Soil salinity is a major abiotic factor limiting crop production but an amendment with compost, zeolite or unisal may mitigate the effects of salinity stress on plants. The objective of the present study was to determine the effects of compost, zeolite and unisal on growth of barley plant irrigated with diluted seawater. Barley was the grown on a calcareaus soil treated with compst, zeolite and unisal at the rates of 0 , 4, 8 and 12 % and irrigated with seawater diluted to electrical conductivity (EC) levels of 2.5, 5.0 and 7.5 dS m-1 while tap water was as the control (EC = 0.44 dS/m. Irrigation with 5.0 and 7.5 dS m-1 saline waters significantly suppressed fresh and dry weight of barely plants. However, a substantial increase in plant biomass of salt stressed barley was observed with the three amendments followed the order, compost > unisal > unisal. The application of compost, zeolite or unisal also enhanced K + , Ca +2 and Mg +2 absorption and decreased Na + , Cl-and SO4 = in barely shoot. Post-harvest soil analysis showed high EC values of soil due to saline water irrigation but concentrations were lower in soils treated with the tested amendments especially zeolite. The overall results indicated that soil amendment with compost or zeolite could effectively ameliorate salinity stress and improve nutrient balance barley plant grown on a calcareous soil.

The objective of this study was to analyze the effect of water deficit stress on the growth of Dipteryx alata plants. The experiment was carried out on a bench in full sun at the Goiás State University experimental unit, in Ipameri town, Goiás. Dipteryx alata seeds were collected from native plants in that municipality and sown in four-liter pots containing a mixture of soil, sand and cattle manure at ratio 3:1:0.5, respectively. The experiment was set up following the completely randomized design with five treatments (plants irrigated for 25 days with water volumes corresponding to 0%, 25%, 50%, 75%, and 100% of daily evapotranspiration) and six replicates. Treatments were applied when the plants were 60 days old, and at 85 days the plants were assessed for the following parameters: plant height, stem diameter, number of leaves, foliar chlorophyll concentration (a+b ), total carotenoids, relative water content, transpiration, leaf, stem and root mass ratios, and total biomass. During early development, the Dipteryx alata plants were highly sensitive to water deficit, significantly slowing down vegetative growth. Accordingly, in order to remain alive, the plants drastically reduced transpiration as a result of high stomatal sensitivity.

O presente estudo teve como objetivo identificar a(s) estratégia(s) de sobrevivência de plantas de Tectona grandis sob déficit hídrico para fomentar programas de melhoramento genético. O trabalho foi conduzido em casa de vegetação coberta com plástico transparente e laterais fechadas com sombrite 50%. As sementes de Tectona grandis foram semeadas em vasos de 12 litros contendo uma mistura de solo, areia e esterco na proporção de 3:1:0,5 respectivamente. Utilizou-se o delineamento experimental inteiramente casualizado com cinco tratamentos e seis repetições. A partir do 101º dia após a germinação, as plantas foram submetidas a regimes hídricos diferenciais: plantas diariamente irrigadas com volume de água correspondente a 0%, 25%, 50%, 75% e 100% da evapotranspiração diária durante 20 dias e, em seguida, submetidas as análises. Em condição de déficit hídrico as plantas de Tectona grandis mantêm-se vivas com reduzido crescimento vegetativo, para tal, as plantas ajustam a área foliar e apresentam como estratégia de sobrevivência um eficiente mecanismo de fechamento estomático em função da elevada sensibilidade dos estômatos. O controle estomático da transpiração pode ser utilizado para pré-seleção de materiais promissores para programas de melhoramento genético.

The development of technologies will certainly contribute to boost the commercial exploitation and domestication of Spondias tuberosa. The objective of the present study was to identify morphophysiological effects of gibberellin on the growth of S. tuberosa seedlings. The experiment was conducted in a greenhouse at the Goiás State University, Brazil, using 300-day-old S. tuberosa seedlings planted in 12-liter pots containing soil (Typic Hapludox), sand, and manure (3:1:0.5). The experiment was conducted in a completely randomized design, with five replications and six treatments consisting of single foliar applications of 30 mL plant-1 of solutions with different gibberellin (GA3) concentrations (0, 150, 300, 450, 600, and 750 mg L-1), using a manual sprayer. The plants were evaluated at 60 days after the applications. The maximum biomass accumulation in S. tuberosa seedlings was found with the use of 415 mg L-1 of GA3. The use of gibberellin accelerated the vegetative growth of S. tuberosa plants and enabled the formation of seedlings with better root system and xylopodium, and aerial parts with greater number of leaves, leaf area, and stem weight.

The objective of the present study was to evaluate the initial growth of Khaya senegalensis plants under water deficit. The work was carried out at Ipameri, Goiás on a bench in full sun following the completely randomized experimental design with six treatments and six replications. 120-day-old mahogany plants (Khaya senegalensis) grown in eight-liter pots were subjected to six treatments for 12 days (plants irrigated daily with 100, 80, 60, 40, 20 and 0% of evapotranspiration) with six replications. At 132 days after emergence, the plants were assessed for: plant height, stem diameter, number of leaves, foliar area, daily transpiration, relative water content, total chlorophylls and carotenoids, leaf, stem and root mass ratios, and total biomass. The data were submitted to F-test and, when significant, to regression test at 5% probability. High stomatal control, reduced transpiration, low leaf concentration of total chlorophylls and increased root system growth to the detriment of the shoot growth indicate that Khaya senegalensis is tolerant to moderate water deficit.