Ecophysiology and multivariate analysis for production of Tachigali vulgaris in Brazil:Influence of rainfall seasonality and fertilization

Studies on fertilization management of species native to the Amazon for energy plantations contribute to the diversity of species use and reduce biological risk due to the excessive use of clones or hybrids of Eucalyptus.This study evaluates the effect of precipitation seasonality and phosphorus and potassium fertilization on gas exchange in a Tachigali vulgaris plantation.Three levels of P(zero,65.2,130.4 kg ha^(-1))and three of K(zero,100.0,200.0 kg ha^(-1))were applied in a 3×3 factorial randomized block design.Gas exchange measurements were conducted in April and November 2018.In low rainfall,high irradiance period,photo synthetic rates were up to four times higher than in the high rainfall period,reaching 20.3μmol m^(-2)s^(-1)in the treatment with 130.4 g kg^(-1)of P and 100.0 g kg^(-1)of K.Factor analysis and principal component analysis reduced the initial eight gas exchange variables to two and three principal components in periods of high and low rainfall,respectively.The multivariate method used in this study readily identified variations in the variables as a function of rainfall,with high reliability in explaining the data set.

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.

Physiological Quality and Seed Production of Corn and Fabaceae in Monoculture and Intercropping

The aim of this study was to evaluate the physiological quality and seed production of Fabaceae and corn in monoculture and intercropping in areas cropped under different management. The following treatments were evaluated: corn + NPK + weed control;corn + weed control;corn + NPK;corn + crotalaria;corn + jack bean. Intercropping raised the average number of corn ears of corn and the seed IVG Weed control positively influenced the final stand and average number of ears. NPK fertilization on corn sowing positively influenced the seed electrical conductivity. The yield of corn plants intercropped with crotalaria and jack bean was statistically similar. However, their absolute values should be considered for economic purposes. Corn seeds derived from intercropping with crotalaria were more effective compared with intercropping with jack bean. Crotalaria and jack bean seeds when intercropped with corn have high production, germination and vigor (IVG and emergence).

Osmoregulators in Hymenaea courbaril and Hymenaea stigonocarpa under water stress and rehydration

The objective of this work was to evaluate the effect of different water deficiency and rehydration levels on the concentrations of osmoregulators in two plant species（Hymenaea courbaril and H. Stigonocarpa） in the Amazon. We adopted a 2×5×5 factorial system,referring to 2 species（H. courbaril and H. stigonocarpa）and 5 stages of hydration and rehydration. The five hydration and rehydration stages were established in:（1）Control treatment E0;（2） Plants with 13 days of stress after incubation—E13;（3） Plants with 26 days of stress E26;（4）The plants that were established after 26 days after incubation and rehydrated for two days（RD2）;（5） rehydrated for two days（RD4）. The plants that were established after 26 days after incubation and rehydrated for four days. The experiment totaled fifty young plants with five replicates.Biochemical measurements were performed at the beginning of the experiment（E0） at 13（E13） and 26（E26） days after the water stress, in which the plants were rehydrated,repeating the analyses after two（RD2） and four（RD4）days. Both species increased the sucrose concentration by18%, with a decrease of 52% in starch content. The RD4 time presented the highest mean starch concentration(0.19 mmol g-1 of the residue for H. courbaril and0.27 mmol g;of residue for H. stigonocarpa). Increased proline concentrations were recorded for controls until RD2 for both species. For glycine betaine, the highest increases in treatments E26 and RD2 were observed for the H. courbaril species. Our rehydration period was not sufficient for total recovery of pre-stress concentrations of all studied solutes.

Seed Quality Evaluation by Tetrazolium Staining of Parkia multijuga Benth

The purpose of this study was to develop a staining pattern through tetrazolium test to evaluate seed viability of Parkia multijuga Benth (fava-arara-tucupi). The seeds were scarified, soaked into water and distilled for 48 hours for tegument removal and then immersed in a 0.05%;0.1%;and 0.3% tetrazolium solution for 6;18 and 24 hours at 35°C, in the dark. The evaluation was performed on the basis of stain intensity and aspect of the tissues. Based on color patterns, the seed images were classified in eight viability classes. Those results were compared with the germination test in a laboratory. The treatment in concentration of 0.1% for 6 hours was considered adequate for the specie, considering the adequate staining and time for analysis.

Spatial-temporal distribution of fatal yellowing in different oil palm genetic materials in eastern amazon

Oil palm (Elaeis guineensis Jacq.) is one of the agricultural crops with the greatest potentialfor vegetable oil production in Brazil. However, a disease of unknown etiology popularlyknown as Fatal Yellowin (FY) has caused damage to Brazilian farmers particularly in theeastern region of the Amazon. So, the objective of this study was to evaluate the spatialdependence of FY on three oil palm genotypes, grown for many years in an organic produc-tion system in the Amazon region. The study area had 4104 ha, divided into 139 plots. Ineach plot, the monthly incidence of disease was monitored forming a database. The num-ber of diseased plants per year, number of accumulated diseased plants, number of dis-eased plants per hectare, growth rate of diseased plants and incidence of accumulateddisease were evaluated. The results indicated spatial distribution of the variables adjustedto the gaussian, spherical and exponential models, with predominance of the first model.This increases the purpose that FY is caused by biotic factors. The highest range achievedin the study was 2929 m indicating the susceptibility of the tested genotypes. Some plotsclose to the river had the highest incidence of the disease on the study, probably associatedwith higher soil moisture.