The main objectives of this research were to study the effects of sustained
deficit irrigation (SDI) and partial drying of root zone (PRD) on yield and
water use efficiency of squash (Cucurbita Pepo, L. Oto) crop. To fulfill
these purposes, a field study was conducted in the experimental farm of
Faculty of Agriculture, at Moshthor, Benha University, Egypt, for the two
successive seasons of late summer (2016 and 2017), under both drip
surface (DSI) and subsurface irrigation (SSDI) systems. Five irrigation
treatments were undertaken. The first (FI-100%) was corresponding to full
crop water requirements (FWR), and soil water deficit was replenished to
field capacity when 50% of the available water was exhausted, depending
on root depth which was predicted by a root depth model. The second
treatment was corresponding to 80% of the FWR (SDI-80%), the third one
was corresponding to 70% of FWR (SDI-70%), the fourth one was
corresponding to 70% of the FWR and partial drying of root zone (SDI-
70%+PRD), and in the last treatment (SDI-50%), the crop was irrigated
at 50% of full water requirement FWR. In the treatment (SDI-70%+PRD),
the root zone was irrigated partially but from alternate laterals. The results
show that surface drip irrigation (DSI) resulted in lower WUE and lower
yield of squash than the sub-surface drip irrigation (SSDI), although with
the subsurface drip irrigation system water consumption is less than with
the surface drip irrigation by 5 %. The treatment (FI-100 %) resulted in
both the highest WUE and squash yield either with surface or sub-surface.
The treatment SDI-80% resulted in WUE and yield not significantly
different from FI-100%. SDI-70%+PRD resulted in WUE and yield almost
equal to those achieved with SDI-80%. |
