Application of Different Rates and Frequencies of Rejuvenator for the Treatments of Brown Bast Syndrome on Hevea brasiliensis

Background: Brown bast is one of the most serious threats to natural rubber production. It is estimated that brown bast leads to an approximately 15-20% decrease in latex yield production. There is currently no effective method to control this problem and an effort to overcome this problem is in progress by the natural rubber producing countries. Methods: This study evaluated the effect and the most suitable rate and frequency of Rejuvenator application to cure brown bast (latex dryness) and improve latex yield. The Rejuvenator treatment was applied to the selected tree with two different treatment frequencies (every 3 days and every 6 days) and three different Rejuvenator concentrations (5 g/L, 10 g/L and 5 g/L). The Rejuvenator was applied 5 times. Data on latex yield and brown bast cure were then recorded 1 month after the application of the last treatment. The treatments used were T1: No Rejuvenator, T2: 5 g/L of Rejuvenator, T3: 10 g/L of Rejuvenator, T4: 15 g/L of Rejuvenator. Result: Of all the treatment used, T3 (10 g/L) resulted in higher production of latex yield and Hevea bark nutrient concentration (g/t/t) than control. It also gave the highest nutrient content in the bark tissue. The findings of this study reveal that the optimum concentration and frequency of Rejuvenator application were established at 10 g/L every 6 days. More so, the findings explain that inadequate nutrients can be attributed to the brown bast syndrome in rubber plantation which can be prevented with the use of a rejuvenator to the tree’s bark.

Latex Harvesting Technologies Adapted to Hevea brasiliensis Muell Clones GT 1; RRIC 100 and BPM 24 Arg. (Euphorbiaceae) belonging to the Moderate Metabolism Class in the Socio-economic Context of Côte d'Ivoire

Improving the productivity of rubber trees has always been a major concern for rubber farmers. The majority of growers opt for overexploitation of the trees. This disturbs the physiological balance of the rubber trees, which leads to the recrudescence of tapping panel dryness and rather to a drop in production. To solve this problem, the present study proposes to define a latex harvesting technology (or technologies) for the moderate metabolism clone class that will allow the improvement of plantation yield and the increase of the economic life of the trees. To achieve this, the GT 1, RRIC 100 and BPM 24 clones of the moderate metabolism class were used as plant material. The results showed that the reduction in tapping frequency had no negative effect on the vegetative state of the trees. This reduction was compensated by a high number of annual stimulations, which resulted in high dry rubber production. Analysis of dry rubber production, radial rubber growth and tapping panel dryness rate indicates that the moderate metabolic class clones performed better with the latex harvesting technologies S/2 d3 6d/7 ET2.5% Pa1(1) 6/y; S/2 d4 6d/7 ET2.5% Pa1(1) 6/y and S/2 d5 6d/7 ET2.5% Pa1(1) 1.

Influence of Downward Tapping Delay on Agronomic Parameters of Upward Tapping Rubber Trees

The nine-year period of downward tapping prior to upward tapping is often considered too long and irrelevant. Thus, a study was carried out to determine the minimum time needed for downward tapping for which the agronomic parameters (rubber production, vegetative growth) of the rubber trees could best be expressed in upward tapping. Clones with slow (PB 217 and IRCA 41), moderate (GT 1) and fast (PB 260 and IRCA 18) metabolisms were used as plant material in the experiments carried out in Gagnoa, Bettié, Daoukro, San Pedro and Divo. The rubber trees were tapped in a half-spiral downward direction at different times followed by quarter-spiral upward or upward tapping. The experimental design was a Fisher block design with 9 treatments and 4 replications. The results showed that upward tapping preceded by downward tapping for 5 and/or 6 years was the best regardless of the metabolic activity class of the clone. Rubber production expressed in kg.ha-1. year-1 [Slow (5y-2675 ± 79) (6y-2488 ± 59) (T9y-2238 ± 45); Moderate ((5y-5417 ± 127) (6y-5094 ± 141) (T9y-3993 ± 58); Fast (5y-5210 ± 239) (6y-4733 ± 500) (T9y-3723 ± 245)] resulting from these upward tappings increased with an increasing gradient of clone metabolism without, however, detrimental to vegetative growth (cm. yr-1) [Slow (5 yr-3.90 ± 1.27) (6 yr-4.05 ± 1.48) (T9 yr-3.40 ± 1.13); Moderate ((5 yr-3.02 ± 0.25) (6 yr-2.80 ± 0.05) (T9 yr-2.39 ± 0.02); Fast (5 yr-4.27 ± 0.42) (6 yr-3.97 ± 0.28) (T9 yr-3.60 ± 0.05)]. These results show that upward tapping in year 6 is more advantageous than tapping in year 10.

