scholarly journals Assessments of Humic Substances Application and Deficit Irrigation in Triploid Watermelon

HortScience ◽  
2020 ◽  
Vol 55 (5) ◽  
pp. 716-721 ◽  
Author(s):  
Kuan Qin ◽  
Daniel I. Leskovar
Keyword(s):  
Humic Substances ◽  
Soil Quality ◽  
Deficit Irrigation ◽  
Citrullus Lanatus ◽  
Total Yield ◽  
Sustainable Systems ◽  
Irrigation Deficit ◽  
Triploid Watermelon ◽  
Sustainable Agricultural Systems ◽  
Property Changes

Soil organic matter degradation and water limitation caused by intense farming activities are some of the major threats affecting agricultural production. Accordingly, the concepts of sustainable agricultural systems with optimized irrigation and improved soil quality can be adapted to address these issues. During this 2-year field study, two management factors—humic substances (HS) as organic inputs (HS vs. control) and deficit irrigation as the irrigation method (50% vs. 100% based on evapotranspiration)—were evaluated based on triploid watermelon (Citrullus lanatus cv. Fascination) yield and soil property changes. HS application increased watermelon early yield by 38.6% and total yield by 11.8% compared with the control; the early yield mainly increased under deficit irrigation. Compared with full irrigation, deficit irrigation increased water use efficiency (WUE) without significantly affecting total yield. In addition, HS application significantly increased the soil organic carbon (SOC) content, which was found to be positively correlated with crop WUE. These results indicate that soil organic inputs with HS and deficit irrigation are valuable strategies to establish sustainable systems for watermelon production, which will not only increase yield and WUE but also significantly improve soil quality and save irrigation water.

scholarly journals Influence of Plant Density and Cultivar on Mini Triploid Watermelon Yield and Fruit Quality

2009 ◽  
Vol 19 (3) ◽  
pp. 553-557 ◽  
Author(s):  
S. Alan Walters
Keyword(s):  
Plant Density ◽  
Citrullus Lanatus ◽  
Total Yield ◽  
Higher Plant ◽  
Grade Distribution ◽  
Plant Densities ◽  
Triploid Watermelon ◽  
Marketable Fruit ◽  
Serving Size ◽  
Lower Plant

Mini triploid (seedless) watermelons (Citrullus lanatus) are a growing segment of the U.S. watermelon market due to their small, one-serving size. Although mini triploid watermelons were first released and commercially grown about 6 years ago, little information is available for optimum planting densities that are needed to achieve the greatest percentage of marketable fruit in the 3- to 8-lb range. In 2006 and 2007, the fruit grade distribution response to six plant densities (2489, 3111, 4149, 6223, 8297, and 12,446 plants/acre) of four mini watermelon cultivars (Betsy, Petite Treat, Valdoria, and Vanessa) was measured at the Southern Illinois University Horticulture Research Center in Carbondale. ‘SP-1’ was used as the in-row pollenizer at 25% of the total planting. Although all cultivars responded similarly to the plant densities evaluated, ‘Vanessa’ provided the greatest fruit number and weight per acre, and percentage of fruit in the mini grade, compared with the other cultivars. Marketable mini triploid watermelon yield dramatically increased with closer in-row spacings. At lower plant densities (wider in-row spacings), a greater proportion of icebox-sized fruit (>8 lb) was produced, and the amount of marketable, mini-sized fruit (3–8 lb) declined. The grade distribution of mini triploid watermelon numbers and weights were the greatest at the highest plant density evaluated [0.5 ft in-row spacing (12,446 plants/acre)], with about 80% of the total yield in the mini grade. The greatest net revenues were also obtained at this high density. This study indicated that it is critical for producers of mini triploid watermelons to recognize the dramatic impact that plant density has on marketable fruit yield (3–8 lb). Growers of mini triploid watermelons will see a drastic improvement in revenues with closer in-row spacings compared with the approximate 2 ft in-row spacings currently used (about 4000 plants/acre). The increased cost of higher plant densities are more than offset by the greater return on investment.

scholarly journals Effects of Irrigation Deficit and Application of Some Growth Regulators on Defense Mechanisms of Canola

2015 ◽  
Vol 43 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Seyed Ahmad KALANTAR AHMADI ◽  
Ali EBADI ◽  
Jahanfar DANESHIAN ◽  
Soodabeh JAHANBAKHSH ◽  
Seyed Ataollah SIADAT ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Deficit Irrigation ◽  
Defense Mechanisms ◽  
Agricultural Research ◽  
Foliar Application ◽  
Maximum Activity ◽  
Flowering Stage ◽  
Relative Water ◽  
Irrigation Deficit ◽  
Main Factor

A split-plot experiment arranged in a randomized complete blocks design with three replications was carried out in Safiabad Agricultural Research Center of Dezful in order to investigate the effects of foliar applications of ascorbic acid (AsA), salicylic acid (SA) and methanol (Me), under deficit irrigation conditions, in canola; there were 3 levels of irrigation as the main factor (irrigation after 70 mm evaporation from the pan as control, cessation of irrigation at the flowering stage and cessation of irrigation at the appearance of siliques) and 10 levels of foliar applications as sub-factor (100, 200 and 300 mg.l-1AsA; 100, 200 and 300 µM SA; 10, 20 and 30% (w/v) methanol; and foliar application of distilled water as control). Foliar applications were made during both budding and initiation of flowering stages. Results indicated that antioxidant enzymes showed different responses to deficit irrigation and foliar application treatments. Maximum catalase (CAT) and polyphenol oxidase (PPO) activities were observed under cessation of irrigation at flowering stage and foliar application of 300 µM SA, while ascorbate peroxidase (APX) reached its maximum activity under the same irrigation conditions and foliar application of 300 mg.l-1AsA. SA had more influence to increase in CAT and PPO activity under cessation of irrigation at flowering stage. The relative water content (RWC) was also decreased due to the drought stress caused by the cessation of irrigation. Foliar application of SA (100 μM) and Me (10% w/v) had more influence to maintain RWC compared to ascorbic acid under irrigation cessation at flowering stage.

