Suitability of crops,fruit trees/plants to plant parasitic nematodes

Fifteen economically important plant species were tested for their suitability to commonly occurring plant parasitic nematodes viz, Hoplolaimus indicus, Helicotylenchus indicus, Tylenchus filiformis, Rotylenchulus reniformis, Tylenchorhynchus brassicae, Pratylenchus zeae and Meloidogyne incognita. The plants reacted differently to different nematodes. Moreover, eight fruit trees/plants were also tested for their suitability to nematodes.     

Heavy-metal accumulation in crops grown on sewage sludge amended with metal salts

Poplar (Populus euramericana Robusta), oats (Avena sativa L. Leander), maize (Zea mays L. Ona 36), English ryegrass (Lolium perenne L.), butter head lettuce (Lactuca sativa L. Reskia), spinach (Spinacia oleracea L. Subito) and French beans (Phaseolus vulgaris Prelude), were grown in pots with pure sewage sludge (pH 6.7), amended with Cd, Cr, Cu, Ni, Pb and Zn acetates, either added singly or in combination, to study metal effects on plant growth and metal uptake. Phytotoxic metal doses varied with metal and plant species, increasing in the order Cd<Ni<Cu<Zn<Cr and Pb. The threshold dose of toxic metals applied in combination was generally lower than that of metals given singly. Addition of Cd, Ni and Zn was clearly reflected in the respective plant concentrations. This was much less so for Cu, whereas Cr and Pb concentrations were not affected in most plant species. Critical plant (leaf) metal concentrations were lower for metals applied in combination than for single metals. Because of such phenomena the use of critical levels as a diagnostic tool for determining potential multiple metal toxicity is limited.     

The Influence of the Application of Mineral Fertilizers with the Biopreparation Supresivit ( Trichoderma Harzianum ) on the Health and the Yield of Different Crops

The biopreparation Supresivit based on spores from the fungus Trichoderma harzianum was applied as a dressing mixed with mineral fertilizers: NPK, LAV (ammonium nitrate with limestone) and DASA (ammonium nitrate and ammonium sulphate). Our experimental plots with spring barley, winter wheat, winter oil rape, maize and potatoes were fertilized with the mixtures of the biopreparation (1 g, 0.5 g and 0.1 g per 1 kg of fertilizer). There were two check variants, the first variant without any fertilization and without biopreparation, the second with fertilizer and without biopreparation. We observed the infestation of plants with pathogenic fungi and yield parameters. In our experiments it was indicated that Trichoderma harzianum suppresses pathogenic fungi at the concentration 0,5 g of Supresivit per 1 kg of the fertilizer and higher ones. The plants from treated plots had lower infestation - decreasing about 5-15% superficial infestation: tan spot of barley - yellow leaf spot on cereals and leaf blotch of barley, winter wheat - leaf spot of wheat, tan spot of wheat, take-all etc., winter oil-seed rape - black leg and collar rot, potatoes - blight fungus etc. Simultaneously the effect on higher yields was observed.     

主要作物远缘杂交概况

本文综述了水稻、小麦、玉米、棉花、大豆等作物的远缘杂交的概况。这五种作物远缘杂交中,利用的野生近缘植物有水稻的尼瓦拉野生稻、普通野生稻和药用野生稻,小麦的黑麦、偃麦草、冰草、山羊草、簇毛麦、赖草、鹅观草、新麦草、旱麦草,玉米的类玉米和摩擦禾,棉花的墨西哥野生棉、异常棉、瑟伯氏棉、李奇蒙德氏棉、司笃克氏棉和比克氏棉,大豆的野生大豆和半野生大豆。通过远缘杂交获得了新物种如小偃麦、亚比棉等,还获得了大批异附加系、异代换系、易位系等种质材料,以及生产上推广的优良品种。     

Biocontrol of Pests on Plant Crops in Denmark: Present Status and Future Potential

In this review, the status of biocontrol in plant crops in Denmark is analysed and factors governing the present use and future potential are described. In glasshouse vegetables, biocontrol is the dominant method to control pests while it is much less used in glasshouse ornamentals. On outdoor crops, the use of biocontrol is negligible. The main factors determining future prospects include: research, political initiatives, the scale of organic farming, the interest of companies marketing and advising on biocontrol, and public opinion. Good communication between scientists, advisers, growers, government authorities and the public has occurred for many years in Denmark, and has been essential for the successful implementation of biocontrol in glasshouses. Future development of microbial control (to which some organic growers and some members of the public show concerns) will require both research and a debate among the partners, particularly about environmental safety.     