Green productivity analysis of raw rubber production

Rubber is a well-known commodity that has been cultivated for a relatively long time in Indonesia. Rubber plays an essential role in contributing foreign exchange incomes, job opportunities, and providing industrial raw materials. In 2014, Indonesia became the second-largest rubber producer after Thailand, with a rubber yield of 3,979 tons. Increased rubber production is linear to the environmental damage that occurs so that productivity improvement tools based on environmental or green productivity are needed. This research aims to determine the factors influencing productivity level and improvement efforts by considering the environmental performance indicator. The method used is the Environmental Performance Indicator (EPI). Two expert respondents filled the weighted result, i.e., academician and head of waste treatment. The selection of alternative improvement using Benefit-Cost Ratio (BCR). The result is Multi Soil Layering (MSL) which could save the cost of IDR 253,651,626.2 per year or 70% water savings. This alternative can increase productivity by 11.12% from 76.13% to 85.25% and raise the EPI value of 0.766 from 0.201 to 0.967.

Productivity from the different rubber-based farming system models in Cotabato Province, Philippines

In the Philippines, the production of rubber cup lumps has decreased in recent years. Despite the expansion of the rubber industry for environmental and economic benefits, knowledge about the productivity and income of the rubber-based farming system is minimal. Hence, this research assessed and estimated the productivity and income of farmers from the different rubber-based farming system models in Cotabato Province, Philippines, where one of the major crops is rubber. It is important to determine the productivity of rubber and how its productivity was affected by the introduction of other crops. Through this, the income of farmers and welfare were measured. This research was carried out in 2016, where rubber was among the priority crops being promoted in the area. It investigated 3 different rubber-based farming models, namely: FM1 (rubber+ banana), FM2 (rubber+ cacao), and FM3 (rubber+ coconut). The study revealed that the farmers’ income increased by engaging in intercropping compared to the monocropping system. Thus, as the income of the farmer increases, the household’s basic needs, particularly food consumption, will be attained since income does not solely depend on rubber production but also other crops grown. The result also shows that farming model 3 provides higher returns to the farmers than the other rubber-based farming models. Hence, the study is useful for the farmers to adopt different rubber-based farming systems to increase income and reduce risks from farming. This study also serves as a basis for the policymakers for future agricultural development.

DAMPAK TEKNIK SADAP SPIRAL TERHADAP PENERIMAAN PETANI KARET DI KABUPATEN TANJUNG JABUNG TIMUR

One of the way to increase rubber productivity and its production, is by focusing to recommended tapping techniques. In East Tanjung Jabung Regency although the recommended rubber tapping technique (i.e. spiral tapping technique) had been socialized, but there were still many rubber farmers who done a non-spiral tapping techniques. This will certainly affect the amount of latex production and the rubber plants life duration. The low amount of rubber production will lead to a low number of sales, so it will have an impact on the low revenue of rubber farmers. The purpose of this study was to find out the impact of the application of spiral tapping techniques on rubber crops toward farmer. The results showed that simultaneously the independent variables had a Significant effect on the Farmer revenues. Partially, rubber production and rubber prices had showed a significant effect on farmer’s revenues, while the age of crops and tapping techniques, had no significant effect on the farmer’s revenues. Although the variables of tapping techniques did not significantly effect to the farmer revenue but it gave the higher revenue than the other tapping techniques.

Effect of Late Upward Tapping on the Productivity of the Metabolically Active Hevea brasiliensis Clone PB 260 in Southwestern Cote d'Ivoire

In order to evaluate the improvement of rubber productivity of rubber trees by late upward tapping. A study was conducted at SCASO (Société Civile Agricole du Sud-Ouest) on the PB 260 clone of the active metabolic class. The experimental set-up is a Fisher block design with eight treatments and three replications. The treatments compared were bled in reverse in the eleventh year of harvest, in quarter spiral every 3, 4, 5 and 6 days, with stimulation frequencies of 6, 8, 10, 12 and 13 times a year. The parameters measured were rubber production, isodiametric growth, sensitivity to dry notching of trees and physiological profile. The results show that the different latex harvesting technologies improve the rubber productivity of PB 260 (5469 kg.ha-1.yr-1) with a low dry-nut rate (1.2%) and satisfactory radial vegetative growth (3.9cm.yr-1). The physiological profile of the trees is balanced, but the treatments significantly influenced the different parameters except sucrose. Trees bled in S/4U d3 gave better results due to their high yield with an acceptable dry notch rate. Late reverse tapping is therefore a good latex harvesting technology for improving rubber productivity after down tapping.