Response of Pear Trees’ (<i>Pyrus bretschneideri</i> ‘Sinkiangensis’) Fine Roots to a Soil Water Regime of Regulated Deficit Irrigation
Yang Wu,
Zhi Zhao,
Feng Zhao,
Xiaolei Cheng,
Pingping Zhao,
Songzhong Liu
Affiliations
Yang Wu
Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture and Rural Affairs, Beijing Engineering Research Center for Deciduous Fruit Trees, Beijing 100093, China
Zhi Zhao
Department of Irrigation and Drainage, China Institute of Water Resources and Hydropower Research, Beijing 100048, China
Feng Zhao
Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture and Rural Affairs, Beijing Engineering Research Center for Deciduous Fruit Trees, Beijing 100093, China
Xiaolei Cheng
Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture and Rural Affairs, Beijing Engineering Research Center for Deciduous Fruit Trees, Beijing 100093, China
Pingping Zhao
Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture and Rural Affairs, Beijing Engineering Research Center for Deciduous Fruit Trees, Beijing 100093, China
Songzhong Liu
Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture and Rural Affairs, Beijing Engineering Research Center for Deciduous Fruit Trees, Beijing 100093, China
A field experiment was conducted to evaluate the effects of regulated deficit irrigation (RDI) on the fine root redistribution of mature pear trees in 2009 and 2010. The experiment consisted of four RDI treatments: MRDI-1 and SRDI-1, in which the trees received irrigation replacing 60% and 40% of pan evaporation (Ep) during Stage 1 (cell division stage), and MRDI-1+2 and SRDI-1+2, in which the trees received irrigation replacing 60% and 40% of Ep during Stage 1+2 (cell division and slow shoot growth stage). All the RDI-treated trees received irrigation replacing 80% of Ep (full irrigation) in other stages, and the control trees were fully irrigated during the whole growth season. The results showed that the fine root length density (RLD) of mature pear trees was reduced by water stress. The resumption of full irrigation boosted fine root growth. The RLD of the SRDI-1-treated trees in the irrigated zones recovered in early July, they maintained water and nutrient absorption during the fruit enlargement stage, and the final fruit yield was significantly improved. The RLD of trees in the irrigated zones with MRDI-1 and MRDI-1+2 recovered in July and September, respectively, but there were no significant differences in fruit yield between the MRDI-1, MRDI-1+2, and the control. This indicates that the fruit yield was not negatively or positively impacted by the redistribution of moderate water stress applied during either Stage 1 or Stage 1+2.
