Search

The demand for organically grown products is increasing because many people are concerned about the environment and believe that organic products are healthier than conventional ones. Some studies have shown that organically produced tomato fruits contain higher levels of antioxidants, polyphenols and carotenoids than those produced conventionally. The objective of this study was to evaluate the influence of organic and inorganic fertilization on agronomic and quality characteristics of the processing tomato. The 2-year experiment was laid out in a randomized complete block design, with three replications and three fertilization treatments (untreated, compost and inorganic fertilizer). The results showed that the highest fruit number per plant (98.5), average fruit weight (63.6 g) and fruit yield (168.0 t ha−1) were obtained under inorganic fertilization. The highest total soluble solids (4.39 °Brix) and total soluble solids to titratable acidity ratio (17.4), L* (43.4) and a* (35.4) values, as well as the highest lycopene content (88.5 mg kg−1 f.w). were achieved through the application of organic fertilizer. Significantly higher total soluble solids and total soluble solids to titratable acidity ratio in organically grown tomatoes are particularly important to the processing tomato industry. Finally, the highest lycopene content produced under organic fertilization as well as the non-significant difference between the organic and conventional tomatoes in terms of lycopene yield make organic processing tomatoes suitable for lycopene production.

Lolium spp. are troublesome weeds mainly found in winter cereal crops worldwide, including Europe. In recent years resistant mechanisms have been evolved to several important herbicides. In this study we investigated the mechanisms responsible for conferring glyphosate resistance in some Lolium spp. populations. A holistic approach was used, based on dose-response experiments, determination of shikimic acid concentration in plant leaf tissue, as well as molecular analyses. More specifically, in three Lolium spp. populations the existence of a mutation in the Pro-106 codon of the 5-enolpyruvylshikimate-3 phosphate synthase (EPSPS) gene was investigated as well as the relative transcript levels of four ABC-transporter genes were monitored at three time points after glyphosate application. The results demonstrated that glyphosate resistance is a multifactor phenomenon. Relative transcript levels of the ABC-transporter genes were abundant at very early time points after glyphosate treatments. Dose-response experiments and shikimate analyses were in accordance with the findings of the quantitative PCR (qPCR) analyses. We suggest that relative expression ratio of ABC-transporter genes can be a useful tool to rapidly identify Lolium spp. populations resistant to glyphosate. [ABSTRACT FROM AUTHOR]

Sorghum halepense (L.) Pers is a common and noxious worldwide weed of increasing distribution in many European countries. In the present review, information on the biology, ecology, agricultural, economic and environmental impact of johnsongrass is given, and the current status of this weed in Europe is discussed. Furthermore, special attention is given to the important role of field trials using glyphosate to control weeds in arable and perennial crops in many European countries. Some of the factors which affect control efficacy and should be taken into account are also discussed. Finally, several non-chemical alternative methods (cultural, mechanical, thermal, biological, etc.) for johnsongrass management are also presented. The adoption of integrated weed management (IWM) techniques such as glyphosate use, crop rotation, and deep tillage is strongly recommended to control plant species that originate from both seed and rhizomes. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Pylos, Greece to compare the effect of different types of fertilization on yardlong bean (Vigna unguiculata subsp. sesquipedalis) crop. The conventional treatment plots were fertilized with an inorganic fertilizer, whereas the organic treatments plots received organic compost. Data analysis confirmed no significant correlation between plant height and type of fertilization, but there was significant correlation between length of pods and type of fertilization. In particular, morphological characteristics of yardlong bean were enhanced by inorganic fertilization in comparison with the organic fertilization. Organic farming increased significantly the number on root nodules in comparison with conventional farming. [ABSTRACT FROM AUTHOR]

Environmental concerns and several adverse effects of reliance on and improper use of pesticides make necessary the use of alternative methods. Allelopathy has a rather unexploited potential in integrated weed management and ought to be further studied. The allelopathic effects of velvet bean (Mucuna pruriens (L.) DC. var. utilis) on seedling emergence and first growth of the important weed rigid ryegrass (Lolium rigidum L.) were evaluated in a pot experiment conducted at Agricultural University of Athens. Leaf residues of velvet bean were used to determine their inhibitory potential on seedling emergence and growth parameters including height, leaf number, tillering and fresh and dry weight of rigid ryegrass. Moreover, the allelopathic potential of inflorescence residues of chia (Salvia hispanica L.) on rigid ryegrass was also evaluated. Our results revealed a significant weed suppressive ability of the studied plants. The plant residues incorporated into the soil significantly reduced the seedling emergence and growth parameters of rigid ryegrass as compared to the control. In particular, velvet bean's residues also reduced height, leaf number and biomass of rigid ryegrass up to 26, 51 and 62%, respectively. The indicated allelopathic activity of velvet bean and chia could be further exploited in future studies, by using either allelochemicals as models for future herbicides or the plants as useful cover crops or mulches in terms of integrated weed management. [ABSTRACT FROM AUTHOR]