Effects of Various Frequencies and Concentrations of Stimulation on
Performance of Some Hevea Clones
*S. Mak
1, S. Yin
1*and R. Lacote
2 AbstractThe experiments have been conducted at the Experimental Station of the Cambodian Rubber Research Institute (CRRI) in Kampong Cham province to evaluate the response of three Hevea clones (GT 1, RRIM 712 and IRCA 230) to different concentrations and frequencies of stimulation under S/2 d4 tapping system. The results over a period of seven years showed that the high yield was obtained in S/2 d4 ET 2.5% Pa(1) 12/y in clones RRIM 712, IRCA 230 and GT 1. The yields were increased without increasing the incidence of TPD in the clones tested. The four rounds of stimulation with 3.3% Ethephon was not sufficient, which would be increased to six rounds.
Keywords: Hevea, clone GT 1, IRCA 230, RRIM 712, yield, stimulation.
1Cambodian Rubber Research Institute (CRRI), P.O. Box 1337, Phnom Penh, Cambodia. 2CIRAD-PERSYST TA-B34/02, 34398 Montpellier Cedex 5, France.
*e-mail: [email protected] ; [email protected]
INTRODUCTION
Since the inception of tapping, efforts have been made to improve the process of latex harvesting. Yield stimulation offers opportunities for reducing frequency of tapping from high frequency tapping (HFT) to low frequency tapping (LFT) and increasing land and labour productivity (Sivakumaran and Chong, 1984, Lukman 1995, Gohet, 1996, Thanh, 1996 and 1998, Vijayakumar et al., 2001). Intensity of stimulation was modulated according to clonal characteristics (Serres et al.,1988, Jacob et al., 1989, Gohet et al., 1995 and 1996, Lacote et
al., 2010) ).
In Cambodia, the S/2 d3 7d/7 tapping system with stimulation has been used in routine. Cambodian Rubber Research Institute (CRRI) has been developing research on tapping system to evaluate the influence of stimulation on yield with given low frequency tapping S/2 d4. The objective of the experiment is to investigate the effects of various frequencies and concentrations of stimulation on performance of some hevea clones in Cambodia. However, major approaches in the latex harvesting research for bringing down the cost of production are the increase of land productivity, increase of tapper productivity and increase of economic life of the trees.
MATERIALS AND METHODS
In 2006, CRRI established a research on low frequency tapping system S/2 d4 with variation of frequencies of ethephon stimulation and the experiment was laid out in the Experimental Station to identify the optimum stimulation frequencies under tapping of half spiral cut in panel BO-1and now changed to panel BO-2 in different clones such as clone GT 1, RRIM 712 and IRCA 230.
Experimental details:
1. Clone : GT 1 (6m x 3m, 555 trees/ha) Panel: BO-2
Year of planting: 1997 Design: RCBD
Year of panel opening: 2004 Number of replications: 4 Year of trial beginning: 2006 Plot size: 120 trees Number of treatments: 4
2. Clone : RRIM 712 (6m x 3m, 555 trees/ha) Panel: BO-2
Year of planting: 1997 Design: RCBD
Year of panel opening: 2004 Number of replications: 4 Year of trial beginning: 2006 Plot size: 108 trees Number of replications: 4
3. Clone : IRCA 230 (6m x 3m, 555 trees/ha) Panel: BO-2
Year of planting: 1997 Design: RCBD
Year of panel opening: 2004 Number of replications: 4 Year of trial beginning: 2006 Plot size: 90 trees Number of replications: 4 Note: the trials for all clones were started after two years of tapping.
Details of treatments are given below:
T0 = S/2 d4 7d/7.ET 2.5%.Pa(1). 4/y (control) T1 = S/2 d4 7d/7.ET 2.5%.Pa(1). 8/y T2 = S/2 d4 7d/7.ET 2.5%.Pa(1). 12/y T3 = S/2 d4 7d/7.ET 3.3%.Pa(1). 4/y
Table 1 Agenda of stimulations:
Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb
4/y S S S S
8/y S S S S S S S S
12/y S S S S S S S S SS SS
S: Stimulation
SS: Stimulation two times per month
Method of stimulation was panel application and concentrations of ethephon applied were 2.5% and 3.3%, obtained by water dilution (5% stock of commercial ethephon product).
Yield data of individual plots were recorded in all tappings. Latex weight was determined and converted into dry weight using DRC values estimated gravimetrically. Estimation of dry weight of cup-lump was based on 50% DRC. Other parameters recorded are incidence of TPD, girth increment.
In CRRI Station, rainfalls for ten years from 2004 to 2013 were lower than 1800 mm/year (Table 2).
