Chitosan has been reported to have antimicrobial property to some pathogen species as well as an elicitor of resistance in plants , particularly Systemic Acquired Resistance (SAR). A bioassay of chitosan against Xanthomonas oryzae pv, oryzae (Xoo) was conducted to determine its antimicrobial property against bacterial blight pathogen and the optimum concentration that is most inhibitory to the pathogen. Chitosan was also tested as foliar spray to rice plants to evaluate its potential to induce SAR against bacterial blight disease. Chitosan treatments (300 ppm, 400 ppm, and 500 ppm) possessed antimicrobial property against Xoo in vitro, producing zones of inhibition which were generally significantly bigger than those of the control (streptomycin, acetic acid, and sterile distilled water) at 2, 4. and 6 days after inoculation. Chitosan-sprayed plants showed significantly shorter bacterial blight lesions which were comparable to the plants sprayed with streptomycin, and Boost, a commercial plant defense activator and a known inducer of SAR, Chitosan is found effective in reducing bacterial blight lesions in rice plants due to its antimicrobial property and also most likely due to the induction of SAR.

Structure-activity and species specificity of the three synthetic sweetpotato weevil pheromones, (Z)-3-dodecenyl-(E)-2-butenoate of C. formicarius, dodecyl-(E)-2-butenoate of C. brunneus and decyl-(E)-2-butenoate C. puncticollis and their corresponding precursor free alcohols and trans-crotonic acid were assayed on virgin males of the three weevil species in the laboratory using one-arm olfactometer with bidirectional airflow. Each of the sex pheromones was specific lo its conspecific males, however, a pheromone of a particular species may become active to another species only at higher amount to elicit the same degree of response. The free alcohol precursor of the pheromone of C. formicarius, 3-Z- dodecen-1 -ol, showed sexual stimulation on C. brunneus and C. puncticollis while dodecan-1-ol functioned as an aggregation compound. The decan-1-ol, precursor of C. puncticollis pheromone, had the lowest attraction index regardless of weevil species tested. Males of C. formicarius and C. brunneus exposed to trans-crotonic acid performed a complete series of mating behavior from antennae elevation to copulation while C. puncticollis exhibited the initial stage of mating behavior but copulation was not reached. This indicates that the crotonate part of the ester played a crucial role in activity of sex pheromone of sweetpotato weevils. The unsaturation of the aliphatic chain was only important in C. formicarius pheromone for higher level of attraction and not to the African weevil species. The dichloromethane extract of the pheromone glands containing the known sex pheromone at concentration lower than the synthetic pheromone used had higher atrraction index. This suggests the possibilty of other componds present in the pheromone boquets working synergistically for increased sexual activity. In GC and GC-MS, other compounds were detected at higher amount than the identified pheromones which may play an important role in the attraction and successful mating of the Cylas spp.

An in vitro method was developed for plant regeneration of Phalaenopsis amabilis variety and hybrid using flower stalk cuttings. Experiments were conducted to overcome persistent contamination of stalks, break bud dormancy and induce regeneration of shoots. Results showed that incorporating 50 mg/l streptomycin in agar-solidified Vacin and Went (VW) medium inactivated or killed fungal and bacterial microorganisms that may have been left after sterilizing the stalks with 95% ethyl alcohol and 20% chlorine bleach. The stalk explants cultured in VW medium added with 5 mg/1 benzylamino purine broke bud dormancy and induced the regeneration of shoots. The regenerated shoots exhibited three growth patterns, namely; vegetative, reproductive and dormant. The vegetative shoot produced multiple adventitious shoots in VW medium containing a combination of 5 mg/1 benzylamino purine and 0.1 mg/1 indole acetic acid. The regenerated shoots resembled the source plants and rooted easily in plant growth regulator-free medium. These were established in the screenhouse after acclimatization. The vegetative shoot has potential for clonal propagation of Phalaenopsis species.

A strong belief by Clavaria farmers that there is 'gold in Gmelina growing' turned out to be a huge frustration among tree out growers in southern Philippines in the late 1990s. The lack of a market study and appropriate government support system to address farmers' tree growing risks resulted in a great loss, not only financially but also in terms of local people's confidence in tree growing tn the area. A large number of tree growers returned to subsistence fanning while others opted to have their land rented out lo multi-nationals for high value crops production (including bananas and pineapples). However, the majority shifted lo fruit bearing trees. Ten farmers were interviewed using Problem in Context analysis, and they made various recommendations for government to improve the financial performance and regulatory environment for tree farming. These recommendations included the removal of the cutting permit requirements for limber grown in private woodlots, setting the wood price regulatory system 10 safeguard the interest of small tree growers, providing wood market information and strategic networks for tree growers to find alternative markets or use for their timber produce, and encouraging the private sector to establish small wood processing plants in every municipality in order lo provide ready markets for timber produce. It was also suggested that government initiate contract tree growing between the private sector and farmers' groups, provide more planting area for interested tree growers, and assist small tree farmers to form or strengthen local cooperatives.

