Leguminous Tree Research Articles

A sustainable embedded shade management system for tea cultivation

Tea farming stands on a vast area. The quality and quantity of products enormously depend on the management and control of the environmental conditions of the tea farms. Feasible and continuous monitoring of the plantations’ parameters is needed to achieve the desired farm output. 50%-60% of the light intensity needs to be filtered on each tea plant throughout the year. Traditionally, shading is achieved by planting leguminous trees inside the farms. So it is extensively required to monitor the shading capacity continuously to overcome the degradation of the farm’s product. In this paper, a simple, sustainable shade management system is designed. The system is embedded with Atmega 2560 controller, and a wireless network has been achieved using the ZigBee module. A systematic array of LDRs acquires light Intensity. The measured parameters are wirelessly transmitted continuously to the central decision support system with associated information like locations, sensor values, etc. The proposed method is easily extensible and user-friendly.

Reinvasion of Native Invasive Trees After a Tree-Thinning Experiment in an African Savanna

Woody plant encroachment has serious negative consequences for ranchers because of the reduction in herbaceous fodder for domestic livestock. A long-term monitoring of a tree-thinning experiment was established near Magudu (northern KwaZulu-Natal, South Africa) in 1990. The objective of this experiment was to determine the optimal tree density that would maximize grass production while benefiting grasses from nitrogen fixation, hydraulic lift, and/or shade from the leguminous trees. The initial dominant species was the nitrogen-fixing tree, Dichrostachys cinerea. There were 12 plots (6 pairs) with trees removed to approximate 0, 179, 277, 428, and 625 trees ha−1, with 1 pair left as a control (unmanipulated). One plot of each replicate (except the controls) was treated with short-acting herbicide (picloram) once in 1990. We collected data on herbaceous cover and species composition, tree species composition, sizes, and mortality. We also used remote sensing to examine the patterns of herbaceous cover. Herbaceous biomass decreased as tree density increased. After 30 yr, the same dominant tree species (D. cinerea) had reinvaded all the removal plots despite the fact that several encroaching species (Vachellia karroo, V. tortilis, V. nilotica) occurred in these plots. These D. cinerea trees were mostly less dense and contained many more juvenile individuals in the cleared and partially cleared plots than those in the control plots after 30 yr. Should maximizing herbaceous cover be the goal, repeated brush management would be necessary to maintain adequate control of woody plants in these savannas.

First report of Fusarium oxysporum causing damping-off of tree bean (Parkia timoriana) seedlings in Northeastern India

Tree bean (Parkia timoriana), is an important multipurpose leguminous tropical deciduous tree species widely grown in the Northeastern states of India. The occurrence of the high incidence of damping-off (86.19%) disease was observed in tree bean nursery grown in Umiam, Meghalaya, a state in Northeastern India. Therefore, a systematic study was undertaken to record the symptoms and characterize the morphological features, the taxonomy of pathogen causing damping-off disease of P. timoriana and confirm it by pathogenicity assay. The infected seeds exhibited typical symptoms of covering with whitish mycelium and cotyledons were completely rotten in later stages of infection and emitted foul odour. Infected seedlings exhibited the symptoms of root rot followed by wilting, dried stem, and complete mortality of the seedlings. The pathogen isolated from the rotten seeds and wilted seedlings consistently showed the association of Fusarium oxysporum and its identity was confirmed based on morphological characteristics and sequences of ITS-rDNA and TEF genomic regions. Five representative isolates (TBSR 1 to 5) exhibited high similarity (>98%) to the known authentic gene sequence of F. oxysporum. The pathogenicity test produced similar to natural symptoms of wilt at 30 days after inoculation, confirming the etiological association of Fusarium oxysporum. To the best of our knowledge, this is the first to report on F. oxysporum causing damping-off disease of P. timoriana in India and worldwide.

Динамика развития ценопопуляций Albizia julibrissin Durazz., встречающихся в Азербайджане

The Albizia julibrissin Durazz. species — one of the relict leguminous trees found in the Republic of Azerbaijan has been investigated. The dynamics of the development of the cenopopulation, in which the species is widespread, was observed in the association of the Persian silk tree or pink silk tree (Albizziaetum julibrissin), and this development was not considered satisfactory. Because the defoliation of species was observed under conditions of middle and older generative age. Observations of weakened and severely weakened viability during the study indicate an unsatisfactory current and future state of the species in this area. The study of the Albizia julibrissin Durazz. species entered in the Red Book of Azerbaijan at the level of cenopopulation allows making predictions about the future population of this plant.

