Scielo RSS <![CDATA[Chilean journal of agricultural research]]> http://www.scielo.cl/rss.php?pid=0718-583920160003&lang=pt vol. 76 num. 3 lang. pt <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<b>Growth and yield of chia (<i>Salvia hispanica</i> L.) in the Mediterranean and desert climates of Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300001&lng=pt&nrm=iso&tlng=pt Chia (Salvia hispanica L.) is a species with seeds that have high essential fatty acid content, which has encouraged increased crop production worldwide. However, the expansion of chia is limited because it is a photoperiod-sensitive plant adapted to areas without cold. The objective of the present study was to determine the effect of different climatic conditions on the growth, grain yield and oil production of chia under irrigation in three geographic areas of Chile: Valle de Azapa (18°30' S lat) with a coastal desert climate, normal desert climate in Canchones (20°26' S lat), and Las Cruces (33°30' S lat) with dry Mediterranean climate with marine influence, and two chia phenotypes: white and dark. Results indicated that desert conditions in the Valle de Azapa (VA) and Canchones (CH) provided better conditions for plant growth; the highest yield (> 2900 kg ha-1) and oil production (> 550 L ha-1). In Las Cruces (LC), at higher latitude, low temperatures present beginning in April coincided with the reproductive stage, affecting yield which was no more than 129 kg ha-1; thus this zone is not recommendable for chia cultivation. This study also determined an 11.8 h day length threshold for the beginning of flowering; when plants are exposed to shorter days flower initiation is more precocious, but when day length is not adequate plants only begin to flower when they have accumulated 600-700 °C d. <![CDATA[<b>Osmopriming improves seeds germination, growth, antioxidant responses and membrane stability during early stage of Moroccan alfalfa populations under water deficit</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300002&lng=pt&nrm=iso&tlng=pt Osmopriming has a positive effect on the enhancement of seeds germination and seedlings growth, especially under stress conditions. This study investigated the effects of osmopriming with polyethylene glycol on alfalfa (Medicago sativa L.) seeds germination and seedlings antioxidant responses under drought stress. Seeds of five Moroccan alfalfa populations and an American Moapa variety were used to investigate the effect of osmopriming on seeds germination, seedlings growth, activities of antioxidant enzymes and membrane stability under two water deficit levels (-0.45 and -0.75 MPa). Seeds were primed with polyethylene glycol (PEG6000) (-0.6 MPa) for 24 h at 25 °C. The results showed that treated seeds presented higher germination rate and growth of 8 d-old seedlings than untreated ones. Particularly, osmoprimed seeds of 'Adis-Tata' (Ad) and 'Riche' (Rc) populations presented the highest final germination percentages of 90.8% and 64%, respectively, and seedlings shoot and root lengths under both levels of water deficit. The priming treatment enhanced the activity of peroxidase (PO) and catalase (CAT) and reduced the malonyldialdehyde (MDA) content and the electrolyte leakage under water deficit. Generally, the success of germination was positively correlated to PO and CAT activities and the degree of membrane stability in drought tolerant populations. However, the positive effect of the osmopriming technique on alfalfa drought tolerance remains limited in some tested populations, and severe water stress could inhibit germination and cause damages of alfalfa seedlings. <![CDATA[<b>Measuring the performance of perennial alfalfa with drought tolerance indices</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300003&lng=pt&nrm=iso&tlng=pt Drought is one of the abiotic stresses that reduces agricultural production in the Mediterranean basin. The selection of crop varieties with performance adapted to water stress has been the subject of numerous studies. In this context, 16 alfalfa (Medicago sativa L.) cultivars from different origins (Algeria, Australia, France, Italy, Morocco, Tunisia, and the United States) were studied under two water regimes (irrigated and rainfed) in the Lower-Cheliff plain of Algeria. The trials focused on the performance of these cultivars according to eight drought tolerance indices. To achieve this, DM yields and water use efficiency (WUE) of a 2-yr experimental study were used. Results showed a regression in mean yields from the third to the fourth year with stress indices of 0.29 and 