Fresh biomass production and partitioning of aboveground growth in the three botanical varieties of Cynara cardunculus L.

Fourteen accessions of Cynara cardunculus were compared with the aim to evaluate the fresh biomass production and its partition, aiming at its potential use for industrial purposes. At anthesis stage, when plants have the maximum vegetative development, stalks, leaves and capitula were weighed separately. The percentage of dry matter per gram of fresh biomass was also calculated. The first capitulum components of each plant: bracts, flowers and remnant receptacle were also weighed separately. The total fresh biomass ranged between 1188 and 3235 g/plant, with variable values within each botanical variety, whereas the partition of the aboveground biomass was strongly affected by botanical variety. In both cardoons varieties, the percentage of dry matter ranged between 30 and 35% for all components of aboveground biomass, whereas in globe artichoke values ranged between 20% for capitula and 40% for leaves. Regarding capitula components, receptacle weight was of greatest importance in globe artichoke and cultivated cardoon. In wild cardoon flowers weight was more important than the other components. Results suggest that Cynara cardunculus var. scolymus and C. cardundulus var. cardunculus, might be considered as double purpose crops if after the capitula (in globe artichoke) or leaves (in cardoon) harvest, the fresh matter remaining is artificially dried and cut. On the other hand, Cynara cardunculus var. sylvestris, might be incorporated into the culture system as an industry or energy crop due the low inputs management that it requires, its adaptability to the local conditions and its aboveground biomass production.     

Variability in essential oil content and composition of Origanum hirtum L., Origanum onites L., Coridothymus capitatus (L.) and Satureja thymbra L. populations from the Greek island Ikaria

Plants belonging to four “oregano” plant species (Origanum hirtum L., Origanum onites L., Coridothymus capitatus L., and Satureja thymbra L.) were collected during flowering from 33 sites located in the eastern part of the Greek island of Ikaria in the Eastern Aegean during April, May and July 2008. C. capitatus and O. hirtum were mostly observed in higher altitudes, whereas O. onites and S. thymbra in lower ones. The spatial distribution of all species was depicted on a GIS map. All four species exhibited essential oil concentrations higher than those reported in earlier literature, namely O. onites 3-4.3%, S. thymbra 4-6.5%, C. capitatus 3.7-5.6% and O. hirtum 5.5-10.0% (v/w). Carvacrol was the main constituent of the essential oils of all species, followed by γ-terpinene, p-cymene and caryophyllene, while thymol was not detected. All constituents varied remarkably among the four species, with carvacrol exhibiting the lowest variation. Carvacrol content varied between 72.3 and 89.2% in O. onites; 46.5 and 58.0% in S. thymbra; 82.9 and 90.9% in C. capitatus; and 84.4 and 93.8% in O. hirtum. By applying hierarchical cluster analysis on the basis of the essential oil constituents two main groups, divided into four subgroups of the taxa were evident. The first group consisted of O. onites and S. thymbra, while the second one of C. capitatus and O. hirtum. The results are discussed in terms of topography and climatic variation.     

Large scale in vitro propagation of Stevia rebaudiana (bert) for commercial application: Pharmaceutically important and antidiabetic medicinal herb

Stevia rebaudiana is a valuable medicinal plant species and it is being used for the treatment of diabetes. Currently, there is a high demand for raw material of this medicinal herb due to ever increasing diabetes disorder among the population. In order to meet the increased demand an efficient in vitro propagation of S. rebaudiana was established. Nodal explants collected from the field were cultured on MS basal medium fortified with different concentrations of BAP (0.5-3.0 mg/l) and KIN (0.5-3.0 mg/l) individually for shoot bud induction. In vitro derived nodal buds were cultured on MS medium supplemented with different concentrations (0.5-3.0 mg/l) of BAP and KIN for multiple shoot bud regeneration. In the second experiment, in vitro derived buds were placed on MS medium supplemented with different concentrations of BAP (0.5-3.0 mg/l) in combination with 0.5 mg/l IAA or IBA or NAA for shoot bud multiplication. The highest frequency (94.50%) of multiple shoot regeneration with maximum number of shoots (15.69 shoots/explant) was noticed on MS medium supplemented with 1.0 mg/l BAP. For large scale plant production, in vitro derived nodal bud explants were cultured on MS medium fortified with 1.0 mg/l BAP, in which about 123 shoots/explant were obtained after three subcultures on the same media composition. Elongated shoots (>2 cm) dissected out from the in vitro proliferated shoot clumps were cultured on half-strength MS medium containing different concentrations of NAA (0.1-0.5 mg/l) and/or MS medium fortified with various concentrations (0.5-2.0 mg/l) of auxins (NAA, IAA and IBA) for root induction. Highest frequency of rooting (96%) was noticed on half-strength MS medium augmented with 0.4 mg/l NAA. The rooted plantlets were successfully transferred into plastic cups containing sand and soil in the ratio of 1:2 and subsequently established in the greenhouse. The present in vitro propagation protocol would facilitate an alternative method for rapid and large-scale production of this important antidiabetic medicinal plant.     