The influence of root trainer eel] volume and seedling density, and composition of growing media was examined in relation to morphological, biomass and seedling quality parameters of four-month old planting stock of three tropical broadleaved tree species viz., Acacia catechu, Azadiractha indica and Pongamia pinnata. The study revealed that a cell volume of 90 cm3 was not sufficient for proper seedling growth of A. catechu and A. indica. However, clear-cut superiority of 300 cm3 cell volume was evident only in the case of A. indica. It appeared that root trainer pots of 150 cm3 cell volume were suitable for growth of planting stock of A. catechu and P. pinnata and 300 cm3 cell volume for A. indica. Significant differences in the growth of planting stocks were observed among growing media treatments. Overall the tree species exhibited fast growth and high biomass as well as favorable seeding quality in growing media containing 80% compost with either sand (A. catechu and A. indica) or soil (P. pinnata) than the other treatments having 50%, 60% or 100% compost.

Mt. Pangasugan which lies up to an elevation of 1,158 m ASL on the wester slope of the Central Cordillera of Leyte is one of the unexplored mountains. Sine directory of Philippine flora is still incomplete, a floristic inventory of the country remaining forest is imperative. The study was conducted to provide a checklist of existing monocot flora in Mt. Pangasugan. A total of 76 species belonging to 14 families and 51 genera were recorded. Family Araceae had the most number of genera while Family Palmae had the most number of species.

The study assessed the carbon stocks or storage within the Community-Based Forest Management (CBFM) Project in Midwestern Leyte Province. The CBFM project area stored an average carbon density of 333 Mg/ha from aboveground biomass down to the soil complex (0-lm depth). The upperstorey biomass had an average carbon density of 166 Mg/ha while 1.94 Mg/ha for the understorey biomass. In addition, floor litter carbon density ranged from 1.38 Mg/ha to 2.75 Mg/ha, root carbon density from 11.0 to 17.4, and soil carbon density from 111 to 221 Mg/ha. The huge amount of carbon stored under the CBFM project is a potential livelihood opportunity for the local people. Several organizations are interested in carbon offset projects where huge amount of fund is involved -- a situation where both farmers and the environment would be benefited.

Fusarium wilt caused by Fusarium oxysporum f.sp. cubense (FOC) is one of the problem diseases attacking abaca. The most effective way of minimizing the damage is through the use of resistant varieties.' The levels of resistance of different abaca varieties/accessions, however, have not been determined yet so this study was conducted to: 1) evaluate the reaction of eight recommended abaca varieties to fusarium wilt, 2) evaluate the reaction of abaca varieties/accessions and abaca relatives from the National Abaca Research Center (NARC) germplasm collection and production area to fusarium wilt, and 3) confirm the reaction of the identified resistant varieties/accessions in a naturally infested field. Among the 8 recommended abaca varieties, Linino showed resistance to FOC having the lowest infection, foliage yellowing and internal vascular discoloration ratings in a pot experiment. This variety was also proven resistant in the field plot screening together with 6 other accessions, namely: Alman No. 2, Alman No. 4, Tinawagan Puti No.. 2, Pakol, CES x Pacol and Pakil No. 1. Of the six, Alman No. 4, Tinawagan Puti No. 2, Linino and Pakil also showed resistance to FOC, when planted in a naturally infested field in Potahongon, Mahaplag, Leyte.

The study surveyed and collected diseased specimens of asyang [Mikania mdata(Burm. F.) B. L. Robinson] from various places of Leyte and Southern Leyte; isolated and identified the promising fungal pathogens (technically known as imcoherbicide) for the control of asyang; and determined the host range of the promising OMoherbicides. Seventeen fungal isolates were found pathogenic to asyang with 4-9 days incubation period. The isolates from the towns of Capoocan (Cap), Matalom (Mat-2) mdTomasOppus (TO) consistently caused significantly higher number of lesions per square leaf centimeter of leaf surface causing early death of leaves than the other isolates. Based on lesion and conidial characteristics, Cap isolate was identified as Ctrcasporamikaniacola Stevens while Mat-2 and TO isolates as Curvulariapallescens is. Moreover, the promising isolates were also found non-pathogenic to different host plants tested.

This study aimed to characterize the chemical and physical properties of soil, and measure the nitrate concentrations at varying soil depths in the manure disposal sites of the Leyte State University piggery and beef cattle projects. Soil chemical analysis revealed that organic matter in both the piggery and beef cattle areas were concentrated in the upper 20 cm and gradually decreased with depth. A similar trend was observed for total N where the 0-20 cm depth contained approximately 0.30% N and this level decreased in the deeper soil layers. The soil in the piggery area was slightly acidic (pH 5.30) while that in the cattle area was near neutral (pH 6.50). The entire soil profile in both sites was generally highest in nitrate at the surface and decreased with depth. Nitrate concentrations were relatively higher when there were more animals in the project site. Solution samples from 120 cm lysimeters yielded high levels of nitrate (about 200 mg L'1), an indication that this ion was being moved to greater soil depths.