Table 2 Rainfall from 2004 to 2013 in CRRI Station (mm/year) Years Months 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Jan 0 8.0 2.5 10.0 45.8 0.6 19.5 0.0 21.8 0.0 Feb 0 0 17.0 12.5 4.4 59.6 0.0 0.0 4.3 0.5 Mar 0 20.5 34.0 87.4 71.6 44.0 28.4 42.4 34.3 11.9 Apr 65.5 97.9 67.5 21.0 108.2 161.4 71.3 138.6 159.0 88.6 May 46.7 83.4 280.5 221.6 321.6 231.0 121.0 339.1 238.9 272.1 Jun 184.0 124.7 230.7 149.9 130.4 146.8 202.2 139.6 161.2 139.7 Jul 68.3 219.1 215.8 112.2 125.8 303.0 153.5 189.4 358.7 314.9 Aug 148.8 125.2 296.0 192.4 167.8 124.6 161.7 240.5 95.4 223.0 Sep 332.7 228.5 356.2 230.6 245.2 228.2 139.1 219.1 422.1 210.5 Oct 127.2 318.4 166.5 186.8 190.0 189.4 291.1 114.3 144.8 - Nov 13.0 165.8 8.0 51.2 266.4 29.4 57.9 72.4 104.4 - Dec 0.0 56.5 0.0 1.8 0.4 0.0 1.3 16.0 0.0 - Total 986.2 1448.0 1674.7 1277.4 1677.6 1518.0 1247.0 1511.4 1744.9 1261.2
source : Cambodian Rubber Research Institute (CRRI, September 2013)
RESULTS AND DISCUSSION
+ Clone GT 1:
Data on yield (g/t/t) performance of clone GT1 under different frequencies of stimulation during the seven years revealed that yield was higher for the treatment T2 than treatments T0, T1 and T3 and an average yield (g/t/t) of treatment T2 showed significant difference to T0 and T3 at the 5% level (Table 3).
Table 3 Effect of stimulation frequencies on dry rubber yield (g/t/t) of clone GT 1 (Panel BO-1 and BO-2)
during the seven years of trial
Years 1 2 3 4 5 6 7 Average Clone GT 1 (g/t/t) 2006 2007 2008 2009 2010 2011 2012 2006-12 T0: S/2 d4 7d/7 ET 2.5% Pa(1) 4/y 24.9 a 33.2 b 32.4 a 36.1 a 37.8 b 41.8 b 36.8 a 34.7 c T1: S/2 d4 7d/7 ET 2.5% Pa(1) 8/y 28.8 a 38.5 ab 38.1 a 42.3 a 44.0 ab 54.9 a 47.4 a 42.0 ab T2: S/2 d4 7d/7 ET 2.5% Pa(1) 12/y 30.6 a 45.3 a 38.2 a 44.9 a 47.4 a 57.4 a 46.2 a 44.3 a T3: S/2 d4 7d/7 ET 3.3% Pa(1) 4/y 24.3 a 37.3 b 33.2 a 40.1 a 37.1 b 49.3ab 43.0 a 37.8 bc LSD = 0.05 2.78 3.30 3.97 5.81 3.65 4.83 4.82 2.62
The data on yield (g/t) performance of clone GT1 under different frequencies of stimulation during the seven years revealed that yield was higher for the treatment T2 than treatments T0, T1 and T3 (Table 4).
Table 4 Effect of stimulation frequencies on dry rubber yield (g/t) of clone GT 1 (Panel BO-1 and BO-2)
during the seven years of trial
Years 1 2 3 4 5 6 7 Average Clone GT 1 (g/t) 2006 2007 2008 2009 2010 2011 2012 2006-12 T0: S/2 d4 7d/7 ET 2.5% Pa(1) 4/y 1591.2 a 2255.5 b 2396.5 a 2379.4 a 2643.8 b 3384.0b 2762.3 a 2487.5 c T1: S/2 d4 7d/7 ET 2.5% Pa(1) 8/y 1845.1 a 2619.6 ab 2815.6 a 2793.1 a 3082.4 ab 4448.6 a 3554.4 a 3022.7 ab T2: S/2 d4 7d/7 ET 2.5% Pa(1) 12/y 1953.5 a 3078.9 a 2826.2 a 2963.5 a 3319.6 a 4650.8 a 3462.3a 3179.3 a T3: S/2 d4 7d/7 ET 3.3% Pa(1) 4/y 1554.4 a 2536.8 b 2456.0 a 2646.4a 2595.9 b 3988.1 ab 3226.3 a 2714.9 bc LSD = 0.05 178.47 225.22 294.59 384.10 255.11 391.97 362.21 190.23
Note: Values followed by same letter are not significantly different from each other.
