ABSTRACT Understanding the green dwarf coconut palm development is essential to improve its management. This study aimed to characterize and understand the seasonality of the green dwarf coconut palm development and yield under rainfed and irrigated conditions in the northeastern region of the Pará state, Brazil. The longitudinal and transverse diameters, fruit mass and yield, in addition to the number of live leaves, live bunches, fruits of the bunches nº 11 and 14 and female fowers were monitored. The coconuts between the bunches nº 20 and 22 showed larger dimensions and biomass (fresh and dry). The partition of the production components varies according to the time of the year, with the liquid albumen mass, which is a component of greater commercial focus, being higher in the rainy season, with lower percentage losses in the irrigated cultivation. The meteorological seasonality plays a key role in fower dropping and fruit abortion, directly contributing to the amount of produced fruits.

RESUMO Compreender o desenvolvimento do coqueiro-anão-verde é essencial para melhorar seu manejo. Objetivou-se caracterizar e entender a sazonalidade do desenvolvimento e a produção de frutos do coqueiro-anão-verde sob condições de sequeiro e irrigação na região nordeste do Pará, Brasil. Foram monitorados os diâmetros longitudinal e transversal, massa e produtividade dos frutos, além do número de folhas vivas, cachos vivos, frutos dos cachos nº 11 e 14 e fores femininas. Os cocos entre os cachos nº 20 e 22 apresentam maiores dimensões e biomassa (fresca e seca). A repartição dos componentes da produção varia conforme a época do ano, sendo a massa de albúmen líquido, componente de maior enfoque comercial, maior no período chuvoso, com menores perdas percentuais no cultivo irrigado. A sazonalidade meteorológica desempenha papel fundamental na queda das fores e no aborto dos frutos, contribuindo diretamente para a quantidade de frutos produzidos.

Abstract Phenological processes are strongly affected by environmental conditions. In this study we investigate the phenological patterns of six tree/shrub species in three Caatinga fragments and analyze the influence of rainfall and air temperature on these processes. Circular statistics was used to analyze the vegetative and reproductive phenophases over 12 months (dry and rainy seasons) in the years 2016 to 2017 and 2018 to 2019. Spearman’s linear correlation test (r) was applied to verify the influence of meteorological variables of the two years of study on the phenological stages for each species. All species showed a seasonal pattern for vegetative phenophases. Reproductive phenophases were recorded in the two study periods only for one species. There was correlation of the phenophases only with rainfall, but not for all species. The amount of rainfall below the historical average indicates that precipitation is the most limiting factor for flowering in the evaluated species.

Resumo Objetivou-se avaliar a adaptação de cultivares de alface com base na metodologia dos graus-dia, em estufa, no vale do Gurguéia. O experimento foi conduzido em ambiente protegido, na Universidade Federal do Piauí - UFPI/CPCE. O delineamento adotado foi em blocos ao acaso, sendo os tratamentos cultivares de alface. As cultivares utilizadas foram: Simpson, Bruna, Palmas e Grand Rapids - TBR. Os dados meteorológicos (temperatura do ar, umidade relativa, pressão atmosférica, velocidade dos ventos e precipitação) foram obtidos em uma estação meteorológica portátil que foi instalada no ambiente protegido. A temperatura do ar durante o experimento apresentou máxima de 33 °C e mínima de 26 °C. As cultivares ‘Simpson’ e ‘Grand Rapids’ apresentaram um ciclo mais precoce (45 dias), quando comparada às demais (52 dias), ambas com constante térmica (CT) de 898 °gd. As cultivares ‘Bruna’ e ‘Palmas’ apresentaram CT = 1050 °gd. Dentre as cultivares avaliadas, as cultivares ‘Palmas’ e ‘Bruna’ obtiveram comportamento e morfologia adequados em relação às altas temperaturas regionais. Dessa forma, conclui-se que as cultivares ‘Palmas’ e ‘Bruna’ possuem potencial produtivo para a região, quando cultivada em ambiente protegido.

Abstract The objective of this study was to evaluate the adaptation of lettuce cultivars based on day-degree greenhouse methods in the Gurguéia Valley. The experiment was carried out in a protected environment, at the Federal University of Piauí - UFPI / CPCE. The experimental design was a randomized block design, with treatments of lettuce cultivars. The cultivars used were: Simpson, Bruna, Palmas and Grand Rapids - TBR. The meteorological data (air temperature, relative humidity, atmospheric pressure, wind velocity and precipitation) were obtained in a portable weather station that was installed in the protected environment. The temperature of the air during the experiment presented maximum of 33 °C and minimum of 26 °C. The cultivars ‘Simpson’ and ‘Grand Rapids’ presented an earlier cycle (45 days), when compared to the others (52 days), both with a thermal constant (CT) of 898 °gd. The cultivars ‘Bruna’ and ‘Palmas’ showed CT = 1050 °gd. Among the evaluated cultivars, the ‘Palmas’ and ‘Bruna’ cultivars obtained adequate behavior and morphology in relation to the high regional temperatures. Thus, it is concluded that the ‘Palmas’ and ‘Bruna’ cultivars have productive potential for the region when cultivated in a protected environment.