Sebatik Island, Nunukan Regency is one of the border area of Indonesia and Malaysia. Cocoa is the major commodity in this area. The objective of this study is to analyze the index and sustainability status of cocoa in the border area of Sebatik Island. The analysis uses Multi Dimensional Scaling (MDS) method, called RAP-SEBATIK (Rapid Appraisal for Cocoa on Sebatik Island). RAP-SEBATIK was employed to visualize the status of cocoa in Sebatik Island for five evaluation dimensions. This study uses primary and secondary data. The attributes that affect sensitively on the index and sustainability status was approached using the Leverage and Monte Carlo Analysis. The analysis on the five dimensions (ecology, economy, social-cultural, infrastructure and technology, law and institutional) indicate that ecological dimension is less sustainable (46.23%), economical dimension is less sustainable (48.58%), socio-culture dimension is sustainable (75.20%), infrastructure and technology dimension is less sustainable (36.39%) and dimension of law and institutional is less sustainable (40.49%). Out of 53 attributes, there were 17 attributes need to be taken care immediately because of the sensitive affect on the increase of index and sustainability status.

The qTSN4 was identified as rice QTL (Quantitative Traits Locus) increasing total spikelet number per panicle and flag leaf area but potentially reducing panicle number depending on the environment. So far, this trade-off was mainly observed at grain maturity and not specifically studied in details, limiting the apprehension of the agronomic interest of qTSN4. This study aimed to understand the effect of qTSN4 and of the environment on panicle sizing, its trade-off with panicle number, and finally plant grain production. It compared two high yielding genotypes to their Near Isogenic Lines (NIL) carrying either QTL qTSN4 or qTSN12, two distinct QTLs contributing to the enlarged panicle size, thereafter designated as qTSN. Traits describing C sink (organ appearance rate, size, biomass) and source (leaf area, photosynthesis, sugar availability) were dynamically characterized along plant and/or panicle development within two trials (greenhouse, field), each comparing two treatments contrasting for plant access to light (with or without shading, high or low planting densities). The positive effect of qTSN on panicle size and flag leaf area of the main tiller was confirmed. More precisely, it could be shown that qTSN increased leaf area and internode cross-section, and in some cases of the photosynthetic rate and starch reserves, of the top 3–4 phytomers of the main tiller. This was accompanied by an earlier tillering cessation, that coincided with the initiation of these phytomers, and an enhanced panicle size on the main tiller. Plant leaf area at flowering was not affected by qTSN but fertile tiller number was reduced to an extent that depended on the environment. Accordingly, plant grain production was enhanced by qTSN only under shading in the greenhouse experiment, where panicle number was not affected and photosynthesis and starch storage in internodes was enhanced. The effect of qTSN on rice phenotype was thus expressed before panicle initiation (PI). Whether early tillering reduction or organ oversizing at meristem level is affected first cannot be entirely unraveled. Further studies are needed to better understand any signal involved in this early regulation and the qTSN × Environment interactions underlying its agronomic interest.

Abstract. Hanafiah DS, Trikoesoemaningtyas, Yahya S, Wirnas D. 2010. Induced mutations by gamma-ray irradiation to Argomulyo soybean (Glycine max) variety. Nusantara Bioscience 2: 121-125. Induced mutation by gamma-ray irradiation is one way to increase genetic variability of plants. This research used gamma-ray irradiation on low doses (micro mutation). The aim of this research was to know the response of doses level by micro mutation on gamma-ray irridation to the growing and development of Argomulyo variety of soybean [Glycine max (L) Merr]. The seeds were irradiated by gamma-ray micro mutation doses, namely 0 gray, 50 gray, 100 gray, 150 gray, and 200 gray. Variations that were obtained of each character at generation M1 and M2 influences plants growth and development either through qualitative and quantitative that finally will influence plant’s production. The average highest genetic variation at M2 generation of soybean was on 200 Gray doses. Results of the research indicated that gamma-ray irradiation on 200 Gray doses effectively caused by plant variation genetic.

Asystasia gangetica (L.) T. Anderson is a weed commonly found on oil palm plantations and can be used as cover crop for mature oil palm plantations due to its tolerance to shading. The use of cover crop is  a soil conservation technique to support sustainable availability of soil nutrients by reducing erosion and nutrients loss, particularly during the rainy seasons. This research aims to determine the roles of A. gangetica as cover crop for measures against erosion and nutrients loss in mature oil palm plantation. This research was conducted in oil palm plantation, Unit Rejosari, PT Perkebunan Nusantara (PTPN) VII, District of Natar, South Lampung Regency from August 2014 to April 2015. The research used split block design in randomized complete block design with two factors and six replications. The main plots were ridge terrace, namely with and without ridge terrace. The sub plots were cover crops, namely with and without cover crops A. gangetica. The results show that using A. gangetica as cover crops in mature oil palm plantations effectively minimized erosion and loss of organic C, N, P, and K by 95.7%, 93.4%, 96.0%, and 90.0 %, respectively. The use of cover crop became more effective when combined with ridge terrace and reduced erosion by 94.1% and loss of organic C, N, P and K by 99.1%, 99.2%, 90.0% and 98.5%, respectively.