Average yield of clone GT 1 during seven years revealed that the yield (g/t) for treatment T2 was higher than treatment T0, T1 and T3 and showed significant difference to treatment T0 and T3 at the 5% level. The result of experiment in Ambanad and New Ambadi estate of India in the initial five years from 1995 to 2000 of clone GT 1 showed that the yield in treatment T3 (S/2 d4 6d/7 ET 2.5% Pa (1) 8/y) was equal to 1093 kg/400 trees = 2732.5 g/t (IRRDB, 2003). If comparison to performance yield for treatment T1 (S/2 d4 7d/7 ET 2.5% Pa(1) 8/y) of experiment in CRRI revealed that the yields were slightly different; this may depend on soil condition.
+ Clone RRIM 712
As for the other clones, data were collected on yield (g/t/t) performance during the seven years applying different stimulation frequencies. It was clear from these data that the resulting yield was higher for treatment T2 as compared to treatments T0, T1 and T3. The yields under treatments T1 and T3 were higher than treatment T0 The average yield in treatment T2 was significant difference to all treatments at the 5% level (Table 5).
Table 5 Effect of stimulation frequencies on dry rubber yield (g/t/t) of clone RRIM 712 (Panel BO-1 and
BO-2) during the seven years of trial
Years 1 2 3 4 5 6 7 Average Clone RRIM 712 (g/t/t) 2006 2007 2008 2009 2010 2011 2012 2006-12 T0: S/2 d4 7d/7 ET 2.5% Pa(1) 4/y 44.2 b 48.5 b 44.9 b 39.0 c 40.8 c 47.0 c 42.4 b 43.9 c T1: S/2 d4 7d/7 ET 2.5% Pa(1) 8/y 51.2 ab 52.0 b 54.2 a 45.5 ab 45.7 b 57.7 b 50.5 ab 51.0 b T2: S/2 d4 7d/7 ET 2.5% Pa(1) 12/y 58.9 a 62.3 a 55.9 a 48.6 a 51.4 a 67.9 a 53.3 a 56.9 a T3: S/2 d4 7d/7 ET 3.3% Pa(1) 4/y 48.7 b 58.0 a 47.4 b 41.5 bc 44.2 bc 57.5 b 48.7 ab 49.4 b LSD = 0.05 4.16 2.33 2.42 2.34 1.99 3.72 4.12 1.92
Note: Values followed by same letter are not significantly different from each other.
In addition, the yield (g/t) performance during the seven years under different frequencies of stimulation also showed that treatment T2 resulted in a higher yield than treatments T0, T1 and T3, with significant differences to that treatments at 5% level. The resulting yields were higher for treatments T1 and T3 as compared to T0 (Table 6).
Table 6 Effect of stimulation frequencies on dry rubber yield (g/t) of clone RRIM 712 (Panel BO-1 and
BO-2) during the seven years of trial
Years 1 2 3 4 5 6 7 Average Clone RRIM 712 (g/t) 2006 2007 2008 2009 2010 2011 2012 2006-12 T0: S/2 d4 7d/7 ET 2.5% Pa(1) 4/y 3095.7 b 3348.1 b 3318.8 b 2732.3 c 3095.2 c 3575.1c 3269.8 b 3205.0 c T1: S/2 d4 7d/7 ET 2.5% Pa(1) 8/y 3582.7 b 3585.2b 4013.1 a 3183.2 ab 3472.9 b 4380.3 b 3890.7 ab 3729.8 b T2: S/2 d4 7d/7 ET 2.5% Pa(1) 12/y 4124.5 a 4298.2 a 4133.9 a 3401.7 a 3909.8 a 5156.2 a 4103.5 a 4161.1 a T3: S/2 d4 7d/7 ET 3.3% Pa(1) 4/y 3405.8 b 3996.6a 3509.9 b 2904.5 bc 3358.9 bc 4368.4 b 3745.2 ab 3612.7 b LSD = 0.05 291.31 160.64 179.07 163.66 151.81 282.84 317.51 141.60
Note: Values followed by same letter are not significantly different from each other.
Regarding the average yield (g/t) of this clone during the seven years, it became clear that treatment T2 gave a significantly higher yield than treatments T0, T1 and T3 at the 5% level.
+ Clone IRCA 230:
In a similar way, data were collected on yield (g/t/t) performance for clone IRCA 230 under different frequencies of stimulation during the initial seven years of tapping. These data clearly showed that higher yields were obtained for treatment T2 as compared to treatments T0, T1 and T3 (Table 7).
