Tree Leucaena Research Articles

Improving productivity of arabica coffee genotype G1 through potassium fertilization

Abstract One of the determinants of coffee productivity is the availability of nutrients in the soil, with potassium being among the essential nutrients required to enhance productivity. Therefore, this study aimed to determine the optimal potassium fertilizer dosage needed to increase the productivity of Arabica coffee plants of the G1 genotype. This study was conducted in the experimental garden of Syiah Kuala University in Bener Meriah Regency, Aceh Province, Indonesia using a Non-Factorial Randomized Block Design (RBD). A total of 132 Arabica coffee trees of genotype G1 were randomly selected based on specific criteria, such as 8 years of age, planted with a spacing of 2.5 x 2.5 m, pruned properly, grown under moderately dense shade of Leucaena trees, and well-maintained. The treatments included a control group without potassium fertilizer and multiple groups receiving potassium fertilizers at 29, 58, 87, 116, and 145 kg K2O per hectare. These potassium sources were derived from potassium chloride (KCl) fertilizer containing 58% K2O and Rice Husk Ash containing 2% K2O, respectively. This resulted in 11 treatment units, each comprising 3 coffee trees replicated 4 times, for a total of 44 treatment units. The results showed that potassium fertilization from KCl and Rice Husk Ash had a significant effect on the increased productivity of Arabica coffee genotype G1. The effect was observed based on the number of productive branches per tree, clusters per branch, fruits per cluster, fruits per tree, the weight of red cherries per tree, parchment coffee per tree, green beans per tree, and the green beans yield at 14% moisture content. The optimal potassium fertilizer dosage was 145 kg K2O per hectare, equivalent to 250 kg KCl or 156.25 g KCl per tree. Additionally, it was observed that potassium sourced from KCl was more effective than potassium from Rice Husk Ash due to the longer time the latter takes to improve the productivity of Arabica coffee.

Thinning enhances success of enrichment planting with selected tree species under a pure stand of Leucaena leucocephala

Increasing the biodiversity of Leucaena leucocephala (hereafter leucaena) stands without losing the benefits provided by the forest structure is a challenge for adaptive management. Here, we report the survival and growth (height, stem, and canopy diameter) of five Atlantic Forest tree species planted underneath a pure stand of the exotic leucaena, which was broadcast sown 35 years before in a 0.6 ha area. Two treatments were compared: thinning (cutting all leucaena trees in 4‐m wide rows, where seedlings were planted) and control (seedlings planted under leucaena canopy), with four replicates each (20 seedlings per plot, four per species, 2‐m spaced). The five species selected were long‐lived emergent trees from seasonal forests, with broad canopy, evergreen, and shade‐tolerant. These traits were expected to allow their survival and growth, and, later on, to shade out the leucaena trees. Seven years after planting, survival was high for all species (around 80%), not differing between treatments or species. On average, stem diameter, height, and crown diameter were, respectively, 69, 44, and 36% higher in thinned than in control plots. Response to thinning differed between species in growth, with Gallesia integrifolia and Luehea divaricata standing out. Our results demonstrate that the species used for enrichment planting, selected by their suitable functional traits, can successfully survive under leucaena stands. Reducing competition by thinning, however, is crucial to enhance their growth. Despite the benefits from thinning, enrichment success strongly depends, therefore, on the abilities of the species selected to face the ecological filters acting on the target ecosystem.

