CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
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Impact of associated intercrops on growth and yield of maize (Zea mays L) in major seasons of south Asia
Get PDFMixed cropping is a feature of smallholder tropical farming systems, and maize (Zea mays L) is the most common highland cereal planted in these systems in Asia, under rainfed conditions. A field study thus determined the effect of intercropping maize with four popular food crops, over two major seasons of tropical Asia. The bean (Phaseolus spp.) intercrop had no significant impact on growth and yields of maize, while cassava (Manihot esculenta) had the most significant adverse effect. The impact of tomato(Lycospersicon esculentum) and sweet potato (Ipomoea batatas) on maize was in-between those of beans and cassava. The bean, tomato and sweet potato – maize intercrops have LER values greater than unity, while that of cassava maize was lower than 1. Optimizing maize production and resource use in smallholder systems through mixed or intercropping thus requires the selection of suitable crop species
ZmSnRK2.8 responds to ABA through the SnRK2-PP2C complex
Get PDFUnderstanding the responses of maize to abscisic acid (ABA) dependent drought tolerance is an important topic for the biotechnological application of functional mechanisms of stress adaptation. Key components that control and modulate stress adaptive pathways include SnRK2 (sucrose non-fermenting 1-related protein kinases 2) proteins. Recent studies indicate that SnRK2 are plant specific kinases that together with ABA ligand PYR/PYL/RCAR proteins and type 2C group A protein phosphatases constitute the central core of abscisic acid perception and signal transduction. Here, we study drought responses in maize by analyzing the mechanism of ZmSnRK2.8 in ABA signaling to establish relevant analogies with other plant species. ZmSnRK2.8 is a very closely related protein to Arabidopsis OST1 (open stomata 1) kinase with nuclear and cytosolic subcellular localization able to auto-phosphorylate S182 or T183 amino acids on its activation loop suggesting that phosphorylation at these sites may be a general mechanism for SnRK2 activation. In addition, ZmSnRK2.8 is activated by ABA and interacts with PP2C phosphatases in a constitutive, ABA independent manner. Together, our data suggest a conserved mechanism of plant responses to ABA and drought stress in maize and point to the potential use of this kinase in improving programs of drought tolerance in crops
Susceptibility of maize varieties to opposite mating type strains of Fusarium verticillioides
Get PDFFusarium verticillioides the causal agent of maize ear rot is world wide distributed heterothalic species with dimictic mating system of reproduction. Presented paper summarizes results of fourth years (2007 – 2010) field studies analyzing disease severity of maize plant after inoculation with opposite mating type strains of the fungus. Genotypes of fourth maize cultivars (Zea mays var indentata, Zea mays var indurata, Zea mays var everta and Zea mays var saccharata) were inoculated with two F. verticillioides isolates KFI 2856 and KFI 3011 representing respectively MAT1-1 and MAT1-2 subpopulation of the species. Infection degree was evaluated using six degree (0 – 5) rating scale at seven days intervals after inoculation. Obtained results revealed that mating type of analyzed species had not significant impact on maize ear infection in any of growing seasons. Reaction of particular maize varieties against ear rot due to F. verticillioides in particular years were stable. The lowest infection degree exhibited plants of Zea mays var everta while the highest susceptibility Zea mays var saccharata. Regardless of cropping seasons significantly less was affected genotypes of sweet maize (Su1) than super sweet (Sh2)
Prey consumption and development of Chrysoperla externa (Neuroptera: Chrysopidae) on Spodoptera frugiperda (Lepidoptera: Noctuidae) eggs and larvae and Anagasta kuehniella (Lepidoptera: Pyralidae) eggs
