Irrigation scheduling and growth of young 'Hamlin' orange trees

Frederick S. Davies, Glen R. Zalman

Abstract


Several methods of scheduling microirrigation are currently used in Florida but few comparisons have been made among these. The objective of this study was to compare growth of 'Hamlin' orange trees [Citrus sinensis (L.) Osb.] on 'Swingle' citrumelo [Poncirus trifoliata (L.) Raf. × C. paradisi Macf.] rootstock using different irrigation scheduling methods. These included the calendar system (irrigating every 3 days if no rain occurred), or irrigating based on soil water depletion (SWD). In year 1, trees were irrigated at 30% SWD all year (30 SWD), at 20% SWD during the first and second flushes and 50% thereafter (20-20-50 SWD), or at 20% SWD during the first flush and 50% SWD thereafter (20-50-50 SWD). In years 2 and 3, trees were irrigated by the calendar system, at 30% SWD all year (30 SWD), 30% SWD during the first and second flushes and 50% thereafter (30-30-50 SWD), or at 50% SWD all year (50 SWD). Trunk diameter was measured about monthly and time and number of growth flushes were monitored for 2 of 3 years. The amount of water applied and number of irrigations/ season in year 1 were significantly higher for 20-20-50 SWD compared with the calendar method, 20-50-50 SWD and 30 SWD in descending order. In years 2 and 3, the number of irrigations and amount of water applied was highest for the calendar method compared with the 30 SWD, the 30-50 SWD and the 50 SWD treatments in descending order. However, trunk diameter was statistically the same for all treatments and measurement dates for all 3 years. The total number of new shoots were the same for all treatments in year 1, but were lower for the calendar vs. the 30-50 SWD treatment in year 3. Thus, under the humid subtropical conditions of Florida, there was no advantage in terms of growth by irrigating on average every 3 days (calendar) vs. every 6 days (30-50 SWD) without rainfall.

Keywords


citrus sp.; water; microsprinkler; soil moisture

Full Text:

PDF

Refbacks

  • There are currently no refbacks.


Proc. Fla. State Hort. Soc.     ISSN 0886-7283