Crop yield response to water - Cra

Lead AuthorSDiego S. Intrigliolo,Juan R. Castel(IVIA, Moncada, Valencia, Spain)PlumContributing AuthorAmos Naor(GRI, University of Haifa, andMigal - Galilee TechnologyCenter, Israel)Introduction and BackgroundPlum species of commercial importance originated between EasternEurope and Central Asia. Cultivated plums include two main species,European (Prunus domestica L.) or ‘prunes’ and Japanese plums (Prunussalicina L.). Both species are medium-size deciduous stone fruit‐trees thatdiffer notably in respect to their climatic requirements. European plums arecultivated in temperate climates to fulfil chilling requirements and to enableproper bud break. They are relatively late flowering, while Japanese plumsgrow better in temperate-warmer regions, as their chilling requirementsare less. Their productive use also differs, as Japanese plums are mainlygrown for fresh fruit, while dried fruit (prunes) is mainly obtained fromEuropean plum varieties. World acreage was over 2.5 million ha in 2009with an average yield of 4.3 tonne/ha. China and Serbia are the two mainworld producers, followed by the United States and Romania (Figure 1).Spain occupies the eighth place with about 191 000 tonne mostly of freshfruit, but is among the three world highest exporters. France is the mainEuropean producer of dried fruit, and Chile is now an important producerand exporter in the Southern Hemisphere (FAO, 2011).Plum species can adapt to different soil types, although they are sensitive towater‐logging, iron chlorosis and salinity. Therefore, the use of rootstocksto cope with these adverse environmental conditions is common. Plum treesgenerally bear fruit at an early age and the fruiting period lasts 5-35 years.Early varieties can be grown without irrigation in arid climates with rainfallas low as 300 mm/ season, and midseason varieties require at least 400-500mm/ season. However, productivity and fruit size in these conditions areusually low and, therefore, most plantations are irrigated, especially in aridand semi-arid climates.The quality features for fresh market include size, colour and a good balancebetween soluble solids and acidity, while for dry fruit production, solublesolids and size are the two most important quality parameters.Developmental Stages in relationto Yield DeterminationCommercial plum tree varieties break dormancy and begin flowering in theNorthern Hemisphere between late-February and mid-April, depending on348crop yield response to water