Nutrient accumulation in bean and fruit from irrigated and non-irrigated Coffea canephora cv. Conilon

R E G U L A R A R T I C L E *Corresponding author: Fábio Luiz Partelli, Universidade Federal do Espírito Santo, Centro Universitário Norte do Espírito Santo, Departamento de Ciências Agrárias e Biológicas, Bairro Litorâneo, CEP: 29932-540, São Mateus, Espírito Santo, Brazil. E-mail: partelli@yahoo.com.br Received: 03 February 2016; Revised: 10 March 2016; Accepted: 13 March 2016; Published Online: 21 April 2016 Covre, et al.: Nutrient in bean and fruit from Coffea canephora Emir. J. Food Agric ● Vol 28 ● Issue 6 ● 2016 403 Serrano et al., 2011; Partelli et al., 2014.). The retained nutrient amounts by coffee plants changes according to the location, time of year, age, organs and the tissues within the same plant (Bragança et al., 2007) and maturation cycle (Partelli et al., 2014). The coffee’s fruiting process comprises a sequence of physiological events and morphological changes ranging from fl ower induction to fruit maturation, having a high demand for mineral nutrients (Carelli et al. 2006; Bragança et al, 2007; Melo et al. 2011; Partelli et al., 2014). During development, fruits are strong sinks for minerals and carbohydrates, therefore competing with other plant organs and often leading to nutritional defi ciencies in those organs of the same coffee plant (Reindeer and Maestri, 1985; Carvalho et al., 1993; Laviola et al., 2008). Physically adequate soil for coffee production can display low availability of some nutrients due to either actual defi ciency or factors which limit the absorption, frequently leading to defi ciency symptoms in coffee crops (Martinez et al., 2003; Partelli et al., 2006; Laviola et al., 2007a). An alternative to acceptable nutrition of crops is the use of organic nutrient sources, such as coffee husk (Serrano et al., 2011). Additionally, it has low cost, especially when the produced coffee is locally processed. The need for renewable options, available in-situ and lower cost for the supply of nutrients for the crop is increasingly important due to the need for more sustainable agriculture (Chemura, 2014). By knowing the amounts of allocated nutrients in Conilon coffee tissues, valuable information can be gathered to assist the planning of the coffee crop fertilization program, as well as its use as a complement to conventional fertilization. Therefore, this study aims at to quantify the concentration and accumulation of nutrients in the husk, beans and fruits from irrigated and non-irrigated Conilon coffee trees. MATERIALS AND METHODS Plant material and experimental conditions The experiment was performed in southern Bahia, Brazil (42’13 “S latitude and 39 ° 25’28’’W longitude) at an altitude of 108 m. Five year old plants from C. canephora cv. EMCAPA 8111 genotypes Clone 02 (Bragança et al., 2001) grown under fi eld conditions and spaced 3.5 x 1.0 m. According to Köppen classifi cation, the climate is Aw, tropical with a dry and rainy season during the winter and summer, respectively (Köppen, 1931; Alvares et al., 2014). The soil is classifi ed as Oxisol (sandy loam dystrophic Yellow Latosol) according to Embrapa (2013). Chemical and physical characteristics of the soil, at 0-20 cm layer were: P: 28.5 mg dm-3; K: 105 mg dm-3; Ca: 4.15 cmolc dm -3; Mg: 1.55 cmolc dm -3; S: 15.5 mg dm-3; B: 1.49 mg dm-3; Cu: 1.9 mg dm-3; Fe: 450 mg dm-3; Mn: 20.0 mg dm-3; Zn: 4.2 mg dm-3; pH: 6.25; H+ + Al3+: 2.85 cmolc dm -3; organic matter: 4.55 dag kg-1; total sand: 730 g kg-1; silt: 110 g kg-1; clay: 160 g kg-1; fi eld capacity: 0.19 cm3 cm-3 and permanent wilting point: 0.13 cm3 cm-3. A completely randomized design with two treatments (irrigated and non-irrigated) with 28 replicates under fi eld conditions were used. The management practices on the crop consisted in weeds control through herbicides and clipping, preventive phytosanitary management, liming, fertilization and irrigation (only on irrigated treatment). To implement the non-irrigated treatment, irrigation of the respective plot was suspended in March of 2011 in order to allow the plants acclimation to drought. In the irrigated treatment, surface drip irrigation was used with one line of emitters per plants lines, spaced every 0.5 m and fl ow of 2.0 L h-1. The air temperatures (maximum, mean and minimum), global solar radiation, rainfall and relative humidity of the air were collected at an automatic weather station located at a distance of 800 m from the experimental area (Fig. 1). The meteorological data were used to determine the reference evapotranspiration (ETo) according to the Penman-Monteith model (Allen et al., 1998). The irrigation management was adopted through water balance, based on crop evapotranspiration (ETc), rainfall measured at the site and water storage characteristics of soil. A daily soil water balance (for both irrigated and non-irrigated conditions) was calculated to identify water defi cit periods (Fig. 1). Both irrigated and non-irrigated treatments