Fábio Teixeira Delazari

Morpho-physiological characteristics by sweet potato cultivars as function of irrigation depth

The sweet potato is an alternative energy source, but its sustainability depends on efficient water use. The objective of this study was to evaluate sweet potato morpho-physiological characteristics, and water use efficiency (WUE). Irrigation depths of 50, 75, 100, and 125% of crop evapotranspiration (ETc) were applied. The morpho-physiological indicators, WUE, leaf area index (LAI), leaf water potential, leaf temperature, and leaf chlorophyll index (ICF), were evaluated. The WUE of the sweet potato cultivars increased until the 75% water depth of the ETc. The LAI of these cultivars increased with irrigation depth, with higher values at 100% of the ETc. The leaf water potential of the two sweet potato cultivars was lowest with the lower irrigation depth. Leaf temperature was closer to that of ambient temperatures in treatments with greater irrigation depth. The increase of the WUE with the greater accumulation of dry biomass is due to greater CO2 diffusion by stomata. The reduction in the growth of these plants is due to water stress limiting stomatal conductance, transpiration, leaf growth (LAI) and chlorophyll concentration, proportional to soil moisture conditions. The functional relationship between soil moisture and growth is essential to optimize irrigation management at different growth stages.

Efeitos da irrigação na produção e no desenvolvimento do cafeeiro na região oeste da Bahia

Irrigation redesigned the distribution of the cultivation of coffee in Brazil, and upon this, new studies in water consumption and in its relationships with production and growth in coffee became necessary. The objective of this work was to evaluate the effects of irrigation on the production and growth in coffee irrigated by drip irrigation, in the West region of Bahia. For this, a trial was carried out in the farm Cafe do Rio Branco, located in Barreiras – BA. The experiment was caried out with adult plants of coffee of the variety Catuai Vermelho, approximately 3.5 years old and set up in a randomized block design, with five treatments and four replicates. The treatments corresponded to 75, 85, 100, 125 and 150% of the irrigation depth and were calculated by the Irriplus software. It was evaluated the productivity, water use efficiency (WUE), vegetative development, sieve classification, as well as the yield and maturation of fruits. A significant effect of the irrigation depth in yield, WUE and maturation of fruits (green and cherry) was observed at the end of four consecutive harvests. The estimated maximum productivity (60 sc ha-1), was obtained with 129% of the irrigation depth and a maximum WUE (5.7 kg mm-1) obtained with 75%. As to maturation, they were significant only for green (19.7%) and cherry fruits (67.5) with the irrigation depths of 119 and 121%, respectively. There was no significant effect of the different irrigation depths in the vegetative development, sieve classification and yield of fruits.