Customary rights and societal stakes of large-scale tobacco cultivation in Malawi     

Alois Mandondo  Laura German 《Agriculture and Human Values》2015,32(1):31-46

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Apple Variety Assessment with Analytical Hierarchy Process     

Črtomir Rozman  Monika Hühner  Matej Kolenko  Stanislav Tojnko  Tatjana Unuk  Karmen Pažek 《Erwerbs-Obstbau》2015,57(2):97-104

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Occurrence of (+)- and (-)-gossypol in wild species of cotton and in Gossypium hirsutum Var. marie-galante (Watt) Hutchinson     

Stipanovic RD  Puckhaber LS  Bell AA  Percival AE  Jacobs J 《Journal of agricultural and food chemistry》2005,53(16):6266-6271

Gossypol occurs as a mixture of enantiomers in cottonseed. These enantiomers exhibit different biological activities. The (-)-enantiomer is toxic to animals, but it has potential medicinal uses. Therefore, cottonseed with >95% (-)-gossypol could have biopharmaceutical applications. The (+)-enantiomer shows little, if any, toxicity to nonruminant animals. Thus, cottonseed with >95% (+)-gossypol could be more readily utilized as a feed for nonruminants. The (+)- to (-)-gossypol ratio in commercial Upland (Gossypium hirsutum) cottonseed is usually about 3:2, whereas that in commercial Pima cottonseed (Gossypium barbadense) is approximately 2:3. Herein are reported the (+)- to (-)-gossypol ratios in the seed from 28 wild species of cotton (194 accessions), 94 accessions of G. hirsutum var. marie-galante, and 3 domesticated species (11 accessions). It was found that some or all of the accessions of Gossypium darwinii, Gossypium sturtianum, Gossypium areysianum, Gossypium longicalyx, Gossypium harknessii, and Gossypium costulatum produce an excess of (-)-gossypol but none >65%. At least one accession of Gossypium anomalum, Gossypium mustelinum, Gossypium gossypioides, and Gossypium capitis-viridis contained >94% (+)-gossypol. One of the 94 accessions of G. hirsutum var. marie-galante (i.e., no. 2469) contained 97% (+)-gossypol.  相似文献   

Relationships between available soil water and indicators of plant water status of sweet sorghum to be applied in irrigation scheduling   总被引：3，自引：0，他引：3  

Ružica Stričevič  Endre Čaki 《Irrigation Science》1997,18(1):17-21

Optimal crop production depends greatly on available soil water, and it is therefore important to know when and how much to irrigate in order to attain agronomic potential. In this work, plant indicators are used to assess water stress. These are compared with available soil water to find the critical point for irrigation scheduling of sweet sorghum. The experimental trial was carried out in Bečej, in the Vojvodina region, on a sweet sorghum crop, grown in moderate climatic conditions on a well-drained, deep chernozemolic meadow soil. Plant indicators tested were predawn and midday leaf water potential and crop and air temperature difference. All the methods were sensitive to water deficit in plants, but not all can be used for irrigation scheduling. The predawn leaf water potential was the most reliable parameter among those tested due to its relative independence from weather conditions and a valid indicator of plant water status. This was not the case with canopy-air temperature difference. The predawn leaf water potential corelation with available soil water indicates that the threshold value for irrigation scheduling of sweet sorghum is when the former has decreased to –0.45 MPa. This corresponds to a soil water depletion to about 10% of available water in the active root zone. The canopy-air temperature difference was sufficiently sensitive to indicate the onset of mild plant water stress, although it showed a certain threshold value when water shortage appeared, which occurred when the air and canopy temperature were the same. Received: 9 April 1996  相似文献   

Measurement of in situ Phosphorus Availability in Acidified Soils using Iron-Infused Resin     

Karolina Tahovská  Petr Čapek  Hana Šantrůčková  Jiří Kaňa  Jiří Kopáček 《Communications in Soil Science and Plant Analysis》2016,47(4):487-494

A hybrid anion resin was tested for in situ phosphorus (P) availability measurement in soils of two stands recovering from acidification and having different P-sorption characteristics. The phosphate (P-PO₄) sorption capacity of the resin (before saturation) was 48 µmol g^?1. Sorption and elution were tested under P-PO₄ concentrations common in acidic soils (0–0.42 mmol l^?1) either with or without the presence of sulfate (0.2 mmol l^?1). The efficiency of P-PO₄ sorption was independent of the sulfate and was 100 ± 0.2% (n = 56, ± SD). The P-PO₄ recovery stabilized after six elution steps (each: 50 ml of 0.5 M sodium hydroxide, resin/solution 5:1). The efficiency of P-PO₄ recovery was 80 ± 7% and was used to evaluate field measurements. We determined the amount of P-PO₄ in the field using resin bags in three consecutive years. The results indicate that bioavailable P is negatively related to the soil ability to retain P.  相似文献   

