The effect of evaporative demand on the growth of well-watered kikuyu

✍ Scribed by G.J. Murtagh

• Publisher: Elsevier Science
• Year: 1978
• Weight: 627 KB
• Volume: 19
• Category: Article
• ISSN: 0002-1571
• DOI: 10.1016/0002-1571(78)90024-9

✦ Synopsis

A study was made of the effect of evaporative demand (potential evapotranspiration, E t) on the growth of heavily fertilized and well-watered kikuyu pasture. Mean weekly growth rates on an irrigated pasture, adjusted for differences in temperature during the various growth periods, declined significantly when the mean E t increased above 3.5 mm day -1 . Using growth rates at lower E t as a no-stress control, tlce maximum reduction in growth rate (57%) occurred at the highest E t (5.0--5.8 mm day -1 ). When frequent leaf wetting was used to modify the possible effects of evaporative demand on the internal water status of the plant, the growth rate still declined with increasing E t, but to a lesser extent than on irrigated pasture. The leaf wetting was done at 20-min intervals and evidently this interval was too long to fully ameliorate the evaporative demand effect when mean E t exceeded 4. 5 mm day -1 . It was concluded that the growth of kikuyu is sensitive to evaporative demand even'on wet soil and that cloudy periods enhance growth by reducing E t.