scholarly journals Adjustments of Irrigation Scheduling Model for Bell Pepper

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 573c-573
Author(s):  
Vanessa Drouot ◽  
Eric H. Simonne ◽  
James B. Witt

An irrigation scheduling model represented by 12.7 DAT * 0.5 * ASW = D(DAT – 1) + [Ep(DAT) * CF(DAT) – R – I] was tested in central Alabama for Spring-grown bell pepper (Capsicum annuum L.). In the model, DAT (days after transplanting) is crop age; effective root depth is 12.7 DAT with a maximum of 250 mm; usable water (mm3·mm–3) is 0.5 ASW; deficit on the previous day is D(DAT–1); evapotranspiration is pan evaporation [Ep(DAT)] times a crop factor value [CF(DAT) = 0.15 + 0.018 DAT – 0.0001 DAT * DAT]; rainfall (R) and irrigation (I) are in mm. The model called for 13 irrigations between 17 and 85 DAT. Under the current N recommendation rate for bell pepper (112 kg/ha), marketable yield increased quadratically from 36% to 148% of the model rate. Highest marketable yields occurred near the model rate. Under a N rate of 170 kg/ha, yields increased linearly. These results suggests that the model provided adequate moisture to maximize bell pepper marketable yields under the recommended N rate.

1990 ◽  
Vol 115 (2) ◽  
pp. 226-230 ◽  
Author(s):  
Doyle A. Smittle ◽  
W. Lamar Dickens ◽  
James R. Stansell

An irrigation scheduling model for snap bean (Phaseolus vulgaris L.) was developed and validated. The irrigation scheduling model is represented by the equation: 12.7(i - 4) × 0.5ASW = Di-1 + [E(0.31 + 0.01i) - P - I]i, where crop age is i; effective root depth is 12.7(i - 4) with a maximum of 400 mm; usable water (cm3·cm-3 of soil) is 0.5 ASW, deficit on the previous day is Di-1; evapotranspiration is pan evaporation (E) times 0.31 + 0.01i; rainfall (mm) is P, and irrigation (mm) is I. The model was validated using a line source irrigation system with irrigation depths ranging from 3% to 145% of tbe model rate in 1985 and from 4% to 180% of the model rate in 1986. Nitrogen fertilization rates ranged from 50% to 150% of the recommended rate both years. Marketable pod yields increased as irrigation rate increased in 1985. Irrigation at 4%, 44%, 65%, 80%, 150%, and 180% of the model rate produced yields that were 4%, 39%, 71%, 85%, 92%, and 55% as great as yields with the model rate in 1986. Marketable pod yields increased as N rate increased when irrigation was applied at 80%, 100%, or 150% of the model rate in 1986, but pod yields varied less with N rate when irrigation was applied at 4%, 44%, 65%, or 180% of the model.


2014 ◽  
Vol 94 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Olanike Aladenola ◽  
Chandra Madramootoo

Aladenola, O. and Madramootoo, C. 2014. Response of greenhouse-grown bell pepper (Capsicum annuum L.) to variable irrigation. Can. J. Plant Sci. 94: 303–310. In order to optimize water use in bell pepper production information about the appropriate irrigation water applications and agronomic and physiological response to mild and severe water stress is necessary. Different water applications were tested on yield, quality and water stress threshold of greenhouse-grown bell pepper (Capsicum annuum L.) cultivar Red Knight in 2011 and 2012 on the Macdonald Campus of McGill University, Ste Anne De Bellevue, QC. The study was carried out on a soil substrate in the greenhouse. Irrigation was scheduled with four treatments:120% (T1), 100% (T2), 80% (T3), and 40% (T4) replenishment of crop evapotranspiration in a completely randomized design. The highest marketable yield, water use efficiency and irrigation water use efficiency were obtained with T1 in both years. T1 received 20% more water than T2 to produce 23% more marketable yield than T2. Fruit total soluble solids content was highest in T4, and smallest in T1. The mean crop water stress index (CWSI) of the irrigation treatments ranged between 0.08 and 1.18. Leaf stomatal conductance of bell pepper was 75 to 80% lower in T4 than in T1. Regression obtained between stomatal conductance and CWSI resulted in a polynomial curve with coefficients of determination of 0.88 and 0.97 in 2011 and 2012, respectively. The result from this study indicate that the yield derived justifies the use of an extra quantity of water. Information from this study will help water regulators to make appropriate decision about water to be allocated for greenhouse production of bell pepper.