were fertilized annually with: N 500 kg ha-1; P2O5 100 kg ha -1; K2O 400 kg ha -1. The fertilizer was split and applied weekly on irrigated plants, through fertigation, whereas the fertilizer was split 10 times over the two years on nonirrigated plants. The coffee crop was conducted according to programmed cycle pruning system with four orthotropic branches (Verdin Filho et al., 2014). Nutrient accumulation measurements The fruit samples were collected during the harvest of 2012 and 2013 (two harvests), being collected 14 samples per treatment (one per plant) in each harvest. During the harvest, 50 coffee fruits were collected in each plant, being selected only mature fruits (consisting of two beans). Harvested fruits were dried in an oven with forced air at 70 oC for 72 h. Thereafter, the fruits were processed aiming at to separate the beans and husk. Afterward, these fruit parts were weighed on a precision balance to obtain the Covre, et al.: Nutrient in bean and fruit from Coffea canephora 404 Emir. J. Food Agric ● Vol 28 ● Issue 6 ● 2016 straw, bean and total fruit dry mass. Thereafter, the samples (straw, bean and fruit) were fi nely ground in a wiley mill and used to macro (N, P, K, Ca, Mg and S) and micronutrients (Fe, Zn, Cu, Mn and B) analysis following the methodology described by Silva et al. (2009). The amount of husk and bean dry mass in a processed bag of 60 kg of coffee was estimated, considering the relationship found between bean and straw from fruit. Accumulation of macro and micronutrients in the husk and beans were calculated by dry mass x the concentration of each nutrient. Macro and micronutrients accumulated in the fruits were obtained from the sum of the macro and micronutrients contained in the husk and bean. All data were submitted to a one-way ANOVA, followed by a mean using the Student’s t–test, using Genes software (Cruz, 2013). A 95% confi dence level was adopted for all tests. RESULTS AND DISCUSSION The maintenance of an adequate mineral nutrition and of the balance between the several minerals is crucial to plant development. Such preservation of adequate mineral contents and balance within the plant is determinant for the expression of stress tolerance mechanisms on coffee (Ramalho et al., 2013), and assume a particular importance under predicted future conditions of climate changes and global warming (Martins et al., 2014), which are expected Fig 1. Global solar radiation, maximum, mean and minimum air temperatures (a); rainfall, irrigation and relative humidity (b); water defi cit (in nonirrigated and irrigated treatments) and total reference evapotranspiration (ETo) (c), determined during the experimental period between July 2011 and July 2013. c b a Covre, et al.: Nutrient in bean and fruit from Coffea canephora Emir. J. Food Agric ● Vol 28 ● Issue 6 ● 2016 405 to simultaneously alter temperature and water availability to main crops, including to coffee (Rodrigues et al., 2016). The concentration and accumulation of nutrients in Conilon coffee showed no statistical differences between water treatments in husk, beans and the whole fruit (Table 1). Fruit dry mass production of Conilon coffee is not mainly infl uenced by the drought (non-irrigated plants) at the end of fruits physiological maturity stage (Table 1). The production of one ton (1000 kg) processed Conilon coffee resulted in production of 520.7 and 536.7 kg of husks by irrigated and non-irrigated plants, respectively (Table 1). Therefore, for each produced bag, the husk biomass represented ca. half of processed bean biomass, representing ca. 35% and. 65% of total fruit biomass, respectively, what agrees with Matiello et al. (2010) who claim that 2 kg Conilon coffee beans yields 1.3 kg of processed coffee. To the high yield of genotype 02 found here it would have contributed that only with perfect coffee fruit were used, that is, from fl owers which undergone complete syngamy with fertilization of the two ovules of fl ower. Additionally, the genotype 02 shows low proportion of “moca” beans (Pereira, 2015). These values are somewhat higher than those found for C. arabica genotypes that showed values in the range of ca. 43% to 59% of coffee beans yields to processed coffee (Gaspari-Pezzopane et al., 2005; Matiello et al., 2010; Palva et al., 2010). As regards the mineral contents in the fruit tissues, the macronutrient concentration of husk and beans showed no statistical difference between the irrigated and non-irrigated treatments, except for P concentration in the husk where non-irrigated plants presented a 33.3% higher value than irrigated plants (Table 2). This contrasted with the impact of extreme temperatures in mineral contents at leaf level (Ramalho et al., 2013; Martins et al., 2014), and might be linked to the strong sink effect of the fruits that could withdraw minerals from other plant organs, together with the mineral availability provided by the applied fertilization in the present experiments. The largest macronutrients concentrations in the coffee hus