Alley Cropping and Organic Compost: An Efficient and Sustainable Agro-Ecological Strategy for Improving Turmeric (Curcuma longa L.) Growth and Attributes

Alley cropping is a sustainable agriculture approach that improves ecosystem services while also promoting biodiversity. The current study was conducted over two seasons, 2019/2020 and 2020/2021, to examine the impact of leucaena–turmeric alley cropping and organic compost addition as agroforestry systems on the growth, yield and characteristics of the turmeric crop. Alley cropping included four treatments: control (turmeric as sole crop), turmeric cultivated between leucaena trees pruned at 1 m height, leucaena trees pruned at 1.5 m height and unpruned leucaena trees. Meanwhile, organic compost rates were control (received recommended NPK) and 17 and 34 m3 ha−1. This study’s results showed that growing turmeric in between rows of unpruned leucaena resulted in maximum turmeric plant growth, production and characteristics. Minimum turmeric growth and yield parameters were recorded with plants grown between pruned leucaena at 1 m and those where the turmeric was the sole crop. In addition, compost addition at 34 m3 ha−1 led to maximum growth, yield and attributes of the turmeric crop. Compost addition and alley cropping were shown to be an effective and sustainable agro-ecological system for increasing turmeric output and quality. The study demonstrated the importance of selecting the appropriate crop–tree combination in this system and it was discovered that leguminous leucaena trees significantly contributed to improving fertility and nutrient availability, which in turn improved the growth characteristics of turmeric, particularly the leaf-area index and its nutrient content, which are beneficial to the characteristics of the rhizome yield and curcumin content.

The role of leucaena in cattle fattening and breeding production systems in Eastern Indonesia

Cattle farming in West Nusa Tenggara province, Indonesia (NTB) is essential to support the high demand for beef cattle in Indonesia. Leucaena was introduced to smallholders as a high-quality feed to increase cattle production in NTB. A survey was conducted with both leucaena-using and non-leucaena-using smallholder cattle farmers in Sumbawa and West Sumbawa districts, NTB to understand the role of leucaena in NTB smallholder cattle enterprises (mixed breeding/fattening) and the effect of leucaena toxicity on cattle performance, especially cow-calf production. We found that farmers using leucaena feeding systems were able to keep more cattle than farmers using a traditional feeding system (9.1 vs 6.1 head/household). Many leucaena-using farmers (50.1 %) use leucaena for fattening cattle only. Other cattle classes (growers, breeding cows and bulls) were fed leucaena strategically, such as during the dry season (59 % of leucaena-using farmers) and at specific stages of pregnancy and lactation (41 % of leucaena-using farmers). Leucaenausing farmers in rainfed areas planted more leucaena (4,500 vs 1,984 trees) and fattened more bulls (5.8 vs 3.5 head/ household) than farmers in high-rainfall areas. Transmigrant Balinese farmers planted significantly more leucaena trees (7,500 vs 2,354 trees) and raised more fattening bulls (7.8 vs 3.7 head/household) than the local Sumbawanese farmers. Most Balinese farmers had been practising leucaena feeding systems since they migrated to Sumbawa, for a long as 3 decades. Most leucaena-using farmers (74 %) had observed symptoms of illness associated with leucaena toxicity in their cattle such as hair loss and salivation. Few farmers feeding leucaena to breeding cows (5 %) reported instances of reproductive failure. Almost all non-leucaena-using farmers (93 %) reported symptoms of illnesses associated with plant toxicities (among other potential causes), most commonly skin lesions, diarrhoea, cataract, and listlessness. It was concluded that the priority use of leucaena in Sumbawa was for fattening cattle rather than breeding cattle. Leucaena supports smallholder farmers in Sumbawa to have more intensive, productive and income-earning cattle enterprises, but questions remain over whether it should be used for feeding breeding cows.

Short rotation coppice of leguminous tree Leucaena spp. improves soil fertility while producing high biomass yields in Mediterranean environment