Evaluation of the yield potential and physicochemical properties of the biomass of Salix viminalis × Populus tremula hybrids

This study presents the characteristics of four Salix viminalis × Populus tremula hybrids, produced for the first time in the world grown in a three-year field experiment. Shoot weight per plant and major biomass yield components, including plant height, number of shoots per rootstock and shoot diameter, were determined. The infection severity caused by leaf rust (Melampsora sp.) was also evaluated. The biomass of three-year-old hybrid plants was subjected to chemical analyses and calorimetric tests to determine the energy value of biomass as solid fuel. Among the studied genotypes the highest yield was achieved by one of the studied hybrids. Its biometric parameters did not differ significantly from the standard genotype, and they were superior to the parameters of the maternal form. All Salix × Populus hybrids were more susceptible to rust infections than their maternal form and one hybrid was more resistant to infections caused by fungi of the genus Melampsora. Two hybrids have optimal biomass parameters as regards both calorific value and amount of carbon, hydrogen, sulfur and nitrogen.     

Monitoring resistance of field populations of diamondback moth Plutella xylostella L. (Lepidoptera: Yponomeutidae) to five insecticides in South China: A ten-year case study

Diamondback moth Plutella xylostella (L.) is a cosmopolitan pest of crucifers and it is particularly notorious for its resistance to commonly used insecticides. To provide a basis for future resistance management strategies, this study evaluated the resistance status of this pest to five insecticides, namely abamectin, β-cypermethrin, fipronil, monosultap and phoxim, in South China from 1999 to 2009 with 4-6 populations tested each year. Laboratory bioassays using a standard leaf-dip method were conducted on 3rd instar larvae which were the progeny of field collected insects. LC₅₀ values were estimated by probit analysis and resistance factors were calculated by comparing the field populations with a fully insecticide-susceptible lab population. The results showed that the diamondback moth populations generally had low resistance to abamectin from 1999 to 2005, but that resistance increased significantly during 2007-2009 with resistance factors as high as 122.4. Resistance factors for β-cypermethrin in 35 populations tested were high to very high in all 10 years with values ranging from 32.2 to 683.6. Resistance to fipronil had a progressive increase and increased markedly from 2007 to 2009 with one resistance factor of 56.1. Resistance to monosultap was low in 2004, but increased progressively from 2007 to 2009 with one resistance factor of 129.1. Resistance to phoxim was low to moderate from 2004 to 2008, but was moderate and high in 2009 with resistance factors ranging from 58.7 to 129.1. These results indicate that resistance of diamondback moth populations to most commonly used insecticides in South China has increased and is now generally high.     

Evaluation of a phenological model for strategic decisions for hemp (Cannabis Sativa L.) biomass production across European sites

The optimal combination of yield and quality of hemp fibres from field grown crops is around flowering. Therefore prediction of flowering time would support in planning production and optimization of the cultivar choice for different agro-ecological zones. In the current paper the validation of a recently published model (Amaducci et al., 2008a) is carried out for four varieties across a wide range of sites and thus of air temperature-photoperiod combinations. The model was evaluated by comparing its output to field observations of the duration between emergence and 50% flowering. The model output and observed times from emergence to 50% of flowering generally corresponded well, but some discrepancies were apparent. The biggest discrepancies between estimates and actual data were observed at extreme latitudes. The level of accuracy of the model predictions is satisfactory for strategic decision regarding sowing and harvesting time and cultivar choice, but tactical decisions (e.g. time of harvest based on flowering time) cannot be accurately supported.     

