A 3-year study was conducted in central California to compare the effects of furrow, microjet, surface drip, and sub surface drip irrigation on vegetative growth and early production of newly planted `Crimson Lady' peach [Prunus persica (L.) Batsch] trees. Furrow treatments were irrigated every 7, 14, or 21 days; microjet treatments were irrigated every 2-3, 7, or 14 days; and surface and subsurface drip (with one, two, or three buried laterals per row) treatments were irrigated when accumulated crop evapotranspiration reached 2.5 mm. The overall performance showed that trees irrigated by surface and subsurface drip were significantly larger, produced higher yields, and had higher water use efficiency than trees irrigated by microjets. In fact, more than twice as much water had to be applied to trees with microjets than to trees with drip systems in order to achieve the same amount of vegetative growth and yield. Yield and water use efficiency were also higher under surface and subsurface drip irrigation than under furrow irrigation, although tree size was similar among the treatments. Little difference was found between trees irrigated by surface and subsurface drip, except that trees irrigated with only one subsurface drip lateral were less vigorous, but not less productive, than trees irrigated by one surface drip lateral, or by two or three subsurface drip laterals. Within furrow and microjet treatments, irrigation frequency had little effect on tree development and performance with the exception that furrow irrigation every 3 weeks produced smaller trees than furrow irrigation every 1 or 2 weeks.
David R. Bryla, Thomas J. Trout, James E. Ayars, and R. Scott Johnson
G.H. Neilsen, P. Parchomchuk, D. Neilsen, R. Berard, and E.J. Hague
`Gala' apple (Malus domestica Borkh) on M.26 rootstock was subjected, in the first five growing seasons, to NP-fertigation and a factorial combination of treatments involving method and frequency of irrigation. Two types of emitters (drip or microjet) were used to apply the same quantity of water at high (daily), intermediate (about weekly) and low (about bi-weekly) irrigation frequencies. Although initial tree vigor and yield were higher for drip-fertigated trees, by the end of the study microjet fertigation produced larger trees of similar yield. These microjet fertigated trees had higher leaf P, K and Cu but lower leaf N, Mg, and Mn than drip-fertigated trees. Soil pH and extractable Mg and K concentrations were higher and extractable-P concentrations lower directly beneath microjet-emitters as a result of the larger fertigated soil volume relative to drip-emitters. High frequency irrigation improved tree growth but had less effect on leaf nutrient concentrations or soil chemical changes than lower frequency irrigation. Leaf N concentration was most affected by irrigation frequency, tending to decrease with daily irrigation.
Esmaeil Fallahi, Denise Neilsen, Gerry H. Neilsen, Bahar Fallahi, and Bahman Shafii
), information on the tree growth, yield, and fruit quality in new apple cultivars under various regimes of drip or microjet sprinkler irrigation systems in the Pacific Northwest is lacking. Water Use Study At The University Of Idaho Experiment description and
Esmaeil Fallahi, Bahar Fallahi, and Michael J. Kiester
because fruit from nontreated plots had smaller size ( Assaf et al., 1975 ). Irrigation with a drip system uses less water than sprinkler irrigation ( Fallahi et al., 2007b ; Proebsting, 1994 ). However, irrigation through microjet sprinkler systems can
Genevieve Pelletier and C.S. Tan
A time domain reflectometry (TDR) technique was used to measure water in the soil profile to derive wetting patterns of drip and microjet irrigation systems in a peach [Prunus persica (L.) Batsch] orchard. A distinct cone shape of >50% available soil water (ASW) extending from the emitter down to a depth of >45 cm was observed in the drip system. The 50% ASW zone in the microjet system was an elongated semicircle from the soil's surface down to a depth of 35 cm. TDR can be used successfully to determine wetting patterns of various irrigation systems to develop better irrigation scheduling.
George Hochmuth, Dan Cantliffe, Craig Chandler, Craig Stanley, Eric Bish, Eric Waldo, Dan Legard, and John Duval
Experiments were conducted in two seasons in Dover, Fla. (central Florida), with bare-root and containerized (plug) strawberry (Fragaria ×ananassa) transplants to evaluate transplant establishment-period water use, plant growth, and flowering responses in the 3-week transplant establishment period. Strawberry plug plants were established with 290 gal/acre water applied only with the transplant at planting time, while 200,000 gal/acre from microjet or 1 million gal/acre of water from sprinkler irrigation were used to establish bare-root transplants. Root, shoot, and crown dry matter of plug plants rapidly increased during the establishment period, while there was a decline in leaf area and root and crown mass of bare-root plants, even with sprinkler or microjet irrigation. Water applied with the bare-root transplant only at planting was not enough to keep the plant alive during the establishment period. Large plug plants, but not irrigated bare-root plants, began flowering at 3 weeks after planting. Plug plants were used to successfully establish strawberry crops with low water inputs.
