Category Archives: Volume 5 No. 3 & 4 (1983)

Pre-Havest Factors Affecting Vascular Streaking and Quality of Cassava Tubers


Author(s): Marcelo A. Quevedo and Ofelia K. Bautista

Abstract

Detopping of cassava plants at different degrees before harvest was under-taken to determine its effect on vascular streaking and quality during storage. Detopping the plants at 50-100% and stripping of all the leaves substantially delayed vascular streaking of the tubers during storage at ambient condition. However, it reduced the dry matter and starch contents of the tubers. A positive relationship was observed between severity of rotting and streaking but not be-tween vascular streaking and percentage rotting.

Keywords : Cassava. Detopping. Vascular streaking, Starch. Dry matter. Rotting. Disease severity.

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Variability and Heritability of Some Metric Traits of Solanum khasianum Clarke


Author(s): S. Pal and K.K Singh

Abstract

Genetic variability and heritability were estimated in Solanum khasianurn Clarke. Phenotypic variability ranged between 0.03 for fruits/bunch and yield/ plant, and 787.39 for number of fruits/plant. Genotypic variability was highest (497.07) for number of fruits/plant and lowest (0.01) for fruits/bunch and solasodine content. Genotypic coefficients of variability were high for number of branches/plant, number and yield of fruits/plant, and solasodine yield/plant indicating the potential for advancement by selection. Heritability estimates were high for days to flowering and fruiting, and number and yield of fruits/ plant; medium for number of branches, flowers/bunch, fruits/bunch and solaso-dine yield/plant; and low for days to maturity, height and solasodine content. Genetic advance varied between 0.08 for solasodine content and 36.49 for number of fruits/plant. Genetic advance expressed as percent of mean was highest (36.02%) for solasodine yield/plant and lowest (0.15) for solasodine content. The characters with high heritability estimates did not show high genetic ad-vance indicating non-additive gene effects and therefore low expected genetic gain by selection. In the case of number of branches, number and yield of fruits/ plant, and solasodine yield/plant, high phenotypic coefficient of variability asso-ciated with high genotypic coefficient of variability and high genetic advance in-dicated the possibility of improvement with respect to these characters by mass selections.

Keywords : Solanum khasianum. Solasodine. Genotypic variance. Heritabi- lity. Genetic advance. Mass selection.

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Effects of Mudpress Used as Soil Conditioner and Organic Fertilizer on Mungo Grown on Maasin Clay


Author(s): Victor B. Asio, Rodolfo G. Escalada and Raquel B. Capuno

Abstract

Mudpress application increased the pH and nutrient level of the soil. More-over, it favored the growth and development of mungo. The number of days from seeding to flowering and maturity decreased but the leaf area and herbage weight increased with the use of mudpress. The number, length and weight of pods, weight of 100 seeds and grain yield likewise increased in plants applied with mudpress. Results strongly indicate that application of mudpress particularly at the rate of 60 tons/ha is significantly more effective in enhancing growth and development of mungo as well as in increasing its yield than inorganic fertilizer.
Increasing the level of mudpress application decreased the bulk density of the soil. The use of 60 tons/ha of the material resulted in the lowest bulk density value of 1.27 g/cc. The highest value of 1.61 g/cc was obtained from the soil treated with inorganic fertilizer.

Keywords : Mudpress. Maasin clay. Soil conditioner. Organic fertilizer. Bulk density. Mungo.

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Effect of Fertilizer Application on the Yield and Protein Content of Soybean Harvested at Various Stages of Maturity


Author: Edgardo E. Tulin

Abstract

Fertilizer application significantly increased the yield of soybean when harvested not earlier than 35 days after flowering. The crude protein content of soybean was not influenced by fertilizer application regardless of its stage of maturity. With or without fertilizer application, significant differences existed the only between crude protein content of the sample harvested at 15 days after and flowering and those harvested at the other three stages of maturity. However when fertilizer was applied, significant difference was also observed between the protein content of samples harvested at 25 and 45 days after flowering. Furthermore, fertilizer application significantly influenced the total protein yield of soybean. Without fertilization, there was no significant increase in the total protein yield when plants were harvested at 25 days after flowering instead of 15 days after. When the plants were fertilized, a significant increase in total protein yield for every 10-day increment in maturity was observed. Higher it yield, crude protein content and total protein yield were obtained when the plants were harvested 45 days after flowering than when harvested at 15, 25 and 35 days after flowering. Yield and protein content of the beans increased linearly as time of harvest was delayed from 15 to 45 days after flowering.

Keywords : Fertilizer application. Soybean. Yield. Protein content. Stages of maturity. Total protein yield.

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Effects of Animal Manure Application on the Growth and Yield of Corn


Author(s): Elphe P. Ponsica, Rodolfo G. Escalada and Bernadita F. Quirol

Abstract

Application of chicken dung and cow manure at higher rates, seemed to hasten tasseling, silking and maturity of the corn plants and favor production of larger ears, more grains, and higher shelling percentage. Overall performance of the crop was better with application of 9 to 12 Oa of chicken dung than inorganic fertilizer and cow manure at all rates. The.bulk density and pH of the soil were not significantly affected by application of either inorganic or organic fertilizers. An increase in the NPK contents of the soil was noted when 6 Oa or more of animal manure was applied.

Keywords : Corn. Growth. Yield. Farm manure. Bulk density. Soil nu-trients. Tropical soils.

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Incidence, Symptom Development and Transmission of Taro Feathery Mosaic Disease


Author(s): Manuel K. Palomar, Rhodora P. Gloria and Constancio M. Napiere

Abstract

A survey of taro-growing areas in Eastern and Central Visayas showed about 10% infection with taro feathery mosaic disease (TFMD). TFMD-infected plants produced the characteristic feathery mosaic with or without mottling of leaves. The symptoms would sometimes be a slight green streak/irregular spots along or in between leaf veins. Symptoms of infection may disappear from a mature leaf and then reappear on the young leaf. Using the Kalpao variety of taro, manual inoculation showed 70% infection after 12.4 days of incubation while insect inoculation gave 63% infection after 15.2 days. The taro planthop-per, Tarophagus proserpina Kirk., was found to be a vector of taro feathery mosaic disease.

Keywords : Colocasia esculenta. Kalpao taro. Tarophagus proserpina. Di-sease distribution. Symptomatology. Feathery mosaic disease.

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