scholarly journals SENSITIVITY OF FRENCH PRUNE PRODUCTION TO WATER DEPRIVATION AT DIFFERENT STAGES OF FRUIT GROWTH

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 656c-656
Author(s):  
Bruce Lampinen ◽  
K. A. Shackel ◽  
S. Southwick ◽  
D. Goldhamer ◽  
B. Olson

During this three year study, irrigation water was withheld from trees in a commercial drip irrigated french prune orchard (Butte County, CA), during different periods within the double sigmoid fruit growth pattern (stage I - III), and postharvest. Tree water stress associated with early season water deprivation was minimal, due to the presence of stored soil moisture and low evaporative demands. For mid and late season water deprivation there was no fruit growth stage that was particularly sensitive to water stress, although severe and prolonged stress caused smaller fruit with lower quality. For the three year average, irrigation treatments caused no statistically significant effects on fruit set or drop relative to the control, however most of the stress treatments increased return bloom relative to the control, resulting in higher fruit loads and higher yields. These results suggest that moderate water stress may enhance economic prune productivity.

Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Douglas D. Buhler ◽  
Orvin C. Burnside

Field and greenhouse research was conducted during 1980 and 1981 to evaluate the effects of carrier volume, surfactant concentration, and treatment date on glyphosate [N- (phosphonomethyl)glycine] toxicity to annual-grass weeds and volunteer small grains. Glyphosate phytotoxicity increased as carrier volume was decreased from 190 to 24 L/ha. The presence of a surfactant in the spray solution did not influence grass control when glyphosate was applied in a carrier volume of 24 L/ha. When glyphosate was applied in 48 or 95 L/ha, the presence of surfactant resulted in better grass control than glyphosate without surfactant. When applied in 190 L/ha, glyphosate with 0.5% (v/v) surfactant gave better grass control than glyphosate alone or commercially formulated glyphosate. When glyphosate was applied to plants under water stress, little control was achieved regardless of plant growth stage. Glyphosate application to grass after head initiation also resulted in reduced control. Maximum weed control with glyphosate was attained when applications were made to seedlings growing actively because of adequate soil moisture and favorable temperatures.


Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 277-282 ◽  
Author(s):  
M. S. Ahmadi ◽  
L. C. Haderlie ◽  
G. A. Wicks

Under greenhouse conditions, postemergence herbicide effectiveness was greater when barnyardgrass [Echinochloa crus-galli(L.) Beauv.] plants were 5-or 10-cm tall as compared to 15-or 20-cm tall. Absorption of14C-glyphosate [N-(phosphonomethyl)glycine] decreased from 58% of applied to 47% as plant height increased from 5 to 15 cm, and an additional reduction (to 32% of applied at 5 cm) occurred when terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] was added to glyphosate. Translocation of14C-glyphosate was reduced in older plants or when terbutryn was added to glyphosate. Water stress studies included soil moisture levels of 10, 20, 30, and 40% moisture (PW). Herbicide treatments were less effective at soil moisture levels below field capacity (30 PW). When soil moisture was 10 PW (-37 bar) absorption of14C-glyphosate was greatly reduced in plants treated at both 7.5-and 15-cm heights with or without terbutryn. At 10 PW only 15 to 20% of applied14C was absorbed whereas at 40 PW, absorption was over 45% and 62% with and without terbutryn, respectively. The addition of terbutryn to glyphosate resulted in decreased translocation for all soil moisture levels except the 20 PW treatment at the 15-cm height. Translocation of14C was greatly reduced for plants in soils at 10 PW for both herbicide treatments.


Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 895-900 ◽  
Author(s):  
S. R. Kendig ◽  
J. C. Rupe ◽  
H. D. Scott

The effects of irrigation and soil water stress on Macrophomina phaseolina microsclerotial (MS) densities in the soil and roots of soybean were studied in 1988, 1989, and 1990. Soybean cvs. Davis and Lloyd received irrigation until flowering (TAR2), after flowering (IAR2), full season (FSI), or not at all (NI). Soil water matric potentials at 15- and 30-cm depths were recorded throughout the growing season and used to schedule irrigation. Soil MS densities were determined at the beginning of each season. Root MS densities were determined periodically throughout the growing season. Microsclerotia were present in the roots of irrigated as well as nonirrigated soybean within 6 weeks after planting. By vegetative growth stage V13, these densities reached relatively stable levels in the NI and FSI treatments (2.23 to 2.35 and 1.35 to 1.63 log [microsclerotia per gram of dry root], respectively) through reproductive growth stage R6. After R6, irrigation was discontinued and root densities of microsclerotia increased in all treatments. Initiation (IAR2) or termination (TAR2) of irrigation at R2 resulted in significant changes in root MS densities, with densities reaching levels intermediate between those of FSI and NI treatments. Year to year differences in root colonization reflected differences in soil moisture due to rainfall. The rate of root colonization in response to soil moisture stress decreased with plant age. Root colonization was significantly greater in Davis than Lloyd at R5 and R8. This was reflected in a trend toward higher soil densities of M. phaseolina at planting in plots planted with Davis than in plots planted with Lloyd. Although no charcoal rot symptoms in the plant were observed in this study, these results indicated that water management can limit, but not prevent, colonization of soybean by M. phaseolina, that cultivars differ in colonization, and that these differences may affect soil densities of the fungus.


