Pollinia ofPhalaenopsiswere preserved in nine different organic solvents: acetone, ethyl ether, xylene, toluene, nitro-ethane, nitro-methane, benzene, tert-butyl acetate and n-pentane, and silica gel. Then, the morphological changes in the exine of these preserved materials were observed under a SEM, and the survival rate, seed formation by pollination as well as the formation of protocorms affected by such preservation were evaluated.
1. Onlyca. 40% of the pollinia preserved in nitro-ethane and acetone, respectively for eight months survived.
2. Pollinia kept in silica gel for six months hardly survived.
3. The epidermal pattern of the pollinia preserved for a long period of time with a lower survival rate, was much flatter than that of the fresh ones based on SEM observations.
4. Although pollination with pollinia preserved in tert-butyl acetate or benzene was successful, the enlargement of the capsules was less conspicious than in the case of pollination with normal fresh pollinia.
5. The seeds produced through pollination of the materials preserved in ethyl ether, acetone, tertbutyl acetate readily formed protocorms.
6. This concluded that the survival rate, pollination and seed production ofPhalaenopsispollinia were better when organic solvents such as tert-butyl acetate, benzene and ethyl ether were used for a long period of time than when the pollinia were preserved in silica gel of a low temperature.

View full abstract

Out of coconut cultivars, ‘Spicata’palm has branchless inflorescence with an abnormally large number of female flowers. Using‘Spicata’palms grown in Northern Mindanao Island, we evaluated agronomical and botanical characteristics as follows: precocity to flowering, emission of female flowers and bunches, fruit and copra yield, lipid content of copra, and fatty acid composition of lipid. Although‘Spicata’plams bore a large number of female flowers, several of them developed into mature fruits due to low setting percentage: 125 female flowers per bunch from which only 4.5 mature fruits were produced on the average. Aside from this peculiarity, other traits were almost comparable to those from‘Laguna’belonging to tall cultivar group of coconut. On the basis of data collected, oil productivity of a‘Spicata’palm was estimated to be 10-15 kg per year.

View full abstract

This experiment was taken effect of different soil moisture on growth and yield ofAmaranthusspp. (C4 plant) as plant of fallow paddy field. Plant materials wereAmaranthus caudatusandA. hypochondriacusof Grain Amaranthus, andA. tricolorof Vegetable Amaranthus. The plant was cultivated in 1/2000a Wagner's pot under different soil moisture condition.
The soil moisture conditions were 60-70% of soil moisture, 80-90%, 95-100%, and each consisted of 8 replications.
The results of this investigation are as follow:
1. The difference of soil condition affected growth of root system ofA. hypochondriacusandA. tricolor. The two cultivars showed vigorous growth and high yeeld.
2. On the other hand root system growth ofA. caudatuswas less affected. Further, the growth and yield ofA. caudatusdeteriorated under high soil moisture condition.

View full abstract

Effects of different day temperatures at a constant night temperature on the relative growth rate, transpiration rate and net photosynthetic rate were investigated at 100 days after seeding in plants of four pepper varieties with immature fruits. Two varieties which belonges to the bell pepper type bore large fruits. The other two varieties which belonges to the long pepper and cone pepper types bore small fruits. Plants were grown for 7 days in phytotrons under natural light conditions in which day/night temperatures were set at 37/22, 32/22, 27/22°C.
Transpiration rate and stomatal conductance increased with the day temperature. Responses of the netphotosynthetic rate to the day temperatures differed from the responses of the transpiration rate. Changes in the net photosynthetic rate were related to the day temperatures and the presence of immature fruits in plants.
Response of the relative growth rate (RGR) to day temperatures differed among the varieties. Changes in RGR depended on the fruit growth and fruit size. In the plants from the varieties with large fruits, the maximum amount of dry matter accumulated in the fruits and the growth of the leaves was inhibited of a high day temperature. In the plants from the varieties with smaller fruits, the growth of the leaves increased with the day temperature, Dominant sink at a high day temperature was represented by immature fruits in the varieties with large fruits and leaves in the varieties with small fruits.

View full abstract

Applications of gibberellin (GA), benzylaminopurine (BA) and succinic acid-2, 2-dimethylhydrazide (SADH) separately or in some combinations to flowers and fruits of young‘Tosa Buntan’pummelo (Citrus grandis (L.) OSBECK) trees grown in plastic houses during the fruit-growing period were undertaken in 1990 and 1991. The concentrations (ppm) were 20 for GA, 200 for BA and 1000 for SADH.
A large fruit size was observed in the trees treated with GA+BA at 1 or 2 months after anthesis. Single spray of GA, BA or SADH in the same period did not exert a significant effect on the fruit size. Formation of a neck at the stem end was associated with GA application. The application of GA and SADH did not affect the internal fruit quality. Application of BA at 2 months after anthesis resulted in a slightly higher content of total soluble solids (TSS) in the fruit juice. Acid content was not significantly different among the treatments in all the experiments.

