Precision irrigation is essential to improve water use efficiency (WUE), defined as the amount of biomass produced per unit of water used by plants. Our objective is to evaluate the effect of different soil volumetric water content (VWC) in plant growth, fruit yield, quality, and WUE of cherry tomatoes grown in a greenhouse. We tested four VWC thresholds (0.23, 0.30, 0.37, and 0.44 m3 m−3) to trigger a drip irrigation system in two tomato cultivars (‘Sweet Heaven’ and ‘Mascot F1′). The experiment was arranged in a split-plot design with four replications. We used capacitance sensors connected to an open-source, low-cost platform to monitor and control the irrigation in real-time based on demand. Plants were watered every time the soil VWC dropped below the set thresholds. The treatment with VWC 0.44 m3 m−3 resulted in the highest fruit yield, with 102.10% higher WUE when compared to the VWC 0.23 m3 m−3 in both cultivars. Fruit quality traits such as longitudinal and equatorial diameter increased asymptotically with soil water content. In contrast, treatments with deficit irrigation increased the fruit soluble solids by 15.73% in both cultivars. These results strongly suggest that accurate control of the soil VWC is essential to modulate the fruit yield and quality attributes in tomatoes produced in the greenhouse.

In recent years, in the Brazilian Savannah, there is a growing interest in the cultivation of tree species, which stand out for their environmental and commercial importance. The objective of this work was to evaluate the initial growth of African mahogany (Khaya ivorensis) plants on substrates and irrigation levels and to select the productive characteristics that result in ideal conditions for production .The experiment was installed in a randomized block design, with four replications, in split-plot, in the scheme 5 x 3, plots composed of five daily irrigations levels (6, 8, 10, 12, 14 mm) and four subplots substrates: S1-100% OXISOL RED; S2-50% OXISOL RED and 50% sand and S3-45% OXISOL RED, 45% sand, and 10% of tanned. The evaluated characteristics were plant height, stem diameter, number of leaflets, root system length, dry matter mass of roots, dry matter mass aerial part, dry matter mass seedling, ratio between roots dry matter mass and aerial part and seedling quality. The depth irrigation of 6 mm dia-1 was the most indicated and the S1 substrate provided the highest quality to the African mahogany, under the conditions in which the study occurred.

No abstract

A finalidade do trabalho, foi obter dados para o melhor conhecimento dos fatôres físicos do solo, que influenciam a incidência de murcha do algodoeiro, causada por Fusarium oxysporum f. vasinfectum (Atk.) Snyder & Hansen. Foi estudada a influência do tamanho das partículas de areia e porcentagem da mesma no solo. O primeiro ensaio mostrou que, a porcentagem de areia tinha um efeito sôbre a incidência de murcha na variedade IAC - 12. A maior incidência de murcha, foi notada nos tratamentos que possuiam maior porcentagem de areia. No segundo ensaio, foi notado o efeito do tamanho das partículas de areia sôbre a incidência de murcha na variedade IAC - 12. A incidência foi mais intensa nos substratos com Areias Fina e Média. O terceiro ensaio mostrou que a resistência da variedade RM4, ao Fusarium, aparentemente não foi afetada pela porcentagem de areia ou pelo tamanho das partículas.

Os cormilhos tipo 7 produziram bulbos e cormilhos dos tipos de 1 a 8 em maior quantidade que o tipo 8 e os bulbos tipos 1, 2, 3, 4 e 5 mais pesados. Os cormilhos tipo 8 também produziram bulbos e cormilhos dos tipos 1 a 8, porém seus cormilhos foram mais pesados que os cormilhos produzidos pelo tipo 7.