Mission to PT RSUP coconut plantation, Indonesia, August 2008

Trial RS CC 08, which has been very well maintained for 4 years, is in excellent condition, with 21-year-old coconut palms displaying an excellent vegetative appearance typical of the PB 121 hybrid and a good nut load. A treatment effect is beginning to be seen with the naked eye, as is an effect on yield. Trial RS CC 10 came to a close as planned in February 2008. The next experiment RS CC 10bis, which was launched in September 2007, is using the same palms to study the effect of interrupting mineral fertilization after five years. In 2008, the coconut palms are still under the effect of the fertilizer rates applied under the former RS CC 10 protocol. Coconut palm growth in experiment RS CC 11 is now uniform. The specific effect of the treatments can now be seen better with: confirmation of the efficiency of coconut husk ash; palms fertilized with NaC1 are slightly retarded compared to those fertilized with KCI (though worse could have been expected given the strong contrast in the respective leaf contents for K and Na, which confirms that it is primarily Cl that controls growth); and an application rate effect, with better growth for the whole rate than with the half rate, all fertilizers combined. Trial RS CC 12 was planted in November 2007, based on the protocol revised last year (reduction in area from 50 to 12.5 hectares). Two main points appear in 2008: strong Oryctes pressure on the young palms in replantings, due to the fact that the stems of the old coconut palms remained on the ground for too long in the vicinity of the young coconut palms; and low Sufetula pressure on the root systems of the young palms, showing for the moment that the cultural prevention techniques tested against this pest are efficient. A detailed protocol for preparing the future RS CC 13 planting density trial has been left on site: an appropriate location needs to be selected and the necessary plants produced in the nursery. In the prolonged absence of potassium fertilization, the potassium deficiency considerably worsened between 2007 and 2008, as shown by numerous examples of severely affected coconut palms throughout the plantation. If potassium fertilizer is not applied without delay, a general collapse in yields is to be feared in the near future. Around 40,000 MYD seednuts need to be harvested immediately to replant 100 hectares of new seed gardens to produce PB 121 hybrid seednuts from 2013 onwards. (Résumé d'auteur