Infrared thermometry is a possibility of detection of plant water stress by measuring the temperature of a portion of the canopy without requiring physical contact with the sheets. The purpose of this study was determining the crop water stress index in tomato cherry using the leaf temperature in plants as an indicator of water stress. Plants were grown in a greenhouse situated in the Department of Biosystems Engineering at the Escola Superior de Agricultura "Luiz de Queiroz "in Piracicaba, São Paulo. The plants were conducted in eight 500L boxes. The soil of the boxes is Oxisol eutrophic typical. Previously, were defined two groups: with induced water stress (T0; 24 plants) and without water stress (T1; 24 plants). The temperature of canopy was measured before irrigation using a thermal camera which captures infrared images. The leaf and air temperatures were used to calculation of crop water stress index (IEHC) in two moments: 41 and 47 days after transplanting (DAT) using the lower basal limit (LBI) and a theoretical method. The leaf temperature in group T0 was higher than observed in group T1. We found that: i) highest IEHC in both groups was less than 0.7; ii) IEHC based on theoretical method or LBI, showed that stressed plants have higher IEHC than plants with less water stress. The results indicate that water stress in tomato cherry could be estimated by IEHC based on LBI.

The availability of water resources has a direct impact on the economy of a country and the development of the main production processes, from agriculture, irrigation, and food production, to energy generation and water supply. The regional economic and social development is influenced by an adequate management of water resources because it stimulates the economy by expanding and ability to provide water for multiple uses, directly impacting on the generation of employment the improving the quality of life of the population. Venezuela has abundant surface water resources in the large basins. The northern part of Venezuela, where the highest percentage of the population and the main economic activities are based, face a severe water scarcity. Irrigation systems under public sector administration are characterized by large budgetary restrictions, with works for rehabilitation, operation, and maintenance generally carried out with inefficient results, due to lack of adequate technical supervision. There is a gap of official information that allows highlight the crisis that the agricultural sector has faced in the last decade. Another, very important aspect is Venezuela's severe energy crisis which began to present a deficit of electric power generation that has been alarmingly evident since 2009, which has worsened for more than a decade, causing the lack of electricity supply in large regions of the country for periods of time exceeding 100 h, contributing to aggravate the country's economic crisis. Due to the situation described, Venezuelan food systems have been seriously affected mainly by the advanced deterioration of irrigation infrastructure and the water availability on production processes. This paper explores and analyses the influence of water management on production Venezuelan economics and society, focus in three pillars representing the qualitative and quantitative relationships of water management and its impact on the system considering the aspects related to the sustainability of Venezuelan agri-food systems, analyzing the fundamental aspects for food production, main indicators related to the national economy, addressing the challenges to ensure food security.

The responses of oregano plants to water limitation from soil and seasonal phenological cycle are not fully understood yet. The aim of the present research was to help understanding the production of oregano essential oil and biomass facing soil water deficit, which was studied in different seasons. Oregano was subjected to drip irrigation, the water deficit being assessed in the vegetative and pre-flowering stages, as well as whole cycle analysis, through water matric potentials in the soil. The matric potential -60.8 kPa adopted in the irrigation handling during the oregano cultivation interval, led to higher essential oil content and yield. The same potential applied during the oregano pre-flowering stage resulted in the best mean of oregano fresh biomass production. The best dry biomass production was reached by using the matric potential -91.2 kPa in the oregano pre-flowering irrigation management. Water restriction in the soil throughout the entire phenological cycle favored essential oil production, whereas the water restriction during the pre-flowering stage enabled high oregano dry biomass production. The highest values for biomass and essential oil productions were reached for the oregano plants cultivated during spring/summer.

It was aimed to evaluate the effect of doses of phosphorus and different doses of bovine manure on growth of melon Galia. The experiment was carried out in greenhouse utilizing pots filled with soil Chromic Luvissoil in design completely randomized with a 5 x 2 factorial arrangement, comprising five doses of bovine manure (0, 12, 16, 20, 24 t ha-1) and two doses of phosphorus (0 and 400 mg dm-3), with three replicates, totaling 30 experimental units. The results indicated that interaction of phosphorus with organic matter was significant effect on total dry mass of the melon plant. There was a reduction of the total dry mass when the plants were fertilized at the highest doses of bovine manure. The P content from leaf and stem increased gradually at higher doses of phosphorus. The phosphorus content in the soil increased according to the doses of organic material available.

In order to study the effect of downgrade rate of water table in the growth of sugar cane (Saccharum spp, cultivate 867515), an experiment in was carried under randomized block design with factorial arrangement (3 × 5 + 1) and 4 replications, applying the flood irrigation system in 3 stages of development (67, 210 and 300 days after planting - DAP) with 5 downgrade rate of water table (3, 6, 9, 12 and 15 days) and the control (no flood). The plants were grown in soil columns of 240 liters, filled with Yellow Oxisol by 300 days after planting and monitored as the height of the stem, number of leaves, stem diameter, number of internodes, number of tillers, leaf area, growth increment, rate relative growth, leaf area index, leaf area ratio and specific leaf area. The stages of development that the flooding was applied at a rate of lowering of the groundwater level variables influenced the growth of cane sugar. The plants drenched at 210 days after planting for 12 days had higher growth of stem, leaf number, leaf area and leaf area index. Plants exposed to water logging after 67 and 210 days after planting obtain better physiological indices that the witness and those who received the 305 DAP waterlogging. It is recommended that the spacing between drains is estimated to be able to lower the water table, after a reloading project to 30 cm deep in 15 days.