RESUMO O objetivo do trabalho foi analisar, técnica e economicamente, a cultura do meloeiro rendilhado cultivado em ambiente protegido. Foram realizados simultaneamente dois experimentos utilizando-se delineamento inteiramente casualizado (DIC) cujas plantas do melão tipo Gália foram submetidas a cinco lâminas de irrigação definidas por 50, 75, 100, 125 e 150%, da evapotranspiração da cultura, com quatro repetições. Os experimentos se diferenciaram apenas pelo não uso (SC) ou uso (CC) de cobertura plástica do solo (mulching). As lâminas de água ótimas economicamente foram 208,83 e 186,88 mm, que resultaram nas produtividades de 50,85 e 44,51 t ha-1 para os experimentos SC e CC, respectivamente. Os resultados permitiram concluir que as lâminas ótimas econômicas ficaram bastante próximas daquelas que produziram as maiores produções físicas, para ambos os experimentos.

ABSTRACT The objective of this study was to analyze technically and economically the irrigated ‘Gália’ melon (Hybrid Nectar), cultivated in greenhouse with and without using plastic mulch covering on the soil. Simultaneously, two experiments were conducted using a completely randomized design (CRD), in which melon plants were submitted to five water availability levels, defined by 50, 75, 100, 125, and 150% of crop evapotranspiration, with four replicates. The difference between experiments were only about the soil covering with plastic mulch: with (CC) or without (SC) plastic mulch. The economically optimal irrigation depths were 208.83 and 186.88 mm, resulting in yields of 50.85 and 44.51 t ha-1 for the experiments with and without mulching, respectively. The results showing the economically optimal irrigation depths were very close to those that produced the highest yield.

ABSTRACT The study aimed to evaluate the “Gália” melons productive characteristics grown in greenhouse under different irrigation levels, and conducted with and without soil cover by plastic mulching. Experiments I (WC) and II (WtC) were conducted simultaneously in a protected environment, using a completely randomized design (CRD), where plants of Gália melons (Hybrid Nectar cv.) received five levels of water depth defined by 50, 75, 100, 125 and 150% of evapo-transpiration (water requirement), with four replications, differing only by utilization (WC) or not (WtC) of plastic mulching. The results showed that the variables productivity, average weight, length and diameter of the fruits were affected by different levels of water replacement in the soil regardless the use or not of the soil cover. The largest reductions in productivity 46.32 and 32.03% were observed for the treatment of 50%, compared to the treatment of 100% for experiments I (WtC) and II (WC), respectively.

Objetivou-se, neste trabalho, avaliar as tensões de água no solo em duas fases fenológicas (vegetativa e reprodutiva) da cultura da pimenta Cayenne, cultivada em ambiente protegido e irrigada por gotejamento. Foram instalados dois experimentos utilizando-se um delineamento inteiramente casualizado cujos tratamentos foram definidos por quatro tensões de água no solo (20, 40, 60 e 120 kPa) e quatro repetições. Os maiores valores de massa média de frutos por planta foram obtidos para a tensão de 20 kPa, sendo 1936,83 e 2091,59 g por planta e os coeficientes de rendimento obtidos foram 0,81 e 1,01, para as fases vegetativa e reprodutiva, respectivamente. Com base nos resultados apresentados concluiu-se que: a produtividade da cultura apresentou comportamento inversamente proporcional à tensão de água no solo e a tensão de 20 kPa mostrou-se mais adequada para promover as irrigações nas fases estudadas. Os coeficientes de rendimento identificaram a fase reprodutiva como a mais sensível ao deficit hídrico.

This study aimed to evaluate the effect of different soil water tensions at different phenological stages (vegetative and reproductive) on Cayenne pepper cultivated in greenhouse and with drip irrigation. A completely randomized design was used, using four soil water tensions (20, 40, 60 e 120 kPa) as treatments with four replications, in two experiments (1 e 2), related to the phenological stages (vegetative and reproductive), respectively. The higher values of fruits mean weight per plant were obtained with 20 kPa soil water tension, being 1,936.83 and 2,091.59 g plant-1 and the yield coefficients obtained were 0.81 and 1.01, for vegetative and reproductive stages, respectively. It was concluded that the crop yield presented inversely proportional behavior to the soil water tension, and the 20 kPa tension showed most appropriate to promote the irrigation on the studied stages. The yield coefficients identified the reproductive stage as the most sensitive to the water stress.

Neste trabalho se utilizaram dados experimentais obtidos na UFLA, no período de março a julho de 2004, com o objetivo de avaliar a produtividade de grãos e de óleo além de outras características agronômicas de dois genótipos de girassol (Helianthus annuus L.): H250 e H251, no período de entressafra; esses dados provieram de quatro experimentos conduzidos com tratamentos de lâminas de água referentes à reposição pela irrigação por gotejamento, de 0 (L0), 75 (L1), 100 (L2) e 130% (L3) da evapotranspiração estimada para a cultura correspondendo, respectivamente, às lâminas de água de 117,20, 350,84, 428,70 e 522,14 mm. A produtividade de grãos e de óleo, a altura das plantas e o diâmetro dos capítulos, aumentaram em função do aumento das lâminas de água, enquanto as cultivares utilizadas indicaram diferenças em relação aos fatores produtividade de óleo, peso de 1000 aquênios e altura de plantas. Notou-se eficiência técnica na produção, mesmo sem irrigação, com produtividade média de 1924,27 kg ha-1 e, na condição irrigada, notaram-se aumentos significativos, chegando aos 2863,12 kg ha-1 para a lâmina de 522,14 mm (130% Etc) aplicada no ciclo da cultura. Os genótipos podem ser utilizados na entressafra, em Lavras, como opção na rotação de culturas.

In this study the experimental data obtained in the period from March to July of 2004 in the Federal University of Lavras (UFLA) were used, with the objective of evaluating the productivity of grains and of oil and other agronomic characteristics of two sunflower genotypes (Helianthus annuus L.) (H250 and H251), irrigated in the late summer growth period. The experiment was carried out with four treatments of drip irrigation water depths of 0 (L0), 75 (L1), 100 (L2) and 130% (L3) of the evapotranspiration estimated for the crop, corresponding, respectively, to the water depths of 117.20, 350.84, 428.70 and 522.14 mm. The productivity of grains and of oil, the height of sunflower plants and the capitulum diameter increased with water depth. The used cultivars presented differences of oil productivity, weight of 1000 achene's and plants height. There was an technical efficiency in production, even without irrigation, with average productivity of 1924.27 kg ha-1 and, in irrigated condition, there was increase of this productivity reaching the 2863.12 kg ha-1 for water depth of 522.14 mm (130% ETc) applied in the crop cycle. The analyzed genotypes can be used during the summer cycle, in Lavras, as an option in the crop rotation.