Sz. Kang et al., An improved water use efficiency for hot pepper grown under controlled alternate drip irrigation on partial roots, SCI HORT A, 89(4), 2001, pp. 257-267
Hot pepper plants were grown in pots with their roots divided and establish
ed in two separate containers. Water was applied through a drip irrigation
system in three ways: alternate drip irrigation on partial roots (ADIP), fi
xed drip irrigation on partial roots (FDIP), even drip irrigation on whole
roots (EDIW). For each irrigation method, water was applied when the soil m
oisture content was below either 65 or 55% of the field capacity. Results s
howed that when irrigation started at 65% of the field capacity ADIP signif
icantly increased the root/shoot ratio compared to all the other treatments
. When irrigating at this moderate (i.e. 65% of the field capacity) soil mo
isture level, ADIP did not significantly inhibit leaf photosynthesis, but d
id markedly restrict stomatal opening. Compared to EDIW. there was a relati
vely small reduction in biomass for ADIP, but the reduction for FDIP was si
gnificant. Surprisingly, ADIP maintained high yield with up to 40% reductio
n in irrigation compared to EDIW and FDIP. Moreover, the maximum yields and
best water use efficiency occurred in ADIP and rewatering at 65% level at
the same time. FDIP did not show better results than the controls because t
he yield was considerably reduced. In conclusion, ADIP is an effective and
water-saving irrigation method in hot pepper production and may have the po
tential to be used in the field. (C) 2001 Elsevier Science B.V. All rights
reserved.