The use of woody nitrogen-fixing plant species as multipurpose and energy crops aims to enhance biomass yield while improving soil properties. Yet, the effectiveness of this option is still under debate especially the use of short rotation cropping in water and nutrient limited environments. This study investigated whether short rotation coppicing of four taxa of multipurpose biomass woody legume Leucaena spp. can improve soil conditions when grown for biomass under a Mediterranean environment. Biomass yield, mineral composition and heat value of the biomass and the mineral and organic matter content of soil were evaluated. Under favorable growing conditions, woody dry biomass production was up to 29 Mg ha−1 year−1 with slight but significant differences between the four taxa that were tested. After 11 years of cropping, the soil showed higher fertility and microbial activity compared to the uncropped plot. Leucaena cultivation increased soil nitrogen by 35 %, dehydrogenase activity by 98 %, and organic matter and carbon content (by 41 %). Annual cuttings resulted in the highest biomass production, followed by two and three year cuttings. The mineral composition and the calorific capacity of woody biomass make it suitable for commercial use as an energy source (generating on average 151 MW h ha-1 year-1). In conclusion, short rotation coppicing of nitrogen-fixing woody species results in high biomass production rates with the restoration of degraded soils, constituting a sustainable agroforestry system for rural areas.

Leucaena leucocephala: A fast-growing tree for the Malaysian particleboard industry

Leucaena leucocephala (Lam) de Wit is a fast-growing tree species often used as lead (shade) tree that can be cultivated in Malaysia. This species has potential as an alternative resource for the Malaysian furniture and panel board industries in the coming years because of a shortage of the current frequently used raw material (rubberwood). A study on growth performance and potential as particleboard resource material was done. In terms of growth performance, the preliminary study indicated that Leucaena trees grew at a rate of 44% from the first month to the forth month and 43% from 6 to 12 months. As for particleboard manufacturing, Leucaena: Rubberwood admixture bound with urea formaldehyde (8%, 10%, and 12% resin content) to a density of 700 kg/m3, showed promise of usability when all boards pass the Type P2 board requirement of EN312:2010. In general, L. leucocephala wood is a potential raw material for the manufacture of wood composites.

First record of the seed beetle <i>Merobruchus paquetae</i> (Chrysomelidae, Bruchinae) in the exotic tree <i>Leucaena leucocephala</i>

We record for the first time the host association of the seed beetle Merobruchus paquetae with the invasive legume tree Leucaena leucocephala. This species of beetle was associated in Colombia to the native legume tree Pseudosamanea guachapele.

Leucaena feeding systems in India

Keynote paper presented at the International Leucaena Conference, 1‒3 November 2018, Brisbane, Queensland, Australia.Since its introduction to India in 1976 Leucaena leucocephala ssp. glabrata has spread rapidly, especially in the last couple of decades, mainly due to its use as either firewood or pulpwood. Use of its foliage for feeding livestock has been mainly a by-product of this activity. The foliage is highly nutritious because it has high protein concentration and good palatability, and the tree can withstand repeated defoliation. Research carried out by Indian scientists on leucaena has focused on mainly agronomic management, agroforestry studies of mixed cropping systems, mimosine toxicity, germplasm testing and economic evaluation. Feeding leucaena has had a positive impact on the dairy industry in particular. It is rarely purchased for fodder and is usually poached by smallholders from existing plantations, most of which are established by animal rearers for their own purposes. More widespread use of leucaena for fodder could be achieved in India by introducing varieties with either reduced seed production or sterile ones, which can be easily propagated vegetatively. In addition, psyllid resistance, suitable mechanized harvesting methods and training livestock owners in proper management of leucaena trees should help in making this high quality fodder more popular in India.

Seed rain along a gradient of degradation in Caribbean dry forest: Effects of dispersal limitation on the trajectory of forest recovery