Sulphur isotope characteristics of two north Bohemian forest catchments     

M. Novák  S. H. Bottrell  H. Groscheová  F. Buzek  J. Černý 《Water, air, and soil pollution》1995,85(3):1641-1646

Sulphate concentrations and ³⁴S ratios were monitored in bulk precipitation, spruce throughfall, and soil water (depth of 30 and 90 cm) at ervená jáma (CER) and Naetín (NAC), two severely polluted sites in the Czech Republic, between December 1992 and September 1994. Throughfall [SO₄ ^2–], up to 80 mg L^–1 in winter and as low as 7 mg L^–1 in summer, was higher than [SO₄ ^2–] in bulk precipitation (annual average 6 mg L^–1). There was a distinct seasonaity in S isotope abundances, with lower ³⁴S_BULK in summer (+4 per mil CER, + 6 per mil NAC) and lower ³⁴S_TF in winter (+3 per mil CER, +4 per mil NAC). Wintertime ³⁴S_BULK was around +8 per mil at CER and +10 per mil at NAC, summertime ³⁴S_TF was close to +7 per mil at both sites. For only a 1- month period in spring, bulk precipitation S became isotopically lighter than throughfall S. Bulk precipitation data from CER were in good agreement with those from the nearby monitoring station Lesná (LES), typically differing by less than 10 mg L^–1 and 2 per mil in [SO₄ ^2–] and ³⁴S, respectively. Suction lysimeters (soil depth of 30 and 90 cm) yielded higher sulphate concentrations and lower ³⁴S ratios compared to both bulk and throughfall precipitation. Little seasonality was observed in [SO₄ ^2–] at 30 cm (around 40 mg L^–1); at 90 cm [SO₄ ^2–] was higher in winter (70 mg L^–1) than in summer (45 mg L^–1). ³⁴S at 90 cm was <+5 per=" mil=" in=" 1993=" and=" up=" to=" +7.5=" in=" 1994,=" lower=" in=" the=" first=" year=" and=" higher=" in=" the=" second=" year=" compared=" to=" the=" depth=" of=" 30=" cm.=" sulphur=" fluxes=" at=" cer=" and=" nac=" are=" characterized=" by=" distinct=" isotope=" compositions=" and=" can=" therefore=" be=" used=" to=" trace=" s=" pathways=" and=" transformations=" in=" the=" forest=">  相似文献   

RFLP analysis of Hypericum perforatum L. somaclones and their progenies     

Jana Halušková  Eva Čellárová 《Euphytica》1997,95(2):229-235

Three adjacent EcoRI fragments of the rDNA unit from Lycopersicon esculentum, eleven anonymous genomic and two anonymous cDNA clones from Brassica napus and three restriction endonucleases: BamHI, EcoRI and EcoRV were used for RFLP analysis of the genome of Hypericum perforatum L. A polymorphic band identified with EcoRI and two rDNA probes in five somaclones originated from the same genotype was detected in all progenies of two somaclones indicating the inheritance of the molecular changes. rDNA unit heterogeneity represented by two types of RFLP pattern revealed among somaclones and seed-derived control plants using EcoRV and two rDNA probes may indicate an alloploid origin of Hypericum perforatum. The occurrence of the identical RFLP patterns in some R₀ somaclones and seed-derived plants and their progenies may be related to the apomictic mode of reproduction which is assumed to be prevalent in Hypericum perforatum. The differences in RFLP patterns of progenies when compared with the maternal plants (1 out of 10 progenies of one control plant and 1 out of 8 progenies of one somaclone) may indicate that some progenies have originated through sexual recombination. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

A new pyrrole alkaloid from seeds of Castanea sativa   总被引：1，自引：0，他引：1  

Hiermann A  Kedwani S  Schramm HW  Seger C 《Fitoterapia》2002,73(1):22-27

A new pyrrole alkaloid, methyl-(5-formyl-1H-pyrrole-2-yl)-4-hydroxybutyrate (1), was isolated from sweet chestnut seeds and its structure elucidated on the basis of data from NMR spectroscopy and by comparison with synthetic analogues.  相似文献   

Die Becksche Handfäevorrichtung für Forstwirtschaftszwecke     

kgl. bayer. Förster Alois Bed 《European Journal of Forest Research》1912,34(12):613-617

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Quantification of humeroulnar incongruity in labrador retrievers with and without medial coronoid disease     

Proks P  Necas A  Stehlik L  Srnec R  Griffon DJ 《Veterinary surgery : VS》2011,40(8):981-986

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