R.A. Marathe

Plant growth, nutrient uptake, water use efficiency and yield of pomegranate as affected by irrigation scheduling in loamy soils of semi-arid regions

A field experiment was conducted on loamy soil of National Research Centre on Pomegranate, Solapur, Maharashtra for three consecutive years (2010 to 2013) to assess the water requirement of pre-bearing and bearing plants of pomegranate cv. Bhagwa. The treatments consisted of replenishment of irrigation water equivalent to 30, 40, 50, 60, 70, 80 and 90% of cumulative pan evaporation (CPE) on alternate day laid out in randomized block design with four replications. The results of the study showed that during pre-bearing year, maximum plant growth can be achieved with the application of irrigation equivalent to 60% of CPE, while during bearing period it should be 70% of CPE. In three-year-old plants, maximum fruit yield (6.79 kg/plant) and irrigation efficiency (0.473 t/ha-cm) was observed in 70% CPE treatment. Leaf content of N (2.25%), Cu(124.9 ppm) and Mn (80.7 ppm) was also highest in this treatment. Fruit cracking to the extent of 58.8, 45.3 and 37.7% was recorded from the plants supplied with 30, 40 and 50% of CPE irrigation, respectively which reduced fruit yield drastically.

Root distribution pattern of pomegranate in different soil types

Root distribution pattern forms the crux for optimum utilization irrigation, fertilizers and other inputs. Therefore, root distribution in terms of root weight and root activity (i.e. root length) in pomegranate cv. Bhagwa was studies in three different soil types on four-year-old trees of pomegranate. Roots were collected from six radial distances (0–30, 30–45, 45–60, 60–75, 75–90 and 90 cm and above) and seven depths (0–15, 15–30, 30–45, 45–60, 60–75, 75–90 and above 90 cm). It was observed that total quantity of feeder roots (diameter up to 5 mm) under shallow, medium deep and deep soil was 992.7, 1,100.0 and 1,176.3 g, respectively. Cumulative root length (activity) was the highest in medium deep soils (2,722.8 m) followed by shallow (2,332.4 m) and the lowest in deep soil (2,084.0 m). On weight basis, contribution of small roots (2 < to < 5 mm) in total weight was the highest whereas, on the basis of root length, contribution of very fine roots (< 0.5 mm) was exceptionally high compared to other categories of the roots. Root growth or root activity of pomegranate plants was better in shallow, light textured soils compared to deep, clayey soils. In these soils major portion of the root activity was observed in 0–60 cm radial distance and 0–45 cm vertical distance. In deep, clayey soils more or less uniform distribution of roots was observed up to 90 cm distance.