Aspects of the allelopathic potential of horseweed (Conyza albida)

The allelopathic effects of three plant tissues of Conyza albida (stems, leaves and inflorescences) on oat growth were further investigated using in vivo tests. Oat growth (fresh and dry weights of above and underground parts) was significantly inhibited from phytotoxic activity of upper leaves and inflorescence tissues of C. albida in pot experiments. The inhibition was significantly higher than in the case of stems. The inhibiting action of crude extracts and volatile compounds from young plants (rosette) were examined using two bioassay methods: (a) seed germination and radicle growth of oat and (b) fresh weight of duckweed plants. Both bioassayed species exhibited great phytotoxic response from the young plants, collected in winter, confirming the results of previous studies. © 2007 Academic Journals

Integrated weed management in winter cereals in southern Europe

Winter cereals are important crops in Southern Europe. Nowadays, the main objective of cereal growers is to reduce production cost and maximize seed yield. Weeds are the main factors associated with increased production costs and reduced yields. Weed control is carried out by cultural methods, but also by applying herbicides. The most common methods used to manage the weeds in cereals are crop rotation, planting a dense crop, mulching and intercropping with legumes. Moreover, wheat cultivars differ in their competitive ability against weeds. The cultural methods cannot alone control the weeds, but rather reduce the weed population in the crops. In many cases, the chemical method is the most effective weed control method. It is also the method that is widely adopted by farmers and an important tool of integrated weed management strategies. In the case of organic agriculture, the role of several cultural practices such as crop rotation, competitive crops and cultivars, change of sowing time and density, false seed bed technique, use of clean certified seed and intercropping is crucial for the overall weed management. © 2016 Nova Science Publishers, Inc. All rights reserved

Effects of cropping system (organic and conventional) on the fiber quality index, spinning consistency index and multiplicative analytic hierarchy process of cotton (Gossypium hirsutum L.)

Markets for organically produced high quality cotton (Gossypium hirsutum L.) are projected to increase. Field experiments were conducted in Palamas, Karditsa in Central Greece, to compare the effects of two cropping systems on fiber quality of three cotton cultivars. The experiments, conducted during three years, were laid out in a split plot design with four replicates, two main plots (organic and conventional system) and three sub-plots (cotton cultivars). Findings suggest that fiber quality index (FQI), spinning consistency index (SCI) and multiplicative analytic hierarchy process (MAHP) are three indices that could be integrated in a useful protocol for the evaluation of different cropping systems for cotton cultivation. In particular, our results indicate that in general there was not any superiority of conventional compared to the organic cropping system regarding fiber quality as shown by the above mentioned indices. Regarding the length of the cotton fiber, this was positively correlated with micronair and the uniformity index of the cotton fiber. The organic system resulted to higher values of SCI than the ones of the conventional (1547.9 and 1522.3, respectively). The present 3-years study shows that organic cultivation of cotton can ensure high fiber quality and this was clearly confirmed by means of the several important indices