Evaluation of post-emergence herbicides for the control of wild oat (Avena fatua L.) in wheat and barley in Argentina

Wild oat (Avena fatua L.) is the most troublesome weed in cereal crops in Argentina. With the aim of studying the effects of different herbicides, doses, and wild oat growth stage at application on weed control and crop yield, field experiments were conducted in wheat and barley crops during three growing seasons in the south of Buenos Aires Province, Argentina. Treatments were post-emergence applications of new herbicide, pinoxaden + cloquintocet mexyl (5%-1.25%), at doses that ranged from 20 g to 60 g a.i. pinoxaden ha⁻¹, applied at two to three leaves and the beginning of tillering of wild oat. In addition, standard treatments were included and applied at the same wild oat growth stages. Diclofop methyl at 511 g a.i. ha⁻¹ and fenoxaprop-p-ethyl at 55 g a.i. ha⁻¹ were applied in barley. In wheat, diclofop methyl was replaced by clodinafop-propargyl + cloquintocet mexyl (24%-6%) at 36 g a.i. clodinafop-propargyl + 9 g cloquintocet mexyl ha⁻¹ and in 2008/09 wheat experiments, iodosulfuron plus metsulfuron methyl (5%-60%) at 3.75 g a.i. ha⁻¹ + 3 g a.i. ha⁻¹ also was included. In both crops, pinoxaden at 30 g a.i. ha⁻¹ and at higher rates, fenoxaprop-p-ethyl and clodinafop-propargyl gave the best control of wild oat. In 2006/07 wheat crops, treatments applied at tiller initiation provided better control than the early timing averaged across herbicides. However, wheat yield generally was greater with early application. In barley, wild oat control and crop yield were similar regarding time of application. Variations in crop yield were correlated with grain number m⁻² both in wheat and barley, but relationships between both grain number and spikes m⁻² and with grains per spike were identified only in wheat.     

Chemical characterization of barks from Picea abies and Pinus sylvestris after fractioning into different particle sizes

The composition of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) barks was studied after grinding and fractioning into different particles sizes.Both barks fractionated well and with similar fraction yield profile. The yield of fines was low and the major fractions were larger particles, i.e. 2.4% and 3.1% of particles under 0.425 mm and 66.0% and 50.3% of particles over 2 mm, respectively for spruce and pine bark.The chemical composition of spruce and pine barks, as a mass weighed average of all granulometric fractions was, respectively: ash 3.3 and 4.6%; total extractives 21.6 and 18.8% (hydrophilic extractives were dominant), lignin 27.9 and 33.7% and holocellulose 42.7 and 37.6%. Suberin accounted for 1.3% and 1.6% of spruce and pine bark, respectively. The non-cellulosic monosaccharides showed in both barks predominance of arabinose followed by xylose and mannose.Ash elemental composition showed that N represented about 35% of the total inorganics, Ca 35% and K 17%. Zn, Cu, Ni, Cr and Pb were present in both barks at levels under 1% of the total inorganics. Spruce bark had in average higher contents compared to pine bark, except for Pb and Cr.Size reduction of spruce and pine bark did not apply randomly to the different components and instead resulted into partial separation of the inorganic and organic matter into different size particles. Fine particles concentrated higher amounts of inorganic material and of extractives.     

不同施肥及采剪措施对香叶天竺葵出油率及生物产量的影响

为研究施肥措施及采剪时期对香叶天竺葵的出油率及生物量的影响,于2011年3～9月对云南省农业科学院热区生态农业研究所试验基地种植的香叶天竺葵(Pelargonium gravelens L.)进行不同施肥方法及不同采剪时期对出油率和生物量影响的试验研究.结果表明:施N、P、K复合肥比单一施氮肥出油率高,施N、P、K复合肥的同时再进行叶面喷施磷酸二氢钾出油率最高;春季进行采剪的香叶天竺葵出油率低,夏秋季采剪则出油率较高;采剪50 cm以上的壮枝,保留底部弱嫩枝条继续生长的采剪措施,其可采剪次数以及所获得的生物量与整株一次采剪完相比明显增加.说明不同施肥方法及采剪时期的选择对香叶天竺葵出油率影响较大,采剪措施是获得香叶天竺葵生物产量的关键因素之一.     

