Category Archives: Volume 8 No. 3 (1986)

Transitivity of Consumer Preference: A Comparison between Categories of Selected Variables


Author(s): Marciano T. Sacay and Jose M. Alkuino, Jr

Abstract

The study relates the consistency of choice and preference among Filipino consumers to selected variables. One hundred twenty-four respondents categorized into high school students, college students, professionals and farmers were included in the survey. Transitivity of responses were compared among categories of variables such as age, sex, occupation, education and civil status. Significant differences across categories of all variables except age were observed. Professionals, college graduates, and females had the highest transitivity of responses under categories of occupation, education and sex, respectively.

Keywords : Consumer reference. Transitivity. Age. Sex. Education. Occupation. Civil status.

Full PDF :
pdf

Rhizosphere and Rhizoplane Microflora of Coffee Seedling as Influenced by Collar Rot and by Seed Pre-treatment


Author(s): P. Venkatasubbaiah and K.M. Safeeulla

Abstract

Rhizophere and rhizoplane microflora of coffee seedlings were studied by the dilution plate technique. The number of fungi, yeast and bacteria was higher in the rhizosphere than in the non-rhizosphere and rhizoplane. Rhizoctonia solani, the incitant of collar rot of coffee seedlings, altered the rhizosphere and rhizoplane microflora. The microflora of coffee seedlings obtained from seeds pre-treated with Carboxin and Quintozene markedly differed from that of seedlings with no seed treatment. Among the fungi isolated, Aspergillus spp. were the most predominant followed by Fusarium spp. R. solani was observed in the rhizosphere and rhizoplane of the untreated and collar rot-infected seedlings only. Seed treatment with fungicides decreased the fungal flora associated with plant roots.

Keywords : Coffee. Rhizosphere. Rhizoplane. Microflora. Seed treat-ment. Collar rot.

Full PDF :
pdf

Evaluation of Five Insecticides against the Black Leafhopper (Ricania speculum Walker) Attacking Patola [Luffa cylindrical (L.) Roem]


Author(s): Ma. Teofila O. Oben. Andrea C. Matarong and Nelson M. Esguerra

Abstract

In the small plot trial; diazinon, permethrin, malathion, methyl parathion and endosulfan at the manufacturers’ recommended rates and sprayed 4 times starting at flowering significantly controlled the nymphs of the black leafhopper. Highest yield and net return were obtained in malathion-treated plants. Diazinon gave the lowest yield and net return but these were still higher than those of the unsprayed control.
The results of the preliminary screening tests were confirmed in the large plot trial. Except for carbofuran, all other insecticides provided immediate control of the black leafhopper nymphs. Under non-shaded condition, yield was highest on endosulfan-treated plants while the methyl parathion-treated plants gave the highest net income/ha under shaded condition. These insecticides also seemed to have no deleterious effect on predatory spiders.

Keywords : Black leathopper (Ricania speculum Walker). Chemical control. Patola [Luffa cylindrica (L.) Roemi. Yield. Net return.

Full PDF :
pdf

Evaluation of Physio-Chemical Properties of Cocoyam (Xanthosoma) Flour


Author(s): Roberta Dizon-Lauzon, Roger Roy P. Garana and Linda B. Mabesa

Abstract

The physico-chemical characteristics of cocoyam flour were evaluated. The fiber, ash and carbohydrate contents of cocoyam flour were higher than those of wheat flour. Gelatinization of the starch fraction was noted to be between 68 and 72°C. Least gelating concentration was optimum at 8%; water and fat absorption capacities were 87.5% and 97.1%, respectively; and maximum viscosity was observed at a concentration of 8%.

Keywords : Cocoyam. Fiber. Ash. Carbohydrates. Gelatinization. Viscosity. Fat and water absorption.

Full PDF :
pdf

Effect of Stem and Foliage Scab Disease on the Growth and Yield of VSP-1 Sweet Potato Variety


Author(s): Josefina C. Nayga and Ruben M. Gapasin

Abstract

Sweet potato plants inoculated with scab at 2 and 4 weeks after planting (WAP) were severely infected as shown by deformation of leaves and stunted plant growth. Scab infection also caused early death of main vines. However, this was not observed in plants inoculated at 6 and 8 WAP.
Significant differences in disease severity ratings, leaf area and number and weight of marketable roots were observed among the different treatments but not in fresh vine weight, and number and weight of non-marketable roots. Total root yield of plants inoculated with scab at 2 and 4 WAP was reduced relative to the control by 27.8% and 24.5%, respectively. Eight-week old inoculated plants had a yield reduction of only 4.4%.

Keywords : VSP-1. Sweet potato. Stem and foliage scab (Sphacelorna batatas Saw.). Disease severity ratings.

Full PDF :
pdf

Effects of Pectinase, Cellulase and Nutrient Addition on Fermentation of Sweet Potato Mashes


Author(s): Richard N. McArdle and John C. Bouwkamp

Abstract

Addition of either cellulose or pectinase mixture to pre-heated sweet potato mashes at the time of yeast inoculation increased ethanol production up to twice that of untreated mashes, possibly by enhancing the post-heating activity of the native amylase and/or by lowering the viscosity of the mash, thus allowing better mixing and providing more chances for analyses attack on starch granules. With enzyme addition, heating mashes beyond 60°C did not increase ethanol yield. However, ethanol production was higher if enzymes were not added. The use of a common yeast nutrient supplement, corn steep, was detrimental to fermentation.

Keywords : Sweet potato [Ipomoea batatas (L.) Lam] genotypes. Fermentation. Prefermentation heating. Pectinase. Cellulase. Corn steep. Ethanol yield.

Full PDF :
pdf