0.88, respectively. The study of correlations showed that DM yields were well correlated to mean production (MP) and the stress tolerance index (STI). For the two trials and based on yield and STI index, 'Mamuntanas', 'Ameristand 801S', 'Erfoud 1' and 'Ecotipo siciliano' had the best performance. However, 'Coussouls', 'Magali', 'Prosementi', 'Africaine', and 'Gabes-2355' performed poorly. Discriminant function analysis showed that the variables that discriminated in the cultivar groups for yield in the irrigated trial were modified STI, WUE, and the superiority index (Pi). The ANOVA test of cumulative yield and the regression rate confirmed that under environmental conditions similar to the Lower-Cheliff plain, 'Mamuntanas', 'Ameristand 801S', 'Erfoud 1', and 'Ecotipo siciliano' were perennial and performed under irrigated conditions while 'Erfoud 1' performed in the rainfed trial. <![CDATA[<b>Comparison of graphical analyses for maize genetic experiments</b>: <b>Application of biplots and polar plot to line x tester design</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300004&lng=pt&nrm=iso&tlng=pt Graphical techniques have become important tools to show results of maize (Zea mays L.) breeding experiments in current literature. The present study compared different graphical techniques to determine the best parental lines and cross combinations for yield and kernel quality traits in maize breeding experiments. We measured single plant yield, protein content, oil content, carotenoid content, oleic acid, and linoleic acid in a 5 x 2 line x tester design. Genotype + genotype x environment (GE) biplot, principal component analysis (PCA) biplot, and polar plot were used to analyze data and compare them with conventional line x tester analysis. In the conventional analysis, parents with high means and positive general combining ability (GCA) values were A680 and HYA for single plant yield, IHP for protein content, IHO and HYA for oil content, A680 and Q2 for carotenoid content, IHP for oleic acid content, and A680 for linoleic acid content. The B73 tester exhibited positive GCA values for most investigated traits. The HYA x B73 combination was the best cross in terms of single plant yield, protein, and oil contents. Results showed that biplot methods had both advantages and disadvantages. The PCA biplots can be used alone while the GGE biplot and polar plots are both useful for combining ability, heterosis, and gene action analysis in a line x tester design. Overall, graphical analysis results were very similar to conventional analysis. Consequently, it was assumed that the graphical methods used could be useful to analyze/present data from maize breeding experiments carried out with a line x tester design. <![CDATA[<b>An accurate prediction of maize crosses using diallel analysis and best linear unbiased predictor (BLUP)</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300005&lng=pt&nrm=iso&tlng=pt A major obstacle in corn (Zea mays L.) breeding programs is how to obtain strains which, when combined, ensure increased productivity in all crop characteristics. Therefore, the objective of this study was to evaluate the prediction efficiency of hybrid maize using diallel analysis and the best linear unbiased predictor (BLUP). Eight synthetic varieties were sown in a diallel scheme and the hybrid and their parents were then evaluated in three separate environments; both combining ability and predicted breeding values (BLUPs) were estimated. Correlations between the BLUP and combining abilities were also obtained. Combining ability analysis revealed that both additive and non-additive types of gene action were important in the studied traits. There was a moderate to high correlation between the mean square of the combining ability and the predicted breeding values. This shows that BLUP can be used to select the best parents for different traits, especially for ear height and ear position, which had the highest correlations. The parent VAR-01 had significant general combining ability (GCA) values, and it can be used in crosses to reduce plant height, ear height, and ear position while the parent VAR-06 can participate in crosses to increase ear height, plant height, and ear position. The result obtained for combining ability was moderately to highly consistent with BLUP results, but selection must be carefully undertaken. <![CDATA[<b>Multiple marker-traits associations for maize agronomic traits</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300006&lng=pt&nrm=iso&tlng=pt Association analysis is a relatively novel approach in quantitative traits