Growth and Visual Symptoms of Nutrients Deficiency in Mangosteens(Garcinia mangostana L.)

The aims of study were to evaluate growth and characterize the visual symptoms of macronutrient and micronutrient deficiencies in mangosteens. The seedlings were cultivated in nutritive solution containing all required macronutrient and micronutrients and in solutions with omission of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn, using the missing element technique. The experimental design was completely randomized with five replicates and twelve treatments. Symptoms of nutrient deficiency were accompanied by photographic records and described from beginning until complete definition, in which the plants were collected. Growth was evaluated through of dry mass production and nutrient contents. Nutrients omissions resulted in morphological alterations, characteristic symptoms of nutritional deficiency, promoted the reduction in dry mass production in plant, in which the Fe was most limiting, followed by N, and S. Macronutrients and micronutrients contents, without deficiencies (complete treatment) and deficient in mangosteen leaves were respectively: N (16.4 and 12.5 g kg-1);P (1.1 and 0.2 g kg-1);K (10.2 and 8.1 g kg-1);Ca (6.7 and 1.9 g kg-1);Mg (1.1 and 0.1 g kg-1);S (3.0 and 2.2 g kg-1);B (20 and 16 mg kg-1);Cu (7 and 3 mg kg-1);Fe (266 and 86 mg kg-1);Mn (58 and 17 mg kg-1). The decreasing order in appearance of visual symptoms of deficiency was N > S > K > B > Ca > P > Mg > Mn > Cu > Zn.

Nitrogen Metabolism,Carbohydrates and Sucrose in Young Plants of Paricá(Schizolobium amazonicum)Submitted to Different Dosages of Aluminum

The paricá [Schizolobium amazonicum Huber ex Ducke] is a native species of the Amazon region, belonging to the Fabaceae family and is a legume that has great social and economic importance, raw material for the manufacture of wood panels. Heliophilous, with wood of light density and good workability. Amazonian soils are highly weathered and characterized by high acidity, so Al harms the growth and development of sensitive plants, as well as the presence of resistant and/or tolerant plants. Thus, in this work, we sought to study the biochemical metabolism alterations generated in young plants of Schizolobium amazonicum Huber ex Ducke affected at different dosages of AlCl3. The research was conducted in a greenhouse of the Federal Rural University of Amazonia, using pre-scarified paricá seeds, which were seeded in plastic containers of 3.5 L capacity, with black soil fertilized with NPK 15-15-20. On the 8th day after sowing (DAS), thinning of 5 seedlings was performed for 2, and on day 12 of 2 for 1 seedling. The treatments started after 1 month and 22 days of sowing and the plants were collected 24 days later. A completely randomized experimental design (RED) was used, with 6 treatments (Control, Al 15 mg/L-1, Al 30 mg/L-1, Al 45 mg/L-1, Al 60 mg/L-1 and Al 75 mg/L-1) with 5 replicates each (one plant/pot) totaling 30 experimental units. The AlCl3 dosages resulted in considerable changes in the biochemical variables evaluated, especially when the 75 mg·L-1 dosage was applied. The considerable reduction in some variables such as nitrate reductase, glycine betaine and total soluble carbohydrates of these compounds to the applied AlCl3·6H2O dosages, is a way to create resistance mechanisms to try to overcome stress or as a way of showing limitations in the applied dosages. The species was sensitive to the AlCl3 dosages, and resisted only 23 days to the imposed stress. However, it presented defense mechanisms that were able to prolong the physiological activities;since without them, the time of exposure to the stress would possibly be less.