Modification of Rubber (Hevea brasiliensis Muell. Arg.) Spacing for Long-term Intercropping

Abstract

Low prices of rubber has been a serious problem to rubber growers in Indonesia. Rubber-based intercropping systems offers a practical solution to this issue and increasing overall productivity, for example by growing upland rice and maize between the rubber tree rows. This study was aimed to determine the suitable spacing in rubber planting to facilitate long-term rubber-based intercropping systems. A field experiment was established in a smallholder rubber plantation in the Tanah Laut Regency, South Kalimantan with area of 50 ha. Two planting patterns of rubber clone PB260 were tested: (1) single row planting pattern (SR) by 6 m x 3 m, and (2) double row planting pattern (DR) by 18 m x 2 m x 2.5 m. The experiment showed that the girth of the rubber trees with the SR system at the 1st tapping year was slightly larger than that in the DR system, even though statistically it was not signifi cant. The latex yield per tree of SR and DR systems were similar, however, latex yield per hectare of SR system was higher than the DR system due to a higher tree population in the SR system. The DR system was technically suitable for long term intercropping, because when the rubber tree reached 8 to 9-year-old, the light penetration was > 80% at distance of about 4 m from the rubber tree rows. Economically, DR system can increase the added values for rubber farmers because it allows long term intercropping. Rubber-based intercropping with DR system is suitable to be applied, especially by smallholders, with a marginal benefi t cost ratio of around 2.07. Keywords: Hevea, intercropping system, rubber planting pattern, spatial arrangement

Rubber-Based Agroforestry Systems Associated with Food Crops: A Solution for Sustainable Rubber and Food Production?

“…Meanwhile, the penetration of light in the DR system is > 80% within 4 m of rubber rows. Thus, the DR system is more suitable for long-term food crop production than conventional RAS (Sahuri et al, 2019;Sahuri et al, 2021).…”

“…These clones have a potential latex yield of about 2.5-3 tons per ha per year. These clones can be used for single-row as well as double-row systems with wide spacing (Sahuri et al, 2021(Sahuri et al, , 2019). In the case of RAS with a DR system, more clones should be suitable.…”

“…Interestingly, new varieties adapted to shade have been developed by the Indonesian Center for Food Crops and could be promoted for RAS with conventional density and DR system. However, cassava was shown to favor development of white root disease in rubber tree plantations (Sahuri et al, 2019). Consequently, growing cassava under rubber trees is not recommended to control white root disease outbreaks.…”

PENINGKATAN PERTUMBUHAN DAN HASIL KARET MELALUI SISTEM TUMPANG SARI BERBASIS KARET (Improvement The Growth and Yield of Rubber Through Rubber Based Intercropping System)

“…Tumpang sari diantara pohon karet berjarak tanam 6 m x 3 m atau 7 m x 3 m hanya dapat dilakukan saat pohon karet berumur 1-2 tahun setelah tanam, lebih dari itu tajuk atau kanopi pohon karet sudah menutup (Xianhai, Mingdao, & Weifu, 2012;Sahuri, 2019c). Pada pohon karet berumur > 2 tahun pengurangan cahaya dapat mencapai 50% dan tanaman sela yang ditanam di bawah naungan 50% memberikan hasil yang lebih rendah dibandingkan dengan keadaan tanpa naungan dengan penurunan hasil mencapai 60% (Fikriati, 2010;Pringadi, Toha, & Guswara, 2012;Sahuri, 2019).…”

“…Khongdee & Pansak, (2015) Sistem tumpang sari ini dapat meningkatkan produktivitas kebun karet, sehingga meningkatkan pendapatan petani. Sistem tumpang sari karet dapat meningkatkan produktivitas lahan kebun karet dan pendapatan rumah tangga petani (Romyen, Sausue, & Charenjiratragul, 2018;Sahuri, 2019c). Sistem tumpang sari karet lebih menguntungkan secara ekonomi daripada yang monokultur (Snoeck, Lacotea, Kéli, Doumbiac, Chapuseta, Jagoretd, & Goheta, 2013;Romyen, Sausue, & Charenjiratragul, 2018).…”