The aim of this study was to evaluate the water productivity into biomass and into sugar for 23 sugarcane varieties (second ratoon crop) under two levels of drip irrigation. Two experiments were conducted in a greenhouse. Experiment 1 comprised nine sugarcane varieties grown in a clay soil and Experiment 2 was composed of 14 varieties in a sandy-loam soil. Moreover, two irrigation treatments were adopted: T100 - full irrigation with 100% crop evapotranspiration replacement, maintaining soil moisture near field capacity for each variety; and T70 - irrigation with 70% T100 water depth. Water productivity was evaluated in terms of stem fresh biomass (WPFB) and sugar (WPGSY). The results showed that WPFB ranged from 11.45 to 18.45 kg m-3. The highest values were observed for varieties CTC14, CTC6, RB867515, and SP81-3250 (in T100) and for the varieties CTC6 and CTC14 (in T70). The WPGSY values ranged from 1.68 to 2.22 kg m-3, with emphasis placed on CTC6, RB9675-15, SP81-3250, and RB925211 (in T100) and on CTC6, CTC14, and SP81-3250 (in T70).

Knowledge of how certain crops respond to water stress is one of the prerequisites for choosing the best variety and best management practices to maximize crop water productivity (WP_c). The selection of a more efficient protocol for managing irrigation depths throughout the cultivation cycle and in the maturation process at the end of the growth period for each sugarcane variety can maximize bioethanol productivity and WP_c for bioethanol, sugar and biomass, in addition to the total energy captured by the sugarcane canopy in the form of dry biomass. This study aimed to evaluate the effect of four irrigation depths and four water deficit intensities on the maturation phase for eight sugarcane varieties under drip irrigation, analyzing the responses related to WP_c for bioethanol, sugar and biomass. These experiments were conducted at the University of São Paulo. The plots were positioned in three randomized blocks, and the treatments were distributed in a factorial scheme (4 × 8 × 4). The treatments involved eight commercial varieties of sugarcane and included four water replacement levels and four water deficits of increasing intensity in the final phase of the crop season. It was found that for each variety of sugarcane, there was an optimal combination of irrigation management strategies throughout the cycle and during the maturation process. The RB966928 variety resulted in the best industrial bioethanol yield (68.7 L·Mg⁻¹), WP_c for bioethanol (0.97 L·m⁻³) and WP_c for sugar (1.71 kg·m⁻³). The energy of the aerial parts partitioned as sugar had a direct positive correlation with the availability of water in the soil for all varieties. The RB931011 variety showed the greatest potential for converting water into shoots with an energy of 1.58 GJ·ha⁻¹·mm⁻¹, while the NCo376 variety had the lowest potential at 1.32 GJ·ha⁻¹·mm⁻¹. The productivity of first-generation bioethanol had the highest values per unit of planted area for the greatest water volumes applied and transpired by each variety; this justifies keeping soil moisture at field capacity until harvesting time only for WR100 water replacement level with a maximum ethanol potential of 13.27 m³·ha⁻¹.

Devido à dificuldade energética no meio rural e à necessidade de irrigação, mesmo em pequenas propriedades, tem aumentado o uso do carneiro hidráulico, o qual por meio do princípio do golpe de aríete bombeia água sem o uso de energia elétrica. Contudo, seu rendimento em função da altura bombeada não é tão eficiente. Por meio deste estudo, objetivou-se com a adição de uma válvula retentora na entrada do carneiro ter um ganho de eficiência. A válvula tem a função de formar uma barreira física para a água que retorna, após seu golpe, com a válvula de sucção. O projeto foi desenvolvido com delineamento em blocos casualisados, com 4 blocos. Foram instalados 1 carneiro hidráulico de PVC (convencional) e 1 carneiro hidráulico com retentor que foram avaliados ao mesmo tempo. A altura de queda foi a mesma, variando 1 metro da altura bombeada a cada 4 dias. Foram realizadas 4 repetições para cada altura analisada e avaliou-se a vazão de saída por meio de hidrômetros, pressão de entrada e saída do sistema, vazão de entrada, volume de água perdida e número de batidas por minuto, sendo possível medir sua eficiência. O carneiro hidráulico com válvula apresentou um rendimento inferior na maioria das alturas estudadas, o bombeamento foi superior ao convencional somente aos 9 metros de altura, o que prejudica a relação custo-benefício.

Coffee is traded on a stock exchange on which the goods are priced and influence their value both in the physical market and in the futures market, which causes doubts in coffee growers about the most opportune moment for trading. Then, the goal of this work was to consider the most favorable and unfavorable months over the years for the arabica and robusta coffee trading in the physical market and arabica coffee in the future market. The work was carried out using historical data on the price of coffee in Brazil, stratifying it into periods and listing for each year of evaluation the percentage of months with the first and second highest and lowest prices. Arabica and Robusta coffee were assessed respectively from 2018 to 1981 and from 2018 to 1995. Arabica coffee in the futures market was analyzed from 2018 to 1980. The evaluation was performed using descriptive statistics and correlation analysis among the modalities of coffee trading in Brazil. Great instability was observed between the months of high and low prices for coffee trading. This shows the uncertainties existing in the market; however, it is possible to observe a trend of the most favorable and unfavorable months for commercialization. It is determined that for arabica coffee, December and January are the most favorable and unfavorable months for trading, respectively. For robusta coffee, the most favorable and unfavorable sales months were June and January. Arabica coffee in the futures market January was the best month for trading and February in the opposite condition, in alternate years, the least favorable month.