Category Archives: Volume 3 No. 3 (1981)

Prevalence and Economic Importance of Liverfluke Infestation in Slaughtered Carabaos and Cattle


Author(s): Marissa T. Sabarez, L. M. Ancheta, D. C. Maniwang, S. C. Vencilao and T. J. Fernandez, Jr.

Abstract

Separate surveys were conducted in Baybay and Ormoc, Leyte to determine the prevalence of liverfluke infestation or fascioliasis and the economic importance of infested livers of slaughtered carabaos and cattle. Results showed that there was no significant relationship between the age of the animal and infestation rate. However, there was an increasing trend of infection in cattle from 1-8 years old. The type of pasture (lowland or upland, dry or wet) was found to be significantly related to liver-fluke infestation rate (P < .05). There was significant relationship between the established system of feeding roughage and liverfluke infestation rate in carabaos but not in cattle. An average liverfluke prevalence rate of 18, in cattle and 595o in carabaos was found in Ormoc City. In Baybay , the prevalence rate was 57% in carabaos and 18.5% in cattle. The average percentage liver condemnation for acre beat was 22.7o, and 2.42% for cattle, which would amount to an average annual tee of P5865 and P462 per year, respectively.

Keywords : Carabao. Bos bubalus bubalis. Cattle. Bos sp. Liverfluke infestation. Fascioliasis. Trematode. Fasciola gigantica. Distribution. Effect of pasture area and management practice. Economic importance.

Full PDF :
pdf

An Ecological Survey of the Weed Flora in the Major Root Crop Areas in the Philippines


Author(s): M. I. Galinato and Percy E. Sajise

Abstract

Different root crop-growing areas in the Philippines were surveyed during the net season to determine the weed species associated with different root and tubes crops, namely, sweet potato, cassava, yam and white potato. Wet season quantitative vegetation analysis of weed species associated with root crops in the Philippines has shown the existence of 8 weed community types, namely: Cyperus rotundus, Paspalum conjugatum, Ageratina adenophora, Pennisetum polystachyon. Digitaria sanguinalis, Dactyloctenium aegyptium, Eragrostis tenalila, Desmodium triflorium. A total of 70 weed species was encountered in the quantitative vegetation analysis. Some environmental factors such as pH, climatic type, soil type, weed control practices and elevation were determined to explain the community patterns.

Keywords : Weed flora. Weed community types. Root crops. Sampling Ecological survey. Philippines.

Full PDF :
pdf

Effect of Brown Leaf Spot Disease on the Growth and Yield of Sweet Potato


Author(s): Carlos S. de la Cruz, F. L. Loreto and M. K. Palomar

Abstract

Polybagged sweet potato plants were inoculated with conidia of Cercospora batatae scraped from sweet potato leaves infected with brown leaf spot. The completely randomized design was followed in laying out the experiment. Leaves inoculated at different ages showed varying responses to infection with significant differences in the number and size of lesions and percentage of defoliation. Leaves inoculated 01 15-21 days old were found most susceptible to the disease. Initial symptom of the disease was first observed as light green lesions approximately 0.5 mm in diameter 2 weeks after inoculation. The lesions increased gradually until they reached 3 to 4.2 mm diameter 32 days after inoculation. Coalition of lesions was observed at this stage followed by subsequent defoliation. Inoculated plants showed decrease in yield resulting from the adverse effects on yield components. The two trials yielded 9.57.7o, 5.05.7o and 26.233/4 reduction in weight of tubers, roots and tops, respectively. The number of tubers also decreased in inoculated plants. Analysis of variance of weight of tops showed significant difference from the uninoculated ones while the other parameters were not significantly different.

Keywords : Sweet potato. Brown leaf spot. Cercospora batatae. Symptomatology. Lesions. Defoliation. Effect of pathogen. Yield and yield components.

Full PDF :
pdf

Seasonal Abundance of Red Spider Mite and Its Predators on Selected Cassava Accessions


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

Abstract

In an unsprayed cassava planting, the cassava red spider mite population fluctuated in lesser magnitude in moderately resistant Accessions 8, 12 and 46 than in Golden Yellow and susceptible Accessions 35, 36 and 38. Irrespective of the susceptibility level, population buildup of the spider mite in ViSCA occurred during low rainfall months which, during the two-year period covered, were from December 1978 to April 1979, August and September 1979 and in May, June and July 1980. In some instances, factors other than rainfall seemed to reduce mite population. Temperature and relative humidity did not show adverse effect on spider mite population. Predaceous insects such as coccinellid and staphylinid beetles, cecidomyiid fly and thrips (in decreasing order of abundance) and predaceous phytoseiid mites fluctuated in population density only slightly and showed minimum buildup despite the presence of high mite population. Factors other than predators could have helped also in reducing mite population in certain months. It is suggested that field planting should be planned such that the critical stage of growth of cassava which usually occurs during the third to the fifth month from planting will not coincide with the population peaks of the cassava red spider mite to avoid significant loss in tuber yield.

