The objective of this study was to identify sorghum varieties that have growth and grain yield potential under saline conditions. The study was conducted in 2016 at a greenhouse of the Embrapa Semiárido, in Petrolina, state of Pernambuco, Brazil (9° 8’ 8.9’’ S, 40° 18’ 33.6’’ W, and altitude of 373 m). A randomized block experimental design, with a 6 × 5 factorial arrangement, and three replications was used. The treatments consisted of six grain sorghum varieties (1011-IPA, 2502-IPA, 2564-IPA, 2600-IPA, Ponta Negra, and Qualimax), and five salinity levels of the irrigation water (ECw = 0, 1.5, 3.0, 6.0, and 12.0 dS m-1). Plant height, stem diameter, dry matter yield, width and length of the +3 leaf, total leaf area, water use efficiency, and grain yield were evaluated. The sorghum varieties 2502-IPA and 1011-IPA presented the highest grain yields when using an ECw of 6.0 dS m-1, followed by Ponta Negra, Qualimax, and 2600-IPA. The 2564-IPA, 2600-IPA, and Qualimax varieties were more sensitive to the salinity effects, with reductions of 50% of the production with ECw of 3.52, 2.75, and 4.38 dS m-1, respectively.

RESUMOO estudo das condições climáticas da região de Petrolina se faz necessário devido sua importância no cenário agrícola nacional. O objetivo do trabalho foi caracterizar os perfis pluviométricos, classificar por meio da utilização de técnica quantílica e a realização de balanço hídrico para diferentes regimes hídricos observados. Foram utilizados da estação meteorológica convencional (OMM: 81991) localizada no município de Petrolina-PE, os dados de precipitação pluvial e temperatura média do ar condensada. Além do uso da técnica de Quantis que classifica os anos de acordo com o índice pluviométrico anual como muito seco, seco, normal, chuvoso e muito chuvoso, foi utilizado o balanço hídrico pelo método de Thornthwaite e Mather. Na caracterização pluviométrica observou-se um quantitativo anual, variando entre 107,20 e 1023,50 mm, com média de 496,83 mm, a cada dois anos é possível observar uma precipitação pluvial igual ou inferior a 462,92 mm. Ao avaliar o balanço hídrico para os distintos regimes pluviométricos obtidos, pode-se verificar que todos os regimes pluviométricos apresentaram uma deficiência que se estende por todo o ano, com exceção para anos chuvoso e muito chuvoso que apresentam reposição nos meses iniciais do ano. Palavras-chave: ciclo hidrológico, climatologia, planejamento agrícola LOPES, I; GUIMARÃES, M. J. M.; MELO, J. M. M.; RAMOS, C. M. C. WATER BALANCE FOR PRECIPITATION REGIMES IN THE PETROLINA, PE REGION ABSTRACTThe study of the climatic conditions of the Petrolina region is necessary due to its importance in the national agricultural scenario. The objective of this work was to characterize the rainfall profiles, to classify by means of the use of quantile regression technique and the achievemnt of water balance for different water regimes observed. Data for rainfall and average temperature of the condensed air were provided by the conventional meteorological station (OMM: 81991) located in the city of Petrolina, PE. In addition to the Quantis technique, which classifies years according to the annual rainfall index as very dry, dry, normal, rainy and very rainy, the water

A B S T R A C TThis study aimed to evaluate the cultivation of forage sorghum subjected to different leaching fractions with saline effluent from fish-farming under semiarid conditions. The experiment was set in a randomized block design, with four blocks, in split plots, composed of four leaching fractions (0; 5; 10 and 15%) and three forage sorghum varieties ('Volumax' , 'F305' and 'Sudão'). Irrigation was performed using saline effluent from fish farming with electrical conductivity of 2.5 dS m -1 . The analyzed variables were: plant height; stem diameter; width, length and number of leaves; fresh and dry matter yield, and relative contents of potassium and sodium in the shoots. Forage sorghum under saline effluent irrigation and leaching fraction of 15% shows a yield increase of 25%, in comparison to sorghum without the leaching fraction. The variety 'Volumax' was more sensitive to salinity than the others, since it showed lower shoot growth and low values of leaf area, fresh matter and dry matter.Cultivo de variedades de sorgo forrageiro irrigado com efluente salino da piscicultura em condições semiáridas R E S U M O O presente trabalho objetivou avaliar o cultivo de variedades de sorgo forrageiro submetido a diferentes frações de lixiviação com efluente salino da piscicultura em condições semiáridas. Foi adotado o delineamento experimental em blocos ao acaso, com quatro blocos, em parcelas subdivididas compostas por quatro frações de lixiviação (0; 5; 10 e 15%) nas parcelas e três variedades de sorgo forrageiro (Volumax, F305 e Sudão) nas subparcelas. A irrigação foi realizada com efluente salino da piscicultura (CE de 2,5 dS m -1 ). As variáveis avaliadas foram altura da planta; diâmetro do colmo; largura, comprimento e número de folhas; produtividade de massa fresca e seca, além de teores de sódio e potássio na parte aérea. Observou-se que o sorgo forrageiro irrigado com efluente salino, com fração de lixiviação de 15% apresentou um aumento percentual de até 25% na produtividade quando comparada à do sorgo sem fração de lixiviação. A variedade Volumax mostrou-se mais sensível à salinidade que as demais em virtude de apresentar o menor crescimento da parte aérea e baixos valores de área foliar e matéria fresca e seca.

