The tomato (Solanum lycopersicum) is the second most produced vegetable globally, playing a significant role in national and international economies. This crop is highly sensitive to water deficit and thermal stress, which directly affect yield and fruit quality. Foliar application of calcium carbonate (CaCO₃) may be a possible strategy to minimize the effects of these abiotic stresses. This research aimed to determine: (a) the effects of different water replacement levels (WRLs) and photoprotector strategies (Ps) applied to the canopy on production and harvest quality of tomato fruit, (b) thermal responses—Crop Water Stress Index (CWSI) and soil temperature and (c) crop water productivity (WP_c). The research was conducted at the University of São Paulo (USP/ESALQ), Piracicaba, State of São Paulo, Brazil. The experimental design adopted was randomized blocks, with four blocks and nine treatments, totaling 36 plots. The treatments were arranged in a 3 × 3 factorial scheme, with three WRLs (70, 100 and 130% of the required irrigation depth) and three photoprotector strategies (without photoprotector, with photoprotector and with photoprotector + adjuvant). Biometric and thermal responses, productivity, harvest quality and WP_c were determined. The highest plant height and stalk diameter values were found in the treatment with photoprotector and adjuvant, with an average of 0.98 m and 0.0130 m, respectively. For the variables soil temperature, CWSI and tomato productivity, no significant differences were observed. The general average productivity obtained was 77.9 Mg ha⁻¹. The highest WP_c values were found in the WRL 70 treatments, with an average of 23.6 kg m⁻³. No significant differences were observed for pulp firmness. The highest average value of soluble solids was observed in the treatments with photoprotector (4.8 °Brix) and the highest average value of titratable acidity was observed in the WRL 130 treatments (0.36%). Therefore, deficit irrigation resulted in water savings without compromising tomato productivity and the application of photoprotector and adjuvant increased tomato quality.

Cacao is a species of great economic and social importance. Expanding the area grown with this crop has been limited by its climatic requirements. Agroclimatic zoning for agricultural sector and creation of land suitability maps by fuzzy logic contribute to such production expansion. In this sense, this study aimed to develop rainfall zoning for cacao in Bahia state using the fuzzy logic method. The used data came from rainfall historical series of 519 meteorological stations distributed throughout the state. Geostatistical analyses were used to quantify the spatial dependence degree of studied variable and kriging was used to develop maps representing mean monthly rainfall. These maps were submitted to continuous classification by fuzzy mapping for identification of high-risk areas for cocoa growing based on rainfall. Based on the fuzzy method, the southern mesoregion of Bahia state presented the highest rainfall uniformity, suggesting that this area is more suitable for cocoa growing.

Adequate fertilizer concentration and use of shade nets can favor the development and yield of agricultural crops. The objective of this investigation was to evaluate the growth of roselle plants with nutrient solutions of different electrical conductivities (EC_ns) (1.0, 2.0, 3.0, 4.0 and 5.0 dS m⁻¹) and under different colored shade nets (red, blue, black) compared with full sun. The experiments were conducted in a controlled greenhouse environment and in full sun in the Plant Production Department of ESALQ-USP, Piracicaba, SP, Brazil. The experiments were organized using a 4 × 5 randomized block design. The results of analysis of variance and regression showed a significant impact of EC and colored shade nets on plant height, stem diameter, number of leaves, number of flowers, fresh and dry mass of shoots and fresh and dry calyxes. The data were subjected to analysis of variance and regression, which showed a quadratic effect for the variables studied, with increasing values up to 3.0 dS m⁻¹; after this value, there was a decrease. Increasing EC_ns up to approximately 3.0 dS m⁻¹ promoted increments of 2.34% in plant height, 7.21% in number of leaves, 19.76% in shoot fresh mass and 12.38% in shoot dry mass.