Frações oxidáveis do carbono em solos sob leguminosas florestais fixadoras de nitrogênio em pastagens degradadas

ABSTRACT: The chemical fractionation of C by an increasing oxidation gradient, has shown to be a fast and promising methodology to detect changes in C lability. The objectives of the present study presents were: to evaluate the level of lability of soil organic C after conversion of degraded pasture into leguminous trees; evaluate the influence of soil depth on the lability of soil organic C. The experimental area consisted of pure plantations of Acacia auriculiformis, Mimosa caesalpiniifolia and Inga sp., a pasture and a secondary forest. The oxidizable organic carbon was determined by wet oxidation and allowed separation of four fractions according to the lability level (labile, moderately labile, moderately recalcitrant, recalcitrant). Labile fraction was the predominant fraction in all vegetation covers and depths. The conversion of degraded pasture into forest legume plantations and the soil depth promoted changes in the chemical composition of C. The continuous deposition of vegetable residues 13 years of leguminous trees favored the distribution of labile and moderately labile fractions along the soil profile and the recalcitrant fraction in the topsoil. The reference covers contributed to the recalcitrant fraction in the soil below 20 cm depth.

Genetic and symbiotic characterization of rhizobia nodulating legumes in a mining area in southeast Brazil

Identification and selection of nitrogen-fixing bacterial strains for inoculation into native leguminous tree species can assist in the recovery of degraded areas. Additionally, native strains from these areas are genetic resources adapted to these conditions and are thus suitable for selection. The aim of this study was to symbiotically and genetically characterize 18 bacterial strains from the Rhizobium and Bradyrhizobium genera isolated from Machaerium nyctitans, Platypodium elegans, and Ormosia arborea grown in a nursery in an iron mining area. Three experiments were conducted under axenic conditions in a greenhouse. The nodulation capacity of the strains was evaluated by the number (NN) and dry matter (NDM) of nodules. Symbiotic efficiency was evaluated based on the following parameters: SPAD index (SPAD), shoot dry matter (SDM), root dry matter (RDM), and total dry matter (TDM) of the plants, relative efficiency (RE), shoot nitrogen content (SNC), and total nitrogen content in the plant (TNC). The atpD and gyrB housekeeping genes and the nifH gene were sequenced for phylogenetic analysis, and the nodC and nodD symbiotic genes of the strains were amplified. Out of the 18 strains, 16 were authenticated by nodulation capacity in the species of origin. The SPAD variable allowed for the detection of differences between treatments before the SDM. Additionally, the SPAD index showed correlation with TNC, and the strain Bradyrhizobium sp., UFLA01-839, which may represent a new species, was outstanding in Machaerium nyctitans. The nifH, nodD, and nodC genes were detected in UFLA01-839.

Impacts of climate change on the geographic distribution of African oak tree (Afzelia africana Sm.) in Burkina Faso, West Africa

Afzelia africana Sm – a multipurpose leguminous tree species – is threatened in West Africa – a climate change hotspot region. Yet, although the impacts of land use on this species dynamics have been widely reported, there is a little literature on the impacts of climate change on its spatial distribution. This study aimed to predict the impacts of climate change on the geographic distribution of A. africana in Burkina Faso. A total of 4,066 records of A. africana was compiled from personal fieldwork and vegetation database. Current and future bioclimatic variables were obtained from WorldClim website. For future climatic projections, six global climate models (GCMs) were selected under two emission scenarios (RCP 4.5 & RCP 8.5) and two horizons (2050 & 2070). Presence data and bioclimatic variables were processed in ArcGIS software and used in the algorithm MaxEnt (maximum of entropy) to predict the species distribution. Findings showed that maximum temperature of warmest month and mean temperature of coldest quarter mostly affect the habitat suitability of A. africana. About 25.54% of Burkina Faso land surface was currently suitable for A. africana conservation. Under future climatic projections, all the climate models predict climate-driven habitat loss of the species with a southward range shift. Across the two emission scenarios, the spatial extent of suitable habitats was predicted to decline from 9.43 to 23.99% and from 12.29 to 25% by the horizons 2050 and 2070, respectively. Habitat loss and range shifts predicted in this study underline the high vulnerability of A. africana to future climate change. Reforestation actions and the protection of predicted suitable habitats are recommended to sustain the species conservation.

