Propagation methods such as in vitro micropropagation have been developed and improved to increase the multiplication rate in a short time and improve the seedlings quality. The objective of this study was to evaluate the efficiency of the different BAP concentrations on micropropagation of ‘Farta Velhaco’ banana during in vitro multiplication phase. The treatments were: T1 – control (0 mg L-1); T2 - 0.5 mg L-1; T3 - 1 mg L-1; T4 - 1.5 mg L-1; T5 - 2 mg L-1; T6 - 2.5 mg L-1; T7 - 3.0 mg L-1; T8 - 3.5 mg L-1 and T9 - 4.0 mg L-1 of BAP added to the MS culture medium. The total number of shoots produced per explant initial subculture every 30 days was evaluated. The highest number of shoots is recorded 2.5 mg L-1 BAP concentration, which promotes 3 shoots per explant in the 4th subculture. The 4.0 mg L-1 BAP concentration reduces the number of shoots.

In guava plants, production pruning can be performed twice a year, and the return of growth is dependent on the physiological responses that are altered by the different cultivation environments and adopted management. From this perspective, this study aimed to characterize the photosynthetic dynamics of guava plants influenced by different pruning and fruit thinning intensities during two growing seasons in the region of Currais, Piauí, Brazil. The plants were distributed in a randomized block design with a factorial arrangement (3 × 3 × 2) consisting of three pruning intensities (short, medium, and long) and three fruit thinning intensities (0, 10, and 20%) during two growing seasons. The data were subjected to a cluster analysis and canonical discriminant analysis to discriminate treatment groups based on the variables. Through a cluster analysis for the evaluated treatments, it was possible to split the two pruning seasons into five different groups clustered for the first pruning season and the second pruning season. The highest assimilation values were observed in the first pruning season and especially in plants that received short pruning with 0% fruit thinning, medium pruning with 10% and 20% fruit thinning, and long pruning with 10% fruit thinning. Through the graphic representation of the canonical discriminant analysis, the first two variables explained 93.40% of the total variance contained in the nine original variables. The highest means of ambient PAR, transpiration, leaf temperature, internal carbon, and ambient temperature were observed in the second pruning season and in plants that received short pruning with 10% and 20% fruit thinning, medium pruning with 0% and 20% fruit thinning, and long pruning with 0%, 10%, and 20% fruit thinning favors a higher photosynthetic accumulation in guava plants. We observed a multiplicity of responses; however, short pruning with 10% thinning should be considered for both seasons.

The aim of this study was to evaluate the effect of potassium fertilization on yield and final quality of guava fruit variety ‘Paluma’, grown at the Irrigated District of Baixo Açu-RN, Brazil. The experimental was carried out in a completelyrandomized blocks design in split plot with five treatments (0, 0.5, 1.0, 1.5 and 2.0 kg K2O plant-1) with four repetitions. The subplots were composed of two harvest seasons and the following characteristics were evaluated: number of fruits, commercial production, total production, commercial yield, average weight of commercial fruits and average weight of total fruit. For fruit quality the following characteristics were evaluated: vitamin C, soluble solids content, firmness, titratable acidity, flesh pH, fruit length and. With an increasie of K2O dose, a linear increase in the number of fruits was observed and ahigher yield was obtained when a dose of 0.370 kg K2O per plant was applied and a higher fruit firmness was obtained with a dose of 1.2 kg K2O per plant.

This study was carried out in an Atlantic forest remnant in Southeastern Brazil and aimed to spatially model the soil water content (SWC) and net precipitation (NP) on a monthly time scale and to assess the spatial behavior of these hydrological variables in the different seasons. NP is defined by summing throughfall and stemflow, which have been collected after each rain event and accumulated monthly. Soil moisture measurements were carried out monthly up to a depth of 1.00 m and then integrated to obtain the SWC. The exponential semivariogram model was fitted for both hydrological variables, and the goodness-of-fit was assessed by a cross-validation procedure, spatial dependence degree (SDD) and spatial dependence index (SDI). This model provided adequate performance for SWC and NP mapping according to the cross-validation statistics. Based on the SDD, both variables have been classified as a ‘strong spatial dependence structure’. Nevertheless, when the SDI was assessed, NP showed less spatial dependence, while the SWC maintained almost the same performance. Kriging maps pictured the regional climate seasonality due to higher values of both variables in spring and summer than in autumn and winter seasons. However, correlations between NP and SWC are not expressive in the studied period.

The rainfall-forest canopy interaction can impact on the chemical and physical rain-water features and is expected that different forests will have different effects on throughfall rain-water quality parameters. This study aimed (i) to compare chemical and physical rain-water quality variables observed in both gross precipitation and throughfall measured in two different forest stands (Atlantic semideciduous forest remnant - AFR, and a Eucalyptus urograndis plantation - EUP). Each stand was monitored with 8 internal rain-gauges and one external rain-gauge, encompassing the period from March 2015 to March 2016. The results pointed out a seasonal behavior of chemical and physical rain-water variables. Gross precipitation and throughfall presented different behaviors for pH, NH₃, NH4+ and Ca hardness for AFR, and NH₃, NH₄ ⁺, Phosphate, Chloride, Ca hardness, Total Dissolved Solids and Conductivity for EUP. Besides, significant differences between the stands were found in terms of throughfall indicators for some of the rainfall events, remarkably NH₃ and NH₄ ⁺ which were always higher at AFR. Our findings reinforce that trees and forests promote rain water enrichment with nutrients, performing key role on environmental services such as nutrient water and air pollution mitigation.

A maioria dos plantios de bananeira ainda é realizada utilizando mudas tradicionais, mas outros métodos de propagação, como a micropropagação in vitro, vêm sendo desenvolvidos e aperfeiçoados, para elevar a taxa de multiplicação em curto espaço de tempo e melhorar a qualidade da produção de mudas. Contudo, a contaminação é um dos maiores problemas desta técnica. Este trabalho teve por objetivo avaliar a eficiência da descontaminação de explantes de bananeira com o uso de diferentes concentrações de cloro ativo durante a assepsia do explante. O delineamento experimental utilizado foi inteiramente casualizado e constituído de cinco tratamentos e cinco repetições, sendo cada repetição representada por 5 explantes em diferentes concentrações de cloro ativo, sendo: T1 (testemunha, sem cloro ativo); T2 (0,5%); T3 (1,0%); T4 (1,5%), e T5 (2%). Os dados obtidos foram submetidos à análise de variância, e as médias, comparadas pelo teste de Tukey, a 5% de probabilidade. Os resultados permitiram concluir que a maior eficiência dentre os tratamentos testados foi a imersão dos explantes em hipoclorito de sódio com 2% de cloro ativo, sendo as doses testadas não tóxicas aos explantes, permitindo o desenvolvimento normal dos mesmos, concluindo assim que essa concentração possa ser utilizada para o controle de contaminações para micropropagação de bananeira cv. Grande Naine.