fully matched with the amount of water used by the crop. We need to develop irrigation strategies that would optimize water and oxygen supply to the roots, which would ensure better root growth and function thereby ensuring better plant growth, increased
availability of the required amount of irrigation water, which is a scarce resource in many areas. In terms of crop management, DI strategies have demonstrated their feasibility for yield improvement in arid and semiarid areas ( Gómez-del-Campo et al., 2014
Three irrigation strategies [10% leaching, 0% leaching (pulse), and ebb-and-flood] and two constant liquid feed fertilizer treatments, 150 and 300 ppm N, were applied to poinsettias, `Freedom Red' and `V-17 Angelika Red', with a harvest date of November 25, 1995. There were no differences in plant dry weights among the three irrigation strategies at the 150 ppm N treatment. At 300 ppm N, 10% leaching irrigation grew plants with the greatest dry weights, followed by the ebb-and-flood treatment and the pulse treatment, respectively. The 10% leaching and ebb-and-flood plants had the greatest growth index, while the pulse treatment growth index was lower. Growth index was greatest for the 10% leaching strategy for `Freedom Red', while ebb-and-flood had the lowest index. The growth index was greater at 150 ppm N for `Freedom Red' compared to 300 ppm N. `V-17 Angelika Red' was not influenced by fertility level. Pulse irrigation grew marketable poinsettia plants at lower fertility levels.
product quality and waste of water resources. Few studies have reported the irrigation scheduling strategy for leafy greens by using subirrigation such as E&F irrigation. Irrigation frequency and flood time were identified as two key factors in the E
with excessive irrigation demands, what conservation strategies can draw households’ attention to the pressing need of further outdoor water use reductions? Education campaigns that engage the public on water conservation concerns are one of the most
). However, there is still an opportunity to devise more cultural and irrigation strategies to make production systems more water-efficient and sustainable. The crop yields are generally highest with optimal water application, but crops can adapt and produce
densities. The use of fertilization methods and irrigation systems that target the root zone of young trees, in conjunction with higher tree densities, may be a strategy for improving the productivity of young citrus orchards during the HLB era in the Indian
In rockwool-grown greenhouse vegetables, unsatisfactory spatial root development, rapid root collapse, and increased incidence of root diseases are very common. Improved water management could alleviate these problems to some extent, because this could favorably modify water-air distribution in the slab, thereby improving greenhouse vegetable yield and quality. The present study tested six irrigation strategies on the productivity of rockwool-grown tomatoes (cv. Rapsodie) during Jan.o–Aug. 2004. The four treatments, based on electronic Grodan? water content meters (WCMs), received irrigations when the slab water content (SWC) was ≈60%, 70%, 80%, and 90% while the other two treatments, based on balances, applied irrigations after a 700- or 500-g loss in the daily-adjusted slab weight (LDASW). Initially, we noticed a heterogeneous EC build-up in the slabs across various treatments, which probably distorted the expression of treatment effects (if any) on plant growth, yield, and water use. To minimize this problem, an EC control strategy of applying extra irrigation was devised and adopted in two sequential phases: 1) application of a 30-minute-long extra irrigation twice a week (for 7 weeks); and 2) extra irrigation(s) using the irrigation control routine of an Argus computer when the slab EC was ≈3.5 mS/cm (for 5 weeks). Slab EC was well controlled in both these phases and we observed significant treatment effects on root growth and marketable yield. Analyzing the results, we concluded that irrigating at 70% to 80% SWC was best for maximum root growth as well as marketable yield. The two irrigation treatments based on the 700- and 500-g LDASW were well maintained and performed equally well, producing marketable yields comparable to those produced by irrigating at 70% and 80% SWC.
Petunia `Midnight' were grown in drainage lysimeters in an open-sided clear polyethylene covered shelter to evaluate growth responses in response to alternative irrigation strategies. Three irrigation methods were evaluated: tensiometer-controlled automatic irrigation system, regularly scheduled irrigation utilizing an automated controller, and human perception of plant irrigation need. Drainage lysimeters (250 L) were backfilled with native sand field soil to simulate landscape conditions and managed with Best Management Practices. Following establishment, lysimeters irrigated by an automated controller were irrigated 1.3 cm daily. Tensiometer-controlled lysimeters were irrigated when plant available water (2.5 kPa to 1.5 MPa) had declined to 70% or less, and were irrigated back to field capacity. Canopy growth indices and leaf gas exchange measurements were evaluated relative to irrigation strategies. Actual evapotranspiration was calculated for each replication. Daily irrigation resulted in significantly higher assimilation rates, transpiration rates, and final shoot dry weights than the other treatments tested. Assimilation rates and transpiration rates were significantly higher for tensiometer-controlled irrigation than the human judged treatment, but no differences were found in final shoot dry mass.
Partial rootzone drying (PRD) and regulated deficit irrigation (RDI) were evaluated separately over two years on Vitis vinifera L. variety `Cabernet Sauvignon' for their applicability to commercial vineyards in Texas and to investigate their potential for enhancing grapevine acclimation and cold hardiness. PRD treatments compared the alternating-half-rootzone water application strategy of PRD to an equal volume of water applied to the entire rootzone and a 2× volume of water applied to the entire rootzone. RDI treatments compared the effects of deficit irrigation at different developmental stages of grapevine: post-fruit set to veraison; veraison to harvest; post-harvest; and a no-deficit control. The PRD treatment plots performed similarly to the equal volume treatment plots for yield and fruit composition. The double-volume treatment had a trend to higher yield in 2002 and statistically significant higher yields in 2003, and slightly lower soluble solids content of fruit in 2002. Thus, the two deficit treatments, PRD and Equal, experienced only a small reduction in performance while enabling reduced water usage. The PRD alternating-half-rootzone strategy demonstrated no advantage over a standard deficit irrigation strategy. Grapevines irrigated with the RDI strategy responded to this treatment most during the post-fruit set to veraison stage of development, which had lower yields and higher fruit soluble solids compared to the no-deficit treatment in 2002. Both PRD and RDI deficit irrigation strategies significantly increased the earliness and rate of periderm development on shoots in both years, but did not result in consistently greater cold hardiness compared to no-deficit treatments.