Table 7 Effect of stimulation frequencies on dry rubber yield (g/t/t) of clone IRCA 230 (Panel BO-1 and
BO-2) during the initial seven years of trial
Years 1 2 3 4 5 6 7 Average Clone IRCA 230 (g/t/t) 2006 2007 2008 2009 2010 2011 2012 2006-12 T0: S/2 d4 7d/7 ET 2.5% Pa(1) 4/y 30.6 ab 47.9 b 35.5 a 38.0 b 32.5 b 44.0 d 42.5 b 38.7 b T1: S/2 d4 7d/7 ET 2.5% Pa(1) 8/y 36.6 ab 54.3 ab 44.1 a 46.3 a 39.7 a 60.0 b 55.9 a 48.1 a T2: S/2 d4 7d/7 ET 2.5% Pa(1) 12/y 39.4 a 58.1 a 44.6 a 47.2 a 41.3 a 67.9 a 55.7 a 50.6 a T3: S/2 d4 7d/7 ET 3.3% Pa(1) 4/y 28.4 b 50.9 ab 35.6 a 38.2 b 33.9 b 53.9 c 48.2 ab 41.3 b LSD = 0.05 4.38 3.81 5.10 3.07 1.75 2.57 3.97 1.68
Note: Values followed by same letter are not significantly different from each other.
Similar concussions can be derived for yield (g/t/) performance of clone IRCA 230 under different frequencies of stimulation. The yield was higher for treatment T2 than for treatments T0, T1 and T3, which the differences was significant to treatment T0 at 5% level (Table 8).
Table 8 Effect of stimulation frequencies on dry rubber yield (g/t) of clone IRCA 230 (Panel BO-1 and
BO-2) during the initial seven years of trial
Years 1 2 3 4 5 6 7 Average Clone IRCA 230 (g/t) 2006 2007 2008 2009 2010 2011 2012 2006-12 T0: S/2 d4 7d/7 ET 2.5% Pa(1) 4/y 2021.6 ab 3255.5 b 2624.5 a 2581.1 b 2628.6 b 2729.7d 3269.0 b 2730.0 b T1: S/2 d4 7d/7 ET 2.5% Pa(1) 8/y 2416.4 ab 3691.4 ab 3262.7 a 3148.8 a 3219.1 a 3720.1 b 4300.7 a 3394.2 a T2: S/2 d4 7d/7 ET 2.5% Pa(1) 12/y 2601.0 a 3949.0 a 3301.4 a 3207.8 a 3345.2 a 4206.5 a 4288.3 a 3557.0 a T3: S/2 d4 7d/7 ET 3.3% Pa(1) 4/y 1875.3 b 3457.1 ab 2629.5 a 2598.5 b 2745.0 b 3341.8 c 3709.9 ab 2908.1 b LSD = 0.05 288.38 259.28 377.62 209.08 141.82 159.48 305.78 120.77
Note: Values followed by same letter are not significantly different from each other.
The average yield (g/t) of clone IRCA 230 during the initial seven years of tapping for treatment T2 was higher than for treatments T0, T1 and T3, which the differences was significant to treatment T0 and T3 at 5% level (Table 8).
Figure 1 showed that the yield (g/t) for treatment T2 at first to sixth year of clone RRIM 712 was higher than that of clones GT 1 and IRCA 230 and the yield at seventh year was slightly lower than clone IRCA 230 but was still higher than yield of clone GT 1. The yield (g/t) for treatment T2 at sixth year of clone GT 1 was higher than of clone IRCA 230.
Figure 1 Yield comparison of clones GT 1, RRIM 712 and IRCA 230 for treatment T2
during the initial seven years (2006-2012)
The average yields (g/t) for the treatment T2 of clones GT 1, RRIM 712 and IRCA 230 during the initial seven years were higher than other treatments of all clones. Figure 2 showed that the average yield (g/t) for treatment T2 of clone RRIM 712 was higher than that of clone GT 1 and IRCA 230.
Figure 2 Average yields (g/t) of clone GT 1, RRIM 712 and IRCA 230
for treatment T2 during initial seven years
Table 9 shows that girth increment (cm) for treatments T0, T1, T2 and T3 of clone GT 1 were grown bigger than girth increment (cm) of clone RRIM 712 and IRCA 230. The percentage of tapping panel dryness (%TPD) for
treatments T0, T1, T2 and T3 of clones GT 1 and RRIM 712 were higher than the percentage of TPD for all treatments of clone IRCA 230.