Get PDFThe Chrysopidae family comprises natural enemies of agricultural and forest pests. This work evaluated the prey consumption and development of one species, Chrysoperla externa (Neuroptera: Chrysopidae), fed with Spodoptera frugiperda (Lepidoptera: Noctuidae) or Anagasta kuehniella (Lepidoptera: Pyralidae) in laboratory conditions. Chrysoperla externa was reared with: newly laid or one-day-old S. frugiperda eggs; newly hatched, one- or twoday- old S. frugiperda larvae; or one-day-old A. kuehniella eggs. The number of prey offered varied with the development stage of C. externa. Larvae of C. externa and prey were transferred every 24 hours to fresh vials. Duration of the larval stage of C. externa was similar when fed with newly laid or one-day-old S. frugiperda eggs, newly hatched S. frugiperda larvae or A. kuehniella eggs. Larval survival of C. externa was 90.0 ± 2.5% when fed with A. kuehniella eggs and 73.3 ± 18.32% with newly hatched S. frugiperda larvae. Chrysoperla externa consumed high numbers of eggs of A. kuehniella and high weights of one-day-old eggs or newly hatched larvae of S. frugiperda or eggs of A. kuehniella. Chrysoperla externa could not be successfully reared in the laboratory on one- or two-dayold S. frugiperda larvae, but could on eggs of both preys and newly hatched S. frugiperda larvae
Water-yield relations of maize (Zea mays L) in temperate climatic conditions
Get PDFA field study was carried out from 2001 to 2007 in order to determine the water-yield relationship of maize in the Vojvodina region, a northern part of the Serbia Republic. The yield response factor (Ky) was calculated to express the response of maize to water stress both for the growing season and specific growth stages. To assess the ef¬fectiveness of irrigation on maize yield, an irrigation water use efficiency (IWUE) and evapotranspiration water use efficiency (ETWUE) were determined. The study indicated that in the climatic conditions of Vojvodina maize is most sensitive to water stress in the flowering and pollination stage (Ky = 0.52), but less sensitive in the stages of veg¬etative gowth (Ky = 0.37), grain filling and maturity (Ky 0.41). Values of yield response factor in the growing period (Ky = 0.54) indicated that maize is moderately sensitive to soil water stress in the temperate climatic conditions of Vojvodina. The IWUE and ETWUE were in intervals of 0.47 to 3.00 kg m-3 and 0.67 to 2.34 kg m-3 respectively, mostly depending on the extent of favorable conditions of the season for maize production and irrigation water applied. The parameters Ky, IWUE and ETWUE could be used by maize growers as a guide in the study region in terms of op-timum utilization of irrigation water for the planning, design and operation of irrigation projects and for improving the production technology of the crop
Effect of irrigation frequency during the growing season of winter wheat on the water use efficiency of summer maize in a double cropping system
Get PDFOur aim was to investigate the potential effects of irrigation frequency during the growing season of winter wheat on the water use efficiency (WUE) of summer maize in a double cropping system. To this end, we conducted a field experiment with winter wheat cultivated with 1, 2, and 3 irrigation applications with 120 mm water at the time of stem elongation, heading, or milking. The results showed that later irrigation applications increased soil moisture before sowing (SMBS) of summer maize. Summer maize grain yield was enhanced in both the common and excessively rainy years with increased SMBS; however, irrigation during the later growing season of winter wheat in rainy years could increase deep percolation of summer maize. In common and rainy years, the more the SMBS, the higher was the grain yield of summer maize. The highest WUE for summer maize was obtained when it was grown after winter wheat irrigated with 120 mm water at milking or 60 mm water at each, the stem elongation and heading stages. Considering the combined WUE of winter wheat and summer maize, the authors think that winter wheat should be irrigated at the stem elongation and heading stages to achieve reasonable WUE and grain yield for both crops
Behaviour of Quality Protein Maize (QPM) genotypes under well irrigated and water stress conditions in subtropical climate