1993 ◽  
Vol 118 (6) ◽  
pp. 726-730 ◽  
Author(s):  
Eric H. Simonne ◽  
Doyle A. Smittle ◽  
Harry A. Mills

An irrigation scheduling model for turnip (Brassica rapa L.) was validated using a line-source irrigation system in a 2-year field trial. The model used a water balance, a variable root length, and a crop factor function of plant age (i). Evapotranspiration was computed daily as class A pan evaporation times a crop factor [CF(i) = 0.365 + 0.0154i-0.00011i2]. Irrigation according to the model maintained soil water tension at <25 kPa at a 30-cm depth. When rainfall amounts were less than water use, leaf yields responded quadratically to irrigation rates, from 0% to 160% of the model rate, and the highest leaf yield with the lowest water applications corresponded to the model rate. Therefore, this model could replace the “feel or see” methods commonly used for scheduling irrigation of leafy vegetables grown in the southeastern United States.


1997 ◽  
Vol 7 (2) ◽  
pp. 138-142
Author(s):  
Regina P. Bracy

Field studies were conducted in Spring 1991, 1992, and 1993 to determine if stand deficiencies of 10%, 20%, or 30% affected bell pepper (Capsicum annuum L.) yield and fruit size. Subsequent replanting to a 100% stand and timing of replanting also were evaluated for effects on fruit yield. Stand deficiencies of up to 30% and replanting to a complete stand 2 or 3 weeks after initial transplanting did not affect yield per acre and average weight per fruit of bell pepper plants grown on polyethylene-mulched beds during 3 years of tests. Bell pepper plants grown in 10%, 20%, or 30% deficient stand had greater marketable yield per plant than plants grown in 100% stand. Replanting to a complete stand 3 weeks after initial transplanting decreased early marketable yield and production per plant over replanting 2 weeks after initial transplanting.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 529B-529
Author(s):  
Eric H. Simonne ◽  
Joseph M. Kemble ◽  
Arnold W. Caylor

Most potato (Solanum tuberosum L.) is produced as a non-irrigated crop in the southeastern United States. This practice makes potato yields dependent on rainfall pattern and amount. An irrigation scheduling method based on a water balance and class A pan evaporation data (Ep) was evaluated in Spring 1996 on a fine sandy loam soil with `LaSoda' potatoes. Planting date was 9 Apr. and standard production practices were followed. The model was (12.7 DAH + 191) * 0.5 ASW = D(DAH-1) + [Ep (0.12 + 0.023 DAH - 0.00019 DAH*DAH) - R(DAH) - I(DAH)], where DAH is days after hilling (DAH = 0 on 14 May), ASW is available soil water (0.13 mm/mm), D is soil water deficit (mm), R is rainfall (mm) and I is irrigation (mm). Root depth expanded at a rate of 13 mm/day to a maximum depth of 305 mm. Root depth at hilling was 191 mm. Controlled levels of water application ranging between 0% and 161% of the model rate were created with drip tapes. The model scheduled irrigations on 35, 39, 43 and 49 DAH. On 85 DAH, potatoes were harvested and graded. Irrigation influenced total yield, marketable yield, and combined US #1 grades (P < 0.01; R2 > 0.85). Mean marketable yields were 19, 28, and 21 t/ha for the 0%, 100%, and 160% irrigation rates, respectively. These results suggest that supplementing rainfall with irrigation and controlling the amount of water applied by adjusting irrigation to actual weather conditions could increase potato yields. Excessive water, as well as limiting water, reduced potato yields.


HortScience ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 701-706 ◽  
Author(s):  
Qingren Wang ◽  
Waldemar Klassen ◽  
Edward A. Evans ◽  
Yungcong Li ◽  
Merlyn Codallo

Mulching in vegetable cultivation has been widely used to conserve water and improve yield. Field experiments with four treatments, including yard waste compost combined with plastic mulches in raised beds for winter fresh market bell peppers (Capsicum annuum L.), were conducted at two experimental sites [Pine Island Farm (PIF) and Tropical Research and Education Center (TREC)] in Miami-Dade county for two different years each. The treatments were: 1) control (PM): plastic mulch alone; 2) MC33: fumigation of the soil with a mixture of methyl bromide and chloropicrin and covered with plastic mulch; 3) herbicide/OM: organic mulch sprayed with herbicides (S-metolachlor and napropamide) without plastic mulch; and 4) PM/OM: organic mulch covered by plastic mulch. The treatment of PM/OM at both experimental sites in 2 years each increased the total marketable yields of bell pepper by 1.5- to 3.2-fold, total extra large fruit yields by 2.0- to 5.7-fold, and total large fruit yields by 1.4- to 2.6-fold, respectively, on average compared with the control, although some exceptions occurred between the two years at the TREC site. Under most circumstances at both experimental sites in two different years each, the PM/OM treatment also improved the total marketable yield and fruit quality (such as extra large fruits) for the first two harvests, which shows a preference to provide winter fresh market vegetables to meet a high demand. The economic benefit by PM/OM was the greatest among all the treatments. The results suggest that the application of organic mulch combined with plastic mulch can improve bell pepper yield and quality as a result of the improvement of soil fertility, especially the early harvests of winter fresh market fruits, which has shown a potential in the development of sustainable agriculture.


