Collection and morphological characterization of Panicum coloratum L. in Argentina

Panicum coloratum (Poaceae) is a perennial grass native to South Africa, distributed all over the world, but poorly adopted by ranchers in Argentina. Adapted to a wide range of soil and climatic conditions, it constitutes a good forage resource for zones with edaphic and climatic restrictions, where cattle rising activities are here displaced. The high polymorphism in the species has made it difficult to delineate sub specific taxonomic categories. It has been classified in botanical varieties, types and/or cultivars. In order to document the morphological variability in P. coloratum and to investigate the differences between var. makarikariense and var. coloratum, a collection was gathered in INTA Rafaela composed by fourteen accessions from different provinces of Argentina: six accessions of var. makarikariense and eight from var. coloratum. The evaluation of 152 individuals gives evidence of a wide morphological variation in the collection in traits related to forage and caryopses production; seven out of nine traits showed significant differences between var. makarikariense and var. coloratum. Based on the study of local type specimens, a morphological key to distinguish between P. coloratum varieties is provided. These results report new information about the diversity in P. coloratum in Argentina and provide valuable insights for future use of the collection as the base material of a breeding program.     

Effects of arbuscular mycorrhizal inoculation on growth,yield, nitrogen,and phosphorus nutrition of nodulating bean varieties in two soil substrates of contrasting fertility

A pot experiment was conducted to study the response of nodulated bean (Phaseolus vulgaris L.), vars. Ceca and Montalbán, to inoculation with the arbuscular‐mycorrhizae (AM) Glomus spurcum strain IES‐3 and G. mosseae strain IES‐8 in two non‐sterilized non‐amended soil substrates (S‐l and S‐2) of contrasting fertility. S‐l was an acid soil (pH 5.0) with 77% exchangeable aluminum (Al), low available phosphorus (P) (3.5 ug g^‐1 dry soil) and 1.8% organic matter. S‐2 was a soil with pH 7.0, 7.9 μg P g^‐1 dry soil, 9.6% organic matter and no exchangeable Al. Plants growing in S‐1 (S‐1 plants) and S‐2 (S‐2 plants) soils were sampled at the beginning of the flowering stage. S‐1 and S‐2 plants were nodulated by the rhizobial populations native of each soil. S‐1 plants of both varieties did not respond to AM inoculation in term of shoot and root mass, P content, relative abundance of ureides (RAU) and seed yields. Only the total chlorophyll, chlorophyll‐a, chlrophyll‐a/b ratio and nodule mass were significantly enhanced in AM‐inoculated plants. Increased total reducing sugars concentration was detected in roots of S‐1 plants inoculated with G. mosseae. S‐2 plants displayed significantly higher shoot and nodule mass as well as increased total chlorophyll, chlorophyll‐a, chlorophyll‐a/b ratio and P content than S‐1 plants, regardless of the variety and AM inoculation. S‐2 plants of the var Ceca showed a two fold increase in seed yields but similar RAU values (>60%) when compared to S‐1 plants of the same variety. In contrast, the significant increase in RAU detected in S‐2 plants of the var Montalban was not translated into higher seed yields. In S‐2, the productivity of plants of the var Ceca doubled that of the var Montalban. For both bean varieties the highest significant P content and seed yield were observed exclusively in S‐2 plants inoculated with G. mosseae. This Glomelean strain enhanced the sink‐source ratio of the S‐2 plants as evidenced by the higher total reducing sugar concentration in the root mass. Arbuscular‐mycorrhizae inoculation significantly decreased the acid phosphatase activity in the rhizosphere of S‐1 and S‐2 plants, respectively, pointing toward a negative effect of foreign AM on the native microbial biomass. The effectiveness of the rhizobial populations native of each soil type and the weak response elicited by G. mosseae in S‐2 plants do not justify, at present, the inclusion of foreign inocula in the bean crops carried out at S‐1 and S‐2 soils of the Sucre State of Venezuela. Results also indicated the higher adaptability of var Ceca to conditions prevailing in S‐1 and S‐2.     

Effect of Calcium Foliar Application on the Characteristics of Blueberry Fruit during Storage

ABSTRACT

Effect of calcium (Ca) foliar application on blueberry fruit characteristics during storage was investigated. Calcium applications began 28 d after flowering, two levels (3.9 g Ca^{2 +} and 39 g Ca^{2 +}) and a control without calcium were used (0.0; 3.0, and 30 mL L^?1). The fruits were harvested on day 103 and were stored for 56 d at 2 ± 1°C. At harvest time the fruits had a significant statistical different concentration, which were maintained until the last day of storage. The fruit from the 30 mL L^?1 treatment was the highest. The lowest texture levels are found with the treatment without calcium, which shows a statistically significant change from storage day 29. The LMP percentage did not varied in the fruit from the treatment with 30 mL L^?1, but did in the fruit without calcium. Hunter L, b, and the index chromes were influenced by the applied calcium levels, significantly greater at 30 mL L^?1; and by the time of storage in the fruits with treatment of 30 mL L^?1.     

