Standardization of Water Requirement in Almond cv. Shalimar

The present investigation was carried out at Central Institute of Temperate Horticulture (CITH) Srinagar on eight year old almond plantation [Prunus dulcis (Mill.)] cv. Shalimar during 2008-2009 and 2009-2010. The study was undertaken to determine the effect of different irrigation levels vis-a-vis various phenological stages on vegetative development and yield parameters. The experiment carried out in RCBD with four replications, consisted of four different irrigation levels viz., 0% ETc (I0), 100% ETc (I1), 75% ETc (I2) and 50% ETc (I3), and four crop phenological stages viz., fruit growth stage (C1), kernel filling stage (C¬2), preharvest stage (C3) and throughout the season (C4). Irrigation applied at various phenological stages did not increase vegetative growth of almond in terms of trunk girth and leaf area during 2008. However a significant increase in trunk girth and leaf area was noticed with irrigation during 2009. Bloom intensity and fruit set significantly increased with irrigation during 1st year which further increased during the subsequent year. Maximum bloom intensity (40.97%) and (46.16%), and fruit set (36.02%) and (39.09%) were recorded with highest irrigation level when applied throughout the season (I1 C4) during the respective years. Nut weight, kernel weight and their size recorded a significant improvement with irrigation. Highest nut weight (3.0 and 3.15g) and kernel weight (1.55 and 1.63g) were recorded in I1C4 during 1st and 2nd year, respectively. Yield of almond improved significantly with irrigation. Maximum yield (2.68Kg/tree) was recorded with 100% ETc level, applied throughout the growth stage (I1C4) during 1st year which further improved during 2nd year to the tune of 3.10Kg/tree. Shelling percentage of almond also recorded a significant increase with irrigation in both the years. Shelling percentage of 52.49 and 53.55% were recorded in I1C4 during the respective years. It is pertinent to mention here that most of the flowering and yield attributes of almond recorded at100% ETc level were statistically at par with 75% ETc level of irrigation at C1 and C4 stages. The percentage of defective kernels in terms of shrivelled kernel were recorded highest in control trees while as irrigated trees recorded the lowest. The NPK content of almond leaves increased significantly with irrigation. Similarly, Leaf Relative Water Content (RWC) was significantly higher in trees receiving highest irrigation level as compared to control trees. The water use efficiency was lowest at highest irrigation level compared to all other treatments. Hence, for commercial production, this nut crop needs to be irrigated for its optimal growth and development during the growing season. Furthermore, irrigation is very necessary for enhancing the flowering and fruiting characteristics of mature almond plantation and for long term productivity. 75% ETc level seems to be the best irrigation level wherein highest yield potential besides a saving of 25% water is achieved. Moreover, the flowering stage and especially early fruit growth stages seem to be the critical stages of irrigation in almond wherein water stress conditions can adversely affect the growth and development of this nut crop and that the post harvest irrigation in almond may prove to be beneficial in increasing the subsequent year flowering and fruit set. The two months prior to harvest are relatively less sensitive to water stress, when the process of dry matter accumulation goes on and where we can use Regulated Deficit Irrigation (RDI) strategies without adversely affecting the yield potential of this nut crop