János Nagy

Evaluating the effect of year and fertilisation on the yield of mid ripening (FAO 400–499) maize hybrids

The high degree of climate variability is one of the highest risk factors of production, which has to be taken into consideration at all times even within the framework of modern agriculture.One of the most important opportunities of adapting to changing climatic conditions is the evaluation of plant types and genotypes according to fertility and genotypes.The effect of year on the yield of maize was examined through using a twenty-two year yield sequence. Weather was changeable in the examined period, therefore the effect of fertilisation was very different as well. The relationship between the quantity of precipitation in the winter period and growing season and the unfertilised treatments can be easily detected. The quantitative relationship between the two variables is average, because beside the total quantity of the precipitation the periodical distribution is also a significant factor that influences yield. Significantly small yield is not always accompanied by the lowest amount of precipitation (1...

Trehalose overproduction affects the stress tolerance of Kluyveromyces marxianus ambiguously

A thermotolerant Kluyveromyces marxianus mutant was developed by exposing yeast cultures repeatedly to 48°C incubation temperature, and the strain was characterized with a significantly increased trehalose content. Unexpectedly, the strain was sensitive to alcohol, osmotic and oxidative stress, which correlated with the increases in the trehalose concentrations. Intracellular glutathione levels declined in both wild-type and mutant cells when exposed to elevating incubation temperatures. Finally, we reached the surprising conclusion that neither trehalose nor glutathione metabolisms should be aimed at in future strain development programs with K. marxianus.

Comparison of Several Methods for Calculation of Reference Evapotranspiration

Abstract The knowledge of the evapotranspiration of natural ecosystems and plant populations is of fundamental importance in several branches of science, research and practical uses. Nevertheless, the harmonisation of the large number of methods and user needs often causes problems. The objective of the analyses was to explore the output range and sensitivity of models of different physical approaches under local conditions. We performed descriptive statistical and sensitivity analysis of 10 commonly used estimation models - one of them with two variants. Correlation between modelled and measured evapotranspiration data series was assessed. The magnitude of the model outputs, their variability and responses to the changes of selected atmospheric parameters were evaluated. Priestley-Taylor, Penman-Monteith-FAO-56, Shuttleworth-Wallace (parameterized with alternative radiation balance), Szász and Makkink proved to be the most sensitive methods. As regards the systematic error, Makkink and Shuttleworth-Wallace showed the best agreement with pan evaporation, while Shuttleworth-Wallace, Blaney-Criddle and Makkink models were found to be the closest to the Penman-Monteith-FAO-56 method as a reference value. Kivonat A referencia párolgás néhány becslő módszerének összehasonlító vizsgálata. Számos tudományterület és kutatási téma, valamint gyakorlati alkalmazás számára bír alapvető fontossággal a növényállományok, természetes ökoszisztémák evapotranspirációjának ismerete. A nagyszámú módszer és a változó felhasználói igények összeegyeztetése azonban gyakran problémát okoz. A vizsgálatok célja az volt, hogy helyi viszonyok között is megismerhessük az eltérő fizikai megközelítést tükröző modellek kimeneti értéktartományát, érzékenységét. Leíró statisztikai-, valamint érzékenységvizsgálatot végeztünk 10 gyakran alkalmazott becslő modell eredményeire, ezek egyikének esetében két modellváltozatra is. Vizsgáltuk a kiválasztott módszerek korrelációját egymáshoz, illetve mért adatsorhoz képest. Értékeltük a modellkimenetek nagyságrendjét, azok változékonyságát, valamint az egyes légköri paraméterek változására adott reakcióját. A vizsgált módszerek közül a Priestley-Taylor, Penman-Monteith-FAO-56, Shuttleworth-Wallace (egyedi sugárzási egyenleggel parametrizálva), Szász és Makkink modell bizonyult a legérzékenyebbnek. Szisztematikus hiba tekintetében a Makkink és a Shuttleworth-Wallace mutatta a legjobb egyezést a mért értékekkel, míg a Penman-Monteith-FAO-56 módszert referenciaként választva ahhoz a Shuttleworth-Wallace, a Blaney-Criddle és a Makkink modell állt a legközelebb.

