Category Archives: Volume 14 Nos. 1 – 4 (1992)

Socio-economic Aspects of Technological Change in Coconut Farming: The case of the Coconut Planting/ Replanting Program


Author(s): Myrna M. Avila, Buenaventura B. Dargantes and Alana M. Abarca

Abstract

The beneficiaries of the National Coconut Planting/Replanting Program (NCP/RP) has been recipients of the program for 5 to 6 years. Their average project farm size was 1.05 hectares mostly located on flat terrain about 3 kilometers from the recipients’ residence. Majority of these farms were still unproductive at the time of the interview. However, those with productive farms were able to harvest an average of 172 kilograms per hectare of copra in 1986. Technical support services were sought from the technicians of the Philippine Coconut Authority (PCA) and the Department of Agriculture (DA).
Stalking and layouting were found to have an average adoption score of 96 percent. With only 20 percent of the farms productive, the beneficiaries generally assessed the project as unable to help them improve their living conditions. The project even became an added burden, particularly to the tenants, because of the capital inputs required to maintain the farm.

Keywords : Coconut farming. Program recipients. Coconut production practices. Project farms.

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Mass Production of Scotinophara coarctata Fab. Eggs for Mass Rearing Telenomus triptus (Nixon) Parasitoid


Author(s): Victorio A. Perez and Merle B. Shepard

Abstract

Telenomus triptus (Nixon) (Hymenoptera: Scelionidae) is an efficient egg parasitoid of the Malayan black bug (MBB) Scotinophara coarctata (Fab.) (Hemiptera: Pentatomidae), a serious pest of rice in Palawan Island, Philippines. The success in mass rearing T. triptus is dependent on the availability of MBB eggs. The study dealt on the development of techniques in mass producing eggs of MBB for use in mass rearing of T. triptus. Two MBB egg production techniques were described and mass rearing technique of T. triptus was developed.

Keywords : Malayan Black Bug. Scotinophara coarctata. Egg mass production. Telenomus triptus. Parasitoid. Mass rearing.

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Processing and Utilization of Tropical Roots Crops I. Physico-chemical Characterization of Cocoyam Starches


Author(s): Roberta D. Lauzon and Akiko Kawabata

Abstract

Starch was produced from red and white cocoyams following the method developed by the Food Science Section of the Department of Agricultural Chemistry and Food Science (DAC-FS), VisCa, Baybay, Leyte. Purified starch sample were used in the analytical works. Granular size districbution and x-ray diffraction pattern determination were carried following the methods used by Kawabata et al (1981) and Nakagawa (1973), respectively. Chemical properties were determined using the standard methods set by the Association of Official Analytical Chemist (AOAC, 1980).
Starch granules of red and white cocoyams were spherical and semi-spherical in shape. Starch granules of red cocoyam were bigger than starch granules of white cocoyam. Starches from both cocoyams belonged to C type. Moisture content of red and white cocoyam starch was 11.49% and 11.99%, respectively. Inorganic matters content (P,K, Ca and Mg) were higher in red cocoyam than in white cocoyam starch.

Keywords : Cocoyam. Starch. Granules size. X-ray diffraction. Moisture. Ash. Amylose. Iodine affinity.

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Plantlet Regeneration from Meristems of Philippine Sweetpotato Varieties


Author: Villaluz Z. Acedo

Abstract

The solidified Murashige and Skoog (MS) medium added with gibberellic acid (GA3) induced direct organogenesis without any callus formation of the meristems of sweetpotato, varieties VSP-1, VSP-2 and VSP-3. The optimum GA3 concentration varied with variety. On the other hand, benzylaminopurine as medium supplement caused profuse callus growth on the basal portions of the meristem before shoots developed.
Shoot growth of the meristems was much faster in liquid than in solid MS medium supplemented with GA3. Rapid shoot and root development was induced when the cultures were transferred to the solid MS medium containing high sucrose level 1.5 month after.

Keywords : Sweetpotato. Ipomoea batatas L. Meristem culture. Organogenesis. Murashige and Skoog. BAP. GA3 .

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Reaction of Sweetpotato Genotypes to Botryodiplodia theobromae Pat. and Macrophomina phaseolina Tassi


Author(s): Cristina E. Sajise and Carlito Palermo

Abstract

Sweetpotato genotypes were screened for resistence to Botryodiplodia theobromae Pat. and Macrophomina phaseolina Tassi, the two major postharvest pathogens found infecting sweetpotato roots during storage in the Philippines. The effect of different stages of maturity of sweetpotato plants on host resistance and the nature of postharvest disease development were also investigated, Assessment of 437 genotypes for resistance to B. theobrome infection showed that 0.7% and 15% were highly resistant and resistant, respectively. Out of 434 genotypes evaluated for resistance to M. phaseolina only 0.2% and 6% were noted to be highly resistant and resistant, respectively. Majority of the genotypes screened against both pathogens were found to be moderately susceptible to susceptible. Roots taken from 3 months old plants were more resistant to infection by either B. theobromae or M. phaseolina than those taken from 4 and 5 months old plants. The resistant, moderately resistant, and susceptible lesion types were categorized based on visual and histological examinations. Ipomeamarone was detected in inoculated resistant, moderately resistant and moderately susceptible sweetpotato roots but not in susceptible roots. No visible formulation of ipomeamarone was noted in healthy uninoculated roots.

Keywords : Sweetpotato. Ipomoea batatas. Postharvest pathogen. Botryodiplodia theobromae. Macrophomina phaseolina< Resistance.

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Early Responses of Seven Dwarf Coconut Cultivars to Varying Levels of Ammonium Sulfate and Potassium Chloride Application


Author(s): Tessie C. Nunez and Ricardo P. Bales

Abstract

Seven dwarf coconut cultivars which were subjected to different levels of ammonium sulfate and potassium chloride application responded similarly to fertilization. Fertilization generally improved the growth and precocity of these cultivars with the fertilized palms developing bigger girths, taller stand and retaining more functional leaves than the unfertilized one. The former also flowered from 0.19 to 1.29 years earlier than the latter. Fertilizer effects were observed earliest on plant height at 3 months after planting.
Among the cultivars, Camotes, Catigan and Malayan Red Dwarf exhibited better growth. Camotes, Catigan, Lingkuranay and Albuera Dwarf were the early bearers whose mean ages at flowering ranged from 3.08 to 3.39 years from planting.

Keywords : Dwarf coconuts. N-K fertilization. Growth. Precocity. Leaf spot infection.

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