Pongamia: A Possible Option for Degraded Land Restoration and Bioenergy Production in Indonesia

Indonesia has 14 million ha of degraded and marginal land, which provides very few benefits for human wellbeing or biodiversity. This degraded land may require restoration. The leguminous tree Pongamia pinnata syn. Milettia pinnata (pongamia) has potential for producing biofuel while simultaneously restoring degraded land. However, there is limited information on this potential for consideration. This paper aims to address the scientific knowledge gap on pongamia by exploring its potential as a biofuel and for restoring degraded land in Indonesia. We applied a literature review to collect relevant information of pongamia, which we analyzed through narrative qualitative and narrative comparative methods with careful compilation and scientific interpretation of retrieved information. The review revealed that pongamia occurs naturally across Indonesia, in Sumatra, Java, Bali, Nusa Tenggara and Maluku. It can grow to a height of 15–20 m and thrive in a range of harsh environmental conditions. Its seeds can generate up to 40% crude pongamia oil by weight. It is a nitrogen-fixing tree that can help restore degraded land and improve soil properties. Pongamia also provides wood, fodder, medicine, fertilizer and biogas. As a multipurpose species, pongamia holds great potential for combating Indonesia’s energy demand and restoring much of the degraded land. However, the potential competition for land and for raw material with other biomass uses must be carefully managed.

Growth rate, scrotal circumference, sperm characteristics, and sexual behavior of mixed-breed goat bucks fed three leguminous trees

Aim of study: To investigate the effect of feeding foliage of leguminous trees on growth rate, semen characteristics, and sexual behavior of bucks. Area of study: Northeastern Mexico (23°44' N, 99°8' W). Material and methods: Twenty-two young goat bucks were randomly allocated to one of four treatment groups: 33% alfalfa hay (dry matter basis), 33%; Acacia farnesiana; Leucaena leucocephala; or Prosopis laevigata foliage (n=4 for alfalfa; n=6 for the rest of groups). Main results: Average daily gain (ADG) did not differ between bucks fed alfalfa, A. farnesiana, or L. leucocephala (120 ± 26, 134 ± 37, and 103 ± 29 g/d, respectively), but ADG of bucks offered P. laevigata was the lowest (72 ± 8 g; p<0.05). Bucks fed alfalfa had the highest feed efficiency (6.59 ± 1.25 kg of feed consumed/kg of gain; p<0.05) and bucks offered leguminous trees had the lowest (average 9.85 ± 2.3). Bucks offered alfalfa, and A. farnesiana had increased (p<0.05) scrotal circumference (26.6 ± 0.4 and 25.8 ± 1.5 cm) than bucks fed L. leucocephala, or P. laevigata (24.3 ± 1.2 and 24.1 ± 2.0 cm). Mean ejaculate volume was two-fold higher in alfalfa-fed bucks than all other dietary treatments. Sexual behavior did not differ among bucks fed the different legumes. Research highlights: Foliage of both A. farnesiana and L. leucocephala could totally replace alfalfa hay for rearing growing goat bucks in confinement without affecting daily weight gain, most semen characteristics, and copulation ability. P. laevigata reduced body weight and reproductive function.

The large mimosoid genus Inga Mill. (tribe Ingeae, Caesalpinioideae) is nodulated by diverse Bradyrhizobium strains in its main centers of diversity in Brazil

Inga (Caesalpinioideae) is the type genus of the Ingeae tribe in the mimosoid clade. It comprises about 300 species, all trees or treelets, and has an exclusively neotropical distribution, with Brazil as its main center of diversity. In this study, we analyzed the diversity of 40 strains of rhizobia isolated from root nodules collected from ten species of Inga belonging to different types of vegetation in Brazil. Sequences of their housekeeping genes (dnaK, recA, rpoB, gyrB and glnII), 16S rRNA genes, internal transcribed spacer (ITS) regions, as well as their symbiosis-essential genes (nodC and nifH) were used to characterize them genetically. The ability of the rhizobia to form nodules on Inga spp., and on the promiscuous legume siratro (Macroptilium atropurpureum) was also evaluated. A multilocus sequence analysis (MLSA) combined with an analysis of the ITS region showed that the isolates were distributed into four main groups (A-D) within the large genus Bradyrhizobium. Analysis of the nodC and nifH genes showed that the isolates formed a separate branch from all described species of Bradyrhizobium, except for B. ingae. Most of the tested isolates formed nodules on siratro and all isolates tested nodulated Inga spp. Our results suggest a unique co-evolutionary history of Bradyrhizobium and Inga and demonstrate the existence of potential new species of microsymbionts nodulating this important and representative genus of leguminous tree from the Caesalpinioideae mimosoid clade.

