Field Evaluation of Pseudostem Injected Vydate L Oxamyl against Banana Nematodes under Tropical Lowland Conditions in Mindanao, Philippines

Transcription

1 Field Evaluation of Pseudostem Injected Vydate L Oxamyl against Banana Nematodes under Tropical Lowland Conditions in Mindanao, Philippines L. Trueggelmann, M.C. Obello, L.M. Bacus, N.M. Dawi*, Ph. D. R.Q. Soquita*, D.K. Alovera, J.B. Simbajon and C.S. Caharian *DuPont Far East SESSION 4: SOIL AND PLANT HEALTH INTERNATIONAL BANANA SYMPOSIUM Banana Improvement, Health Management, Use Diversification and Adaptation to Climate Change The Lees Hotel, Kaohsiung City, Taiwan November 20, 2012

2 INTRODUCTION Banana nematodes cause yield losses due to root damage by slowing down plant growth, lengthening the time to fruiting, reducing bunch weight, and decreasing the productive life of the farm. Soil application of nematicides was in the past the practical and effective method for large-scale banana plantations to control nematode population. The soon appearing problem of efficacy loss due to enhanced biodegradation after repeated application of the same a.i. was suggested to be mitigated by the rotation of products with different modes of action (Moens et al., 2004).

3 INTRODUCTION However, the negative environmental impacts and the applicator s exposure to the in general highly toxic nematicides are of increasing concern for the public, the producer, the consumer and policy makers. Based on the behavior and spatial distribution with and within the root of the most notorious nematode pests, Radopholus similis, Helicotylenchus spp. and Pratylenchus spp., it was suggested that injection of systemic nematicides into the pseudostem may replace the applications of granular to the soil and thereby overcome biodegradation problems as well as drastically reduce environmental pollution and occupational health risks to workers (Araya and De Waele, 2004).

4 Pseudostem Injection of Oxamyl an Alternative Nematicide Application Method? Gowen (1977) demonstrated that leaf applied Oxamyl can control nematodes in banana seedlings. Promising results for the pseudostem injection with the liquid formulation of Vydate L, active ingredient Oxamyl, were reported from Central America (Araya, 2004). With the aim to test if this new mode of application is also suitable for Cavendish production under Mindanao conditions a field trial was initiated, which included beside the nematicidal effect also observations on the corm weevil (Cosmopolites sordidus Germar) and aphid (Pentalonia negronervosa Cocq.) population.

5 OBJECTIVES TECHNOLOGY VALIDATION - Validate if the pseudostem application of Vydate L (Oxamyl) is also suitable for the control of parasitic nematodes of Cavendish banana in Mindanao. APPLICATION INTENSITY - Evaluate the efficacy of Vydate L in 4 and 3 cycle/year application. ECONOMIC FEASABILITY - Determine the cost effectiveness of Vydate L against banana nematodes. TREATMENTS 1-Vydate L applied 4 cycle/year 2-Vydate L applied 3 cycle/year 3-Untreated

6 Location, Duration, Experimental Design Location : Pristine Meadows Agri-Development Inc. Digos-City, Mindanao, Philippines Duration : Tow years - March 2010 to April 2012 Experimental Design : Randomized Complete Block (RCBD) No. of Replication : Six Plot size : 500 m 2 Soil Type : Clay loam Cavendish Variety : Grand Naine, permanently cropped since 1992 Population/hectare Cropping cycle : 1,860 (average) : 1.2 (10 months harvest to harvest) 1st year harvest : Plants received 2 injection cycle 2 nd year harvest : Plants received 2 to 3 injection cycle

7 TEST PRODUCT AND TARGET PEST Calibrated Philip Drencher Vydate L (Oxamyl) Radopholus similis Helicotylenchus sp.

8 PSEUDOSTEM INJECTION POINTS 1 st Point 5 ml into 20 cm height from ground 5 ml into 20 cm height from ground Non-bearing Follower Sucker Inject 2.5 ml into 10 cm height from ground 2 nd Point 5 ml into 50 cm height from ground 2.5 ml into 50 cm height from ground Drench 0.5, 1.0 and 1.0 ml per petiole

9 ROOT SAMPLING (Permanent data plant before Vydate L Application Cycle according to Davide, 2005) 1 st Left side 2 nd Right side 3 rd Center 4 th Back to Left side ROOT CLASSIFICATION

10 HARVEST DATA PARAMETERS Bunch weight Treatment Label Number of Hands Fruit Age through ribbon color Calibration

11 OTHER OBSERVATIONS BT BM Corm weevil trap Aphid population in sucker plant Bunchy-top and Bract mosaic disease infected plant Blown down plants due to nematode damaged