studies that allows high resolution mapping and time efficient and direct application on breeding material. Since the markers, which are close to the quantitative trait loci stable across environments and genetic backgrounds, may be valuable for marker assisted selection, we chose microsatellite markers previously linked to traits of interest in various mapping studies. A set of 36 microsatellite markers positioned near important maize (Zea mays L.) agronomic loci was used to evaluate genetic diversity and determine population structure. To verify the associations between the markers and traits, a panel of diverse maize inbred lines was genotyped with microsatellites and phenotyped for flowering time, yield and yield components. A relatively high level of polymorphism detected in number of alleles per locus (8.2), average polymorphic information content value (0.64), and average gene diversity (0.684) lines showed the analyzed panel of maize inbred contained significant genetic diversity and was suitable for association mapping. The population structure estimated by model-based clustering method grouped maize inbred lines into three clusters. The association analysis using the general linear and mixed linear models determined significant correlations between several agronomic traits and three microsatellites on chromosomes 3, 5, and 8, namely umc1025, bnlg1237, and bnlg162 consistent across the environments, explaining from 4.7% to 18.2% of total phenotypic variations. The results suggest that the chromosome regions containing quantitative trait loci (QTLs) associated with multiple yield-related traits consistently across environments are potentially important targets for selection. <![CDATA[<b>Studies of phenotypic and genotypic variation in sixteen cucumber genotypes</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300007&lng=pt&nrm=iso&tlng=pt Genetic variability in a crop population is important for successful plant breeding. Sixteen cucumber (Cucumis sativus L.) genotypes were evaluated in the early and late planting seasons to estimate the magnitude of their genetic variability and heritability. Genotypes were also classified into groups based on the performance and determination of the highest discriminating trait that accounted for greater variability using cluster analysis and principal component analysis (PCA), respectively. The measured agronomic traits were vine length, number of branches, number of leaves, and leaf area 8 wk after planting, days to flower initiation, days to 50% flowering, number of staminate flowers per plant, number of pistillate flowers per plant, fruit length, fruit girth, fruit weight per plant, number of fruits per plant, mean fruit weight, and total fruit yield ha-1. A high coefficient of variation was recorded for most traits in both seasons and high variability was found among genotypes. High broad-sense heritability was associated with all the traits in both seasons, except for mean fruit weight in the early planting season and fruit girth, mean fruit weight, and total fruit yield in late planting season. Cluster analysis and its comparison of means showed that 'Beit Alpha', 'Ashely', 'Straight 8', and 'Sumter' from cluster F in the early planting season and 'Beit Alpha' and 'Ashely' from cluster E in the late planting season expressed the best agronomic traits and yield potentials. Hence, selection for any trait would favor genotypes in these clusters. Principal component analysis involved vine length as the most discriminating trait that accounted for greater variability in cucumber in both the early and late planting seasons, and it should be considered in cucumber improvement programs. <![CDATA[<b>Regulation mechanism of exogenous ALA on growth and physiology of <i>Leymus chinensis</i> (Trin.) under salt stress</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300008&lng=pt&nrm=iso&tlng=pt Salt stress is one of major problem hampering plant growth and development to a significant level. In present study, 5-aminolevulinic acid (ALA) was exogenously applied to Leymus chinensis (Trin.) Tzvel. plants at various concentrations (10, 50, and 100 mg L-1) to assess its effects on morphology, physiology, and biochemistry under salt stress conditions (150 mmol NaCl L-1) as compared with control. The results indicated that salt stress substantially impaired growth, physiology and biochemistry of L. chinensis plants; nonetheless, ALA application alleviated the adverse effects of salt stress. Application of ALA improved the leaf length, leaf area, leaf conductance, plant dry biomass, water contents, and