Comparison of chemical treatments for reducing epiphytic Pseudomonas savastanoi pv. savastanoi populations and for improving subsequent control of olive knot disease

The economic impact of the olive knot disease caused by Pseudomonas savastanoi pv. savastanoi (Psv) has dramatically increased in recent years, especially in high-density plantations. Here we report chemical control trials, performed in an olive grove planted with two susceptible cultivars, Arbequina and Picudo, over a four-year period. The effect of treatments made with copper oxychloride, cuprocalcic sulfate plus mancozeb or acibenzolar-S-methyl on the Psv populations and subsequent appearance of the disease were evaluated. Both copper treatments reduced the proportion of samples where Psv was isolated, and greatly reduced Psv populations in trees of cv. Picudo. The effect of copper on Psv populations was observed after the first application, but the greatest differences between copper-treated and untreated plants were observed in the third year, after five copper applications. No resistance to copper was detected in the remaining epiphytic Psv populations in treated plants. The average number of knots per plant was significantly lower in copper-treated plants than in untreated plants. By contrast, acibenzolar-S-methyl did not reduce either Psv populations or the disease during the study. These results support the usefulness of copper treatments for olive knot management. Results indicate that two copper treatments should be performed regularly under an integrated control program, especially in high-density groves, since their efficiency was demonstrated not only in decreasing olive knot incidence, but also in reducing Psv populations.     

Evaluation of augmentative release of Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae) for biological control of Parthenium hysterophorus L.

Augmentative release of biocontrol agents has been largely successful for the management of insect pests but it has not been a common approach for weed management. Augmentation methods need to be developed for weed management, especially for pernicious weeds like Parthenium hysterophorus L., commonly known as pathenium or carrot weed. The leaf beetle Zygogramma bicolorata is a potential biocontrol agent of P. hysterophorus. Initial release of biocontrol agents is subject to uncertainties as to whether timely population built-up will take place in sufficient numbers. Several augmentative releases may be required to ensure early establishment of the biocontrol agents, for successful biological control of noxious weeds including pathenium. We made augmentative releases of larvae or adults of Z. bicolorata each to three sites, severely infested with pathenium at Jabalpur, India consecutively for a period of three years. Initially 10 larvae or adults per sq m were released in each plot, followed by a second, third and fourth release of 3, 1.5 and 1.5 larvae or adults per sq m at an intervals of 3, 7 and 14 days after the first augmentation. The pathenium at augmented sites were completely defoliated in 45 and 60 days by larvae and adults respectively. There was also a reduction in the pathenium density and plant height in the augmented sites as compared to the non-augmented sites. Over a period of 3 years augmentation resulted in a noteworthy negative effect on the weed.     

Assessment of dermal wound healing and in vitro antioxidant properties of Avena sativa L.

Avena sativa L. (Poaceae) has been reported to have traditional utilization against skin diseases and inflammation. Therefore, in this study, the n-hexane, ethyl acetate, ethanol, and water extracts of A. sativa were investigated for their wound healing and antioxidant activities. Total phenol and flavonoid contents of the extracts were established spectrophotometrically. For the wound healing activity, linear incision and circular excision models on rats and mice were evaluated with a standard ointment Madecassol^®. Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelating, and ferric-reducing antioxidant power (FRAP) assays. Significant wound healing activity was observed with the ointment formulation of the ethanol extract at 1% concentration. The histopathological examination results also supported the outcome of both linear incision and circular excision wound models. All of the extracts exerted low antioxidant activity in the applied assays. The present study provides a scientific evidence for the traditional usage of A. sativa in the management of wound healing.     

Variation in oil content and fatty acid profile of Calophyllum inophyllum L. with fruit maturity and its implications on resultant biodiesel quality

Variation in oil content and fatty acid profile (FAP) of Calophyllum inophyllum; a potential biodiesel feedstock species were studied at different maturity stages and biodiesel quality parameters were estimated based on the FAP. A steady increase in oil content was observed with maturity. Variation in palmitic (16:0) and linoleic (18:2) acids followed exactly opposite trends where palmitic acid content has decreased and linoleic acid content has increased 77 days after anthesis. Oleic acid (18:1) content has shown a steady increase. Stearic acid (18:0) content remained steady up to 68 days after anthesis and then felt slightly in 77 days after anthesis. Linoleic and eicosanoic acids were found to exist in low concentrations demonstrated very little compositional variation with fruit maturity. Estimated biodiesel parameters of all maturity stages were found to comply with industrial standards. Even though 48 days after anthesis had the most ideal FAP for biodiesel production, ∼77 days after anthesis is preferred point to harvest due to higher oil content.     

