The aim of this study was to evaluate the 'Tommy Atkins' mango yield and photosynthesis in regulated deficit irrigation (RDI) in semiarid conditions of Bahia, Brazil. The experimental design was a randomized block with five treatments and six replications: T1, irrigation supplying 100% crop evapotranspiration (ETc) in phases: I (beginning of flowering to early fruit growth), II (start of expansion until early physiological maturity) and phase III (physiologically mature fruits); T2, RDI with 50% ETc in phase I; T3, RDI with 50% ETc in phase II; T4, RDI with 50% ETc in phase III; T5, No irrigation. The soil water deficit causes a reduction in photosynthesis. Mango yield in treatment 4 was approximately 5.5 and 2 times greater than in treatments 5 and 2, respectively. The use of RDI with 50% water depth reduction applied in the third phase of 'Tommy Atkins' mango fruit development was efficient. The use of RDI with 50% ETc in the third phase of fruit development provided the best yield of 'Tommy Atkins' mango for the 350 g weight class.

This study aimed to evaluate the fruit yield and the distribution of 'Tommy Atkins' mango root system under different irrigation regimes in the semiarid region of Bahia. The experimental design was completely randomized with five treatments and three replicates: 1 - Irrigation supplying 100% of ETc in phases I, II and III; 2 - Regulated deficit irrigation (RDI) supplying 50% of ETc in phase I (beginning of flowering to early fruit growth); 3 - RDI supplying 50% ETc in phase II (start of expansion until the beginning of physiological maturity); 4 - RDI supplying 50% ETc in phase III (physiological mature fruits); 5 - No irrigation during all three phases. The regulated deficit irrigation supplying 50% of the ETc during phase I and II provided larger root length density of 'Tommy Atkins' mango. Regardless of management strategy, the roots were developed in all evaluated soil volume and the highest density is concentrated from 0.50 to 1.50 m distance from the trunk and in 0.20 to 0.90 m depth in the soil, that suggests this region to be the best place for fertilizer application as well for soil water sensor placement. The application of RDI during fruit set does not influence either root distribution or production. Root system and crop production is significantly reduced under no irrigation conditions.

Forage cactus pear is considered a xerophilic plant, so it is adapted to harsh semiarid conditions and is a forage resource of significant importance for animal production in regions that are subject to food shortage and long dry periods. We aimed to evaluate the morphometric and physiologic characteristics and water-use efficiency of ‘Gigante’ forage cactus pear under different settings of irrigation depth and irrigation intervals with saline water. The treatments included seven conditions of water application: rainfed, 5 liters of water per linear meter every 15 days; 7% reference evapotranspiration (ETo) with a 15-day irrigation interval; 15% ETo with a 7-day irrigation interval; 33% ETo with a 3-day irrigation interval; 50% ETo with a 2-day irrigation interval; and 100% ETo with daily irrigation. Likewise, the use of saline water (3.6 dS m-1) as irrigation water on forage cactus pear did not stress the crop even in the presence of salts. The treatment with saline water and 33% ETo with a 3-day irrigation interval increased the plant height, number of cladodes, cladode area index, green mass and dry matter yields of forage cactus pear.

This study aimed to evaluate reduction strategies of irrigation for proper management of floral induction and production of 'Tommy Atkins' mangoes, in the semiarid region of the Bahia state, Brazil. Five treatments with reduced irrigation levels based on crop evapotranspiration (ETc) were applied in two development stages, FI - flowering and FII – fruiting. Water depths were T1 - 0% of ETc in FI and 100% in FII; T2 - 25% of ETc in FI and 100% in FII; T3 - 50% of ETc in FI and 100% in FII; T4 - 75% of ETc in FI and 100% in FII; and T5 - 100% of ETc in FI and FII. The treatments were arranged in a randomized complete block design with six replications. Photosynthesis and transpiration rates in phases FI and FII were larger at 8 am than at 2 pm, regardless of the strategies used. These strategies lead to smaller values of photosynthesis, transpiration and leaf water potential within flowering stage. Productive characteristics were not affected by irrigation level reduction for flower induction process, only for the cycles evaluated. Strategies with 0% of ETc in FI and 100% in FII or 25% of ETc in FI and 100% in FII are appropriate to flower induction in 'Tommy Atkins' mango.

O sistema radicular de uma planta é responsável pela absorção de água do solo e deve ser considerado nos cálculos da quantidade de água necessária para irrigação. O trabalho teve por objetivo definir a distribuição do sistema radicular do mamoeiro irrigado por gotejamento e microaspersão em solo de Tabuleiro Costeiro do Recôncavo Baiano. Foram feitas duas trincheiras em diferentes posições relativas a duas plantas irrigadas por microaspersão e gotejamento superficial e enterrado a 0,25 m, com as linhas laterais junto à fileira de plantas, com dois gotejadores por planta, cada um a 0,40 m de distância das mesmas. Na microaspersão, usou-se um emissor para duas plantas, entre duas fileiras simples. As amostras de raízes foram extraídas em malha de pontos nessas trincheiras de forma a abranger uma seção completa do sistema radicular. As raízes foram separadas do solo e digitalizadas em computador, sendo as imagens processadas por um aplicativo computacional que estimou o comprimento total e o diâmetro médio das mesmas em cada posição no perfil. O sistema radicular ocupou maior volume de solo na microaspersão em relação ao gotejamento, com maior concentração das raízes na direção do microaspersor. A profundidade efetiva do sistema radicular do mamoeiro irrigado por gotejamento superficial ou enterrado foi de 0,45 m e na microaspersão variou de 0,15 m na direção perpendicular à fileira de plantas a 0,35 m entre a planta e o microaspersor.

Yield-improving and water-saving techniques assume great importance in the cultivation of banana plants under semiarid regions, prone to greater climate variability. The objective of this study was to evaluate yield and water-use efficiency (WUE) response of ‘Prata-Anã’ banana plants to combinations of plant densities and irrigation levels: three irrigation levels, 50, 75 and 100% crop evapotranspiration (ETc), and four plant densities, 1,666 (3.0 x 2.0 m), 2,083 (3.0 x 1.6 m), 2,666 (3.0 x 1.25 m) and 3,333 (3.0 x 1.0) plants ha-1, evaluated in two production cycles. The treatments were laid out in a randomized block design with four replicates. Increasing plant density up to 3,333 plants ha-1 induced reductions in number of leaves at harvest and some yield components; also, longer cycles, and increased yields were observed while maintaining fruit marketable size, regardless of the irrigation level used. Using an irrigation level at 50%ETc and a plant density of 3,333 plants ha-1 led to an increase in WUE of 313.92% in the first cycle and 295.27% in the second cycle compared with 1,666 plants ha-1 irrigated at 100% ETc. Higher yields and WUE can be achieved by using a plant population density of 3,333 plants ha-1 and irrigation levels below 100%ETc.