No abstract

The existence of oil palm plantations as a possible cause of drought in the surrounding areas in Indonesia is a critical issue. Therefore, information related to the effects of oil palm plantations on the surrounding environment in terms of soil water content (SWC) availability is needed. Soil and water conservation techniques in the form  of ridge terracing and cover crops,  such as Nephrolepis biserrata,  can be  expected to potentially improve soil water  reserves, especially in the dry-season, by accumulating water  in the rainy season.  This study aimed to study the effects of N. biserrata as cover crop, together with the potential effects of ridge terraces, on the water balance in mature oil palm plantations.  The research was conducted in mature oil palm plantations, Afdeling III block 375 (planted in 1996) and block 415 (planted in 2005), Rejosari Unit, PT Perkebunan Nusantara (PTPN) VII in Natar District, South Lampung Regency, Indonesia, from August 2014 to January 2015. The research was based on of setting up 15 m x 20 m experimental plots with the following treatments:  (i) without ridge terraces and without N. biserrata (G0T0); (ii) without ridge terraces but with N. biserrata (G0T1); (iii) with ridge terraces but without N. biserrata (G1T0); (iv) with ridge terraces and with N. biserrata (G1T1).   Hydrology parameter data were collected for each treatment plot; water balance was calculated using a water balance equation. The results showed that the use of the cover crop N. biserrata in combination with ridge terraces helped improving SWC reserves by approximately 71% and 12%, respectively.  The use of N. biserrata as a cover crop reduced the rate of water loss by percolation and run-off, by approximately 36% and 80%, respectively, in an area where the annual rainfall is above 2,400 mm per year.  The presence of N. biserrata shortened the period of SWC deficit by extending the period of a water surplus by 70 days when compared with ridge terracing alone (which reduced the period of SWC by 50 days).

Forest clove (Zyzygium aromaticum) is a type of wild clove found in Moluccas. The increasing interest of farmers in cultivating this plant leads to complete their information of morpho-agronomical characteristics which could provide diversity reflecting morpho-agronomical their distribution areas. This study aimed to characterize the morpho-agronomical traits of Forest clove plants in Moluccas. By survey, Forest clove more than 15 year old tree totalling of 50 populations were observed their 54 morpho-agronomical characteristics in two areas (Ambon and Seram) from March to June 2018. Two aromatic cloves, namely Tuni and Zanzibar were used for comparative analysis. The results showed that Forest cloves had a similarity of 78% among the population and grouped into 3 groups with a morpho-agronomical variation of 22%. On the contrary, Forest cloves and comparators (Tuni and Zanzibar) had morpho-agronomical differences of 58%. Based on the main component analysis, there were 11 most influential characters of Forest cloves (leaf size index, leaf length, leaf width, leaf area, petiole length, flower length, diameter of flower tube, ripe flower weight, fruit length, fruit width, and fruit weight) which could be descriptors for this plant species.

Heat stress is a major environmental factor limiting wheat productivity in tropical regions such as Indonesia. The objective of this study was to investigate the adaptability of introduced wheat genotypes in tropical agro-ecosystems. Sixteen spring wheat genotypes were grown at two different altitudes i.e. low altitude (176 m asl) with an average temperature of 29.8 o C located at Leuwikopo Field Experimental Station, Bogor Agricultural University, Darmaga Bogor and high altitude (1100 m asl) with an average temperature of 20.6 o C at Cipanas Field Experimental Station (Ornamental Crop Research Station), Cianjur, West Java, Indonesia from July to November 2012. Plant height, number of tillers, flag leaf area, leaf angle, days to flowering, spike number per plant, empty spikelet number, grain weight per plant and 100 grain weight were observed following the standard methods. Heat susceptibility index was calculated based on grain weight per plant. The results showed that cultivation at a low altitude, hotter environment remarkably affected wheat growth and yield, as reflected in overall reduction of plant height, reduced number of tillers and leaf area, and ultimately reduced yield and yield components for most genotypes compared to the same measures taken at high altitude in lower temperatures. Plant growth before heading was similar in both locations, but the days to flowering was longer in high altitude than that in low altitude. High temperature stress in low altitude reduced the spike number/plant, grain weight/plant, 100 grain weight and increase number of empty spikelet/spike. Based on our results for heat susceptibility index, six genotypes, namely Sbr, Ymh, Astreb/Cbrd, Astreb/Ningma, H-20 and Nias, were characterized as heat tolerant genotypes.