No full textDrought or water stress is one of the prime problems affecting production of maize at global level. A major objective of QPM breeding programs in semi arid tropics or subtropical climatic conditions is to increase genetic potential of QPM genotypes under water stress conditions. In order to identify drought tolerant single cross QPM hybrids an experiment with 85 genotypes was conducted under well irrigated and water stress conditions. Six drought tolerance indices viz, mean productivity (MP), geometric mean productivity (GMP), yield index (YI), tolerance index (TOL), stress susceptibility index (SSI), and superiority measures (SM) were used on the basis of grain yield in water stress (Ys) and well irrigated (Yp) conditions. Highest significant positive correlations were observed among MP, GMP and YI indices. The hybrids 75, 38, 27, and 50 were more drought tolerant based on drought tolerance indices. Three dimensional plot, bi-plot and cluster analysis confirmed these results. Principal component analysis reduced six indices down to two components with 90.71% proportional cumulative variance. Genotypes were grouped by two ways cluster analysis (using Ward’s method) based on Yp, Ys and drought tolerance indices. Also, the results of correlation, 3D graphs, bi-plot and cluster analysis reveals that the most suitable indices to screen QPM genotypes in drought stress conditions were MP, GMP and YI. These indices could be used in QPM breeding programs to introduce drought tolerance in single cross hybrids
Control of the root-knot nematode, Meloidogyne incognita, in organic protected crops in Sicily
Get PDFThe effectiveness of different methods for controlling the root-knot, Meloidogyne incognita, suitable in organic farming in protected crops, was assessed in tomato during the 2009-2010 crop cycle, on sandy soil in a coastal area of southern Sicily (Italy). The treatments tested were: 60 day soil solarization alone and combined with commercial formulations of plant extracts of Quillaja saponaria Molina, Azadiractha indica Juss., Brassica carinata A. Brown, Tagetes spp., mycorrhizal fungi (Glomus spp.), or pellets and extracts of A. indica. The formulations were applied three or four times at intervals of 30 days. Non treated plots served as a control. The application of plant extracts or the mycorrhizal fungi combined with soil solarization significantly reduced the population of M. incognita in the soil and suppressed root galling on tomatoes compared to both non treated and solarized control plots. All plant derived formulations combined with soil solarization increased marketable yield. The greatest increases were obtained using A. indica or the mycorrhizal formulations in combination with soil solarization
A key for the identification of larvae of Anoplophora chinensis, Anoplophora glabripennis and Psacothea hilaris (Coleoptera Cerambycidae Lamiinae) in Europe
Get PDFAnoplophora chinensis (Förster), A. glabripennis (Motschulsky) and Psacothea hilaris (Pascoe) (Coleoptera Cerambycidae Lamiinae) are longhorned beetles native to the far eastern regions of Asia and were recently accidentally introduced into Europe. The three exotic species are harmful insects to broadleaved plant species, and much attention is being paid to prevent further introductions and spread in the European Union. Severe phytosanitary measures are applied with the aim of eradicating outbreaks of the pests. Crucial for control is rapid identification of the longhorned species during phytosanitary inspections, both in entry ports and in the rest of the territory of the European Union. Taxonomic keys and descriptions of the adult morphology are available in the literature, but there are significant gaps in the taxonomy of larval morphology, and thus molecular analyses are required. During monitoring activities, a practical morphological taxonomic key would be a rapid and useful tool for species identification of the larvae. In the present work, a taxonomic key provided with detailed morphological pictures is proposed for the identification of the larvae of the three exotic species A. chinensis, A. glabripennis and P. hilaris among the closely related species of the native fauna of Europe
Molecular and morphometric identification of plant parasitic nematodes
Get PDFDuring a nematode survey in vineyards of the Veneto region (Italy), several soil samples were collected. On morphological and morphometric studies, a population from Conegliano Veneto was preliminarily identified as X. rivesi Dalmasso 1969. To support the morphological diagnosis, a molecular characterization of X. rivesi from Italy using the D2-D3 expansion segments of the 28S rDNA and the ITS containing region was undertaken. PCR-RFLP analyses were also performed to determine species-specific patterns for the Italian population of the nematode. Neighbor-Joining, Minimum Evolution and Maximum Parsimony analyses were used to reconstruct phylogenetic relationships within X. rivesi and other Xiphinema species