12 Figure 1. Average Radopholus similis count/100g root of Vydate L Nematicide Trial (March 2010 to April 2012). Radopholus similis Count/100 g root 18,000 16,000 A 14,000 AB 12,000 A Critical level 10,000 A A 8,000 B A 6,000 4,000 B B 2,000 0 Initial 1st Year 2nd Year Vydate 4 cycle/year Vydate 3 cycle/year Untreated 1 Means followed by the same letter per sampling date are not significant at P< 0.05 by DMRT

13 Figure 1. Average Helicotylenchus sp. count/100g root of Vydate L Nematicide Trial (March 2010 to April 2012). Helicotylenchus sp. Count / 100 g root 80,000 70,000 60,000 50,000 40,000 30,000 Critical level B B 20,000 _ 10,000 0 A A A Initial 1st Year 2nd Year Vydate 4 cycle/year Vydate 3 cycle/year Untreated 1 Means followed by the same letter per sampling date are not significant at P< 0.05 by DMRT B A B A

14 Treatment Application Cycle/Year Premiere Agricultural Services Corporation Table-1. Average Root Quality Status (Root Volume) as Affected by the Application of Vydate L. March 2010 to April Initial (%) Functional Roots 1st Year 2nd Year Overall (2Years) % % +(-) % % +(-) % +(-) Vydate L Vydate L Untreated % and above Damaged Roots Vydate L Vydate L Untreated Dead Roots Vydate L Vydate L Untreated

15 Table-2. Average Harvest Parameters (Bunch Weight, Hand Class, Calibration and Age) as Affected by Vydate L. March April Treatment Application Cycle/Year No. of Samples Bunch Wt. (kg) No. of Hands Initial 1st Year 2nd Year Initial 1st Year 2nd Year Vydate L b 31.3 a 31.3 b 9.9 a 9.9 a 9.5 a Vydate L b 31.7 ab 29.9 a 9.6 a 10.3 b 9.8 a Untreated a 34.0 b 26.4 a 9.7 a 10.4 b 9.3 a Treatment Application Cycle/Year No. of Samples Fruit Age (weeks) Calibration (cm) Vydate L a 10.6 a 11.1 a 45.1 a 44.9 a 44.9 a Vydate L a 10.6 a 11.1 a 45.2 a 44.6 a 44.3 a Untreated a 10.7 a 10.8 a 44.5 a 44.7 a 41.3 a 1 Means in the same column followed by the same letter is not significantly different at P< 0.05 by DMRT

16 Accumulated counts Premiere Agricultural Services Corporation Figure-3. Accumulated counts of corm weevil/trap and blown-down incidence of Vydate L Nematicide Trial. March 2010 to April Corm weevil / trap Blown-down plants due to nematode damaged Initial Months of First Year Month of Second Year Vydate L@ 4 cycle/yr. Vydate L@ 3 cycle/yr. Untreated Vydate L@ 4 cycle/yr. Vydate L@ 3 cycle/yr. Untreated

17 Figure-4. Accumulated number of suckers with aphids infestation and Bunchy Top or Bract Mosaic incidence (March 2010 to April 2012). Number of Suckers w/ Aphids Initial Months of First Year Months of Second Year Suckers w/ Aphids in Vydate L 4 cycle/yr. Suckers w/ Aphids in Vydate L 3cycle/yr. Suckers w/ Aphids in Untreated BT/BM case in Vydate L 4 cycle/yr. BT/BM case in Vydate L 3 cycle/yr. BT/BM case in Untreated Number of BT/BM incidence

18 CONCLUSION Premiere Agricultural Services Corporation Vydate L at 4 and 3 cycles per year application with the rates of 10, 7.5 and 5 ml injected to the pseudostem of nonbearing, follower and sucker plants, respectively, reduced Radopholus population from above the critical level of 10,000 per 100 g root to tolerable levels within one year and further lowered the count after two years application, whereas the population of Radopholus continually increased in the untreated plots. The nematicide at 4 application cycles per year can eventually lower down the Helicotylenchus population after one year but a further reduction was not observed in the second year.

19 CONCLUSION Premiere Agricultural Services Corporation The improvement of good or functional roots and reduction in dead roots corresponded to the reduction in Radopholus and Helicotylenchus population. However, it did not reflect immediately on the volume of marketable fruit after one year application. Instead, after the second year of application a yield increase was observed. The application of Vydate L, either of the three (3) or four (4) cycles per year did not provide a statistically significant reduction of corm weevil and aphid population and blowndown incidents. The rate of Vydate L at early plant stage might not be sufficient against these pests.

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