Mixed Plantations of Eucalyptus and Leguminous Trees: Soil, Microbiology, and Ecosystem Services

Mixed Plantations of Eucalyptus and Leguminous Trees: Soil, Microbiology, and Ecosystem Services

Effects of Tree Species and Soil Enzyme Activities on Soil Nutrients in Dryland Plantations

Long-term afforestation strongly changes the soil’s physicochemical and biological properties. However, the underlying mechanism of different tree species driving change in soil nutrients is still unclear in the long-term dryland plantations of the Loess Plateau, China. In this study, samples of surface soil (0–20 cm) and woody litter were collected from five plantations (≥50 years) of Caragana korshinskii, Armeniaca sibirica, Populus hopeiensis, Platycladus orientalis, and Pinus tabulaeformis and a natural grassland, and tested for the carbon, nitrogen, phosphorus, and potassium contents, as well as the soil sucrase (SC), urease (UE), and alkaline phosphorus (ALP) activities. We found that soil nutrients, enzyme activities, and the litter’s chemical properties obviously varied among five tree species. C. korshinskii significantly increased the soil’s TC, organic carbon (OC), total nitrogen (TN), available nitrogen (AN), and available potassium (AK) by 28.42%, 56.08%, 57.41%, 107.25%, and 10.29%, respectively, and also increased the soil’s available phosphorus (AP) by 18.56%; while P. orientalis significantly decreased soil TN (38.89%), TP (30.58%), AP (76.39%), TK (8.25%), and AK (8.33%), and also decreased soil OC (18.01%) and AN (1.09%), compared with those in grassland. The C. korshinskii plantation had higher quality litter and soil enzyme activities than the P. orientalis plantation. Moreover, 62.2% of the total variation in soil nutrients was explained by the litter’s chemical properties and soil enzyme activities, and the litter phosphorus (LP) and soil ALP had a more significant and positive impact on soil nutrients. Therefore, tree species, LP, and soil ALP were key factors driving soil nutrient succession in dryland plantations. The significantly positive nitrogen–phosphorus coupling relationship in the “litter–enzyme–soil” system revealed that the improving nitrogen level promoted the phosphorus cycle of the plantation ecosystem. Our results suggest that leguminous tree species are more suitable for dryland afforestation through the regulation of litter quality and soil enzyme activities.

Altering Nitrogen Sources Affects Growth Carbon Costs in Vachellia nilotica Growing in Nutrient-Deficient Grassland Soils.

Vachellianilotica (L.) Willd. Ex Del. is a multipurpose leguminous tree that is common in grassland and savanna ecosystems in southern and eastern Africa. These ecosystem soils are reported to be acidic and nutrient-limited, specifically with regards to nitrogen (N) and phosphorus (P). The presence of this plant in these terrestrial ecosystems improves soil fertility benefiting the surrounding vegetation due to its ability to fix atmospheric N. This study seeks to understand the N-fixing bacteria symbiosis and physiological adaptations of V. nilotica in these acidic and nutrient-deficient KwaZulu-Natal soils. The soils used for this study were collected from the Ukulinga Grassland Nutrient Experiment located at the Ukulinga research farm of the University of KwaZulu-Natal, Pietermaritzburg, South Africa. Due to long-term soil nutrient addition treatments, these soils offered a diverse nutrient variation for better understanding the effects of acidity and nutrient variation on microbial symbiosis, plant nutrition, and biomass accumulation of V. nilotica. V. nilotica was able to maintain growth by relying on both atmospheric and soil-derived N across all treatments decreasing carbon (C) growth costs. There was an increased reliance on atmospheric-derived N of un-nodulated high N-treated plants. The plants grown in high N + P soils were able to nodulate with various species from the Mesorhizobium genus, which resulted in increased biomass compared to other plants. The results of this study show that V. nilotica can alter N sources to reduce C growth costs. In addition, both nodulating and free-living soil N2 fixing bacteria such as Caulobacter rhizosphaerae, Sphingomonas sp. and Burkholderia contaminans identified in the experimental soils may play an important role under P-deficient conditions.

No-till alley cropping using leguminous trees biomass: a farmer- and eco-friendly sustainable alternative to shifting cultivation in the Amazonian periphery?

No-till alley cropping using leguminous trees biomass: a farmer- and eco-friendly sustainable alternative to shifting cultivation in the Amazonian periphery?

