Assessing climate change effects on gladiola in Southern Brazil

Abstract

Gladiola (Gladiolus × grandiflorus Hort.) is an important cut flower for small farmers in Brazil. While the El Niño Southern Oscillation, which causes interannual variability to air temperature in Southern Brazil, can shift the optimum planting window of gladiola, an increase in temperature due to climate change can accelerate gladiola flowering and cause injuries by heat. The objective of this study was to assess the potential climate change effects on gladiola optimum planting date for specific market dates and investigate injuries occurrence on spikes in the Rio Grande do Sul State, Brazil. Field experiments were conducted from 2016 to 2018 at four different locations across the Rio Grande do Sul State to evaluate the performance of the PhenoGlad model in simulating the developmental stages of gladiola. The PhenoGlad model was run on climate scenarios of the Coupled Model Intercomparison Project Phase 5 (CMIP5) named RCP2.6, RCP4.5 and RCP8.5 scenarios. The climate change scenarios caused a delay in the optimum planting date to harvest gladiola for All Souls' Day across the Rio Grande do Sul State. For harvesting spikes for Mother's Day, negative anomalies (earliest planting date) occurred in the warmest regions, because the very high temperature extended the crop development. Injuries by heat on spikes reached positive anomalies in 70 % of the years in the warmest regions for scenario RCP8.5. To harvest spikes for Mother's Day, heat injury did not exceed 20 % of the years. Mitigation strategies for farmers to deal with climate change and keep their gladiola production include adjusting the optimum planting date.

Agrometeorological models for predicting seedlings development of two native forest species

“…This is an important step to understand the seedling development pattern in native forest species and improve the modeling of forest species. Besides, our results have practical applications and can be applied to understand the effects on CLN and SPD under climate change (Becker et al, 2020;Costa and Streck, 2018;Florencio et al, 2019;Langner et al, 2018;Streck et al, 2011;Streck et al, 2013 ) to simulate the leaf appearance in forest nurseries, and to verify the ideal SD. Moreover, this approach can be used to determine the time for selling the seedlings (Ferreira et al, 2019b;Martins et al, 2014;Monteiro et al, 2014) as well as ideal moments for management nursery practices (Martins and Streck, 2007).…”

“…Therefore, accurate calibration of coefficients ('a' or LAR max ), reliable prediction of CLN and SPD, and choice of a best development model are important and necessary. All these steps produce information to be used directly or indirectly in guidance and practical applications in forest nurseries (Ferreira et al, 2019b;Martins et al, 2014;Monteiro et al, 2014) and, to verify impacts of climate changes on CLN and SPD (Becker et al, 2020;Costa and Streck, 2018;Florencio et al, 2019;Streck et al, 2011;Streck et al, 2013;Williams and Dumroese, 2004).…”

Climate risk zoning for gladiolus production under three climate change scenarios

“…Planting of gladiolus to meet Mother's Day demand (planting in February) results in a lower occurrence of damage by high temperatures (Becker et al, 2021) since flowering occurs between April and May. In the zoning presented in this study, it was considered the 10% level which is more judicious, therefore, planting for Mother's Day is recommended only in the Rio Grande, Bom Jesus, and Bagé regions.…”

“…For gladiolus, the effect of climate change on flower stems production for two peaks of consumption, Mother's Day (Second Sunday of May) and All Souls' Day (02 November) has been previously studied (Becker et al, 2021). In order to meet the demand for floral stems on All Souls' Day, plantings should occur later in the growing season than is currently recommended, due to the shortening of the crop development cycle, and also a higher occurrence of damage due to high temperatures.…”

“…The 497 municipalities of the RS State were grouped into 23 homogeneous regions (Figure 1) regarding the influence of macroclimatic factors, such as altitude, latitude, continentality, oceanity, and relief (Uhlmann et al, 2020), and each region was represented by a meteorological data grid point. The PhenoGlad model was run for daily planting dates from 01 January to 31 December, for the current period and for each climatic scenario and, the four gladiolus developmental cycles (Early, Intermediate I, Intermediate II and Late), which vary in their developmental cycle from 69 to 121 days for early cultivars and from 85 to 148 days for late cultivars (Becker et al, 2021), for the 23 regions of the State. The recommended planting dates were considered when the PhenoGlad model identified the occurrence of high and low temperature damage in less than 10% of the evaluated years.…”