AbstractQuestionsTropical dry forests that experience severe disturbances (e.g., fires) often remain degraded for long time periods, during which non‐native grasses and trees dominate. One barrier to native tree regeneration in degraded areas may be seed dispersal limitation. To better understand how dispersal limitation influences recovery from degradation, we tested whether the mode and rates of seed dispersal differed in degraded sites dominated either by the exotic tree Leucaena leucocephala or open areas dominated by introduced pasture grasses. We also tested whether L. leucocephala stands facilitate the recruitment of native trees by increasing their seed input compared to open grass areas.LocationGuánica Commonwealth Forest, Puerto Rico.MethodsSeed rain was measured for one year in traps located within five vegetation types that ranged in degree of forest degradation from open grass to intact native forest.ResultsIn open grass areas, seed rain density was similarly low for L. leucocephala and abiotically dispersed native trees (mean [95% CI] = 50.9 [15.1–171.0] vs. 34.2 [10.3–113.5] seeds m−2 year−1), whereas it was even lower for animal‐dispersed native trees (0.14 [0.03–0.67] seeds m−2 year−1). Compared to open grass areas, L. leucocephala‐dominated stands, even those with grass understories, had higher seed rain density of animal‐dispersed trees (43.0 [12.9–143.6] seeds m−2 year−1), but not abiotically dispersed trees (20.8 [6.3–68.5] seeds m−2 year−1).ConclusionsThe dominance of L. leucocephala in disturbed Caribbean dry forests does not appear to be mediated by disproportionate seed arrival in open areas compared to native tree seeds. Rather, subsequent factors such as seed and seedling survival likely favor L. leucocephala in highly degraded areas. Since L. leucocephala stands increase the seed rain of animal‐dispersed native trees, retaining them in highly disturbed Caribbean dry forests may facilitate the regeneration of native forests.

When a seed-feeding beetle is a predator and also increases the speed of seed germination: an intriguing interaction with an invasive plant

Bruchine beetles are usually considered seed predators, particularly because these beetles consume the seed embryo and kill the seeds. Previous studies suggest that under certain conditions, these insects do not kill the embryo. In this study, we asked whether the germination speed of seeds of the invasive tree Leucaena leucocephala is enhanced by the seed-feeding beetle Acanthoscelides macrophthalmus (Coleoptera: Chrysomelidae: Bruchinae). We also tested whether differences in germination between attacked and intact seeds could be related to seed size. We finally examined whether the number of larvae per seed affected seed germination and whether seedling emergence patterns were similar to those exhibited by germination. We found that compared to intact seeds, proportionally faster germination occurred in seeds attacked by A. macrophthalmus in 14 of the 26 populations studied. In addition, those populations that presented greater germination speed in the attacked seeds during the evaluation time also had the largest seeds. Similar to the germination experiments, seedling emergence was faster in the attacked compared to the intact seeds. Our findings show that the germination speed of L. leucocephala seeds can be enhanced by A. macrophthalmus. However, this effect is much more intense when a single larva develops inside the seed. In evolutionary terms, it is possible that the selection for larger seeds is favoured, increasing the speed of seed germination and contributing to predator satiation at the seed level. However, this effect could be minimized by the production of many seeds by L. leucocephala plants, causing predator satiation by “masting” effects, which would favour the selection for higher seed numbers.

Productivity Challenge of Soils Along the Slopes of Mount Oku in Cameroon

Soil fertility is the major determinant of output in Oku today. The objective of this study is based on the techniques used by rural farmers to maximize output on an advanced deteriorating soil. This phenomenon has not only impinged on output but limits the quality of food available to this agricultural dependent people. Over the years, soil constituents became exhausted as a result of continuous cultivation. The planting of Leucaena and Tephrosia tree species in farms played a challenging role in ameliorating output. The methodology adopted by this study centered on the administration of questionnaires, observation, interviews and field visits. A total of 38 Leucaena and Tephrosia trees were counted on four nearby farms. In these farms selected maize seeds were planted at regular ring distance around the trees. The results obtained revealed that, quality maize was harvested at closer perimeter to the soil fertilizer trees. This strategy maximized sustainable soil management and promoted agro forestry activities in Oku. The study concluded that soil fertility is improved upon by planting soil fertilizer trees in farms. At least one of these tree species is identified in farms in Oku.