Soil nitrogen cycling under contrasting management systems in Amazon Coffea canephora agroecosystems

AbstractRobusta coffee (Coffea canephora Pierre ex Froehner) is well suited to the humid tropical climate of the Amazon basin. It is often produced under contrasting conditions of low‐input agroforestry systems and intensively managed monocultures that differ in N constraints on productivity. We evaluated indicators of soil N cycling and coffee plant N sufficiency using a full factorial of two input managements (organic vs. conventional) and the absence or presence of the interplanted leguminous tree (LT) Erythrina spp. in a replicated robusta coffee field trial in the Ecuadorian Amazon. Activities of soil protease, three aminopeptidases, N‐acetyl‐β‐D‐glucosaminidase, cellobiohydrolase, and β‐glucosidase were evaluated in tandem with soil NH4–N and NO3–N, potentially mineralizable N (PMN), and permanganate oxidizable C (POXC), as well as coffee leaf N, leaf N/P ratio (N/P), and yield. The LT decreased soil enzyme activities, PMN, and extractable NH4–N, as well as leaf N and leaf N/P. Enzyme activities and NH4–N were greater under organic input, but conventional input resulted in greater PMN, leaf N, leaf N/P, and yield. Permanganate oxidizable C and NO3–N were similar across input and interplanting but were more variable in the presence of LT relative to its absence. Lower soil enzymatic activities, labile N pools, and leaf N in coffee systems with Erythrina spp. suggest that, although a common smallholder practice in this region, interplanting this leguminous perennial has marginal impacts on soil N cycling and may not necessarily improve N supply for robusta coffee.

Indigenous spirituality surrounding Serianthes trees in Micronesia: Traditional practice, conservation, and resistance

Spiritual connections to the natural world are fundamental to Micronesian worldviews. Structured interviews gathered ethnoecological information about Serianthes. The kosmos-corpus-praxis conceptual framework analyzed spirituality surrounding this leguminous tree and its connection with Indigenous cosmology, traditional knowledge, and practices. We can summarize the results as follows: (a) interspecies relationships expressed through rituals and oral history guide ethnobotanical practices in Belau (Palau) and Wa’ab (Yap); (b) the tree is critically endangered on Guåhan (Guam) and Luta (Rota). In Luta, the tree is celebrated as a flagship species for endangered plant recovery, while the last Guåhan tree has become a rallying point for spiritual resistance when its habitat became threatened by military plans to construct a firing range; (c) spirituality is a fundamental value for island communities; and (d) traditional knowledge holders and scholars strive to work together toward a co-production of knowledge, using spirituality as a fundamental principle toward respectful and sustainable biocultural conservation.

Growth, Physiological, Nutrient-Uptake-Efficiency and Shade-Tolerance Responses of Cacao Genotypes under Different Shades

Cacao is an understory plant cultivated in full-sun monocultures, multistrata agroforestry systems, where cacao trees are planted together with fruit, timber, firewood, and leguminous trees, or within thinned native forests. In agroforestry systems of cultivation, cacao is subjected to excess shade due to high density, excess growth, and the unmanaged pruning of shade trees. Cacao is tolerant to shade, and the maximum photosynthetic rate occurs at an irradiance of around 400 μmol m−2 s−1. However, excess shade further reduces the irradiance, which is detrimental to photosynthesis and growth functions. Intra-specific variation is known to exist in cacao for the required saturation irradiance. A greenhouse study was implemented with 58 cacao genotypes selected from four geographically diverse groups: (i) wild cacao from river basins of the Peruvian Amazon (PWC); (ii) Peruvian farmers’ collection (PFC); (iii) Brazilian cacao collection (BCC); and (iv) national and international cacao collections (NIC). All of the cacao genotypes were subjected to 50% and 80% shade where photosynthetic photon flux density (PPFD) was 1000 and 400 μmol m−2 s−1, respectively. Intra-specific variations were observed for growth, physiological and nutritional traits, and tolerance to shade. Cacao genotypes tolerant to shade were: UNG-77 and UGU-130 from PWC; ICT-2173, ICT-2142, ICT-2172, ICT-1506, ICT-1087, and ICT-2171 from PFC; PH-21, CA-14, PH-990, and PH-144 from BCC; and ICS-1, ICS-39, UF-613, and POUND-12 from NIC. Genotypes that tolerate excess shade may be useful plant types for maintaining productivity and sustainability in agroforestry systems of cacao management.

