The effect of irrigation regime on biomass and resin production in Grindelia chiloensis.

ZAVALA, J.A.; RAVETTA, D.A.

FIELD CROPS RESEARCH

Año: 2001 vol. 69 p. 227 - 236

0378-4290

Grindelia chiloensis (Corn.) Cabr. is a shrub native to Patagonia, Argentina and can accumulate as much as 25% resin in its leaves, with net primary productivity between 90 and 170 g per year per plant when growing in native stands. Under cultivation, 67.4 g of resin per plant have been produced (about 2.24 Mg ha(Corn.) Cabr. is a shrub native to Patagonia, Argentina and can accumulate as much as 25% resin in its leaves, with net primary productivity between 90 and 170 g per year per plant when growing in native stands. Under cultivation, 67.4 g of resin per plant have been produced (about 2.24 Mg ha ÿ1). The objective of this study was to assess the effect of irrigation regime on biomass and resin production on G. chiloensis. In order to achieve this objective, four irrigation treatments were performed during 1996±1997 and 1997±1998: (i) weekly irrigation (7d), (ii) irrigation at 20-day intervals (20d), (iii) irrigation at 40-day intervals (40d), (iv) non-irrigated (N-I). It was found that the intermittent water supply at 40d was suf®cient to promote canopy development, and increase water use ef®ciency (WUE) and resin production per plant (RP) with highest resin production (approximately 5.12 Mg ha1). The objective of this study was to assess the effect of irrigation regime on biomass and resin production on G. chiloensis. In order to achieve this objective, four irrigation treatments were performed during 1996±1997 and 1997±1998: (i) weekly irrigation (7d), (ii) irrigation at 20-day intervals (20d), (iii) irrigation at 40-day intervals (40d), (iv) non-irrigated (N-I). It was found that the intermittent water supply at 40d was suf®cient to promote canopy development, and increase water use ef®ciency (WUE) and resin production per plant (RP) with highest resin production (approximately 5.12 Mg haG. chiloensis. In order to achieve this objective, four irrigation treatments were performed during 1996±1997 and 1997±1998: (i) weekly irrigation (7d), (ii) irrigation at 20-day intervals (20d), (iii) irrigation at 40-day intervals (40d), (iv) non-irrigated (N-I). It was found that the intermittent water supply at 40d was suf®cient to promote canopy development, and increase water use ef®ciency (WUE) and resin production per plant (RP) with highest resin production (approximately 5.12 Mg ha ÿ1 in 1997). In order to achieve high levels of RP, above ground biomass was maximized at the expense of a reduction in WUE. A concomitant increase in WUE (at the leaf level; WUEL) and leaf resin content with water stress and time was found. This result supports the hypothesis that epicuticular resin could in¯uence water transpiration (E), as it represents an additional barrier to gas diffusion from the epidermis and through the stomatal pores.1 in 1997). In order to achieve high levels of RP, above ground biomass was maximized at the expense of a reduction in WUE. A concomitant increase in WUE (at the leaf level; WUEL) and leaf resin content with water stress and time was found. This result supports the hypothesis that epicuticular resin could in¯uence water transpiration (E), as it represents an additional barrier to gas diffusion from the epidermis and through the stomatal pores.L) and leaf resin content with water stress and time was found. This result supports the hypothesis that epicuticular resin could in¯uence water transpiration (E), as it represents an additional barrier to gas diffusion from the epidermis and through the stomatal pores.E), as it represents an additional barrier to gas diffusion from the epidermis and through the stomatal pores.