Biochar enhancement of facilitation effects in agroforestry: early growth and physiological responses in a maize-leucaena model system

Biochar, or pyrolyzed organic matter intended for use as a soil amendment, has a variety of properties of interest from the perspective of agroforestry, in particular its potential to increase soil C sequestration and enhance yields by increased retention of soil mineral nutrients. Nitrogen-fixing legumes commonly show large growth responses to biochar, and we hypothesized that combinations of legumes and non-legumes would show increased enhancement of yields in mixture due to enhanced facilitation related to increased nutrient retention. This hypothesis was tested in a glasshouse pot trial involving the leguminous tree leucaena (Leucaena leucocephala), and maize (Zea mays) grown for 120 days in mixture and monoculture in both an unamended soil and soil amended with a slow-pyrolysis coconut husk biochar at 10 t/ha. Responses were quantified in terms of biomass production and partitioning, leaf-level gas-exchange, leaf chlorophyll content, and (for leucaena) root nodule formation. Consistent with predictions, leucaena showed more pronounced growth and physiological responses to biochar than did maize. The system also showed increased total biomass yields relative to monocultures in the two-species mixtures with biochar (relative yield in mixture [RYM] = 1.69; 95% CI 1.41–1.81), but not in the control treatment (RYM = 1.25; 95% CI 0.93–1.76), and positive effects of biochar on yield were generally greater for both species when grown in mixture. Growth responses to biochar were most pronounced for stem and root biomass, and growth responses were consistent with changes in leaf-level photosynthesis and chlorophyll content. In addition, biochar had large effects on biomass partitioning, enhancing stem allocation in both species. Our results suggest that biochar additions may augment facilitative interactions in agroforestry and intercropped systems on acidic, nutrient-deficient soils by enhancing system nutrient retention.

Loss of NifQ Leads to Accumulation of Porphyrins and Altered Metal-Homeostasis in Nitrogen-Fixing Symbioses

Symbiotic nitrogen fixation between legumes and rhizobia involves a coordinated expression of many plant and bacterial genes as well as finely tuned metabolic activities of micro- and macrosymbionts. In spite of such complex interactions, symbiotic proficiency remains a resilient process, with host plants apparently capable of compensating for some deficiencies in rhizobia. What controls nodule homeostasis is still poorly understood and probably varies between plant species. In this respect, the promiscuous Sinorhizobium (Ensifer) fredii strain NGR234 has become a model to assess the relative contribution of single gene products to many symbioses. Here, we describe how a deletion in nifQ of NGR234 (strain NGRΔnifQ) makes nodules of Vigna unguiculata, V. radiata, and Macroptilium atropurpureum but not of the mimisoid tree Leucaena leucocephala, purple-red. This peculiar dark-nodule phenotype did not necessarily correlate with a decreased proficiency of NGRΔnifQ but coincided with a 20-fold or more accumulation of coproporphyrin III and uroporphyrin III in V. unguiculata nodules. Porphyrin accumulation was not restricted to plant cells infected with bacteroids but also extended to the nodule cortex. Nodule metal-homeostasis was altered but not sufficiently to prevent assembly and functioning of nitrogenase. Although the role of NifQ in donating molybdenum during assembly of nitrogenase cofactor FeMo-co makes it essential in free-living diazotrophs, our results highlight the dispensability of NifQ in many legume species.

Symbiotic efficiency of native rhizobia in legume tree Leucaena leucocephala derived from several soil classes of Brazilian Northeast region

Symbiotic efficiency of native rhizobia in legume tree Leucaena leucocephala derived from several soil classes of Brazilian Northeast region

Spread of common native and invasive grasses and ruderal trees following anthropogenic disturbances in a tropical dry forest