Impact of organic manure and chemical fertilizers on artemisinin content and yield in Artemisia annua L

Artemisinin isolated from the aerial parts of Artemisia annua L. is a promising and potent antimalarial drug. It posses remarkable activity against both chloroquinine resistant as well as chloroquinine sensitive strains of Plasmodium falciparum. It is also useful in the treatment of cerebral malaria. The relatively low content of artemisinin in A. annua and unavailability of cost effective and viable synthetic protocol however, are major obstacles to the commercial production of the drug. The enhanced production of artemisinin is hence, highly desirable, which can be achieved by adequate and judicious supply of plant nutrients. The present experiment was therefore, designed to study the effect of organic manure (15 tonnes ha⁻¹) and chemical fertilizers (N₄₀₊₄₀, P₄₀, K₄₀, S₁₅₊₁₅ kg ha⁻¹; nitrogen, phosphorus, potassium and sulphur) on the accumulation of artemisinin and biomass in various plant parts through the developmental stages of A. annua L. Artemisinin yield (kg ha⁻¹) was also determined through the developmental stages of A. annua L. Artemisinin content and artemisinin yield of dried leaves were increased significantly at pre-flowering stage in the plants treated with NPKS (27.3% and 53.6%) and NPK (18.2% and 33.5%), respectively, when compared with control. Maximum dry yield of leaf ranging from 2596 to 3141 kg ha⁻¹ was observed at pre-flowering stage with various treatments.     

Timing and efficacy of insecticides for control of mussel scale, Lepidosaphes ulmi, on apple using predictive models

The timing and pattern of mussel scale (Lepidosaphes ulmi (L.)) crawler emergence was monitored in relation to air and bark-surface temperatures using sticky band traps around branches in apple orchards in Kent, UK in three successive years, 2007-2009. The emergence and migration of the crawlers lasted for over 4 weeks at a high level, much longer than had been previously reported. In all three years, there were clearly two peaks of emergence of the crawlers, possibly because there is a diapausing and non-diapausing form of the insect. A temperature sum model developed in the 1990s in The Netherlands using air temperatures predicted the peak emergence of crawlers to within 5-16 days; however, the model was less accurate when tree bark temperatures for the north or south of the tree were used. We have developed two models to predict the emergence of the crawlers by revising the original Dutch model. The observed emergence period (5-95%) was longer than the predicted in all three years but the two revised models performed better than the original Dutch model.In two experiments, in 2007 and 2008, the efficacy of a wide range of insecticide products at different timings during crawler emergence was evaluated. Of the 7 products compared as single or two sprays (spray volume 500 l ha⁻¹) at different emergence timings, or with the addition of adjuvants or as winter treatments, thiacloprid 480 g/l SC (375 ml ha⁻¹) and acetamiprid 20% w/w SP (375 g ha⁻¹) gave the best and similar control, reducing the percentage of fruits infested by 94%. Two sprays of fenoxycarb 25% w/w WG (600 g ha⁻¹) gave the poorest control (28%). Two sprays of spirodiclofen 240 g/l SC (600 g ha⁻¹), chlorpyrifos 75% w/w WG (960 g ha⁻¹) or flonicamid 50% w/w WG (140 g ha⁻¹) gave intermediate results, reducing the percentage infestation by 72% on average. Adjuvants gave no additional value to the treatments when applied in admixture and winter applications of mineral oil (spray volume 1000 l ha⁻¹), alone or in admixture with chlorpyrifos or thiacloprid were not effective at controlling mussel scale the following growing season.Overall, acetamiprid and thiacloprid were the most efficacious insecticides and this study indicates that sprays are best applied in the latter part of the migration (after 50% emergence) with an interval between sprays of at least two weeks to span the long emergence period of the pest.     

Identification of deletion mutants with improved performance under water-limited environments in rice (Oryza sativa L.)