A rúcula é uma importante hortaliça folhosa herbácea, de ciclo curtoe de rápido crescimento vegetativo. Nos últimos anos, tem-se observado aumento tanto no consumo quanto no plantio desta hortaliça. O sistema radicular das plantas desempenha papel fundamental que vai além da fixação e sustentação das plantas no solo. Fundamental à absorção de água e nutrientes, está, portanto, diretamente relacionado ao crescimento da parte aérea das plantas. O aumento da conscientização ambiental da população tem elevado o apelo por práticas de produção agrícola sustentável e que produza alimentos com qualidade e segurança. O uso de resíduos orgânicos como fertilizantes, tem se estabelecido como uma alternativa para esse fato. Ainda, o uso de biochar (finos de carvão vegetal) tem importante papel como condicionante físico do solo, proporcionado melhor desenvolvimento radicular, e potencialmente contribui para eficiência no uso da água, haja vista sua capacidade de reter água no solo. Neste trabalho, objetivou-se avaliar o crescimento e desenvolvimento do sistema radicular da rúcula ( Eruca Sativa Miller) em função da aplicação de doses crescentes de manipueira (água residuária do processamento da mandioca) e de biochar (finos de carvão). O experimento foi conduzido na Área de Experimentação Agroecológica da escola Agrícola de Jundiaí/Universidade Federal do Rio Grande do Norte. Utilizou-se o delineamento em blocos inteiramente casualizados (DBC), com quatrorepetições. As doses de manipueira aplicadas foram: 0, 60, 90 e 120 m³ ha -1 . Como cobertura morta do solo, foi utilizado o mulching. As variáveis morfométricas analisadas foram massa de matéria fresca, comprimento radicular (cm), volume radicular (cm -3 ), massa de matéria fresca, e densidade radicular. Foi observado efeito linear crescente para as variáveis massa de matéria fresca, comprimento e volume radicular, massa de matéria seca da raiz, observando-se efeito aditivo do mulching sobre os tratamentos. A densidade radicular expressou comportamento positivo apenas para o cultivo sem o uso do mulching como cobertura morta. Para as condições deste experimento, recomenda-se a dose de 60 m³ ha -1 de manipueira, uma vez que esta proporcionou melhores resultados técnicos para o crescimento e desenvolvimento radicular. Quando ao biochar, recomenda-se a dose técnica de 3.500 kg ha -1 , em função de esta ter proporcionado ganho para as variáveis analisadas.

An efficient water management in irrigation is essential to optimize water efficiency, especially when using brackish water. Thus, the present study was carried out aiming to analyze gas exchanges, pod production, and the water status of peanut plants under increasing levels of salinity (electrical conductivity of 0.12, 1.6, 2.8, 4.0, and 5.2 dS m-1) and the application of the irrigation depth via pulses. A randomized block design in a 5 × 2 factorial scheme was used with four replications, adding up to forty experimental units. The experiment was carried out in drainage lysimeters, at the Federal Rural University of Pernambuco, in open fields from September to November 2019. It was concluded that the use of pulse drip irrigation did not mitigate the deleterious effect of salinity but promoted higher grain and pod production compared to continuous drip irrigation. It was also found that the use of brackish water via pulse drip irrigation promotes greater water use efficiency compared to continuous drip irrigation, and that the increase in the electrical conductivity of the water reduced the water, pressure, and osmotic potentials, along with the osmotic adjustment.

The water status of crops is directly affected by soil water availability. As such, this study aimed to analyze water relations in maize (double-cross hybrid AG 1051) under different soil moisture contents (80, 90, 100, 110, and 120% of field capacity - FC) and fertilization systems (conventional and fertigation). The experiment was carried out in a greenhouse at the Agricultural Engineering Department of Universidade Federal Rural de Pernambuco, in the municipality of Recife, Pernambuco state, Brazil, from August to October 2019. The experimental design was randomized blocks with a 5 × 2 factorial scheme, four replicates and a total of forty experimental units. At soil moisture levels below 100% of field capacity (100% FC), fertigation increased the relative water content, leaf succulence, leaf water potential, and osmotic adjustment of maize plants. When compared to conventional fertilization, fertigation resulted in higher transpiration rates and better water use efficiency in crops irrigated at 95% of field capacity (95% FC). In plants submitted to soil moisture levels below 100% FC, the fertilization system influenced water, osmotic, and pressure potential, and osmotic adjustment occurred.