Effect of nitrogen doses on the chlorophyll concentration, yield and protein content of different genotype maize hybrids in Hungary

-1 ) in a multifactorial field experiment with four replications and a split plot design in Eastern Hungary (47°33’ N, 21°26’ E, 111 m asl) in two years (2009 and 2010). Nitrogen fertilisation significantly (p < 0.001) increased Chl content in both years. In the dry year (2009), the Chl content did not increase as a result of N fertilisation above 120 kg N ha -1 , while the efficiency of higher N rates (150 kg N ha -1 ) could be shown in the wet year (2010), varying per hybrid. The weather-induced abiotic stress effects on yield and protein content could be reduced by N fertilisation, but this required high input costs. In 2009, both hybrids were treated with the highest N fertiliser dose (150 kg N ha -1 ) in order to reach the statistically highest yield (Mv 277 hybrid 6.76 t ha -1 ; Kenez hybrid 9.86 t ha -1 ), and protein content (Mv 277 hybrid 10.2 g per 100 g dry matter; Kenez hybrid 9.8 g per 100 g dry matter), while lower N fertiliser doses were enough in the favourable crop year of 2010. The correlation analysis results showed that weather parameters significantly influence the closeness of correlations, but are always positive. We concluded that the on-site measurement of leaf chlorophyll (SPAD) serves as a good indicator of the N demand of maize, as the difference between Ndeficient and adequate N treatments is thereby more easily made. Therefore, the Chl content of maize leaf can be used effectively in developing recommendations for soil N replenishment.

Impact of Pesticide Productivity on Food Security

The seven billion global population is projected to grow by 70 million per annum, increasing by 30 % to 9.2 billion in 2050. This increased population density is projected to increase demand for food production by 70 % notably due to changes in dietary habits in developing countries towards high quality food, e.g. greater consumption of meat and milk products, and to the increasing use of grains for livestock feed. The availability of additional agricultural land is limited. Furthermore, more agricultural land will be used to produce bio-based commodities such as bioenergy or fibre instead of food and feed. Thus, we need to grow food on even less land, with less water, using less energy, fertiliser and pesticide than we use today. Given these limitations, sustainable production at elevated levels is urgently needed. The reduction of current yield losses caused by pests are major challenges to agricultural production. This review presents (1) worldwide crop losses due to pests, (2) estimates of pesticide-related productivity, and costs and benefits of pesticide use, (3) approaches to reduce yield losses by chemical, as well as biological and recombinant methods of pest control, and (4) the challenges of the crop protection industry. However, as long as there is a demand for pesticide-based solutions to pest control problems and food security concerns, the externality problems associated with the human and environmental health effects of pesticides needs also to be addressed.

Defence Strategies of Annual Plants Against Drought

Eszter Nemeskeri1, Krisztina Molnar2, Robert Vig3, Attila Dobos3 and Janos Nagy2 1Research Institute and Model Farms, Center of Agricultural Sciences and Engineering, University of Debrecen 2Institute for Land Utilisation, Technology and Regional Development, Center of Agricultural Sciences and Engineering, University of Debrecen 3Hungarian Academy of Sciences University of Debrecen Research Group of Cultivation and Regional Development Hungary

Evaluation of the impact of crop year and fertilisation on maize yield using a novel method

The utilization of bio-effects (BEs), including various plant growth promoting microorganisms has been addressed to the sustainable agriculture. In this study, a combination of a bacterial BE (Proradix WG) based on Pseudomonas sp (DMSZ 1314) with root growth promoting and pathogen suppressive properties and a Laminaria seaweed extract (NEMATEC) were tested to investigate the nutrient acquisition of maize (cv Colisee) from sewage sludge and sewage sludge compost as recycling products from poppy shell-based alkaloid production on a low P organic farming soil (clay loam pH 6.8, 20 mg CAL-P/kg soil). The experiment was conducted in pots (3 kg soil) under controlled growth chamber conditions with phosphate (P) as major limiting nutrient. All organic fertiliser amendments had a positive effect on plant growth but did not reach the values of a full mineral P fertilisation. In the sewage sludge compost treatment, plant biomass production and particularly root length were increased by inoculation with Proradix while no effects were detectable in the sewage sludge treatment. No further improvements could be observed by additional inoculation with the seaweed extract NEMATEC. The results suggest that a proper selection of organic fertilisers with compatible BEs is a prerequisite for successful strategies to improve utilisation efficiency of organic recycling fertilisers.