Root anatomical traits contribute to deeper rooting of maize under compacted field conditions

© The Author(s) 2020. To better understand the role of root anatomy in regulating plant adaptation to soil mechanical impedance, 12 maize lines were evaluated in two soils with and without compaction treatments under field conditions. Penetrometer resistance was 1–2 MPa greater in the surface 30 cm of the compacted plots at a water content of 17–20% (v/v). Root thickening in response to compaction varied among genotypes and was negatively associated with rooting depth at one field site under non-compacted plots. Thickening was not associated with rooting depth on compacted plots. Genotypic variation in root anatomy was related to rooting depth. Deeper-rooting plants were associated with reduced cortical cell file number in combination with greater mid cortical cell area for node 3 roots. For node 4, roots with increased aerenchyma were deeper roots. A greater influence of anatomy on rooting depth was observed for the thinner root classes. We found no evidence that root thickening is related to deeper rooting in compacted soil; however, anatomical traits are important, especially for thinner root classes

Food for thought: how nutrients regulate root system architecture

The spatial arrangement of the plant root system (root system architecture, RSA) is very sensitive to edaphic and endogenous signals that report on the nutrient status of soil and plant. Signalling pathways underpinning RSA responses to individual nutrients, particularly nitrate and phosphate, have been unravelled. Researchers have now started to investigate interactive effects between two or more nutrients on RSA. Several proteins enabling crosstalk between signalling pathways have recently been identified. RSA is potentially an important trait for sustainable and/or marginal agriculture. It is generally assumed that RSA responses are adaptive and optimise nutrient uptake in a given environment, but hard evidence for this paradigm is still sparse. Here we summarize recent advances made in these areas of research

Potential impacts of a Turkish EU-membership on agri-food markets

This paper examines possible impacts of a Turkish accession to the EU on the agricultural markets in Turkey and the EU. AGMEMOD, an econometric, dynamic, multi-market, partial equilibrium economic model for EU agriculture at Member State level, has been extended with a model for the Turkish agricultural sector and afterwards applied to gain quantitative insights into Turkish accession effects. To establish a model for Turkey, the implementation of the model equations required parameter estimates, or the specification of synthetic model parameters. A database with time series on Turkish agricultural production, market balances and prices, macroeconomic variables and policy variables was developed in order to estimate such model parameters and to build an operational Turkish agriculture sector model. Most results show that the dominant impact of the Turkish accession on Turkish agriculture is a reduction of domestic producer prices, which induces further market effects. The - mostly decoupled - CAP support payments will induce smaller incentives to increase production than those which Turkish farmers receive prior to the EU accession. In Turkey effects of accession to the EU will be mostly negative for crop producers (except for tobacco), whereas the consumers are expected to gain from lower market prices. In contrast, producers of sheep meat, broiler and dairy milk could gain from an accession due to lower feed costs

SUPPLY RESPONSE IN FRANCE, GERMANY, AND THE UK: TECHNOLOGY AND PRICE

We extend the methodology of a two-step profit function to obtain area and yield elasticities. We then estimate the effects of price and technology on crop output of France, Germany, and the UK. Area elasticities were obtained by adding area shadow price equations to the standard dual model of output and input equations. Change in output is dominated by technology in the UK and mixed in France and Germany. The results indicate policies affecting price will have diverse responses across countries and crops.Demand and Price Analysis,

Publications of the NASA space biology program for 1980 - 1984

A listing of 562 publications supported by the NASA Space Biology Program for the years 1980 to 1984 is presented. References are arranged under the headings which are plant gravitational research, animal gravitational research, and general. Keyword title indexes and a principal investigator listing are also included

Institutions and economic policies for pro-poor agricultural growth

"This paper draws together findings from different elements of a research project examining critical components of pro-poor agricultural growth and of policies that can promote such growth in poor rural economies in South Asia and Sub-Saharan Africa. Agricultural growth, a critical driver in poverty reducing growth in many poor agrarian economies in the past, faces many difficulties in today's poor rural areas in South Asia and Sub-Saharan Africa. Some of these difficulties are endogenous to these areas while others result from broader processes of global change. Active state interventions in 'kick starting' markets in 20th century green revolutions suggest that another major difficulty may be current policies which emphasize the benefits of liberalization and state withdrawal but fail to address critical institutional constraints to market and economic development in poor rural areas. This broad hypothesis was tested in an analysis of the returns (in agricultural growth and poverty reduction) to different government spending in India over the last forty years. The results reject the alternate hypothesis underlying much current policy, that fertilizer and credit subsidies, for example, depressed agricultural growth and poverty reduction in the early stages of agricultural transformation. The results show initially high but then declining impacts from fertilizer subsidies; high benefits from investment in roads, education and agricultural R&D during all periods and varying benefits from credit subsidies over four decades; low impacts from power subsidies; and intermediate impacts from irrigation investments. These findings demand a fundamental reassessment of policies espousing state withdrawal from markets in poor agrarian economies. Given widespread state failure in many poor agrarian economies today, particularly in Africa, new thinking is urgently needed to find alternative ways of 'kick starting' markets ways which reduce rent seeking opportunities, promote rather than crowd-out private sector investment, and allow the state to withdraw as economic growth proceeds. Authors' AbstractAgricultural growth ,Poverty, Rural ,South Asia Rural poor ,Africa, Sub-Saharan ,Agrarian economies ,Globalization ,Green Revolution ,Poverty alleviation ,Government spending policy India ,

Cloning and characterisation of a maize carotenoid cleavage dioxygenase (ZmCCD1) and its involvement in the biosynthesis of apocarotenoids with various roles in mutualistic and parasitic interactions

Colonisation of maize roots by arbuscular mycorrhizal (AM) fungi leads to the accumulation of apocarotenoids (cyclohexenone and mycorradicin derivatives). Other root apocarotenoids (strigolactones) are involved in signalling during early steps of the AM symbiosis but also in stimulation of germination of parasitic plant seeds. Both apocarotenoid classes are predicted to originate from cleavage of a carotenoid substrate by a carotenoid cleavage dioxygenase (CCD), but the precursors and cleavage enzymes are unknown. A Zea mays CCD (ZmCCD1) was cloned by RT-PCR and characterised by expression in carotenoid accumulating E. coli strains and analysis of cleavage products using GC¿MS. ZmCCD1 efficiently cleaves carotenoids at the 9, 10 position and displays 78% amino acid identity to Arabidopsis thaliana CCD1 having similar properties. ZmCCD1 transcript levels were shown to be elevated upon root colonisation by AM fungi. Mycorrhization led to a decrease in seed germination of the parasitic plant Striga hermonthica as examined in a bioassay. ZmCCD1 is proposed to be involved in cyclohexenone and mycorradicin formation in mycorrhizal maize roots but not in strigolactone formatio

The impact of the mid-term review on the German agricultural sector

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