ABACA Activities in the Philippines - Unido

More documents

Recommendations

Info

Ref. No. CFC/FIGHF/09 CFC/UNIDO/FIDA 34 1. Fiber yield, biomass – measured by weight per unit area 2. Loss in yield as a measure of host resistance – estimated based on a control which could be obtained from agronomic evaluation trial. Compute losses in yield due to diseases. Use the equation, % Loss = (Yield of healthy plants - yield of diseased plants)/ Yield of healthy plants x 100. Yield of healthy plants can be from agronomic trials. Loss is an indication of tolerance. When two varieties have the same amount of disease but different losses in yield, it means that the one with the lower loss is more tolerant/resistant. Analysis of data Disease incidence on the selected varieties were observed through qualitative description of the kind of symptoms manifested on 20 samples in each replication from the time of planting. The percentage disease incidence were statistically analyzed particularly analysis of variance (ANOVA) to compare possible tolerance/resistance of the varieties. The rate of disease development and areas under the disease progress curve to determine quantitative differences brought about by the different types of resistance was also done and to ascertain the relationship between disease incidence and plant growth development, regression and correlation analyses were undertaken. The regressions were performed on means of infection rate, AUDPC, incubation time over four replications with the disease incidence as the dependent variable. Regression model with predetermined combination of predictors was tested. The resulting equation: Y disease incidence = a + b x 1 + b x 2 + b x 3 where a = intercept or constant b = coefficient value x 1 = mean incubation period x 2 = mean infection rate x 3 = mean AUDPC The resulting analysis was assessed by aptness of residual plot, coefficient of determination and F test. Multiple regression analysis was also done to determine the effect of independent variables (incubation time, infection rate and AUDPC) on the expression of the disease (bunchy-top and mosaic) manifested on the eight varieties. Yield loss relative to the degree of host tolerance to the virus was also analyzed. Ranking of entries Resistance analysis was used to rate the varieties. Lower infection rate, smaller AUDPC, flatter disease progress curve, longer incubation time were considered as the criteria in evaluating varieties for resistance. When resistance was observed, it was considered as the primary parameter in varietal selection. The varieties were evaluated based on a Selection Index = ƒ(fiber yield, Y disease incidence ) where resistance to the viruses and good agronomic characteristics are given relative weights. Since viral diseases constitute the current problem, more weights were put on resistance. 4. Results and Discussion 4.1 Result of evaluation of varieties used for the regional screening There are about 200 abaca varieties/accessions widely planted in the different parts of the country in Luzon, Visayas and Mindanao where the prevailing conditions suit abaca production. These varieties are characterized and maintained in FIDA seedbanks and experiment stations in Sorsogon (Luzon varieties), Leyte (Visayas varieties) and Davao City (Mindanao varieties). Same germplasm are kept in genebank collection of the National Abaca Research Center in Leyte State University and Abaca Seedbank Collection in the College of Forestry, University of the Philippines Los Baños (UPLB). Together with a plant breeder from the Institute of Plant Breeding in UPLB, primary data on the agronomic characteristics of the varieties/accessions generated by FIDA seedbanks were used to select varieties used for the regional screening. Among the collection, 40
Ref. No. CFC/FIGHF/09 CFC/UNIDO/FIDA 35 varieties/hybrids/accessions were chosen based on the average yield of 800 kg/harvest/year and the varieties are listed as follows; Luzon varieties 1. Musa tex 50 (Lausigon x Maguindanao) 5. Tinawagan pula 8. Luno 2. Musa tex 51 (Itom x Lausigon 45) 6. Tinawagan puti 9. Socorro 3. Musa tex 52 (Itom x Lausigon 39) 7. Lausigon 10. Lagonoyon 4. Abuab Visayas varieties 1. Inosa 5. Lagurhuan 9. Musa tex 80 (Linawaan x Linino) 13. Sogmin 2. Itisog 6. Linawaan 10. Musa tex 81 (Linawaan x Laylay 14..Soglin 3. Laguis 7. Laylay 11. Soglagur (Sogmin x Lagurhuan) 15. Sinamoro 4. Layahon 8. Minenonga 12. Tangongon-visayan. 16. Putian Mindanao varieties 1. Bongolanon 5. Tangongon 9. Kutay-kutay 13. Putian-Jolo 2. Bontang (Bongolanon x Tangongon) 6. Tange 10. Kaunayan 14. Kutay-kutay-Jolo 3. Maguindanao 7. Puti 11. Igit 4. Maguino (Maguindanao x Inosa) 8. Pula 12. Parang 4.2 Result of evaluation of varieties in the regional screening trials Out of the 40 varieties evaluated based on high yield for the regional screening, only 38 varieties were evaluated of which ten (10) varieties were screened in Albay, 16 varieties in Leyte and 12 varieties in Davao due to difficulty in propagating the planting materials needed for the trial. All the varieties identified were observed for tolerance/resistance to the diseases and those which really showed relatively high degree of severity were completely eliminated. The experimental plants were observed and infection rate, incubation time and disease incidence were noted and computed. An abaca plant grown in Albay, infected with bunchytop disease (BTD) caused by BTV showed stunted growth, rosette arrangement of stiff narrow, erect leaves emanating from the upper end of the pseudostem and the leaves are starting to show abnormal color (darkgreen or uneven distribution of green leaf color) (Fig. 1). 4.2.1 For the bunchy-top trial 4.2.1a Albay The bunchy-top trial for Luzon varieties was conducted in Tabiguian, Tabaco, Albay. Out of eight Luzon varieties planted, only five were included in the analysis and these are: Musa tex 50, Musa tex 51, Lausigon and Abuab. Luno, Lagonoyon and Socorro were not included because of low survival rate. Figure 4 shows the constructed disease progress curve for bunchy-top infection in abaca varities in Albay. The computed percent infection are as follows; Musa tex 50, 31.90%; Lausigon, 25.80%; Fig. 1. Stunted abaca plant showing rosette arrangement of stiff, narrow erect leaves and abnormal leaf color during early stages of growth.
Page 1: ABACA Improvement of Fiber Extracti
Page 4 and 5: Ref. No. CFC/FIGHF/09 CFC/UNIDO/FID

ABACA Activities in the Philippines - Unido

Create successful ePaper yourself

Delete template?

Save as template?