Effects of water deficit on Mediterranean and temperate cultivars of tall fescue

Abstract

Two glasshouse experiments were carried out to evaluate the morphological and physiological responses to water deficit of Mediterranean and temperate tall fescue (Festuca arundinacea Schreb.) cultivars. In Expt 1, 3 cultivars were studied: 2 temperate cultivars, Grasslands Advance (GA) and El Palenque (EP); and a Mediterranean cultivar, Maris Kasba (MK). Water deficit was induced in containers of 4 plants of a single cultivar by withholding water. In Expt 2, plants of EP and MK were grown together in the same container and received water daily with gradation in intensity of water deficit achieved by varying the daily water ration per container.All cultivars in each experiment exhibited commonly reported responses to water deficit, characterised by diminished evaporative surface area and increased root : shoot ratio. The response of MK was primarily morphological and MK plants had smaller plant size, higher root : shoot ratio, and a lower growth rate compared with temperate cultivars. By contrast, response of temperate cultivars was primarily physiological; stomatal conductance of temperate cultivars was lower and these cultivars had a greater tendency for leaf lamina osmotic adjustment than MK under the most stressful water deficit conditions studied. The morphological adaptations of MK were very effective in delaying the onset of water deficit in Expt 1 when plants were grown with others of the same cultivar, but rendered MK plants uncompetitive and more susceptible to water deficit in Expt 2 where plants of MK where interspersed with plants of a temperate cultivar.Additional keywords: plant water relations, roots. S . G . A s s u e r o , C . M a t t h e w , P . K e mp , D . J . B a r k e r , A . M a z z a n t i A R 0 1 0 2 3 Wa t e r d e f i c i t e f f e c t s o n c o n t r a s t i n g t a l l f e s c u e s S . G . A s s u e r o e t a l .

Summer dormancy in Festuca arundinacea Schreb.; the influence of season of sowing and a simulated mid-summer storm on two contrasting cultivars

“…Our results contrast with the work of Assuero et al (2002) who showed differences in water status between tall fescue cultivars, depending upon their origin. However, their trial was in a confined soil volume and could not account for the role of the deep root system of tall fescue in maintaining positive turgor and growth over dry periods (Garwood and Sinclair 1979;.…”

Plant drought survival under climate change and strategies to improve perennial grasses. A review

“…Malinowski et al (2011) also observed that summer-dormant tall fescue was less competitive than continental tall fescue when both types were grown in binary mixtures with alfalfa, especially when constrained by low soil moisture availability in summer. Summer-dormant tall fescue may be able to coexist only with species expressing a similar growth pattern (Malinowski et al 2008) and may not be tolerant of a summer-active competitor (Assuero et al 2002). In non-native environments such as those of the Southern Great Plains, summer-dormant tall fescue is not expected to be able to take advantage of summer soil moisture, in contrast to native temperate and warm-season flora, because its growth pattern is highly restricted.…”

Relative effects of irrigation and intense shade on productivity of alley-cropped tall fescue herbage

“…Shade-grown tall fescue has fewer tillers plant -1 , lower specific leaf mass (SLM) and CO 2 exchange rate, and more leaf lamina air space than plants at high irradiance (Allard et al 1991a, b;Burner and MacKown 2006). Tall fescue responds to water stress by reducing plant size and growth rate, decreasing evaporative surface area, increasing root-shoot ratio, and reducing stomatal conductance (Assuero et al 2002).…”