Table 9 Result of girth increment (cm) and %TPD for seven years from 2006 to 2012
GT 1 RRIM 712 IRCA 230 Treatments Girth Increment (cm) %TPD Girth Increment (cm) %TPD Girth Increment (cm) %TPD T0: S/2 d4 7d/7 ET 2.5% Pa(1) 4/y 9.5 11.1 7.1 14.1 7.0 3.8 T1: S/2 d4 7d/7 ET 2.5% Pa(1) 8/y 9.6 21.2 7.2 17.9 7.0 4.7 T2: S/2 d4 7d/7 ET 2.5% Pa(1) 12/y 9.4 13.2 7.2 13.7 6.9 5.0 T3: S/2 d4 7d/7 ET 3.3% Pa(1) 4/y 10.7 15.8 6.4 16.3 7.3 3.9 CONCLUSION
High yield clones are possible with S/2 d4 7d/7 frequency if higher frequency of stimulation are imposed.
For medium yielding clone like GT 1, high stimulation per year can be given without adverse effects.
Productivity of all clones can be increased considerably by 8 to12 stimulation per year under S/2 d4 7d/7 system of tapping.
Yield stimulation under S/2 d4 7d/7 can be practiced in all clones (medium and high yielding) by 8 to 12 stimulation per year.
Incidence of tapping panel dryness is lower for clone IRCA 230 as compared to clones GT 1 and RRIM 712.
ACKNOWLEDGEMENTS
I would like to thank the Cambodian Rubber Research Institute for funding this research, and its researchers and staffs for contributions to this experiment and thanks to researchers and staffs working in Rubber Physiology and Latex harvesting Division for hard working to collect successfully data from experimental plots.
REFERENCES
1. Gohet, E., Prévot, J.C., Eschbach, J.M., Clément, A., and Jacob, J.L. (1995) Hevea latex production:
relationship with tree growth, influence of clonal origin and ethrel stimulation. Proceeding of the Internetional
Rubber Research and Development Board Symposium on Physiology and Molecular Aspects of Breeding of Hevea brasiliensis,1995, Penang, Malaysia, pp. 200-210.
2. Gohet, E., Prévot, J.C., Eschbach, J.M., Clément, A., Jacob, J.L. (1996) Clone, growth and stimulation: latex production factors. Plantation Recherche Développement, (3), pp. 30-38.
3. IRRDB, International Workshop on Exploitation Technology, 15-18 December, 2003, table 12, p. 30. 4. Jacob, J.L., Prévôt, J.C. Roussel, D., Lacrotte, R., Serres, E., d'Auzac, J., Eschbach, J.M., and Omont, H. (1989). Yield-limiting factors, latex physiological parameters, latex diagnosis and clonal typology.
In "Physiology of Rubber Tree Latex"(J. d'Auzac, J-L. Jacob and H. Chrestin,eds.), pp. 345-403. CRC Press Inc, Boca Raton, Florida.
5. Lacote R., Gabla O.R., Obouayeba S., Eschbach J.M., Rivano F., Dian K., Gohet E. (2010).
Long-term effect of ethylene stimulation on the yield of rubber trees is linked to latex cell biochemistry. Field
crops research, 115 (1) : 94-98.
6. Lukman, H.J.G, (1995) To increase the yield of small holder rubber by application of appropriate exploitation system. Indonesian Journal of Natural Rubber Research, 13, (3), pp. 208-211.
7. Serres, E., Clément, A., Prévôt, J.C., Jacob, J.L., Commère, J., Lacrotte, R., and Eschbach, J.M. (1988). Clonal Typology of laticiferous producing vessels in Hevea brasiliensis. In CR. Int. Rubb.Res.Dev. Board,
Expl. Physiol Amél. Hevea. J.L. Jacob and J.C.Prévôt, ed., IRCA-CIRAD, Montpellier, pp. 231-246.
8. Sivakumaran and Chong, K., (1984). Yield stimulation in rubber: current status and improvements for enhanced productivity. Proceeding of the International Planters Conference, 1994, Malaysia, pp. 369-408. 9. Thanh D.K., Sivakumaran, S. and Wong, K.C. (1996) Long term effect of tapping and stimulation frequency on yield performance of rubber clone GT1. Juournal of naturalRubber Research, 11, (2), pp. 96-107.
10. Vijayakumar, K.R., Thomas, K.U., and Rajagopal, R and Karunaichamy, K., (2001) Low frequency tapping systems for reductions in cost of production of natural rubber. Planters' Chronicle,97, (11), pp. 451-454.
