaf samples of 151 plants were collected from different areas in southern Thailand. DNA from the leaf samples was isolated using CTAB buffer and screened by decamer oligonucleotide primers. Among the total of 160 primers screened, 7 primers (OPB-08, OPR-11, OPT-06, OPT-19, OPAB-01, OPAB-09 and OPAB-14) were chosen to analyse for genetic variation in 151 individuals representing 52 dura, 60 tenera and 39 pisifera. Two hundred and nine amplified fragments were obtained from 7 primers with an average of 29.85 RAPD markers per primer. A dendrogram showing genetic similarities among oil palm was constructed based on polymorphic bands using UPGMA (Unweighted Pair-Group Method Using Arithmetic Average). Cluster analysis was performed using the SPSS program, which revealed four major clusters: 1) dura, tenera and pisifera from Paorong Oil Palm Company, Oil Palm Research Center, dura and tenera from private plantation in Krabi, and dura from Thepa Research Station;2) dura and tenera from Thai Boonthong Company, pisifera and tenera from Thepa Research Station, dura, tenera and pisifera from Klong Hoi Khong Research Station; 3) and 4) dura and tenera from Univanit Company, respectively. In general, a similarity index showed relatively high levels of 0.6 or greater

Predicting fresh fruit bunch yield of oil palm

This study aimed to develop the simulation model for predicting fresh fruit bunch (FFB) yield of oil palm through multiple linear regression analysis. Two experiments were conducted at the oil palm plantation of Agricultural and Technology College, Krabi province. Six-year-old Tenera hybrid palms were used for the experiments. These palms were planted in Tha-sae soil series (Typic Paleudults; Fine loamy mixed)with spacing of 9x9x9 m. In the first experiment, 151 Tenera palms were selected and marked randomly throughout an area of plantation about 16 ha. For each selected palm, FFB yield and yield component characters (FFB number and bunch weight) were recorded at every harvesting time for four consecutive years (June 1993 to May 1997). The results showed that the FFB number and bunch weight could be used to predict the FFB oil palm yield. In the second experiment, nine plots of Tenera hybrid palms were arranged. The plot size was 0.48 ha and had twenty palms per plot for data collection for three consecutive years (January 1994 to December 1996). These data included leaf nutrient (N, P, K, Mg and B) contents in the 17th frond, the fresh fruit bunch (FFB) yield and the amount of rainfall. The results showed that N, P, K, Mg and B contents in the leaves, the amount of rainfall and FFB yield in the previous year, together with the N, P, K, Mg and B contents in the leaves (in the predicting year) could be used to predict the FFB oil palm yield

Effect of fertilizer application on yield of oil palm

The effects of fertilizer application rates on leaf nutrient contents and yield of oil palm were investigated at the Agricultural and Technological College Plantation in Trang province during May 1998 - June 2001. A five-year-old oil palm plantation, planted on the Na Tham soil series (Fine loamy, mixed, isohyperthermic Oxic Plinthudults) with spacing 9x9x9 m, was selected for study. A randomized complete block designwith three replications with 20 palms/replication was used. The treatments included six different rates of fertilizer application. The rates of fertilizer were as follows: T1 (farmer practice), T2 (40% of application rate in T4), T3 (70% of application rate in T4), T4 (urea 2,750 g/plant; triple super phosphate 1,500 g/plant; potassium chloride 4,000 g/plant; kieserite 1,000 g/plant; borate 80 g/plant), T5 (130% of application rate in T4) and T6 (170% of application rate in T4). The high leaf nutrient contents of N, P and K at the range of 2.6-2.8%, 0.16-0.18% and 1.13-1.18%, respectively, were found in the high nutrient application rate treatments (T5, T6). However, the amounts of leaf Ca and Mg in T5 and T6 decreased from 0.75-0.80% and 0.33- 0.37% at the beginning of experiment to 0.65-0.70% and 0.22-0.24%, respectively, at the end of the experiment. Small increases of leaf sulphur and boron up to about 0.20-0.22% and 16-19 mg/kg were also found in the high rate of fertilizer treatments. Accumulated fresh fruit bunch yield (FFB) increased according to increasing rate of fertilizer application. Accumulated FFB yield of 268.4 kg/plant in the low fertilizer rate (T1) (farmer practice) and 278.8 kg/plant in T2 were found compared with the highest yield of 370.2 kg/plant in the highest fertilizer application treatment (T6) for the 3 years experiment. Regarding the economic return, the medium rate of fertilizer application (T3) which achieved an accumulated FFB yield of 338.0 kg/ plant gave the highest profit with the VCR (Value: Cost ratio) of 2.53