root activity of L. chinensis under stress and no stress conditions. Additionally, biosynthesis of chlorophyll, carotenoids, free proline, soluble sugars and proteins of L. chinensis plants was also increased following ALA application as compared to control, under salt stress conditions. Moreover, we also observed an enhanced activity of antioxidant defense system in L. chinensis in response to ALA application. ALA elevated the activity of enzymatic antioxidants viz. ascorbate peroxidase (APX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) significantly scavenged reactive oxygen species thus reduced the accumulation of malondialdehyde (MDA) under salt stress as compared to control under both normal and stressed conditions. The effect of ALA on all growth and biochemical attributes was concentration dependent and application of 50 as well as 100 mg L-1 ALA proved better. The results concluded that salt stress tolerance in L. chinensis plants can be increased by exogenously applied ALA at appropriate concentration. It was suggested that L. chinensis plants were treated with ALA application of 50-100 mg L-1 was more beneficial under both normal and saline conditions. <![CDATA[<b>Dynamic of aboveground biomass and soil moisture as affected by short-term grazing exclusion on eastern alpine meadow of Qinghai-Tibet plateau, China</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300009&lng=pt&nrm=iso&tlng=pt Short-term grazing exclusion has large impacts on grassland vegetation and nutrition. In order to study the effects of the short-term rest on aboveground biomass, forage quality, and soil moisture on alpine pasture of the Qinghai-Tibet plateau, cages were used to exclude grazing from July to October on summer pasture used by three typical farms with different stocking rates. The results showed that, within the same month during the forage growth period, the dry weights of the edible forage in the cages were significantly higher than that out of the cages (P < 0.05) under heavy grazing pressure (from 2.47 to 2.48 animal unit equivalent AUE ha-1). Within the same soil depth, soil moisture was significantly different in, and out of, the cages (P < 0.05) and it decreased with depth. The crude protein content for forages in cages was significantly higher than that out of the cages for the farm with a heavy stocking rate and the neutral detergent fiber was significantly lower. This shows that short-term rest periods could effectively increase dry weight and crude protein content of the edible forage for farms with heavy stocking rates. This short-term rest management strategy is recommended for farms with a heavy stocking rate. <![CDATA[<b>Insecticidal activity of <i>Laureliopsis philippiana</i> (Looser) Schodde (Atherospermataceae) essential oil against <i>Sitophilus</i> spp. (Coleoptera Curculionidae)</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300010&lng=pt&nrm=iso&tlng=pt In Chile, the main Coleopteran species of stored grains are Sitophilus oryzae, S. zeamais, and S. granarius. The aim of this study was to evaluate under laboratory conditions the contact and fumigant insecticidal activity, as well as the repellent and antifeedant effects of Laureliopsis philippiana (Looser) Schodde essential oil against adults of Sitophilus spp. The main compounds identified in this essential oil were methyleugenol (61.38%) and safrole (14.76%). Based on the contact bioassay, the highest toxicity was achieved with the concentration of 4.0% (v/w), and S. oryzae was the most susceptible species. Emergence (F1) was reduced as the concentration of the essential oil increased, reaching maximums of 60% in the case of S. granarius and S. oryzae, and 36% in S. zeamais. Mortality by fumigant activity was 100% for the three species of Sitophilus. All of the treatments had a repellent effect. The highest antifeedant activity (82.9%) was recorded at 4.0% (v/w) concentration. Concentrations below 2.0% (v/w) did not affect germination of maize. Based on these results, L. philippiana essential oil has the potential to control Sitophilus spp. weevils. <![CDATA[<b>Fattening performance of crossbred (Polish Holstein-Friesian x Hereford, Limousin or Charolais) bulls and steers offered high-wilted grass silage-based rations</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300011&lng=pt&nrm=iso&tlng=pt In Poland beef cattle are usually fed high-wilted grass silage offered ad libitum and supplemented with concentrate, whereas 'Limousin', 'Charolais' and 'Hereford' bulls are the most frequently crossed with dairy cows to produce beef hybrids. The aim of this