Rice (Oryza sativa L.) is a semi-aquatic member of the grass family that is poorly adapted to dry environments and has greater sensitivity to water-deficits than other important cereals in this family. To increase productivity in aerobic or water-limited environments rice must overcome its adaptations to flooded environments. Deletion mutants offer an alternative genetic resource for improving drought tolerance. Almost 3500 IR64 deletion mutants were screened under vegetative and reproductive stage drought stress in the field and evaluated for leaf drying and/or grain yield. Seven novel conditional mutants of rice which showed gain of function through continued growth as drought stress developed compared to the wild type were identified. Mutant recovery rate was 0.1%. Further evaluation of putative drought mutants revealed that their average shoot biomass at maturity and grain yield per plant under stress exceeded those of the wild type by two-fold. Studies under controlled conditions confirmed mutants to have continued growth of both roots and shoots as drought developed compared to the wild type, and a tendency for greater water extraction. We propose that deletions in these mutants have affected a regulator of the highly conservative growth response common to irrigated lowland rice cultivars. Our results suggest that screening deletion mutants for performance under managed drought stress in the field could be a highly effective way to identify valuable genetic resources for improved drought response and aerobic adaptation in rice.     

Heritability of,and genotypic correlations between,aflatoxin traits and physiological traits for drought tolerance under end of season drought in peanut (Arachis hypogaea L.)

More rapid progress in breeding peanut for reduced aflatoxin contamination should be achievable with a better understanding of the inheritance of, aflatoxin trait and physiological traits that are associated with reduced contamination. The objectives of this study were to estimate the heritability of aflatoxin traits and genotypic (r_G) and phenotypic (r_P) correlations between drought resistance traits and aflatoxin traits in peanut. One hundred-forty peanut lines in the F_4:6 and F_4:7 generations were generated from four crosses, and tested under well-watered and terminal drought conditions. Field experiments were conducted under the dry seasons 2006/2007 and 2007/2008. Data were recorded for biomass (BIO), pod yield (PY), drought tolerance traits [harvest index (HI), drought tolerance index (DTI) of BIO and PY, specific leaf area (SLA), and SPAD chlorophyll meter reading (SCMR)], and aflatoxin traits [seed infection and aflatoxin contamination]. Heritabilities of A. flavus infection and aflatoxin contamination in this study were low to moderate. The heritabilities for seed infection and aflatoxin contamination ranged from 0.48 to 0.58 and 0.24 to 0.68, respectively. Significant correlations between aflatoxin traits and DTI (PY), DTI (BIO), HI, biomass and pod yield under terminal drought conditions were found (r_P = −0.25** to 0.32**, r_G = −0.57** to 0.53**). Strong correlations between SLA and SCMR with A. flavus infection and aflatoxin contamination were also found. Positive correlations between SLA at 80, 90, and 100 DAP and aflatoxin traits were significant (r_P = 0.13** to 0.46**, r_G = 0.26** to 0.81**). SCMR was negatively correlated with aflatoxin traits (r_P = −0.10** to −0.40**, r_G = −0.11** to −0.66**). These results indicated that physiological-based selection approaches using SLA and SCMR might be effective for improving aflatoxin resistance in peanut.     

Effects of crude seed extracts of Annona atemoya and Annona squamosa L. against the cabbage looper, Trichoplusia ni in the laboratory and greenhouse

Antifeedant, growth inhibitory and toxic effects of crude seed extracts of Annona squamosa and Annona atemoya from Fazenda Viveiro Bona, Parasisópolis – Minas Gerais, Brazil, were evaluated against the cabbage looper, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) using different bioassays. Crude methanolic seed extracts deterred feeding of third instar T. ni larvae in a leaf disc choice bioassay. A. squamosa was ∼10 times more active as a feeding deterrent than A. atemoya (DC₅₀ = 2.3 mg/ml vs. 20.1 mg/ml). A. squamosa was ∼three times more active as a growth inhibitor than A. atemoya (EC₅₀ = 38.0 ppm vs. 117.0 ppm). Methanolic seed extracts of A. squamosa and A. atemoya were toxic to third instar T. ni larvae both through topical and oral application. A. squamosa was more toxic through feeding (LC₅₀ = 167.5 ppm vs. 382.4 ppm) whereas, A. atemoya exerted greater toxicity via topical application (LC₅₀ = 301.3 μg/larva vs. 197.7 μg/larva). Both A. squamosa and A. atemoya extracts reduced leaf area consumption and larval growth in a greenhouse experiment. Our results indicate that both A. squamosa and A. atemoya have potential for development as botanical insecticides, especially for local use in Brazil.     

