Category Archives: Volume 3 No. 4 (1981)

Effect of Different Cropping Systems on the Growth and Yield of Sweet Corn and Sweet Potato


Author(s): Luvimin A. Evangelio and Elpidio L. Rosario

Abstract

Sweet corn and sweet potato were grown under 13 different cropping treatments. Double rows spaced at 0.3 m with interval row spacing of 1.0 m appeared to be the optimum treatment combination with a mean yield of 21.99 t/ha. Under this scheme, yield increases of 75% and 66% were noted in sweet corn and sweet potato, respectively. Land equivalent ratio (LER) was significantly affected by cropping systems. Both alternate cropping scheme and double row arrangement had LER greater than 1. The LER values obtained on yield as fraction of monoculture checks for sweet corn and sweet potato indicated a net positive effect between the two cropping patterns. LER notably decreased as the interval row spacing was increased from 1.0 m to 2.0 m for double rows spaced at 0.3 m and 0.5 m. Growth and yield parameters of sweet potato that were significantly affected by the different cropping treatments were: leaf, area per plant, leaf area index (LAI), length of vines at harvest, yield of marketable tubers per hectare, yield of tubers per plant, total dry matter (TDM) per plot, and harvest index (HI). On sweet corn, leaf area per plant, LAI, date to green maturity, weight of ears per plant, TDM per plant and HI were the growth and yield parameters that were significantly affected by the cropping treatments. Parameters that were not significantly affected by the cropping treatments used for sweet potato were: length of vine 30 days after planting, number of marketable and non-marketable tubers per plant, and yield of non-marketable tubers per hectare. Cropping systems did not have a significant effect on plant height of sweet corn 30 and 60 days after planting.

Keywords : Sweet corn. sweet potato. Multiple cropping. Land equivalent ratio. Total dry matter. Leaf area index. Harvest index. Cropping pat-terns. Monoculture.

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Some Factors Associated with the Adoption of Recommended Corn Production Practices in Southern Philippines


Author: Myrna M. Avila

Abstract

A total of 175 corn farmers in the three provinces of Region XI were personally interviewed with the use of an interview schedule. Of the nine recommended corn production practices, the farmers had high adoption rate in six, namely: seed treatment, weed control, thinning, distancing of plants, insect control, and application of fertilizer. Use of high yielding variety, use of machinery and disease control were also adopted by the corn farmers. Most of the farmers adopted five to seven recommended corn production practices. Socio-economic and diffusion variables such as credit, gross income, gross production, quality of road, availability of transportation facilities, use of printed media, contact with corn experts and attendance in informational gatherings were related to the adoption of recommended corn production practices.

Keywords : Corn farmer. Adoption. Recommended practices. Personal variables. Economic variables. Region XI. Southern Philippines.

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Effect of Different Levels of Helicotylenchus Nematode Infestation on the Growth and Yield of Sweet Potato


Author(s): E.A. Lopez, R.M. Gapasin and M.K Palomar

Abstract

Low population density of Helicotylenchus stimulated plant growth. Weights of tops, roots and tubers at a population of approximately 1,000 nematodes per plant were higher than those of the control. Plant growth was not retarded at low levels of nematode population. However, as the population was increased to 10,000 per plant, weights of tubers, roots and tops of sweet potato decreased, but only the difference in root weight was statistically significant. Helicotylenchus spp. tended to be parasitic, instead of pathogenic, to sweet potato.

Keywords : Helicotylenchus spp. Nematode. Population density. Parasitic. Pathogenic. Sweet potato. Growth and yield.

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Fiber Recovery and Quality of Ten Abaca Varieties


Author(s): R.P Bales, R.N. Santiago and N.M Gloria

Abstract

The 10 abaca varieties significantly differed in almost all of the parameters considered. Lawaan x Tangongon had the heaviest weight of fresh stalk and tuxies in the outer and middle groups of leafsheaths, produced the highest weight of dry fiber recovered, and ranked second in terms of tensile strength per group of leafsheaths. Pacol x CES 2 ranked second in terms of weight of fresh stalks, produced the heaviest weight of tuxies from the inner group, ranked second heaviest in the outer and middle groups, but produced the lowest fiber recovery and percentage fiber stretch in the 3 groups of leafsheaths. Furthermore, Pacol x CES 2 produced the lowest tensile strength from the outer and inner groups and ranked second to the lowest in the middle group. Linawaan produced the highest fiber recovery while Ginabaki and Bulao Luno produced the highest tensile strength and percentage fiber stretch in all groups of leafsheaths, respectively. With respect to fiber quality, Bulao Luno, Lawaan x Tangongon, Linawaan, Casilihon, and Amokid had better quality of fiber than the rest of the varieties tested.

