Lemon Kisar (local name) is a main fruit commodity in Kisar Island, nationally recognized as a superior citrus variety based on the Decree of the Minister of Agriculture Number: 864 / Kpts / TP.240 / 11/1998 on the Release of National Superior Citrus Varieties with the name of ‘Jeruk Manis Kisar’ (Kisar Orange). This orange is a local Indonesian fruit crop originally found in Southwest Maluku Regency and has been cultivated for generations.
However, the current development of Kisar sweet orange is quite apprehensive, considering that the population is decreasing every year. Statistically, in 2013 there were about 45,000 plants of Kisar Orange, but until the end of 2016 the remaining plants were approximately 5000 plants. If not handled quickly and seriously, it is estimated that within the next 5 years Kisar orange will be extinct.
The Government of Southwest Maluku Regency through the Reginal Office of Agriculture and Livestock has launched Kisar Citrus Development program (Gerbang Jekis) on the island of Kisar as it is the production center of Kisar orange. The main objective of this program is to maintain and enhance the development of Kisar Orange on Kisar island through various activities in various related sectors.
One of the activities that supports the Jekis Gate program in collaboration with the Indonesian Agency for Agricultural Research and Development through the Indonesian Citrus and Subtropical Fruit Research Institute (Balitjestro) is the Technology Assistance and Escort on Cultivation and Seed Production of Kisar Orange. The objectives of this activity are: 1. To improve the knowledge of staff / officers about the cultivation of citrus crops that loaded in technology, 2.) Support and assist the Agriculture and Livestock Regional Office in implementing the Kisar Orange Development Program (Gerbang Jekis) with expertise and proficiency possessed by designated experts. Implementation of the Gerbang Gate program that must be done immediately in an effort to save the population of Kisar sweet orange is:
- Mass Control of Diplodia Disease
This mass control needs to be done, considering what has been done so far has not been effective enough. The control is done simultaneously by the grower/farmer by cutting the severely attacked plants, throwing and burning the plant with the aim of breaking the cycle of the spores of Diplodia disease to avoid spread elsewhere. For affected plants that could be saved, the disease is controlled using California slurries (sulfur as the active ingredient) applied at the beginning and end of the rainy season. Also, the farmers are introduced to sterilization for tool used such as machetes, saws and knives. The tools are sterilized with 10% bleaching solution or 70% alcohol. This program requires a commitment, especially the owner of the plant, while the program implementation will be guided by staff from the agricultural offices.
2. Maintenance of Mother Plant (PIT) of Kisar OrangeThe selected mother plant of Kisar Orange in the field must be in optimal growth condition, because it is the source of propagation material for Mother Plant which will be duplicated in ICSFRI through “cleaning” process. While waiting for the “cleaning” process which takes 1.5-2 years, branches from PIT Kisar Orange can be picked up as a source of budwood for extension seed (recommendation from which are from ICSFRI and Directorate General of Horticultural Seed) that will be used to replaced the dead plants. Maintenance of mother plant includes : shoot pruning, branch pruning (the one showing disease symptom), aaplication of 5% Benomyl solution for root rot disease and Diplodia, and NPK fertilization with dose of 10 kg /tree.
3. Demonstration Plot for Management of Healthy Citrus PlantsThe plant material for demonstration plot of the management of healthy citrus plants is prepared using adult orange plants that has been produced by several farmers. At the site of the demonstration plot, all components of the maintenance are implemented according to recommendation referring to Integrated Management of Healthy Citrus Orchard (IMHCO). As a comparison, plants owned by farmers which are maintained by existing cultivation techniques in Kisar will be used. It is expected that farmers will apply the technologies that have been implemented in demonstration plot on their crops later on.
4. Demonstration Plot of Kisar Orange Plants derived from Grafting If already prepared, Kisar Orange grafted in ICFRI then sent to Kisar Island to be planted in the demonstration plot. The plot is planned to be about 1 ha area or equivalent of 400 trees on the field belongs to one of the farmers. The maintenance applied is according to Integrated Management of Healthy Citrus Orchard (IMHCO). As a comparison, plants owned by farmers which are maintained by existing cultivation techniques in Kisar will be used. From this demplot, it is expected that new technology could be transferred to farmers.
5. Mother Plant ‘Cleaning’Another potential besides Kisar oranges in Kisar Island is the Kisar Mandarin. This mandarin has a sweet taste, slightly acidic and fresh, yellow skin fruit color with a production potential of 2,000 fruits / plant / year. For variety registration, the plants must be freed from five systemic pathogens of citrus i.e. : Citrus Vein Phloem Degeneration (CVPD), Citrus Tristeza Virus (CTV), Citrus Vein Enation Virus (CVEV), Citrus Exocortis Viroid (CEV) and Citrus Psorosis Virus (CPsV) via “Shoot Tip Grafting” (STG). The cleaning is also done for Kisar Orange, since the mother plant in ICSFRI was positive for some diseases. From the cleaning process, 15 plants for mother plant candidate were obtained. Those plants then planted in insect-proof-screen house which has double doors. The plants were planted in 60 cm x 80 cm pots at Horticultural Parental Seeds Agency. The budwoods of the Foundation Seeds in the Foundation Block can then be harvested / used for Registered Seeds grown in Budwood Multiplication Block (BPMT).
6. Commitment to Implement “Wonreli Agreement”In order to support the implementation of the Gerbang Jekis program, the people of Kisar island made a collective agreement to be followed, known as the “Wonreli agreement”:A. Every Head of Family in Kisar Island should plant Kisar orange at a minimum of 10 trees / family.B. Starting next year, sick plant must be omitted.C. For planting, high quality seed should be used D. Halt the unnecessary application of herbicides If the above points can be implemented well, then the sustainable growth and population of Kisar Orange in Kisar Island can be achieved (Ir. Agus Sugiyatno, MP dan Setiono, SP / tr:bq).