Inter-specific synchrony of two contrasting ungulates: wild boar (Sus scrofa) and roe deer (Capreolus capreolus)

Very few studies on ungulates address issues of inter-specific synchrony in population responses to environmental variation such as climate. Depending on whether annual variation in performance of ungulate populations is driven by direct or indirect (trophic) interactions, very different predictions regarding the pattern of inter-specific synchrony can be derived. We compared annual autumn body mass variation in roe deer (Capreolus capreolus) and wild boar (Sus scrofa) from Poland over the period 1982–2002, and related this to variation in winter and summer climate and plant phenological development [the Normalized Difference Vegetation Index (NDVI), derived from satellites]. Roe deer fawns (∼1.3 kg increase from year 1982 to 2002) and yearlings both increased markedly in mass over years. There was also an increase for wild boar mass over years (∼4.2 kg increase for piglets from 1982 to 2002). Despite our failure to link annual body mass to spring or winter conditions or the NDVI, the body mass of roe deer and wild boar fluctuated in synchrony. As this was a field roe deer population, and since wild boar is an omnivore, we suggest this may be linked to annual variation and trends in crop structure (mainly rye). We urge future studies to take advantage of studying multiple species in order to gain further insight into processes of how climate affect ungulate populations. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Do farmers perceive a deficiency of soil organic matter? A European and farm level analysis

Agricultural soils with too little soil organic matter (SOM) content are characterized by fertility problems. A number of authors have tried to specify threshold values for SOM content to indicate what is ‘too little’, ranging from 1 to 5%, below which yields may be affected. How much SOM content is sufficient, however, depends on a number of environmental factors. In addition, up to date farmers’ perceptions were not included when developing thresholds. Therefore, this study focuses on the following three objectives: (1) to identify a risk indicator on SOM deficiency based on environmental factors and agricultural land use; (2) to test the risk indicator using farmers’ perceptions and (3) to establish threshold values for SOM content based on farmers’ perceptions.For objective 1, literature was reviewed on effects of environmental factors and land use on SOM deficiency. Findings were combined into nine options for a risk indicator on SOM deficiency, mapped at European scale. For objective 2, a farm survey was done among 1452 arable farmers in five European countries (Belgium, Germany, Austria, Spain and Italy). Associations between perceived deficiency of SOM by farmers and environmental factors, land use and the risk indicator were investigated. For objective 3, farmers’ perceptions on SOM deficiency were related to the average SOM content of their fields.Mapping the risk indicator at European scale gives a high to very high risk of SOM deficiency for 7 to 37% of European agricultural land, mainly located in Southern and Eastern Europe. Of the farmers in our survey, 18% perceived a high to very high SOM deficiency. A weak correlation was found between the risk indicator and farmers’ perceptions of SOM deficiency (0.15-0.18, Spearman’s rank correlation). Stronger relations were found between separate environmental factors and perceived SOM deficiency. Apparently, having a more extreme environmental condition for one factor gives a higher chance of perceiving a deficiency of SOM than a combination of moderate environmental conditions. Based on farmers’ perceptions threshold intervals for SOM content were established (sand: 1.2–4.7%, loam: 0.6–2.6% and clay: 1.0–2.4%).If policies on SOM management want to include benefits for productive capacity, targeting areas with a relatively high risk of SOM deficiency, more extreme environmental conditions or with very low SOM contents (below the given threshold intervals) seems most promising.     

Food security in 2044: How do we control the fungal threat?

Plant fungal pathogens place considerable strain on agricultural productivity and threaten global food security. In recent decades, advances in crop breeding, farming practice and the agrochemical industry have allowed crop yields to keep pace with food demand. In this opinion article, we speculate on which recent technological advances will allow us to maintain this situation into the future. We take inspiration that it is 25 y since the first plant disease resistance genes were cloned, and imagine if and how agricultural control of pathogens will be achieved by the year 2044. We examine which technologies are best poised to make the jump from lab bench to field application, and propose that future control measures will likely depend on effective integrated disease management.     

Adaptation of crops to environment

Adaptability is defined as the ability of a crop (or variety) to respond positively to changes in agricultural conditions. The trait is genetically controlled and provides an ability to exploit environmental attributes, both natural and agronomic. Values of relative adaptability can be determined by the regression of the yield of the tested crop over the average yield of compared crops from several environments. We evaluated relative adaptability of 12 staple crops in 12 European countries and compared the yield data over a 43-year period from 1961 to 2003. An additional set of average yield data was also available for the 15 European Union (EU15) member countries. A wider range of 26 crop species was investigated that allowed comparisons between Europe and the USA between 1961 and 2003. Adaptability was closely related to the annual yield increases of the crops studied (r ²=0.999 both in the EU15 and the USA). However, the adaptability of certain crops differed between the two regions. Pulse, maize, millet, wheat and sorghum showed the highest adaptability in the EU15 region, whereas strawberry, pear, tomato, walnut and maize were highest in the USA. The lowest adaptability was found for walnut, pear, apple, cauliflower and hop in the EU15 and for mustard, hop, sugar beet, millet and oat in the USA. In European countries, crops with similar biology, environment and agronomical practices (like the amount of fertilizers and pesticides applied) tended to have similar adaptability values. The data indicate that high adaptability is an important prerequisite for continued yield gains in the best environments.