Search

The use of conglomerate for the development of mycorrhizal inoculants is very important to develop a variety of commercial products made from these microorganisms. According to this a experiment was conducted in order to compare the effect of two mycorrhizal inoculants on growth, development and gasses interchange of maize plants. The experiment was developed under a completely randomized design and the inoculants proved were the first constituted by Glomus cubense specie and the other one was a conglomerate of species (Consorcio Selva). Different mycorrhizal (intensity and frecuence), physiological (stomatal conductance, photosynthetic rate) and growth (height, stem diameter and dry mass) indicators were evaluated. Not differences were detected among the inoculants employed on growth indicators, but in mycorrizal parameters the conglomerate (Consorcio Selva) presented the highest values of the indicator; however, an interesting behavior was observed using Glomus cubense inoculants due to the values obtained for this inoculants were comparable to control, but the effect of this specie was the best obtained on gas exchange variable. These results point to the highest efficiency of this specie and to the functional differences between species on ecological point of view, and they open the possibility of using of cluster in field's condition. [ABSTRACT FROM AUTHOR]

The present work was conducted with the objective of studying the behavior of growth, the net photosynthetic rate, stomatal conductance, hydraulic conductivity of roots and leaf water, osmotic and turgor potencials in seedlins of tomato plants submitted to progressive increase to NaCl in the medium, for this seedlins of tomato plants (Solanum lycopersicum L. Cv. Amalia) were submitted to seven different treatments: control (C) plants were maintained in nutrient solution without NaCl; adapted plants (PC) were submitted to progressive increase of 25 mM of NaCl each four days in nutritious solution, in the others treatments were submitted to 25, 50, 75, 100 and 125 mM of NaCl during all experimental period. The inhibition of dry mass accumulation in root system and stem was observed in non adapted plants, while the leaf dry mass and leaf area were affected in all treatments in relation to control plants. Saline stress decreased net photosynthetic rate, stomatal conductance and root hydraulic conductivity in non adapted plants, however, PC plants showed good osmotic adjustment, which enabled them to maintain leaf pressure potential, decreased leaf water potential and osmotic potential at full turgor while the biologic activity was appropriate. [ABSTRACT FROM AUTHOR]

The physiological response of tomato crop (Lycopersicon esculentum) cv INCA 9 (1) was studied after applying two inoculant forms made up of Glomus sp1 (INCAM 4): one in a solid medium and the other in a liquid medium. The solid inoculant was directly put in the substrate of the pots at a single dose and time, whereas the liquid inoculant was sprayed by means of drop irrigation system at different doses and times. The experiment was carried out in a cooling-equipped polycarbonate greenhouse for temperature and relative humidity control. Results showed that the highest colonization and fungal occupation percentages were reached 40 days after seed germination in the liquid inoculant treatments. Soil moisture values were similar in all treatments, indicating that an adequate irrigation regime was supplied to plants, in order to guarantee the same water requirements during all the experimental period. In general, the values of water relations, gas exchange, dry biomass growth and morphological growth variables were higher when plants were treated with the liquid inoculant through irrigation, independently of the dose and time used. [ABSTRACT FROM AUTHOR]

This research work was aimed at determining the effect of high temperatures on some growth variables and gas exchange in tomato plants of Amalia cv. Plants were grown in pots containing silica sand, which were put in trays adding Hoagland's nutrient solution to them. Treatments consisted of a control having a temperature of 25 gC during the day and 18 gC in the dark period, another treatment in which day and night temperatures increased 5 gC every four days up to 40 with 33 gC and a variant where plants were subjected to a heat shock of 40/33 gC day/night respectively for a period of four days. Once treatment application was concluded, plants were placed under the same conditions of the control treatment for 12 days, to evaluate their recovery. Evaluations on biomass, stomatal conductance and CO2 assimilation rate were recorded at the end of every period of heat treatment and recovery. Data analysis made evident a depressive effect of different variables evaluated when increasing environmental temperature; such effect was not eliminated in some indicators after the recovery period. [ABSTRACT FROM AUTHOR]