Category Archives: Volume 24 No. 1 (2002)

Promotive factors for callus initiation and plant regeneration in upland rice


Author: Marilyn M. Belarmino

Abstract

Factors promotive to the initiation of embryogenic callus and regeneration of plants in upland rice were investigated using mature dehulled seeds. The objectives are to enhance the production of embryrogenic callus and increase regeneration of plants. In upland rice, light incubation as well as 30 sorbitol and 50 mg/L tryptophan were promotive for the formation of embryogenic callus and green shoot buds when added in the rice callus initiation (RCI) medium during the initial culture stage. Likewise, the Combinations of 0.5 mg/L NAA and 0.5 mg/L BAP or, 0.5 mg/L IAA and 0.5 mg/L BAP supplement in the rice plant regeneration (RPR) medium enhanced the production of green shoot buds and plants from callus that were precultured in RCI medium containing 1.0 mg/L abscisic acid. The upland rice regenerants exhibited phenotypic variation from their parental counterparts in the field.

Keywords : callus initiation, culture medium, plant regeneration, promotive factors, upland rice

Full PDF :
pdf

Effectiveness of cassava plastic storage technology and marketability of plastic-packed cassava roots


Author(s): Emma S. Data1, Editha G. Cagasan2 and Joselito B. Layola3

Abstract

This study was conducted to verify the effectiveness of plastic packaging and fungicide treatment in prolonging the shelf life of fresh cassava roots for marketing, determine the acceptability of the plastic-picked cassava among urban consumers, and determine the profitability of marketing plastic-packed cassava.
Results further showed that there is potential market for the plastic-packed cassava. Of the 1.911 packs delivered to the different market outlets, .769 packs (93%) were sold.
In the follow-up survey, it was found that the plastic-packed cassava was generally acceptable among the urban consumer-respondents. All of the 380 respondents revealed that they would like to continue buying the plastic-picked cassava. Among the reasons cited were: the roots remained fresh even if they were stocked for several days (36.8%): the roots tasted sweet and juicy when cooked (32.6%): and the price (P15.00/pack at 2 kg/pack) was just enough (18.7%).
Marketing plastic-packed cassava directly to consumers gave the highest return on investment (ROI) of 189%.

Keywords : plastic-packed cassava, shelf life, marketing

Full PDF :
pdf

Effect of temperature and water activity on quality deterioration and shelf life of dried mangoes


Author(s): Lemuel M. Diamante1, Ken-ichi Ishibashi2 and Kazunori Hironaka2

Abstract

A study was conducted on the effect of storage temperature and sample water activity on ascorbic acid degradation, browning development and shelf life of dried mangoes. The moisture content of dried mangoes increased with water activity at all temperatures which is consistent with the theory of physical adsorption. However, at a water activity of about 0.65. the amount of sorbed water at a given water activity increased with increasing temperature. The ascorbic acid (AA) degradation in stored dried mangoes can be described by a first order reaction. The effect of water activity and temperature on the rate constant for AA degradation can be modeled by a modified exponential equation. The activation energy for AA degradation in dried mangoes was almost constant at 65000 J/mole for water activity range of 0.65 to 0.85. The browning development in stored dried mangoes can be described by a zero order reaction. The effect of water activity and temperature on the rate constant for browning development can be modeled by a modified exponential equation. The activation energy for browning development in dried mangoes was almost constant at 57000 J/mole for water activity range of 0.65 to 0.85. The basis for shelf life prediction in dried mangoes was ascorbic acid degradation since acid degradation since this gave shorter shelf lives as compared with browning development. The shelf lives of dried mangoes decreased with increasing storage temperatures and sample water activity.

Keywords : intermediate moisture foods (IMF), dried mangoes, temperature, water activity, ascorbic acid, browning, rate constant, activation energy, shelf life

Full PDF :
pdf

Cultural management manipulation for baby corn (Zea mays Linn.) production. I. Effects of variety and organic manure growth and yield of baby corn


Author: Reynaldo R. Javier

Abstract

The percentage organic matter and total N and Olsen P in the soil were significantly increased with 120-180 kg N ha-1 organic matter manure application.
The application of organic manure at increasing rates (611P180 kg N ha-1) shortened the days to tassel, silk, and harvest of baby corn; increased the leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR) and herbage yield: and improved the yield components which markedly increased the baby corn yield. The highest marketable and total yield of baby corn were attained by Pioneer 3014 at 180 kg N ha-1 and by VM2 and Davaonon at 120 kg N ha-1 of organic manure application.

Keywords : baby corn, organic manure, hybrid corn, open pollinated corn

Full PDF :
pdf

Growth, development and flower quality of poinsettia as influenced by nutrient level and plant growth regulation method


Author(s): Doris Po Quita and Misael T. Diputado, Jr.

Abstract

Nutrient application, in general, increased plant size and number of leaves per plant and enhanced thy matter production in plant. Low nitrogen to potassium ratio resulted to the production of shorter internodes and with more intense bract color. Plants applied with high N-K. ratio were taller, had longer internodes and bigger bracts.
Paclobutrazol application effectively reduced plant height and intemode length. Pinching, on the oilier hand, reduced plant height but did not reduce internode length. It increased number of leaves per plant. Thus, the combination of paclobutrazol application and low NA( ratio feeding regime produced plants of the best quality.

Keywords : poinsettia, nutrient level, growth regulation, flower quality, paclobutrazol, pinching

Full PDF :
pdf

Natural vegetative strips in degraded calcareous soil environments: Successful stabilization of steep slopes in the Central Philippines


Author(s): Marco Stark1 and Julito Itumay

Abstract

While a good understanding exists of the effects of low-cost natural vegetative contour strips (NVS) and their contribution to enhanced land productivity in deep acidic soil environments, little is known about the benefits and constraints of this soil conservation technology under severely degraded calcareous soil conditions. Shallow calcareous soils are common in Central Philippines covering more than half of the total land area of the Visayan islands. Based on the results from the documentation of the traditional use of NVS in Bohol, the World Agroforestry Centre (ICRAF) has conducted on-farm trials since May 2001 to assess the local practice in more detail. Observations made over a period of I 1/2 years since NVS establishment, confirmed that the vegetative strips are highly effective in collecting eroded sediments in soils derived from either limestone or marl. The accumulation of the eroded in and above the NVS resulted in the formation of terraces that made land cultivation easier and further reduced soil erosion. Consequently, the maize yield on tower terrace zones improved right from the 1st cropping season after NVS establishment, presumably because of the deeper soil and higher water retention capacity resulting from the accumulation of sediment behind the NVS. Improved maize growth compensated for the 20% loss of crop area to the vegetative strips. Together with the findings derived from research on deep acidic soils in Northern Mindanao, findings of this research support the exploration of the NVS technology from ICRAF’s research sites to the major soil environments of the Philippine uplands.

Keywords : natural vegetative strips, soil conservation, calcareous soils, indigenous knowledge

Full PDF :
pdf