2013 ◽  
Vol 27 (4) ◽  
pp. 741-746 ◽  
Author(s):  
Ryan A. Pekarek ◽  
David W. Monks ◽  
Katherine M. Jennings ◽  
Greg D. Hoyt

Greenhouse and field studies were conducted to evaluate bell pepper tolerance to the sulfonylurea herbicides imazosulfuron and thifensulfuron-methyl. Imazosulfuron was applied at 56, 112, 224, 336, or 448 g ai ha−1. Thifensulfuron-methyl was applied at 2.6, 5.3, 10.5, 21.0, or 31.6 g ai ha−1. In the greenhouse over 2 yr, bell pepper injury due to imazosulfuron POST ranged from 12 to 27%. Reductions in plant height and numbers of nodes, buds, flowers, and fruits were generally minor or not observed. Injury from thifensulfuron-methyl POST ranged from 40 to 60% in the greenhouse. Similar trends were observed for leaf chlorosis and distortion. Thifensulfuron-methyl tended to decrease numbers of buds, flowers, and fruits in the greenhouse. In the field at three sites, bell pepper injury due to imazosulfuron applied POST-directed (POST-DIR) was less than 10% at all rating times, and height and yield were not affected. Total and marketable yield averaged 40,300 and 35,810 kg ha−1, respectively, across environments and years. Bell pepper injury from thifensulfuron-methyl applied POST-DIR in the field was less than 20% with all rates and less than 10% when rates less than 10.6 g ai ha−1 thifensulfuron-methyl were applied. Bell pepper stand (plants ha−1) or height was not affected by thifensulfuron-methyl. Thifensulfuron-methyl did not affect total bell pepper yield (39,310 kg ha−1 averaged across environments); however, reductions in Fancy grade yield were observed. No. 1 and cull yield grades tended to increase with increasing thifensulfuron-methyl rate, apparently compensating for lost Fancy yield.


1992 ◽  
Vol 117 (5) ◽  
pp. 717-720 ◽  
Author(s):  
Doyle A. Smittle ◽  
W. Lamar Dickens ◽  
M. Jane Hayes

An irrigation scheduling model for summer squash (Cucurbita pepo L.) was developed and validated during 1986, 1987, and 1989. The model is represented by the equation: 12.7(i - 4) × 0.5ASW = Di-1 + [E(0.14 + 0.015) - P - I]i, where crop age in days is i; effective root depth is 12.7(i - 4) with a maximum of 381 mm; usable water (cubic millimeter per cubic millimeter of soil) is 0.5ASW, deficit on the previous day is Di-1; evapotranspiration is pan evaporation (E) times 0.14 + 0.015i; rainfall (in millimeters) is P; and irrigation (in millimeters) is I. The model was validated during the three years using a line-source irrigation system with irrigation depths ranging from 5% to 160% of the model rates. Nitrogen rates were 50%, 100%, and 150% of the recommended rate. Marketable fruit yields increased as the irrigation depths increased up to the model rate then decreased with greater water application depths. Marketable fruit yields increased as the N rate increased in 1987 and 1989, but yields were similar at all N rates in 1986. The shelf life of marketable fruits was not influenced by irrigation or N rates.


HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 606b-606
Author(s):  
Eric Simonne ◽  
James Bannon ◽  
Marvin Ruf

Sweetpotato (Ipomea batatas L.) is a drought-tolerant crop mostly produced without irrigation. Consequently, sweetpotato may be exposed to temporary water stress. In 1997, an irrigation scheduling model using a water balance and class A pan evaporation (Ep) was evaluated with `Beauregard' on a loam sandy soil. The model was (12.7 DAT + 76) 0.5 ASW = DDAT-1 + [Ep (0.12 + 0.023 DAT – 0.00019 DAT2) – RDAT – IDAT], where DAT is days after transplanting (DAT = 0 on 20 June), ASW is available soil water (15%), D is soil water deficit (mm), R is rainfall (mm), and I is irrigation (mm). Root depth expanded at a rate of 13 mm/day to a maximum depth of 305 mm. Irrigation rates ranging between 0 and 145% of the model rate were created with sprinklers. The model scheduled 10 irrigations between DAT = 26 and 116 (harvest). Irrigation did not alter storage root quality, but did influence all the marketable grades (P < 0.01; R2 > 0.87). However, between 0 and 129% yield increases were linear and small, suggesting that the model overestimated sweetpotato water use. Thus, deficit irrigation between 50% to 70% of the model would have a limited effect on sweetpotato yields.


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