Keywords : Abaca. Fiber recovery. Fiber quality. Group of leafsheath. Tuxy.

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Effect of Different Population Densities and Nitrogen Levels on the Yield and Yield Components of Sorghum


Author(s): Ruth Otaza Escasinas, R.G Escalada and Raymundo M. Trenuela

Abstract

Increasing the population density decreased the panicle length, number of grains per panicle, and weight of grains per panicle although it increased the leaf area index. Population density of 200,000 plants/ha gave the highest grain yield of 2.07 t/ha, followed by 300,000 plants/ha at 2.01 t/ha, and 100,000 plants/ha at 1.72 t/ha. Application of N fertilizer affected to a certain extent the morphological characteristic and yield of the plant. It increased plant height, leaf area index, panicle length, number of grains per panicle, weight of grains per panicle, and stover and grain yields. Although grain yield increased with increasing rates of N from 30 to 200 kg/ha, its magnitude was not big enough to show significant differences. Plots treated with the highest level of N (200 kg/ha) gave the highest grain yield of 2.32 t/ha while the control (0 kg/ha) gave the lowest yield of 1.32 t/ha.

Keywords : Sorghum. Sorghum bicolor. Cosor 3 variety. Population density. Leaf area index. Interplantantra-plant competition. Fertilizer levels. Agronomic characteristics. Yield and yield components.

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Rural Development Information Coverage of Radio Stations Serving the Eastern Visayas


Author: Monina M. Escalada

Abstract

All station managers or program directors of radio stations serving the Eastern Visayas were interviewed to determine the rural development (RD) information coverage of their stations. A purposive random sample of 600 radio-listening farmers from 12 municipalities in the Eastern Visayas provided additional data on listenership to RD information. All the radio stations surveyed broadcast RD information mainly on agriculture. Government agencies were the sources of RD information for most stations. Radio was perceived to be the most effective channel for communicating RD information while drama was the most listened to format. Persons, usually extension technicians, were the most preferred sources of RD information by the farmer-respondents. About 91.5% of the farmer-respondents listened to RD information broadcast which dealt chiefly with agriculture.

Keywords : Rural development. Information. Radio. Programming. Format. Broadcasting. Listenership. Spot announcements. Jingle. Eastern Visayas.

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Effect of Ethyl Methane Sulfonate and Co60 Gamma Irradiation in Winged Bean


Author(s): Jejoma G. Armachuelo and Fernando A. Bernardo

Abstract

Mutation and other effects of Co60 gamma radiation and ethyl methane sulfonate (EMS) in winged bean were determined at the M1 generation. Seed germination was significantly reduced by irradiation at all levels used but only at 0.15% and above for EMS. Delayed seedling emergence, high lethality and pronounced morphological and probably physiological damage due to chromosomal aberrations resulted with the radiation treatments but not with EMS at the doses used. Chlorophyll mutations were observed as yellowish emergent seedlings resulting from EMS treatments and yellow variegations and leaf streaking associated with leaf deformations with irradiation. Violet flowers and seeds were also observed in both mutagen treatments but could not be ascertained as true mutations since the seeds used were not tested for purity. On the yield components, significant reduction in number of seeds per pod, and yields of pods, seeds and tubers were observed in the radiation treatments. Doses of 15 and 25 kr, however, resulted in a higher tuber yield compared with the control signifying a likely induction of favorable gene mutations. No significant effects were induced by EMS treatments on any yield parameter.

Keywords : Winged bean. Psophocarpus tetragonolobus. Mutation. Co60 gamma radiation. Ethyl methane sulfonate. Mutagens. Irradiation. Chlorophyll mutation. Gene mutation. Seed purity. Yield components.

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Reaction of Some Cassava Accessions to Red Spider Mite Tetranychus kanzawai Kishida) Infestation


Author(s): Emilia N Bernardo and Nelson M. Esguerra

Abstract

A satisfactory technique for evaluating cassava accessions/varieties for resisitance to the red spider mites in the field or screenhouse was developed. Of the 295 entries tested, 50 showed varying levels of tolerance to the pest when tested in the field. At a much higher mite population in the screenhouse, however, practically all the accessions showed lower levels of tolerance although leaves of the more tolerant accessions 17, 29, 33, 48 and 49 were still green when the susceptible checks began to get defoliated. Differences in tolerance levels were most evident 3 weeks after artificially infesting each plant with 20 reproducing adult mites. Significant antibiotic effects of the resistant hosts on the pest were not detected.

Keywords : Red spider mite. Tetranychus kanzawai. Evaluation technique. Cassava accessions. Tolerance.

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