Luiz Antonio Biasi

Emprego do estiolamento na propagação de plantas

Etiolation has been used successfully to improve rooting in cuttings of woody fruit-tree and ornamental species. The cuttings rooting is usually better when etiolation is used together with ringbarking or hormone application. Etiolation can be achieved through different forms by covering the stock plants in the field or in the greenhouse. The shoots can be rooted while they are still attached to the stock plant, by stooling or they are removed like cuttings. In this case, after the etiolated shoots have elongated enough, the shading is gradually reduced and an opaque band is wrapped around the base of the new shoot, thereby retaining its etiolated condition while the rest of the shoot turns green in the light. The process is not well understood, although is known that etiolation promove anatomical and physiological tissue changes which are correlated with ease of rooting. The changes include decreased of lignification and suberization of stem tissues, increased of undifferentiated parenchyma and decreased cell wall thickness. The light control of auxin metabolism is also changed, causing changes in phenolic substances content and in the activity of IAA-oxidase and rooting cofactors.

Extração de nutrientes pela parte aérea de carqueja sob a influência de fontes e doses de nitrogênio

This research was aimed at determining the influence of nitrogen sources and levels on the amount and concentration of nutrients extracted from the shoots of carqueja six months after planted. The amount and concentration were correlated to the essential oil and dry matter production. The experiment was conducted at Experimental Station of Canguiri (UFPR), with experimental design in random blocks with seven treatments and four repetitions. The treatments consisted of 4, 8 and 16 grams of nitrogen (N) per plant of urea and manure sources, and a control without N application. The fertilization was done two times with an interval of two months. There was no statistical difference between content and extraction of nutrients for treatments for these soil fertility conditions. Similar results were observed for dry matter and essential oil production. The nutrient extraction for aerial parts presented the decreasing sequence K > N > Ca > S > Mg > P for macronutrients and Mn >Fe > B > Zn > Cu for micronutrients.

Yield and chemical composition of the essential oil of species of the Asteraceae family from Atlantic Forest, South of Brazil

Abstract The essential oil yield and composition of 17 species of the Asteraceae family were evaluated. Samples were obtained by hydrodistillation of the leaves and inflorescences and they were analyzed by GC-MS and GC-FID. A total of 13 species presented essential oils with yields ranging from 0.06 to 3.36% in fresh samples and from 0.07 to 2.53% in dried samples. Erechtites valerianifolius (Wolf) DC. produced the highest essential oil yield from both fresh and dried samples. Seventy-nine constituents were identified in essential oils from Asteraceae species, mainly consisting of monoterpenes and sesquiterpenes.