WATER USE EFFICIENCY OF MICROIRRIGATED CITRUS (CITRUS RETICULATA VAR. BLANCO) TREE - Management, Performance, and Applications of Micro Irrigation Systems - page 227

18.3.4 VEGETATIVE GROWTH RESPONSE
The annual increase in plant height responded significantly to different drip irrigation
levels with the maximum value at 60% Ecp with plastic mulch over plant height (0.45
m) under basin irrigation method (Table 3). The treatments had no significant influ-
ence on stock girth, whereas, a significant increase in the scion girth (41-52 mm) and
canopy volume (0.531-0.991 m 3 ) was observed in response to drip irrigation treat-
ments with plastic mulch in comparison to basin irrigation (39 mm, scion girth; 0.473
m 3 , canopy volume). The maximum scion girth diameter and plant canopy volume
were recorded under drip irrigation at 60% Ecp with plastic mulch followed by drip
irrigation at 80% Ecp with plastic mulch. The better plant growth even with 36% less
water supply under drip irrigation at 60% Ecp with plastic mulch over basin irrigation
might be due better availability and uptake of nutrients facilitated by optimum root
zone soil moisture in this treatment.
The higher annual vegetative growth under drip irrigation with plastic mulch was
also reported in acid lime [10].

TABLE 3 Annual incremental vegetative growth parameters of 'Nagpur' mandarin' under
various irrigation treatments with plastic mulch (Mean data during 2006-2009).

Treatment Tree height

(m)

Stock girth Scion girth

(mm)

Canopy vol-

(mm) ume (m 3 )

* DI at 40% Ecp
+ PM

0.50 45 43 0.593

DI at 60% Ecp
+ PM

0.64 55 52 0.991

DI at 80% Ecp
+ PM

0.55 51 48 0.723

DI at 100% Ecp+ PM 0.47 43 41 0.531

Basin irrigation 0.45 39 39 0.473

# LSD 0.05

0.08 NS 4.1 0.04

* DI = Drip Irrigation; PM = Plastic mulch.
# LSD 0.05 = Least significant difference at 5% probability level.
NS: Not significant.

18.3.5 FRUIT YIELD, QUALITY AND WATER USE EFFICIENCY (WUE)
The number of fruits and average fruit weight in drip irrigation treatments with plastic
mulch were observed to be significantly higher over fruit number and average fruit
weight in basin irrigation (Table 4). In consequence, a significantly higher total fruit
yield was estimated under drip irrigation treatments with plastic mulch in comparable