study was to determine the fattening performance of hybrids produced by crossing 'Polish Holstein-Friesian' (PHF) cows with 'Hereford' (HH), 'Limousin' (LM) and 'Charolais' (CH) bulls, fed silage made from high-wilted grass and supplemented with a small amount of concentrate, depending on sire breed and category. The experimental materials comprised 24 bulls and 24 steers, including 8 PHF x HH, 8 PHF x LM and 8 PHF x CH crosses with initial body weight of approximately 300 kg in each group. The animals were fed grass silage with a DM content of 417 g kg-1, supplemented with concentrate at 35 g DM kg-1 W0.75, for 250 d. Steers were characterized by higher total DM intake per unit of metabolic body weight (P < 0.05): 92.8 vs. 87.0 g; 94.1 vs. 84.6 g; 88.6 vs. 87.0 g (PHF x HH; PHF x LM; PHF x CH, respectively) and bulls - by higher average carcass weight gains (P < 0.01): 700 vs. 631 g; 654 vs. 579 g; 633 vs. 574 g and carcass dressing percentage (P < 0.01): 60.0 vs. 56.4%; 60.2 vs. 58.9%; 60.2 vs. 56.6% (PHF x HH; PHF x LM; PHF x CH, respectively) and better (P < 0.01) silage DM, total DM, crude protein, and net energy utilization. Sire breed had no significant effect on the analyzed parameters of fattening performance but numerically PHF x HH crosses had the highest productivity parameters. <![CDATA[<b><i>Atriplex nummularia</i></b><b> Lindl.</b> <b>as</b> <b>alternative for improving salt-affected soils conditions in semiarid environments</b>: <b>a field experiment</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300012&lng=pt&nrm=iso&tlng=pt Atriplex nummularia Lindl. represents a cost-effective alternative for improving salt-affected soils in arid and semiarid environments due to its high adaptability to salinity and water deficiency. This study aimed to investigate soil physical-chemical changes in response to A. nummularia cultivation under field condition. Additionally, we quantified its biomass yield and phytoextraction potential. Two treatments were evaluated: soil cultivated with Atriplex under two crop densities (1 x 1 and 2 x 2 m), and a control (bared soil) with four replicates. The samples were taken at three soil depths (0-5, 15-20, and 40-45 cm). In general, dry biomass yield for leaves, stems and roots, as well as the bulk density and the hydraulic conductivity of the soil were sensitive to crop densities. Thus, the use of A. nummularia can be recommended for phytoremediation of salt-affected soils, as well as to improve soil physical condition. When it comes to salt phytoextraction per area, we recommend planting A. nummularia at a 1 x 1 m crop density. The greater accumulation of salts was observed in leaves, as observed for Na (82% roughly). However, in order to improve soil physical conditions, we suggest the management of A. nummularia under 2 x 2 m crop density. Pruning was fundamental to increase the biomass yield and, consequently, the phytoextraction of specific ions, e.g., Na, Cl. It was responsible for 83% and 88% of the total dry biomass at 1 x 1 and 2 x 2 m crop density, respectively. <![CDATA[<b>Effect of thermal conversion of pig manure and poultry litter on the content and mobility of Mn and</b> <b>Fe</b> <b>in biochars and in soil after their application</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300013&lng=pt&nrm=iso&tlng=pt By-products of animal breeding and raising can contain considerable amounts of trace elements, including Mn and Fe, due to the fact that their amounts in fodders are purposefully being increased. Thermal conversion of pig manure and poultry litter may have a significant effect on changes in the content and mobility of Mn and Fe in these materials. The aim of the research was to evaluate the effect of thermal conversion of pig manure and poultry litter on the content and mobility of Mn and Fe in biochars and in soil after their application (0.5%, 1%, and 2% amendments to the soil). As a result of thermal conversion of pig manure and poultry litter, an increase in the content of total forms and a reduction of Mn and Fe forms extracted with water were recorded. The 2% amendment of pig manure biochar to soil caused an increase in the content of mobile forms of Fe, whereas poultry litter biochar decreased mobility of this element. Introduction of pig manure biochar and poultry litter biochar to the soil caused a similar immobilization of mobile forms of Mn as in the case of application of thermally unprocessed manure and litter. It has been shown that the content of Fe and Mn extracted with 0.025 M C10H22N4O8 was higher than the content of these elements extracted with 1 M