IntroductionA fundamental challenge to the integrity of tropical dry forest ecosystems is the invasion of non-native grass species. These grasses compete for resources and fuel anthropogenic wildfires. In 2012, a bulldozer from the Puerto Rico Electric Power Authority cleared a 570-m trail from a state road into a mature dry forest section of Guánica Forest to control a wildfire. We monitored colonization by a non-native invasive grass (Megathyrsus maximus), a highly invasive tree (Leucaena leucocephala), and a native grass (Uniola virgata), as well as natural regeneration, along the bulldozer trail. We determined whether bulldozing facilitated colonization by these species into the forest and the extent of spread.ResultsDistance from propagule source and temporal variations strongly influenced colonization by our three focal species. Megathyrsus maximus invaded along the trail from source populations by the state road. The establishment of new colonies of M. maximus seedlings went as far as 570 m inside the forest (i.e., at the end of the bulldozer trail), but we found most new colonies within 270 m of the road. Leucaena leucocephala exhibited a similar spreading pattern. Before disturbance, Uniola virgata was distributed widely across the forest, but the highest densities were found in areas near the latter portion (> 401 m) of the bulldozer trail. Subsequently, the species formed new clumps along more than half of the trail (250 to 570 m), apparently colonizing from undisturbed patches nearby.ConclusionsBulldozing facilitated the invasion of non-native vegetation. The projected community assemblage will be more fire-prone than before since M. maximus carries fire across the landscape better than U. virgata, emphasizing the capacity of invasive plant colonization to alter local ecological processes after only a single wildfire and bulldoze event. Our results provide a valuable baseline for short-term vegetation response to anthropogenic disturbances in tropical semi-deciduous dry forests.

INFLUENCE OF HOST PLANTS, TEMPERATURE AND RELATIVE HUMIDITY ON OCCURRENCE AND POPULATION DYNAMIC OF BLACK VINE THRIPS, RETITHRIPS SYRIACUS MAYET AT EL QASSASEEN DISTRICT, ISMAILIA GOVERNORATE

this study was conducted at El Qassaseen district, Ismailia Governorate in the farm of El Qassaseen Horticulture Research Station and a surroundin area during the period from 8th Aug., 2013 till 11th Jan., 2016 to determine the specific host plants, occurrence ratios and periods on each host, annual population dynamic on the specific plant hosts; also to clear the effect of certain climatic factors (maximum, minimum temperature and mean of relative humidity (RH%)) on the population fluctuations of black vine thrips, Retithrips syriacus Mayet. The obtained results revealed that, this pest is found infesting two hosts: pear (Pyrus communis) family: Rosacea and persimmon (Diospyros kaki L.) family: Ebenaceae throughout the activity period extended from 8th Aug. 2013 till 9th Jan.2014; then migrate to infest the two permanent evergreen trees ( alternative hosts), Leucaena (Legume Forage Tree), (Leucaena leucocephala) family: Fabaceae and Brazilian pepper trees (Schinus terebinthifolius (Raddi)) family: Anacardiaceae throughout the 2nd period extended from 2nd Jan until 20th Aug. 2014. After that, the thrips return again to infest the main hosts of deciduous fruit trees which raised to four hosts, grapevine (Vitis vinifera) family: Vitaceae; jatropha, (Jatropha curcas) L. family: Euphorbiaceae, pear (P. communis); persimmon (D. kaki L.); throughout an activity period extended from 6th Aug. 2014 till 7th Jan. 2015. In the same trend, the thrips insects migrate again to infest the alternative hosts, Leucaena and Brazilian pepper trees throughout the period extended from 7th Jan. until 29th Aug. 2015. After that, it moved again to infest the main four fruit trees hosts throughout an activity period extended from 10th Aug. 2015 till 11th Jan. 2016. The thrips insects moved between main and alternative hosts throughout two overlapped periods observed through January and august months of the three study years. Also, highly significant differences appeared between averages of thrips numbers on different hosts (P˂ O.O1) with highest average numbers of 11.35, 12.83 and 13.06 individuals /leaf on main host, persimmon; 13.02 and 15.98 individuals /compound leaf of alternative host, Leucaena trees. In the same trend, the highly occurrence ratios of 67.33, 38.02 and 32.62 % were recorded on main host, persimmon; while, of 78.09 and 79.78 % (of the total numbers of thrips on the alternative hosts) wererecorded on leucaena trees. The highest population densities of R. syriacus were recorded throughout October on main hosts (where the weekly mean of maximum temperature during the two years of 2014 and 2015 ranged 26.44-35.08 C°, the weekly mean of minimum temp. ranged 17.4-22.59 C° and weekly mean RH% ranged 64.99 - 80.36) and throughout March on alternative hosts (where the max. temp. during the two years of 2014 and 2015 ranged, 22.03-34.25 C°, min. temp. ranged 10.68-21.95 C° and mean RH% ranged 62.62-67.59). In accordance to the correlation and regression analysis, the effects of tested climatic factors (Max., min. temp. and mean RH %) varied as activity period and host plant, where the highest combined effect was (EV %) = 83.15%, recorded on Leucaena trees during 2015, while the lowest, EV% =59.98% was recorded on pear trees during 2014.