W.N. Lipe, L. Baurnhardt, C.W. Wendt, and D.J. Rayburn
Freeze losses to grapes in March, after mild deacclimatizing winters, is the major production risk on the Texas High Plains. Earlier studies indicated the effectiveness of evaporative cooling in reducing grape bud heat summation with a correlated delay in budbreak. Parameters relating to water-use-efficiency were identified. In the current study, these parameters were incorporated to minimize water use. Water was applied through microjets for 25 seconds every 4 minutes any time air temperature exceeded 10°C, 15°C, and Control. Bud temperatures were monitored continuously by thermocouples and data logger, and correlated with budbreak and plant development. Random bud samples were taken weekly prior to budbreak and subjected to differential thermal analysis. A freeze on March 23 (-3.5°C) resulted in differential primary bud losses to Chardonnay during budbreak, and to Cabernet Sauvignon 15 days prior to budbreak. Evaporative cooling significantly increased yields in both cultivars. Differential thermal analysis verified differences in cold stress tolerance in Chardonay prior to budbreak.
Bhimanagouda S. Patil
Two-year field studies at three sites in the Lower Rio Grande Valley of Texas were conducted to evaluate the effects of location, rootstock, and irrigation on sheepnosing of `Rio Red' grapefruit (Citrus paradisi Macf.,) on sour orange (Citrus aurantium L.) rootstock. Based on the equatorial/polar diameter ratio, grapefruit grown in Weslaco had significantly higher percentage of sheepnosed fruits (62.66) than fruit grown in Mission (57.32), while Bayview had a negligible percentage of sheepnosed fruit (4.07). In a second study, `Rio Red' grapefruit grown on Carrizo [C. sinensis (L.) Osbeck × Poncirus trifoliate (L.) Raf.] had significantly higher percentage of sheepnosed fruit (59.46), compared to `Rio Red' grown on Swingle (C. paradisi × P. trifoliata) (47.83). In a third experiment, grapefruit with microjet irrigation had a significantly higher percentage of sheepnosed fruit (53.40), compared to flood irrigation (42.68). Although sheepnosed fruit had significantly greater peel thickness and a lower juice content, fruit quality was better because of higher soluble solids: titratable acidity ratio compared to normal shaped fruits. While significant, the irrigation and rootstock appear have a minor effect on sheepnosing less than growing location.
Frank J. Peryea
Differential fertilizer application method (single dry, split dry, fertigated liquid), irrigation method (drip, microjet), and nutrient source (N vs. N+P in year 2+) were established in Spring 1992 in a newly planted Gala and Fuji apple orchard. In Spring 1993, the drip-fertigated Gala trees had 3 times and the drip-fertigated Fuji trees had 8 times more flower clusters per tree than the other treatments Fruiting was not allowed in 1993. Trunk cross-sectional area (TCSA) in Fall 1992 was not influenced by treatments. By Fall 1993, TCSA was still independent of treatment for the Fuji trees; however, the Gala trees fell into two size groups - (larger) microsprinkler-fertigated and split dry broadcast; and (smaller) drip fertigated and single-time spring dry broadcast. TCSA had increased 284% (Fuji) and 265% (Gala) since planting. None of the treatment effects were substantially influenced by fertigating with N+P vs N only. Leaf concentrations of most nutrients were consistently lower in 1993 than in 1992. Leaf Fe was higher in 1993 because the orchard was dustier. Leaf N was lower in the microsprinkler-fertigated trees than in all other treatments. Fertigation with N+P did not consistently produce higher leaf P than the N-only treatments. Leaf Mn varied with treatment: microsprinkler fertigated < drip fertigated, single dry < split dry. Treatment effects on all other elements were inconsistent (K, Ca, Mg, B, Cu) or absent (Zn, Fe).
Bhimanagouda S. Patil
Field studies were conducted for 2 years, at three sites in the Lower Rio Grande Valley of Texas, to evaluate the effects of location, rootstock, and irrigation on sheepnosing (elongation of the apex) of `Rio Red' grapefruit (Citrus paradisi Macf.). Based on the ratio of equatorial to polar diameter, grapefruit budded on sour orange (Citrus aurantium L.) rootstock grown at Weslaco had a significantly higher percentage of sheepnosed fruits (63%) than did fruit grown at Mission (57%), while the grove at Bayview produced a negligible percentage of sheepnosed fruit (4%). In a second study, `Rio Red' trees grown on `Carrizo' rootstock [C. sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.] produced a significantly higher percentage of sheepnosed fruit (59%) than did those on `Swingle' (C. paradisi × P. trifoliata) (48%). In a third experiment, trees irrigated by microjet had a significantly higher percentage of sheepnosed fruit (53%) than did those that were flood-irrigated (43%). Although sheepnosed fruit had significantly greater peel thickness and a lower juice content, fruit quality was better than that of normal fruit because of a higher soluble solids: titratable acidity ratio. In 1999, the significant irrigation and rootstock effects were less than that due to growing location. Effects of location, rootstock and irrigation varied between years. The interaction between factors and years was mainly due to a lack of low amount of sheepnosing in 1998.