By R. Bourdeix, XXX, and XXX, 2019 in constructon
NB: only time to prepare the document and get the text rougth from scan
NB: only time to prepare the document and get the text rougth from scan
The Agronomy and Farming System section was recently created in 1995. The broad objective of this section is to study agronomic practices and farming system and coconut use adapted to the environment.
Coconut Mineral Nutrition
A fertiliser trial has been set up to determine the fertiliser requirementssfor optimum yield of coconuts.It will help to know the fertiliser requirements of coconut at SRS and the potential of the hybrids under the appropriate fertilisation.
The first feritiliser application was implemented in July 96, tren ches to avoid poaching were set up between all the plots and cover-up with a legume established. The variance analysis has been done by CIRAD on measurements observed on the 3 variables (coconut girth, circumference, number of fronds and length of frond 4).
The results revealed a nosit,jve effect of the Nitrogen and Clorin application on the collar girth and the number of leaves emitted. Vegetative observations will continue to obtain datas on the vegetative status of the palms and fertiliser applications and determine the fertiliser requirements.
Leaf analysiy survey
Leaf analysis consists in measuring nutrient contents in the leaves and comparing them with critical levels determined in field experiments.
Leaf analysis survwas carried out since 1994 to monitor the nutrition of the palms planted in the different blocks in the SRS. The results obtained on leaf
sample collected end of 1995 allowed to recommend fertiliser applications for 1996.
With the development of new hybrids it is important to maintain optimum nutrition in •order to show their maximum potential.
The survey is carried out on Coconut Breeding blocks as the Dwarf collection, Tall Collection, Seedgardens and Progency trials.
The method consists in the collection of leaf samples. The leaflets segments are cleaned, dried, labelled and sent for analysis.
Analysis is done at CIRAD Montpellier.
The foliar analysis results allow to recommend fertiliser applications in the SRS blocks, under the supervision of the Agronomy section.
33 foliar samples were collected in 1997 from which 26 were taken in the various blocks of SRS.
The results revealed low levels of chlorin, potash and nitrogen.
F0iiar analysis survey will continue again in 1997. Collection of samples will be carried out on the last quarter of 1997 to study what, are the effect of the application of fertilisers done on the leaf contents and continue to monitor the nutrition of the coconut palms in the different blocks of SRS.
Foliar analysis
This activity aims to study the nutrition status of the coconut palms in different provinces of PNC. The DAL hybrid coconut multi location trials or observation blocks which have been establish ment in 80-81 are valuable plots to carry out nutrition survey.
The aim of this survey is to better know the nutrition status and make recommendations of fertiliser application when deficiencies are observed.
This agronomy component could give some additive information on the actual performances of the hybrid and talls observed.
Some DAL plots which were surveyed by the coconut breeding section were also used for collection of leaf sample in order to assess the nutrition level of the coconut planted in various Iocations in the country.
The samples were collected and dried at Madang and sent to CIR AD-CP Agro in the Montpellier-France for analysis.
12 sites were surveyed as follows:
1.Pomio-ENB, 2.Natava-ENB, 3. Talasea-WNB, 4.Kise1a New Ireland, 5. Hawaian-East Sepik 6. Mushu-East Sepik, 7. Tigali -Morobe, 8. Bubuletta - Milne Bay, 9. Popondetta Oro, 10.
Waima- Central, 11. Iokea - Gulf, 12. Amele -Madang,
Analysis was made by CIRAD in Montpellier on major elements in March and April 96 and FA results obtained in 1996. The main results of the foliar analysis carried out on the DAL plots contained valuable information for future use.
RehabiIitation
The agronomy section will focus on this subject which is an important issue for the future of the industry. A trial of underplan ting will study the competition from mature coconut trees on underplanted coconut hybrids. Old senile palms grove are often substituted without any planning.
In the worst cases, in badly managed plantations where almost no weeding is practised, fallen nuts may germinate under palm trees and the seedlings are left growing.
In such plantations, palms of different ages are growing in a mixed stand, the density of the palms usually being far too high. Where replanting is carried out according to a planned scheme, the main question is whether to cut down all the old palms before planting the new seedlings or to underplant with seedlings first and gradually remove the old palms.
The method first mentioned is practised in larger estates, the latter in smallholder groves.
However, the tendency now is to replace Tall with precausious and potentially high yielding FI hybrids, spacing is usually less than the original talls and the configuration of the new planting conflicts with the old spacing.
hauling the felled trunks where the breeding of Rhinoceros beetle (Orycete spp.) is a problem, yet the trunk disposal is an unnecessary expense where Rhinoceros beetle or Palm Weevil do not occur.
In another hand, in some areas (islands) land pressure is high and to expand coconut is nil. Lastly replanting is a way to protect the natural resources in limiting extension of cropping in virgin land and using existing infrastructures.
In PNG, a large part of the coconut grove is senile and need to renew in order to maintain and secure copra industry for the future.