View full abstract

Strangulation with a thin wire of the main branch of 3-year-old‘Tosa Buntan’pummelo (Citrus grandis (L.) OSBECK) trees grown in a plastic house was perfomed in mid-November 1990. The duration of the strangulation treatments was 1, 3 and 20 months. Although the numbers of inflorescences, flower buds and flowers opened were much larger in the treated trees than in the control trees, the differences among the treatments were not significant at 5% level in 1991. The number of sexual organs was also larger in the 20-month treatment than in the other treatments in 1992. The percentage of fruit sets was lower in the treated trees than in the control trees, without any significant differences at 5% level among the strangulation treatments in 1991. The girdles after the release of the wire rings in the 1 and 3-month treatments were healed due to the rapid enlargement of the branch girth by late May, while the enlargement rate of the branch girth in the 20-month treatment was lower than that in the other treatments. The contents of sugar and total carbohydrates and C-N ratio in the spring leaves sampled in late August increased with the increase of the duration of the treatment. Fruit growth in the 20-month treatment was slightly depressed in the late growing season. Fruits in the 20-month treatment showed, a lower value for weight, longer shape, more rapid rind degreening and higher content of total soluble solids (TSS) in juice than those in the other treatments.

View full abstract

Salinity tolerance of hexaploid triticale (XTriticosecaleWITTMACK) plants at the seedling, tillering, booting, inflorescence emergence, and milk-ripe stages was evaluated. Two cultivars, “Welsh”and“Currency”, were grown in a glasshouse and irrigated with a 0, 100 and 200 mM NaCl solution at each stage. “Currency”gave a higher grain yield than“Welsh”at all levels of NaCl irrespective of the stages of application. The relative salt tolerance (% of grain yield to the control) in“Currency”was higher than in“Welsh”when 100 mM NaCl was applied at the tillering and milk-ripe stages, and when 200 mM NaCl was applied at all the stages except for the tillering stage. The plants treated with both 100 and 200 mM NaCl at the booting and inflorescence emergence stages showed a high salt sensitivity in relation to grain yield. The plants treated with a 200 mM NaCl solution at the seedling stage were also sensitive to salt in relation to grain yield as in the case of the above two stages. Plants treated at the milk-ripe stage were the most tolerant at both salinity levels. The concentrations of sodium, potassium and chloride ions in the leaves increased with the NaCl treatment and the concentrations were generally higher at the earlier growth stages than at the later ones.

View full abstract

In Indonesia, it is estimated that there are about 20 million hectares of Alang-alang land, which were caused by shifting cultivation and a decline of soil fertility under growing population pressure. If Alang-alang land can be utilized for extending arable land, this approch expects to be an alternative to extend the transmigration sites without clearing the virgin forest. In this report, some technologies for eradicating Alang-alang grass and rehabilitating that land as a permanent field were discussed by taking the case of South Kalimantan.

View full abstract

In the tropical forest areas the endogenous development mechanisms would be hardly formed, because the areas have been under the influence of exogenous economic forces as the areas have been the periphery regions in the periphery countries. The patterns of changes in forest utilization in the tropics, however, do not seem to be uniform. This paper describes and considers the changes in swidden agriculture and the customary law concerning the utilization of the forest products, based on the field surveys at the Kenyah Dayak and the Buginese villages in East Kalimantan, the Wana villages in Central Sulawesi and a village in Siberut island.
Traditional types of swidden agriculture, which produce subsistence crops under the condition of the low population density, whether recurrent type or pioneer type, seem to change toward unsustainable land utilization in the course of economic development along with population increases and the infiltration of cash economy, because the practices concerning the use of swiddens are not so strict as customary law would imply.
In utilizing the forest products, it is crucial whether the customary law has developed well or not before going through the economic development. The areas where the customary law have developed well will possibly develop endogenously, or form the conditions, suitable to peculiar ecosystems, for everybody as individual human being to make good use of the possibilities through satisfying the basic human needs based on their own tradition, referring to exogenous knowledge, technology, institution, etc.. Even in the society with elaborately developed customary law, however, it is uncertain how long the customary law will be effective, because of the contradiction with the national law and the influence of radical economic development. It seems necessary to form the system where forest dwellers could manage the forests with the assurance of the long term right of utilization.

View full abstract