Tag Archives: drought

2097-2109 M. Militello, G. Sortino, G. Talluto and G. Gugliuzza
Split water application for a water supply reduction in Callistemon Citrinus pot plant
Abstract |

Split water application for a water supply reduction in Callistemon Citrinus pot plant

M. Militello¹, G. Sortino²*, G. Talluto¹ and G. Gugliuzza¹

¹Council for Agricultural Research and Economics (CREA) – Research Centre for Plant Protection and Certification (CREA-DC), Bagheria (PA), Italy
²Department of Agriculture, Food and Forest Sciences (SAAF) – University of Palermo -Viale delle Scienze, ed.4, ingresso H, - IT90128 Palermo, Italy
*Correspondence: giuseppe.sortino@unipa.it

Abstract:

Irrigation management in Greenhouse Nursery Production (GNP) is based on empiric methods based on farmer personal experiences with over-irrigation results. The effects of irrigation volume and daily application were studied in a pot experiment carried out on rooted cuttings in a greenhouse The irrigation volume treatment was performed on Full and reduced Treatment. The treatment of water application was carried out with split supply and unsplit supply. The effects of the treatments were evaluated in terms of biomass accumulation and partitioning, leaf area, photosynthesis and stomatal response, chlorophyll content, and water productivity. Callistemon showed a good adaptation to the different treatments tested during the experiment. A positive relation was found between biomass accumulation and irrigation volume, moreover split water application increased plant Dry Weight.
Therefore, the highest biomass accumulation was registered in full irrigation volume in split application treatment, and this behavior was confirmed by the photosynthetic rate. No statistical differences were found, in terms of Relative Water Content (RWC), between the treatments. Stem water potential and stomatal conductance values suggest in Callistemon an anysohidric water stress response behavior.
Our results evidenced that, in Callistemon potted plants, an irrigation volume reduction is possible when a split application occurs during the daytime. A full irrigation volume amounts to 10.8 L per plant during the trial period of 90 days while the reduced volume amounts to 8.2 L per plant. Therefore, an increased water productivity can be obtained if the daily water requirement is split on two applications during the daytime. Our results highlighted a possible reduction in environmental impact of Callistemon greenhouse pot production, through the 25% reduction of the volume irrigation.

Key words:

, , , ,




433-438 A. M. Méndez, D. Castillo , A. del Pozo, I. Matus, R. Morcuende
Differences in Stem Soluble Carbohydrate Contents among Recombinant Chromosome Substitution Lines (RCSLs) of Barley under Drought in a Mediterranean–type Environment
Abstract |
Full text PDF (140 KB)

Differences in Stem Soluble Carbohydrate Contents among Recombinant Chromosome Substitution Lines (RCSLs) of Barley under Drought in a Mediterranean–type Environment

A. M. Méndez¹, D. Castillo² ³, A. del Pozo², I. Matus³, R. Morcuende¹

¹Institute of Natural Resources and Agrobiology of Salamanca, IRNASA–CSIC, Apartado 257, 37071 Salamanca, Spain; e–mail: rosa.morcuende@irnasa.csic.es
²Faculty of Agricultural Sciences, University of Talca, Casilla 747, Talca, Chile
³Instituto de Investigaciones Agropecuarias CRI-Quilamapu, Casilla 426, Chillán, Chile

Abstract:

Drought is one of the major abiotic stresses that dramatically threaten the global food supply and it is becoming an increasingly severe problem in many regions of the world, mainly in Mediterranean areas and/or climates. This study investigates the effect of drought on the stem soluble carbohydrate content and its role in grain filling in different barley genotypes –four recombinant chromosome substitution lines (RCSLs) and the recurrent parent cv. Harrington, which had been growing in two contrasting Mediterranean environments in central Chile. At anthesis, drought stress increased the stem glucose and fructose contents in lines 76 and 78 and fructans in all the genotypes. At maturity, in non-stressed plants the soluble carbohydrate content in the stem decreased, suggesting a mobilization of carbohydrates from the stem into the grain. Drought increased the stem content of fructose, sucrose and fructans in all genotypes. The accumulation of fructans was higher in RCSLs as compared to Harrington, providing evidence that the introgression of the wild ancestor (Hordeum vulgare ssp. spontaneum) into cv. Harrington increases the terminal drought tolerance of barley. Line 89 showed the maximal content of fructans and it could be considered as the most tolerant to terminal drought of all RCSLs. However, this genotype showed the lowest grain weight and yield, indicating that is the most susceptible line of those referred to as grain yield.

Key words:

, , , , ,




433-438 T. Tammets
Estimation of extreme wet and dry days through moving totals in precipitation time series and some possibilities for their consideration in agrometeorological studies
Abstract |
Full text PDF (622 KB)

Estimation of extreme wet and dry days through moving totals in precipitation time series and some possibilities for their consideration in agrometeorological studies

T. Tammets

Estonian Meteorological and Hydrological Institute, Toompuiestee 24, 10149 Tallinn,Estonia; e-mail: t.taam@emhi.ee

Abstract:

Moving totals of daily precipitation are a more exact tool for indicating the most extreme weather periods and their frequency than monthly or 10-day precipitation totals. Therefore the terms ‘extreme wet’ and ‘extreme dry’ are used for the last day of a period of calculating the moving total of precipitation if that is larger or smaller than the specified limits. These terms qualify a day with extra wet or dry meteorological and surrounding conditions. The number of extreme days and limits that lead to a large yield loss vary by crops and phenological phases. Calculation of moving totals in precipitation long time series in any number of successive days allows presenting the dependence of the observed maximal and minimal amount of precipitation on the number of successive days in a period. Such dependence seems to be useful in estimating the climate resources in an area. Examples are given for Jõgeva, Pärnu and Ristna precipitation time series of 1957–2008.Estimation of extreme wet and dry weather conditions on the basis of moving totals ofdaily precipitation allowed distinguishing the most drastic periods and trends of the precipitation regime in Estonia in the last 50 years. A day is considered as extreme wet when the moving total of precipitation is at least 10 mm on 10 successive days leading up to this day. A day is considered as extreme dry when there was no precipitation during the successive 20 days till the observed day. By these criteria years with especially wet or dry periods are easily distinguished. Inter-annual variability of the average number of wet and dry days in Estonia increased notably in 1957–2006. The growing trend of annual total number of extreme (wet + dry) days is statistically significant.

Key words:

, , , , ,