Making a Bad Situation Worse: An Invasive Species Altering the Balance of Interactions between Local Species.

Biological invasions pose a significant threat to biodiversity, especially on oceanic islands. One of the primary explanations for the success of plant invaders is direct suppression of competitors. However, indirect interactions can also be important, although they are often overlooked in studies on biological invasion. The shrub Leucaena leucocephala is a widespread island invader with putative allelopathic effects on the germination and growth of other species. We quantified the impact of Leucaena on plant communities richness on an oceanic Brazilian island and, through nursery experiments, investigated the potential for allelopathic effects on the germination of Erythrina velutina, a native species that is often absent from stands of Leucaena. Additionally, in a manipulative field experiment, we examined the direct and indirect effects (mediated by the native species Capparis flexuosa) of the invader on the development of Erythrina. The species richness in invaded sites was lower than in uninvaded sites, and Capparis was the only native species that was frequently present in invaded sites. In the nursery experiments, we found no evidence that Leucaena affects the germination of Erythrina. In the field experiments, the odds of Erythrina germination were lower in the presence of Leucaena litter, but higher in the presence of Leucaena trees. However, the survival and growth of Erythrina were considerably inhibited by the presence of Leucaena trees. The isolated effect of native Capparis on the germination and growth of Erythrina varied from positive to neutral. However, when Capparis and Leucaena were both present, their combined negative effects on Erythrina were worse than the effect of Leucaena alone, which may be attributed to indirect effects. This study provides the first empirical evidence that the balance of the interactions between native species can shift from neutral/positive to negative in the presence of an exotic species.

Analisis keragaman genetik Ganoderma spp. yang berasosiasi dengan tanaman kakao dan tanaman pelindungnya menggunakan Random Amplified Polymorphic DNA (RAPD) Genetic diversity analysis of Ganoderma spp. associated with cocoa and its shade trees using Random Amplified Polymorphic DNA (RAPD)

AbstractInformation on genetic diversity of Ganoderma spp.causing root rot disease in crops is important to developa proper strategy for the control of Ganoderma disease. Theobjectives of this research were to study the genetic diversityof Ganoderma spp. associated with cacao and its shade trees(Albazia faltacaria, Swietenia mahogani, Adenatheramicrosperma and Leucaena leucocephala) by randomamplified polymorphic DNA (RAPD) analysis. Fourty fivesamples of Ganoderma spp. were used in this research. Theresults showed that DNA amplification using 10 arbitraryoligonucleotide primers produced 220 DNA fragmentsshowing polymorphisms. The cluster analysis showed that 45number of Ganoderma samples had a high variability with thecoefficient value ranged from 0.71 to 0.91. Further analysisusing Winboot software showed that three groups ofGanoderma spp. had a high degree of confidence (>50 %),which were Ganoderma samples from sengon (Paraserianthessp.) of Tasikmalaya, sengon (Paraserianthes sp.) ofPalembang, and mahogany of Jember; whereas the othergroups of samples had a low degree of confidence (<50%).AbstrakInformasi tentang keragaman genetik Ganoderma spp.sebagai penyebab penyakit busuk akar pada tanamanperkebunan sangat diperlukan untuk menerapkan strategiyang tepat dalam upaya perlindungan tanaman perkebunan.Penelitian ini bertujuan untuk mengetahui keragaman genetikGanoderma spp. yang berasosiasi dengan tanaman kakao dantanaman pelindungnya (sengon, mahoni, saga dan lamtoro)dari berbagai wilayah di Indonesia menggunakan penandamolekuler random amplified polymorphic DNA (RAPD).Sebanyak 45 sampel Ganoderma spp digunakan dalampenelitian ini. Amplifikasi DNA dengan 10 primer terpilihmenghasilkan 220 fragmen DNA yang menunjukkan adanyapolimorfisme. Hasil analisis menunjukkan adanya keragamanyang cukup tinggi di antara sampel Ganoderma spp. daripohon inang dan wilayah yang berbeda, dengan nilaikoefisien 0,71-0,91. Berdasarkan analisis bootstrapdiketahui bahwa tiga kelompok sampel Ganoderma spp.memiliki tingkat kepercayaan yang tinggi (>50 %) yaitukelompok Ganoderma spp. yang berasosiasi dengan pohonsengon asal Tasikmalaya, sengon Palembang, dan mahoniJember; sedangkan pengelompokan lainnya menunjukkmenunjukkan tingkat kepercayaan yang rendah (<50 %).