Suppressiveness of steam-exploded biomass of Miscanthus sinensis var. giganteus against soil-borne plant pathogens

Commercial compost is a renewable resource widely used in horticulture as an organic amendment, though its suppression against soil-borne plant pathogens remains limited. Preliminary studies conducted on the disease suppression effect of the biomass waste obtained in a steam explosion plant demonstrated positive results. Steam-Exploded Biomass (SEB) of Miscanthus sinensis var. giganteus, a herbaceous perennial energy crop, is a multifunctional renewable energy resource, which could also be useful in crop protection to find valid alternative to the compost use in horticulture. The purpose of this work was to assess the suppressiveness of SEB against five plant pathogenic fungi that are important in many Italian horticultural cropping systems. Analyses of the microbial inhibitors (furfurals, organic acids and lignosulfonates) present in the SEB were performed by the High Performance Liquid Chromatography technique. Assessment of toxic effect of the furfurals present in the SEB (furfuraldehyde and 5-hydroxymethylfurfural), added to a growing medium at the different concentration ranges, was carried out in vitro on Phytophthora nicotianae, Pythium ultimum, Fusarium oxysporum f. sp. lactucae, F. oxysporum f. sp. melonis and Rhizoctonia solani. The suppressiveness of SEB, added to a potting soil used in horticulture at the different doses, was tested in vivo on tomato/P. nicotianae, cucumber/P. ultimum, lettuce/F. oxysporum f. sp. lactucae, melon/F. oxysporum f. sp. melonis and bean/R. solani. The results showed that furfuraldehyde, 5-hydroxymethylfurfural, lignosulfonates, acetic and formic acid were detected at a concentration of 2.93, 0.28, 4.12, 10.07 and 1.88 g/kg SEB, respectively. The P. nicotianae, P. ultimum and R. solani fungi were highly inhibited by the addition of 3.2 g/L furfuraldehyde and 0.48 g/L 5-hydroxymethylfurfural. Moreover, the inhibitory effect was found not adequate against F. oxysporum at the same concentrations. The SEB increased significantly the suppressiveness level of the peat substrate on P. ultimum in cucumber and R. solani in bean in all the trials. For P. nicotianae in tomato, the SEB addition showed a significant suppression at the 20 and 30% doses, but the change was not significant at the 10% dose. In case of F. oxysporum f. sp. lactucae in lettuce and F. oxysporum f. sp. melonis in melon, the SEB addition showed no suppressive effect with respect to compost in all the trials. In conclusion, the SEB could be used against some soil-borne fungal diseases in place of compost in the potting soil, and its suppressiveness could be related to the concentration of the microbial inhibitors produced during the processing of fresh biomass in the steam explosion plant.     

Chemical composition of the underutilized legume Cassia hirsuta L.

Seven accessions of the underutilized legume, Cassia hirsuta L., seeds collected from seven different agroclimatic regions of Tamil Nadu, India, were analyzed for proximate composition, total proteins, protein fractions, mineral profiles and selected antinutritional factors. Crude protein ranged from 15.52 to 20.74%, crude lipid 3.77–7.04%, crude fiber4.68–6.92%, ash 3.98–6.42% and carbohydrates 62.45–70.16%. Energyvalues of the seeds were 1549–1634 kJ/100 g (DM), which are comparable to those of other legumes. Data on seed protein fractions revealed thatglobulins constituted the bulk of the seed protein as in most legumes. Mineralcontents of the seeds showed greater variation. Potassium was the mostabundant mineral (1029–1786 mg/100 g), whereas manganese was low (2.1–2.2 mg/100 g). Antinutritional factors such as total free phenolics,tannins, L-DOPA and lectins were analyzed. The results of the studydemonstrated that the accessions of C. hirsuta seeds collectedfrom Tamil Nadu, India, could be good sources of some important nutrientsfor humans.