This study aimed to evaluate the distribution of salts along the soil profile, the biometric parameters and the yield of beet cultivars under different leaching fractions using saline effluent from fish farming, under the conditions of the Sub-middle São Francisco Valley. An experiment was conducted at the Caatinga Experimental Field of the Embrapa Semi-Arid, in 2013. The treatments were arranged in split plots composed of four leaching fractions (0, 5, 10 and 15%) in the plots, with saline effluent from fish farming, and three table beet cultivars in the subplots: Scarlet Super, Early Wonder 200 and Fortuna. The analysed parameters were: salt distribution along the soil profile, number of leaves, length and width of leaves and petioles, total and commercial yields. The application of leaching fractions of 10 and 15% promoted better salt distribution along the soil profile. The beet cultivar Fortuna showed the highest commercial yield for a lower leaching fraction.

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Sugarcane is one of the most affected crops by water scarcity. The efficient use of the irrigation water is an alternative to minimize this problem. The objective of this work was to evaluate biometric parameters, yield, and technological quality of sugarcane plants subjected to different controlled water deficit regimes in the sub-middle São Francisco Valley, Brazil. The experiment was conducted in a randomized block design, in two crop cycles, with three replications, with ten treatments consisted of three controlled water deficits (15%, 30%, and 45% of the crop evapotranspiration - ETc), applied at three development stages of the plant - sprouting and tillering (Stage I), grand growth (Stage II), and maturation (Stage III) - and a control with 100% of the ETc throughout the entire crop cycle. The controlled water deficit did not affect the technological quality of the sugarcane in any development stage. The sugarcane yield was higher when using a controlled water deficit of 30% of ETc in the sprouting and tillering stages of the plants. The water deficit of 15% of ETc is recommended for the grand growth, or maturation stages of the sugarcane plants for a greater water use efficiency of the production system.

A aplicação de forma eficiente do Paclobutrazol (PBZ) via sistema de irrigação, para indução floral da mangueira, pode promover uma redução nos custos com mão de obra, no volume aplicado do produto e um menor risco ambiental. O objetivo deste trabalho foi ajustar a dose do PBZ a ser aplicada via sistema de irrigação para manejo da indução floral da mangueira, cultivar Palmer, na região do Submédio do Vale do São Francisco. O experimento foi conduzido na fazenda Special Fruit, Petrolina - PE, em dois ciclos da cultura, no período de agosto de 2014 a maio de 2016. O delineamento experimental utilizado foi em blocos casualizados, com cinco doses de PBZ aplicado via sistema de irrigação (0,7; 1,0; 1,3; 1,6; 1,9 g.i.a.m-1 linear de copa) e uma dose aplicada de forma convencional (1,9 g.i.a.m-1 linear de copa, aplicado manualmente a lanço), com quatro repetições. As variáveis analisadas foram comprimento da panícula, número de panículas, número de frutos por planta, produtividade e as características qualitativas do fruto. Aplicação do paclobutrazol via sistema de irrigação demonstrou-se mais eficiente, a dose 1,3 g.i.a.m-1 linear de copa proporcionou uma maior produtividade e número de frutos por plantas. A maior acidez titulável e firmeza da polpa foram obtidas com a dose 1,0 g.i.a.m-1 linear de copa.

The objective of this study was to evaluate the effect of irrigation water salinity on gas exchange and antioxidative system responses of grain sorghum varieties. An experiment was conducted in a greenhouse located at the headquarters of Embrapa Semiarid Agriculture, Petrolina-PE, Brazil. The experimental design was randomized blocks, in a 6 x 5 factorial scheme. Six varieties of grain sorghum irrigated with saline water with five levels of salinity were evaluated. Photosynthesis and transpiration rate, stomatal conductance, leaf temperature, intrinsic and instantaneous water use efficiency, relative water content and leaf turgor potential were evaluated, as well as the activity of the enzymes catalase, ascorbate peroxidase and superoxide dismutase, and shoot biomass production. It was observed that irrigation with saline water causes reduction in the gas exchange and water status of grain sorghum varieties. The antioxidative system was activated in the six sorghum varieties to avoid the accumulation of reactive oxygen species, and the synchronism between the enzymes led to a better response of shoot dry mass production of the Ponta Negra variety.