Abstract
This study evaluated the effects of aerated irrigation water (oxygation) with subsurface drip irrigation, employing an in-line air injector (Mazzei venturi to introduce 12% air by volume of water) on yield, fruit quality and water use efficiency of watermelon (Citrullus vulgaris) and pumpkin (Cucurbita maxima) in a heavy clay soil. The fruit yield with oxygation increased from 14.5 t ha-1 to 24.6 t ha-1, and 26.3 t ha-1 to 28.9 t ha-1, for watermelon and pumpkin, respectively. The total soluble solids (ºBrix) increased by 19% with oxygation (13.2 vs. 11.1%), and internal fruit crack decreased for watermelon, whereas fruit dry matter increased by 4% (40 vs. 38.4%) and ºBrix by 7% (13.7 vs. 12.8%) in pumpkin. Season long water use efficiency was greater with oxygation compared to the control. The higher yield with oxygation was associated with a more rapid canopy cover, more leaf chlorophyll, and an increase in leaf photosynthetic rate, and leaf transpiration and increase in fruit number and size.
Highlights
Cucurbits are grown as irrigated crops for commercial production (Lee et al, 1995) as they are very responsive to irrigation
This study evaluated the effects of aerated irrigation water with subsurface drip irrigation, employing an in-line air injector (Mazzei venturi to introduce 12% air by volume of water) on fruit yield, quality and water use efficiency of watermelon (Citrullus vulgaris) and pumpkin (Cucurbita maxima) in a heavy clay soil
The effect of oxygation on leaf chlorophyll concentration was notable; SPAD readings were greater for oxygation in watermelon (52 vs. 47) and pumpkin (47 vs. 42), measured 71 and 86 das, respectively (Table 1)
Summary
Cucurbits are grown as irrigated crops for commercial production (Lee et al, 1995) as they are very responsive to irrigation. Cucurbits irrigated with DI and SDI are generally irrigated for long durations at each irrigation event and frequently, in the tropics and sub-tropics (McCann et al, 2007). Such crops tend to develop sustained wetting fronts especially in fine textured soils (Thabet and Zayani, 2008), which predisposes the rhizosphere to a www.ccsenet.org/jas gradual lack of oxygen (hypoxia), leading to a deficit of oxygen in the root zone (anoxia). Most cucurbit crops are susceptible to wet foot and water-logging (Kato et al, 2001) predisposing the root system to various fungi causing root rot (Nischwitz et al, 2004; De Andrade-Junior et al, 1997)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