Apparent nitrogen limitation of Robusta coffee yields in young agroforestry systems

AbstractRobusta coffee (Coffea canephora Pierre ex Froehner) is an important cash crop in the lowland tropics. Similar to Arabica (C. arabica L.), agroforestry is common in these systems, though comparatively little is known about how nutrient inputs and leguminous shade trees influence Robusta nutritional status and yield. We evaluated how shading with leguminous trees across four input systems, defined largely by quantity and form (compost vs. synthetic) of nitrogen (N), phosphorus (P), and potassium (K), influenced Robusta‐based cropping systems in the Ecuadorian Amazon. Soil fertility was largely unaffected by compost and synthetic fertilizer (NPK) inputs or by shade species, and was weakly related to coffee productivity based on principal component analysis (PCA). Though litter appeared to be an agronomically appreciable source of N and P, this was only somewhat reflected in soil extractable N and P, presumably due to nutrient losses under high rainfall conditions (>3,000 mm yr−1). Patterns of variation suggest transfer of N and P from litter to soil to leaf. Conversely, litter K was unrelated to soil K, but soil K was closely related to leaf K. Robusta yields appeared to be largely N limited and were more influenced by input type (i.e., synthetic vs. organic nutrient sources) than by shade species or amount of N inputs in the form of compost or synthetic N, P, and K fertilizers. Additionally, yields across all treatments were significantly higher than regional averages, suggesting that slight investments in inputs can substantially increase productivity in maturing Robusta systems, irrespective of shade tree species selection.

Leaf litter production and litter nutrient dynamics of invasive Acacia mearnsii and native tree species in riparian forests of the Fynbos biome, South Africa

Alien invasive Australian tree species are most prevalent in the Cape Floristic Region (CFR), a global biodiversity hotspot. The plants pose a serious threat as they have replaced indigenous riparian forest vegetation, including many native tree species such as Brabejum stellatifolium and Metrosideros angustifolia along many watercourses. Black wattle (Acacia mearnsii) is a leguminous nitrogen fixer which makes significant contributions to available nitrogen in its new habitats in the fynbos, which is generally low in nutrients. However, the magnitude and the timing of litter associated nutrient input into riparian forests and woodlands and adjacent aquatic environments are not known. In this study, we assessed patterns of leaf litterfall, nutrient return to soil and resorption (N and P) of A. mearnsii and two co-occurring native species in two perennial streams in the Mediterranean-type Fynbos biome of the CFR. Leaf litterfall of A. mearnsii in the riparian forests was significantly greater compared to native vegetation, with two peaks in litterfall, one in mid-autumn, and the other in mid-summer at both streams. In contrast, the native vegetation only dropped leaves in the summer month of December. Acacia mearnsii also returned substantially more nutrients (N and P) during the peak leaf litterfall period (December) than co-occurring native species. However, the co-occurring native species were more efficient in the resorption of nutrients (N and P), with average resorption higher than the global averages of 52% for N and 50% for P. In contrast, A. mearnsii was relatively inefficient in resorbing N (30% mean N resorption) but was more efficient in resorbing P (76% mean P resorption). In addition to fixing N, it is possible that the A. mearnsii stands rely on the return of nutrient-rich leaf litter to soils and through specialized root systems and root symbionts assisting reuse of nutrients. The results highlight the differences in the nutritional economy between native riparian forest species and invasive A. mearnsii. Our findings provide further insight into the success of invasive leguminous woody tree species in nutrient-poor Mediterranean riparian forests.

Extrafloral nectary-bearing leguminous trees enhance pest control and increase fruit weight in associated coffee plants

Plant diversification is a strategy for pest management in agroecosystems. However, a major hurdle in the adoption of this management practice by farmers is related to doubts concerning its effects on crop productivity. Here we assess coffee production and natural control of coffee pests in the presence or absence of leguminous trees bearing extrafloral nectaries (Inga edulis). We compared coffee yield, coffee damage caused by coffee leaf miners (Leucoptera coffeella) and coffee berry borers (Hypothenemus hampei) and parasitism and predation of coffee leaf miners in a replicated field experiment. To evaluate the effect of proximity of the nectar source on natural control, we also assessed pest control and production along transects of 50 m extending from the Inga trees. Production per coffee plant was equal in both systems but coffee fruits were heavier in coffee consorted with Inga trees. In the most productive year, coffee production was higher on plants closer to the Inga trees. Damage caused by coffee leaf miners and coffee berry borers was lower in coffee with Inga trees and increased with distance from the trees. Parasitism of coffee leaf miners and predation by wasps did not increase in coffee consorted with Inga, neither decreased with distance from the trees. Therefore, Inga trees enhanced coffee production and increased natural control of coffee pests.