Environmental performance of cocoa production from monoculture and agroforestry systems in Indonesia

Indonesia is seeking to expand its cocoa production to meet the increased international demand. However, this effort faces economies of scale and ecological challenges. This research aims at evaluating environmental performance of cocoa production from cocoa monoculture and cocoa-agroforestry by life cycle assessment based on ISO 14040 and 14044, with adaptation for local impact indicators. This study defined cocoa-agroforestry as raw and sequential of cocoa–coconut and cocoa–rubber agroforestry, combined with shading trees Leucaena sp. and Gliricidia sepium. The analysis considered cocoa production at farm level, from cradle to on-farm gate boundary for 1 metric tonne of cocoa pod. The results showed that cocoa–coconut agroforestry had the least contribution to global impact categories of global warming, acidification and eutrophication, accounting for 3.67E+01 kgCO2-eq, 4.31E-02 kgSO2-eq, and 2.25E-05 kgPO4-eq respectively. Cocoa–coconut agroforestry also had the highest organic carbon and soil organic matter, conditions supporting the growth and activity of beneficial soil microbeds (Pseudomonas sp. and Trichoderma sp.). In addition, total land equivalent ratio of cocoa–coconut agroforestry had the highest value at 1.36, indicating a highest yield advantage was gained. Therefore, cocoa–coconut agroforestry could be a wise option to promote environmental sustainability of cocoa cultivation.

Macaria mirthae Vargas et al (Lepidoptera: Geometridae): Confirmation of the Use of an Invasive Host Plant in the Northern Atacama Desert of Chile Based on DNA Barcodes.

Macaria mirthae Vargas et al (Lepidoptera: Geometridae) is a geometrid moth native to the northern Atacama Desert of Chile. Its oligophagous larvae are associated with native hosts of the plant family Fabaceae, the most important of which is Acacia macracantha. The invasive tree Leucaena leucocephala (Fabaceae) was recently recorded as a host plant for M. mirthae based on morphology. The taxonomic status of larvae collected on A. macracantha and L. leucocephala was assessed using sequences of the DNA barcode fragment of the cytochrome c oxidase subunit I (COI) gene. Genetic divergence between samples from the host plants was found to be 0%-0.8% (Kimura 2-parameter model). Neighbor-joining and maximum likelihood analyses were also performed, including additional barcode sequences of Neotropical geometrid moths from GenBank and BOLD databases. Sequences of the larvae from both host plants clustered in a single clade with high statistical support in both analyses. Based on these results, it is concluded that M. mirthae has effectively expanded its host range and its larvae are currently feeding on the exotic tree L. leucocephala. Additionally, the importance of this new host association in a highly disturbed habitat is briefly discussed in terms of the field biology of this native geometrid moth.