HortScience ◽  
1993 ◽  
Vol 28 (9) ◽  
pp. 908-913 ◽  
Author(s):  
Susan M. Huslig ◽  
Michael W. Smith ◽  
Gerald H. Brusewitz

Irrigation schedules were evaluated on `Cresthaven' peach [Prunus persica (L.) Batsch.] to determine if water application could he reduced or omitted without affecting fruit size or yield. Tensiometers were used to schedule trickle irrigation during 1984-M. Treatments were no irrigation or irrigation when soil pressure potential at a 30-cm depth reached 40 or 60 kPa, respectively. When production began in 1986, trees were either irrigated until harvest (1-7 Aug.) or until October. Beginning in 1989, class A pan evaporation was used to schedule irrigation by replacing 60% of evaporation. Trees were irrigated from budbreak to harvest or October, from beginning of stage III fruit growth until harvest or October, or trees were not irrigated. The irrigation treatments were in factorial combination using sod middles, with annual ryegrass (Lolium multiforum Lam.) seeded under the trees or a sod-herbicide strip. The ryegrass was seeded in October, then killed at the onset of stage III fruit growth. Water application was reduced 32% to 57% when irrigation was discontinued after harvest compared to irrigation until October. Irrigation before stage III fruit growth did not affect fruit yield, size, or pruning weights compared to trees irrigated at the onset of stage III fruit growth. Trunk size was increased by irrigation; however, there were no differences in trunk size among irrigation treatments. Irrigation occasionally increased fruit size and yield compared to no irrigation. There were few differences in flower bud density, fruit set, yield, or fruit size among trees with reduced irrigation schedules compared to trees receiving irrigation from budbreak until October. Annual ryegrass decreased shoot growth in 1990 and flower bud density in 1991; however, fruit set was not affected. Annual ryegrass depleted excess soil moisture during the spring in some years, then conserved soil moisture after it was killed. Using sod with annual ryegrass under the trees may be a viable alternative to management with sodherbicide strips.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1121G-1121
Author(s):  
Warren C. Micke ◽  
Joseph A. Grant ◽  
Maxwell V. Norton ◽  
James T. Yeager

Under California conditions `Granny Smith' apple does not “self-thin” sufficiently to promote good return bloom nor to provide fruit size desired for the fresh market. Preliminary studies conducted during 1985-87 indicated that 1-naphthyl N-methylcarbamate (carbaryl), 1-naphthaleneacetic Acid (NAA), and 1-naphthaleneacetamide (NAD) could be useful for thinning `Granny Smith'. Detailed studies conducted in 1988 and 89 using dilute handgun applications demonstrated that all 3 materials provided reasonable thinning as shown by fruit set counts. NAA and NAD tended to slow fruit growth as compared to carbaryl. Carbaryl tended to uniformly thin clusters while NAA and NAD were more likely to remove all the fruit from some clusters and few fruit from others, especially in 1988. Compared to the control, all materials applied in 1988 improved return bloom in 1989 with carbaryl having a slightly greater effect than NAA and NAD. As a result of these studies carbaryl at 1.7 to 2.2 kg (active ingredient) per ha as a dilute application is being suggested for grower trials in California.


1995 ◽  
Vol 120 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Bruce D. Lampinen ◽  
Kenneth A. Shackel ◽  
Stephen M. Southwick ◽  
Bill Olson ◽  
James T. Yeager ◽  
...  

The sensitivity of French prune (Prunus domestica L. syn. `Petite d'Agen') to water deprivation at various fruit growth stages was studied over 3 years in a drip-irrigated orchard. The soil was a poorly drained Rocklin fine sandy loam with a hardpan that varied from 4.75 to I m from the surface at the northern end of the orchard (shallow soil condition) to no hardpan apparent to 2 m below the surface at the southern end of the orchard (deep soil condition). Water deprivation during a) the first exponential phase of fruit growth or stage I, b) lag phase of fruit growth or stage II, c) first half of stage II, d) second half of stage II, e) second exponential fruit growth phase or stage III, and f) postharvest was compared to a fully watered control. Water deprivation caused the most severe reduction in tree water status when it was imposed over longer periods of time and during periods of high evaporative demand and also had mm-e severe effects under shallow soil conditions. Compared to the control treatment, deprivation during all of stage II (the most severe deprivation treatment) was associated with increased Ilowering, reduced fruit hydration ratio, and smaller fruit size under all soil conditions. Under deep soil conditions, deprivation during all of stage II resulted in increased return bloom, which was reflected in higher fruit loads and dry t-ha-' fruit yield. However, under shallow soil conditions, even though return bloom was increased with this treatment, fruit loads and dry t·ha-1 fruit yields were the lowest of all treatments. These differences in treatment effects in shallow vs. deep soil conditions were most likely the result of increased fruit drop, which occurred under shallow soil conditions as a result of rapid onset and increased severity ofstress. Treatments that had parallel effects in shallow and deep soil conditions resulted in statistically significant overall treatment effects, while those that had opposing effects in shallow vs. deep soil conditions did not show significant overall treatment effects. Substantial alternate hearing occurred, and, in general, dry fruit yields above ≈9 dry t·ha-1 resulted in a decrease in fruit load the following year, while loads below this value showed a subsequent increase. Based on a separate estimate of the theoretically stable value for each treatment, all deprivation treatments resulted in a higher sustainable fruit load compared to the fully irrigated control. This suggests that, for the purpose of prune fruit production, there may be an optimal level of tree water stress.