Keywords : Cassava. Cassava red spider mite. Population densities. Predators. Rainfall. Susceptible or resistant accession. Golden Yellow cassava. Time of planting.

Full PDF :
pdf

Growth and Development of Cassava under the Traditional and the Mukibat Systems of Planting


Author(s): Ofelia P. Ahit, Sergio E. Abit and Manuel B. Posas

Abstract

Two methods of propagating cassava were compared using 4 levels of fertilizer application. One method was the Mukibat system based on the grafting of Manihot glaziovii with M. esculenta. The other method was the Traditional or the engrafted system using the stalks of the M. esculenta as planting material. Higher rates of NPK application resulted in a significant increase in plant height, leaf area index (LAI), root diameter, root length and root weight of cassava for both methods of planting. However, cassava plants under the Mukibat system had taller stature, larger root diameter and heavier root weight compared to those planted using the traditional system, although the latter had higher LAI.

Keywords : Cassava, Manihot esculenta. Manihot glaziovii. Mukibat and traditional systems of planting. Leaf area index. Root bulking.

Full PDF :
pdf

Growth and Yield of Sweet Potato As Influenced by Different Potassium Levels in Three Soil Types


Author(s): Anabella T. Bautista and Rebecco M. Santiago

Abstract

Both silt loam and sandy loam media were significantly superior than clay loam in enhancing the length of vines and increasing the number of nodes and branches produced on the primary vines of sweet potato plant. Plants grown in silt loam produced the highest average weight of marketable tubers at 0.499 kg/pot, while those in clay loam had the lowest (0.453 kg/pot). In general, there was an increased response of sweet potato as the potassium levels in the soil were increased. This was manifested by longer vines, more nodes produced on the primary vines, and more secondary branches. The highest weight of marketable tubers (0.5688 kg/pot) was obtained 01 600 ppm K, while the lowest (0.3606 kg/pot) in the control. Interaction effects of soil types and potassium levels were significant on the growth and yield of sweet potato. Interactions between silt loam and sandy loam media with the 4 potassium levels were found to be significantly better than the interaction effects of clay loam and the 4 potassium levels.

Keywords : Sweet potato. Soil type. Sandy loam. Clay loam. Silt loam. Soil fertility. Potassium level. Growth and yield.

Full PDF :
pdf

Floral Morphology and Biology, Fruit and Seed Set, Seed Germination and Seedling Development of Taro


Author: J. R. Pardales, Jr.

Abstract

The natural flowering habit of taro was studied in a population comprising of 299 cultivars. The floral biology and the development of fruits and seeds were also determined. Very few cultivars readily produced flowers under natural conditions. Flowering in the field commenced in May and reached its peak in July or August. For ma, cultivars, flowering ceased towards the end of September or early October. The inflorescence of taro is a spadix type. A maximum of two spadices was present in any plant at a time. Floral abortion was very common while natural fruit and seed set was very rare. Artificial pollination within and between cultivars produced little success. Germination of taro seeds was also made and seedling development was studied. Seeds that developed from pollination between cultivars appeared to have better germination than those coming from pollination within variety. Seedling development was very slow during the earl, stage and their vigor varied. Some seedlings were normally green while others lacked the normal green coloration and subsequently died. Other seedlings appeared green during the earl, stage of development but did not grow beyond the cotyledonary leaf stage.

Keywords : Taro. Colocasia esculenta. Pollination. Flowering habit and physiology. Morphology. Fruit and seed set. Seed germination. Seedling development.

Full PDF :
pdf

The Impact of Small-Scale Communal Irrigation Project on Income Distribution


Author: Nerelito P. Pascual

Abstract

The impact of small-scale communal irrigation project on income distribution was determined among factors of production, among earners, and across households. Farm survey data from Quezon Province, Philippines were obtained and analyzed using the “with-without” and “before-after” project comparative methods. Analysis of the relative factor shares was also made using the Constant Elasticity of Substitution (CFS) production function. The return to each production factor was generally higher in the “with, or after” irrigation condition as contrasted to the return to each production factor in the “without” and the “before” irrigation situations. The increase in capital share, however, was generally larger than the increase in labor and management shares. This was mainly attributed to a significantly. lower labor intensity on the irrigated farms compared with the labor intensity on the unirrigated farms. The real returns to the various earners were generally’ larger on the irrigated areas than on those without irrigation facilities. However, the farmers benefited from irrigation more than the landlords and hired laborers in the “before-after” comparison. The indices of income inequality on the distribution of income among the respondents in the “with, or after” and “before” irrigation situations showed that irrigation caused a little improvement in the income distribution across farmer-households.

Keywords : Communal irrigation. Income distribution. Factor shares. Earner shares. Farmer-households.

Full PDF :
pdf