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Abstrak :
Lichens, a unique symbiosis between a mycobiont and a photobiont organism, are known to produce metabolites that can be tapped as biopesticides for agriculture. Such property of the fruticose lichen Ramalina collected within Guimaras Island, Philippines was investigated in this study. A total of 195 specimens were collected and characterized using conventional morphological and chemical analyses. These lichens were identified as Ramalina farinacea, R. roesleri, and R. nervulosa. To test their potential application in agriculture, nine lichen specimens were extracted with acetone and assayed for its inhibitory activities against test bacteria, fungi, and weedy plants. All nine lichen extracts inhibited Pseudomonas aeruginosa (>19 mm ZOI) while only seven lichen extracts inhibited Staphylococcus aureus (13–19 mm ZOI). No inhibitory activity was observed among the fungal plant pathogens Fusarium oxysporum, F. solani, F. verticillioides, Colletotrichum capsici, and C. gleosporioides, and on the Gram-negative bacteria Escherichia coli and Pectobacterium carotovorum var. carotovorum. A decrease in the root (up to 27% reduction) and shoot (up to 39% reduction) lengths, and leaf chlorophyll content (up to 44% reduction) of rice weeds Fimbristylis miliacea, Leptochloa chinensis and weedy rice (Oryza sp.) were also observed. These results, therefore, suggested that the lichen crude extract from Ramalina is a potential biological control for weed management.

Abstrak :
ABSTRACT
Rapid decrease in soilfertiligtfollows clearing of forests in the humid tropics and main processes triggered by the removal of vegetation cover are reviewed. The soil of forests, cleared to provide land for cultivation of annual foodcrops are clearly showing a decrease in fertility. This unfortunate phenomena occur mainly in areas of the Indonesian Archipelago located within a belt consisting of areas with 12 months of rainfall and monthly means of 75 and more millimeters. Monocultural cultivation of annual crops in these areas is likely to deplete soil of its fertility and unlessfloodedfield techniques of cultivation is involved, it might seem very unlikely that in the future, the use ofannualfood crops to cultivate clearedforest lands, such as of common practice today, could be maintained without sacrificing soilfertiliiy and destruction. In many parts of theArchipelago, deforestation ofareas to cultivate annual foodcrops is likely to invite processes leading to the fatal destruction of its soil. Unless arboriculture . (tree cultivation), imitating tropical rainforest forests, is practiced to produce food replacing the present traditional production of staple food starch by annual crops, the degradation of the environment will continue ending in an unsustainable, prohtable agriculture. perennial tree likely to become one off the best candidate

Abstrak :
ABSTRAK
Rapid decrease in soil fertility follows clearing of forests in the humid tropics and main processes triggered by the removal of vegetation cover are reviewed. The soil of forests, cleared to provide land for cultivation of annual foodcrops are clearly showing a decrease in fertility. This unfortunate phenomena occur mainly in areas of the Indonesian Archipelago located within a belt consisting of areas with 12 months of rainfall and monthly means of 75 and more millimeters. Monocultural cultivation of annual crops in these areas is likely to deplete soil of its fertility and unless flooded field techniques of cultivation is involved, it might seem very unlikely that in the future, the use of annual food crops to cultivate cleared forest lands, such as of common practice today, could be maintained without sacrificing soil fertility and destruction. In many parts of the Archipelago, deforestation of areas to cultivate annual foodcrops is likely to invite processes leading to the fatal destruction of its soil. Unless arboriculture (tree cultivation), imitating tropical rainforest forests, is practiced to produce food, replacing the present traditional production of staple food starch by annual crops, the degradation of the environment will continue ending in an unsustainable, profitable agriculture. A perennial tree likely to become on of the best candidate for this purpose is the sagopalm. Metroxylon spp., an incredibility potent starch producer. The capacity and possibility of this starch producing parennial to fulfill the growing needs of food are reviewed here. Sagopalm plantations, or rather forests, covering a total area of not more than half the size of West-Java, would theoretically be sufficient to continually supply food starch to free no less than 400 million population from hunger. The advantages and superiorities of the sagopalm cultivation compared to other food-starch annual cultures are also discussed.