1970 ◽  
Vol 33 (3) ◽  
pp. 391-397 ◽  
Author(s):  
MA Ullah ◽  
MA Haque

Studies on fruiting, bearing habit and fruit growth of jackfruit was carried out at orchard of Jackfruit Research Project, Department of Horticulture, Bangladesh Agricultural University (BAU), Mymensingh during the period from November 2000 to October 2001. Ten jackfruit germplasm of 13 years of age were selected for this study. Fruit bearing habit of jackfruit was cauliflorous i.e., fruits are borne on trunk and branches. The germplasm under study bore fruits on trunk, primary, secondary, tertiary, fourth, fifth and sixth branches of jackfruit trees. On an average, the maximum fruits were borne on primary branches (33.0%) followed by those on trunk (31.5%), secondary (12.3%), and fourth branch (8.4%), while it was the lowest on sixth branch (2.0%). The growth pattern of fruit of jackfruit is characterized by single sigmoid curve. This is true when all aspects of measurements viz, length, diameter, circumference, weight, and volume of fruits; length, breadth, weight of bulb as well as seed were plotted against time from fruit set to haiwesting maturity. Key Words: Bearing habit, fruit growth, jackfruit germplasm. doi:10.3329/bjar.v33i3.1598 Bangladesh J. Agril. Res. 33(3) : 391-397, September 2008


Author(s):  
Kiflom Degef Kahsay ◽  
Kidane Welde Reda

Maize (Zea Mays L.) is one of the most important food crops worldwide. In Ethiopia, it is one of the leading food grains selected to assume a national commodity crop to support the food self-sufficiency program of the country. Maize is fairly sensitive to water stress and excessive moisture stress. This is due to variation in sensitivity of different growth stages to water stress. The study was conducted to determine the water use efficiency of maize under deficit irrigation practice without significant reduction in yield and to identify crop growth stages which can withstand water stress. The experiment was conducted at the Alamata Agricultural Research center experimental site Kara Adishabo Kebele, Raya Azebo district. The experiment was laid out in randomized complete block design (RCBD) with three replications and six levels of irrigation water applications as possible treatments. Analysis was done to yield and water use efficiency of maize using R statistical software and the mean difference was estimated using the least significant difference (LSD) comparison. The highest grain (33.72qt/ha) and biomass yield (148.4qt/ha) was obtained from the 50% deficit irrigation at late growth. The maximum irrigation water use efficiency was obtained from both 50% deficit at all the four growth stages (0.5418 kg/ha) and at 50% deficit at late growth stage (0.446 kg/m3). And by comparing the grain yield obtained at the 50% deficit at late growth stage (33.72 qt/ha) and grain yield obtained at 50% deficit at all growth stages (23.34 qt/ha), the 50% deficit at late growth stage shows better result. The 50% deficit of crop water requirement did not affect the yield components (plant height & number of cobs per plant) of maze. Therefore applying irrigation water by reducing the crop water requirement by 50% at the late growth stage has a significant contribution for sustainable and efficient irrigation water utilization at moisture deficient areas without a significant loss on grain and biomass yield.


HortScience ◽  
2015 ◽  
Vol 50 (7) ◽  
pp. 1070-1074 ◽  
Author(s):  
Lenny Wells

Pecan [Carya illinoinensis (Wangenh.) K. Koch] tree stem water potential (ψ), shoot length, nut yield, and nut quality for the following treatments were evaluated in a commercial pecan orchard in Berrien County, GA; 1) current recommended irrigation schedule, 2) a reduced early season irrigation schedule, and 3) non-irrigated control. Water Stress on pecan occurred at ≈−0.78 MPa using the pressure chamber to measure stem water potential. Regression analysis suggests that irrigation scheduling for mature pecan trees may be needed when volumetric water content reaches 10% on Tifton loamy sand soil. Water stress in pecan is correlated with soil moisture from budbreak through the end of nut sizing. Pecan trees bearing a moderate to heavy crop load may undergo water stress during the kernel-filling stage regardless of soil moisture level. Therefore, it is suggested that water stress during the kernel-filling period is a function of nut development, crop load, or both in addition to soil moisture. The reduced early season irrigation schedule provided a 38% reduction in irrigation water use with no significant effect on pecan tree water stress, yield, or quality, suggesting that pecan trees can tolerate moderate early season water stress with no effect on pecan yield or quality under southeastern U.S. environmental conditions.


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