NH4NO3. <![CDATA[<b>Use of earthworms as a pesticide exposure indicator in soils under conventional and organic management</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300014&lng=pt&nrm=iso&tlng=pt The intensive use of agricultural soils reveals the massive application of agrochemicals. There is no follow-up of the presence of pesticide residues in soil or their toxic effects on organisms that are beneficial for agrosystems, such as earthworms (Lumbricus terrestris L.) The objective of this study was to evaluate the effect of pesticides used in horticultural orchards on earthworms, and the use of earthworms as an indicator through carboxylesterase (CbE) activity, which is an enzyme involved in the detoxification metabolism of organophosphorus, carbamates, and pyrethroids. Eight individuals were place in each polyethylene container and the container were buried under the soil surface in two apple orchards, one under organic management and the other under conventional management. The experiment was carried out in triplicate. A control treatment was conducted in the laboratory. The experiment was repeated in autumn, winter, spring, and summer of the 2014-2015 study period. Three internal gut tissues of the earthworm were measured for CbE activity in the laboratory. Results showed higher CbE activity in the crop-gizzard of the control treatment with 14.22 ± 1.00 μmol min-1 mg-1 in winter; the lowest activity was recorded in soil under conventional management in summer with 6.15 ± 2.77 μmol min-1 mg-1 (p ≤ 0.05). There was a seasonal difference in enzymatic activity that was higher in winter and autumn with 14.22 and 13.93 μmol min-1 mg-1, respectively, and lower in summer and spring with 6.15 and 6.31 μmol min-1 mg-1 (p ≤ 0.05), respectively; enzymatic activity was associated with higher pesticide application. It can be concluded that CbE activity is sensitive to the inhibitory action of pesticides and can therefore be used as a biological indicator of agrochemicals. <![CDATA[<b>Effect of pellets made of waste materials from the paper industry enhanced with seaweed (<i>Ulva lactuca</i> L.) on N mineralization and lettuce production</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300015&lng=pt&nrm=iso&tlng=pt The need to reduce the use of traditional fertilizers and prevent soil degradation demands the search for new ways of fertilization. The combined application of waste materials (generated by the paper industry) and seaweed may be an alternative source of fertilization. The objective of this study was to evaluate the effect of pellets made of waste materials ash and sludge, produced by the paper industry with the addition of seaweed (Ulva lactuca L.) on the production of lettuce (Lactuca sativa L.) as an indicator plant and N mineralization in the soil. Two trials were conducted on an Entisol soil. The first trial evaluated the productive response of lettuce to the combined application of pellet+seaweed. Lettuce plants were grown in pots under greenhouse conditions for 3-mo. Three types of pellets, with and without seaweed added, were applied in doses of 10, 20, and 30 t ha-1. N mineralization was measured by 12 wk incubation, evaluating the three types of pellets with and without the addition of seaweed. The results showed that all the combined pellet+seaweed treatments had higher aerial biomass production (p ≤ 0.05) and increased chlorophyll content. The aerial biomass production reached 4.16 g pot-1 and was 7-fold higher than pellet treatments without seaweed, while chlorophyll content was 17% higher (p ≤ 0.05). In terms of N mineralization, the maximum release was recorded in the Pellet 3+seaweed treatment, reaching 55 mg kg-1. All the treatments with seaweed (p ≤ 0.05) better higher N mineralization values compared to the treatments without seaweed. Similarly, increased values for potentially mineralizable N and mineralization rate constant were observed in the treatments that included pellets+seaweed and seaweed alone compared to those consisting of pellets alone. The pellets+seaweed amendments resulted in an increase in soil N mineralization and production parameters of lettuce. <![CDATA[<b>Adsorption-desorption behavior of thiram: effect of soil type, temperature and pH</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300016&lng=pt&nrm=iso&tlng=pt The present study was conducted in order to investigate the adsorption and desorption behavior of tetramethylthiuram disulfide (thiram) using the batch equilibration technique in two soil namely: Ultisols and Inceptisols. The adsorption-desorption isotherms were expressed