Effect of Foliar Application of Calcium on the Quality of Blueberry Fruits

Effect of foliar application of calcium (0.78 g, 4.68 g, and 7.8 g Ca^{2 +}) in pre-harvest, at three different growing conditions (tunnel, mesh, and ambient), on texture and pectin in blueberries (Vaccinium corymbosum) was studied. Calcium contents in leaves as well in fruits were different (P ≤ 0.05), affected by growing conditions and time. Differences (P ≤ 0.05) in calcium content were found in tunnel cultivar fruit, during the period to cell expansion toward harvest, at calcium foliar level of 5 mL per L (7.8 g). Fruit texture was significantly higher at the beginning of the cell expansion period in the tunnel cultivar fruit, and a linear correlation between calcium concentration and texture was established. Increment in low methoxyl pectin (LMP) was influenced by growing conditions, and was different (P ≤ 0.05) for tunnel cultivar fruit. A good correlation between LMP and calcium content was obtained with the high dose of calcium (5 mL per L).     

Growth and Fruit Chemical Characteristics of Blackberry (Rubus Fruticosus) Cultivated with Vermicompost,Glomus Mosseae and Phosphate Rock

Abstract

The aim of this investigation was to determine the effect of vermicompost (V) and phosphate rock (PR) on blackberry (Rubus fruticosus L. agg.) plants inoculated with Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe (AMF). Plant growth parameters, total phenol compounds and total flavonoids were evaluated on leaves. Anthocyanin contents, soluble solids (SS), pH, titratable acidity (TA) and SS/TA ratio was evaluated in blackberries fruits. Blackberry plants were obtained from cuttings from field plants, which were distributed in soil according to a randomized complete block design with three repetitions. Treatments were vermicompost (10?g plant^?1), phosphate rock (1?g plant^?1), Glomus mosseae (AMF), (1?g plant^?1), PR + AMF, V + PR, V +AMF, V + PR+ AMF and control without any amended. Plant height and stem diameter were measured five months after treatments, while total phenols and total flavonoids in leaves were evaluated eight months later. Anthocyanins, SS, pH, and TA were determined in blackberry fruits ten months after. Plant height was not statistically affected (p≤0.05), although total phenol compounds were higher (21.1?mg g^?1 dry plant) in the V+PR+AMF treatment, whereas the V + AMF treatment produced more dry plant total flavonoids (1.4?mg g^?1), compared with control plants. Blackberries produced with the vermicompost treatment had more anthocyanins (9.54?mg g^?1) than control plants. Soluble solids, pH and titratable acidity were not statistically (p≤0.05) affected by any treatment.     

Fluorine immission to acid soil in the vicinity of an aluminium smelter in Galicia (NW Spain) and its influence on aluminium dynamics

Purpose

The aluminium smelter located in the northern coast of Galicia (NW Spain) is a source of fluoride pollution. Previous papers Gago et al. (Commun Soil Sci Plant Anal 32:2503–2517, 2001, Fluoride 35:110–121, 2002) have identified an area of 3-km radius around the factory being affected by fluoride emissions. This study aims to investigate the influence of fluoride emissions on fluorine concentration and speciation as well as on aluminium speciation in soils in the vicinity of the smelter.

Materials and methods

PVC cylinders containing soil material from the A horizon of an unpolluted forest soil, similar to that in the vicinity of the factory, were placed within the A horizon of soils surrounding the smelter. The cylinders were placed at various distances (up to 3 km) from the factory in the direction of predominant winds. The PVC columns were removed after 6 months, and the soil material inside was divided into two slices (0–10 and 10–20 cm) and analysed for pH, total and available fluorine, exchangeable cations, effective cation exchange capacity (CEC) and oxalate-extracted aluminium. The soil solution was mimicked by aqueous extracts and analysed for pH, electrical conductivity, Ca, Mg, Na, K, total and free fluorine, total Al, acid-soluble Al, non-labile Al, labile Al and labile Al species.

Results and discussion

In the area closest to the factory (0.5 km), total and available fluorine in the upmost 10 cm soil increased by twofold and eightfold, respectively, while soluble fluoride increased by fourfold. Increases were also observed in exchangeable Ca, Mg, Al and CEC. Noncrystalline Al increased significantly at any distance from the smelter. Fluorine, pH, sulphate, aluminium and organic matter increased in the soil solution of surface (<10 cm) samples closest to the factory. Monomeric Al-organic matter complexes prevailed in the liquid phase at 0.5–1 km from the factory whereas inorganic Al complexes did at distances over 1 km. Among the inorganic Al complexes, fluoride complexes prevailed at distances less than 1 km and hydroxylated complexes at distances greater than 1 km. Al³⁺ concentration was always very low.

Conclusions

Emissions from an aluminium smelter led to increased concentrations of fluorine and various forms of aluminium in the nearby soil. These emissions mobilised aluminium, organic matter and probably sulphate from the soil. In the closest neighbourhood of the smelter, it was found that most soluble aluminium was bound to organic matter, hence having low toxicity, while at distances farther than 1 km Al-F and Al-OH complexes prevailed.     

Efficacy of Amblyseius largoensis (Muma) as a biocontrol agent of the red palm mite Raoiella indica (Acari: Tenuipalpidae)

Phytoparasitica - The red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae), is a severe pest of coconut (Cocos nucifera L.), banana (Musa sp.), and some ornamental palms. The predatory mite...     

Lethal and sublethal effects of chemical constituents from essential oils on Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae: Bruchinae) in cowpea stored grains

Journal of Plant Diseases and Protection - The recent use of essential oils has been considered an important approach in pest management programs for stored products. Regarding essential oils, it...     

Fusarium tricinctum associated with Head Blight on barley in Argentina: pathogenicity and potential degradation of the different hordein fractions

Journal of Plant Diseases and Protection - The objective of the present work was to evaluate the pathogenicity of Fusarium tricinctum in barley and to determine the potential effects on grain...