by the Freundlich equation. The adsorption isotherms of thiram was classified as L-type under Gile's classification. The Freundlich's adsorption coefficient (Kd) value for thiram in the Ultisols and Inceptisols soil were 3.78 and 2.10 mL g-1, respectively. Results indicated that soil organic matter was the main factor affecting thiram behavior in the studied soils. The calculated total percentage desorption values from the Ultisols and Inceptisols soil after the fourth desorption process were 39.2% and 51.6%, respectively. The negative Gibb's free energy change (ΔG°) values obtained suggest that thiram adsorption is an exothermic process. The effects of temperature (25, 30, and 35 °C) and soil pH (3, 7, 10) were also studied on adsorption of thiram in the test soils. Results showed that adsorption of thiram was not affected by temperature but clearly affected by soil pH. <![CDATA[<b>Dose dependent rhizospheric Ni toxicity evaluation</b>: <b>Membrane stability and antioxidant potential of <i>Vigna</i> species</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300017&lng=pt&nrm=iso&tlng=pt Different concentrations of Ni are found in agricultural soil released from various environmental sources. The responses of plants grown in such soil-substratum vary accordingly depending upon the concentration of metal present and plant species. To assess the toxic effects of Ni and extent of plant defensive strategies, increasing Ni doses (50, 100, and 150 mg kg-1) were used in sandy-loam soil-substratum at pH 7.9 to evaluate the performance of Vigna species (V. cylindrica [L.] Skeels, V. mungo [L.] Hepper, and V radiata [L.] R. Wilczek). The experiment was conducted in a complete randomized design. Nickel stress was induced by adding various concentrations of Ni chloride in soil substratum. Malondialdehyde (MDA) and antioxidant levels were determined in roots and leaves. Escalating levels of Ni in soil resulted in an affirmative relationship between MDA with that of antioxidants. A dose-dependent increase in the activity of Superoxide Dismutases (SOD), Catalase (CAT), and peroxidases (POD) suggested the existence of a sequence response of these enzymes to scavenge oxidative stress in the roots. However, inadequate production of SOD and CAT appeared to be compensated by the enhanced activity of POD, which acted as potent quencher to reactive oxygen species (ROS) in leaves. At the most elevated Ni dose, SOD, CAT and POD activities were insufficient to counteract ROS generated that led to membrane damage manifested by elevated MDA levels. Nevertheless, SOD and CAT alleviated Ni toxicity in roots while SOD, CAT and POD acted in a concurrent manner to protect leaves from oxidative damage in V. cylindrica. The study clearly indicated a Ni dependent antioxidant enzymes defense system in V. cylindrica. <![CDATA[<b>Seed morphology and anatomy of <i>Rubus geoides</i> Sm.</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392016000300018&lng=pt&nrm=iso&tlng=pt Rubus geoides Sm. is a wild raspberry native in Patagonia. Its domestication can broaden the genetic base of the cultivated raspberry, prevent over exploitation of wild populations, and diversify fruit production in areas where few fruit species can be cultivated, like the Chilean Patagonia. One important step in the domestication of plant species is the unveiling of the reproductive biology of the species, particularly seed germination. The goal of this work was to study seed morphology and anatomy of R. geoides in order to identify possible factors that may affect germination and species identification based on seed morphology, since seed shape, surface sculpturing and raphe characteristics are discriminating factors for species identification within Rubus. Morphoanatomical studies were performed using both scanning electron microscopy (SEM) and light microscopy. Rubus geoides seeds turned out to be similar to those of R. idaeus. Seeds were pale brown, with a semi globular shape, sharpened at the apical region and oval toward the opposite end. Seed size was variable, showing an average 1.9 mm width, 2.6 mm length, and 1.3 mm thickness. Small rounded depressions and ridges sculptured seed surface. The endocarp was hard and rough, and consist of several layers of sclerenchymatous lignified cells with 139 urn averaged thickness, which suggest that to enhanced germination seed may require its weakening or eventual elimination, as is done in other Rubus species. The embryo varied with seed size between 1.6 and 2.0 mm. Energy Dispersive X-Ray Spectroscopy allowed for the identification of the endosperm cells.