scholarly journals Growth Analysis of Watermelon Plants Grown with Mulches and Rowcovers

1995 ◽  
Vol 120 (6) ◽  
pp. 1001-1009 ◽  
Author(s):  
Nader Soltani ◽  
J. LaMar Anderson ◽  
Alvin R. Hamson
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Growth Analysis ◽  
Citrullus Lanatus ◽  
Total Yield ◽  
Carbon Dioxide Concentration ◽  
Male Flower ◽  
Female Flower ◽  
Plastic Mulch ◽  
Area Index

`Crimson Sweet' watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] plants were grown with various mulches and rowcovers and analyzed for relative growth rate (RGR), net assimilation rate (NAR), specific leaf area (SLA), leaf area index (LAI), and crop growth rate (CGR). Spunbonded polyester fabric (SB-PF) and perforated polyethylene film (PCP) rowcovers generally showed greater mean RGR, SLA and CGR than spunbonded polypropylene polyamide net (SB-PP), black plus clear combination plastic mulch and black plastic mulch alone. Plants on mulches and under rowcovers showed significant increases in RGR, NAR, and SLA over plants grown in bare soil. Carbon dioxide concentration inside the transplanting mulch holes was nearly twice the ambient CO, concentration. Growth analysis of sampled watermelon plants during early stages of development under various treatments was predictive of crop yield. Plants under SB-PF and PCP rowcovers produced the earliest fruit and the greatest total yield. An asymmetrical curvilinear model for watermelon growth and development based on cardinal temperatures was developed. The model uses hourly averaged temperatures to predict growth and phenological development of `Crimson Sweet' watermelon plants grown with and without rowcovers. Early vegetative growth correlated well with accumulated heat units. Results indicate a consistent heat unit requirement for the `Crimson Sweet' watermelon plants to reach first male flower, first female flower and first harvest in uncovered plants and plants under rowcovers. Greater variability was observed in predicting date of first harvest than first bloom.

scholarly journals Growth, physiology and yield responses of cabbage to deficit irrigation

2014 ◽  
Vol 41 (No. 3) ◽  
pp. 138-146 ◽  
Author(s):  
C. Xu ◽  
D.I. Leskovar
Keyword(s):  
Plant Growth ◽  
Water Content ◽  
Leaf Area ◽  
Photosynthetic Rate ◽  
Deficit Irrigation ◽  
Total Yield ◽  
Rio Grande ◽  
Fresh Weight ◽  
Growth Physiology ◽  
Yield Responses

Field experiments were conducted in two seasons to investigate growth, physiology and yield responses of cabbage (Brassica oleracea L. cvs Pennant and Rio Grande) to deficit irrigation. In 2012 season, 50% of crop evapotranspiration (ETc) irrigation temporarily decreased plant size, reduced leaf area, fresh weight, relative water content, specific leaf area and gas exchange during late development, and decreased head fresh weight, size, marketable and total yield. Deficit irrigation at 75% ETc had little influence on plant growth and physiology, but it still reduced both marketable and total yield. In 2013 season, 75% ETc irrigation had little influence on plant growth, leaf characteristics, photosynthetic rate, head fresh weight and size, but it temporarily increased chlorophyll and carotenoid content, and decreased stomata conductance, transpiration, and marketable yield. Pennant, the green-head cultivar, had higher photosynthetic rate, head fresh weight, marketable and total yield than the red-head cultivar Rio Grande. In both seasons, deficit irrigations did not influence cabbage head dry weight, indicating that most yield reduction under deficit irrigations is related to water content.  

Effects of Postemergence and Postemergence-Directed Halosulfuron on Triploid Watermelon (Citrullus Lanatus)

2008 ◽  
Vol 22 (3) ◽  
pp. 467-471 ◽  
Author(s):  
Peter J. Dittmar ◽  
David W. Monks ◽  
Jonathan R. Schultheis ◽  
Katherine M. Jennings
Keyword(s):  
Citrullus Lanatus ◽  
Distal Region ◽  
Fruit Weight ◽  
Proximal Region ◽  
Growth And Yield ◽  
Crop Plant ◽  
Fruit Number ◽  
Crop Tolerance ◽  
Triploid Watermelon ◽  
Marketable Fruit

Studies were conducted in 2006 at Clinton and Kinston, NC, to determine the influence of halosulfuron POST (over the crop plant) or POST-directed (to the crop) on growth and yield of transplanted ‘Precious Petite’ and ‘Tri-X-313’ triploid watermelon. Treatments included a nontreated control, 39 g/ha halosulfuron applied POST-directed to 25% of the plant (distal or proximal region), POST-directed to 50% of the plant (distal or proximal; Precious Petite only), and POST. Watermelon treated with halosulfuron displayed chlorotic leaves, shortened internodes, and increased stem splitting. Vines were longest in the nontreated control (Tri-X-313 = 146 cm, Precious Petite = 206 cm) but were shortest in the POST treatment (Tri-X-313 = 88 cm, Precious Petite = 77 cm). Halosulfuron POST to watermelon caused the greatest injury (Tri-X-313 = 64%, Precious Petite = 67%). Halosulfuron directed to 25 or 50% (distal or proximal) of the plant caused less injury than halosulfuron applied POST. Stem splitting was greatest when halosulfuron was applied to the proximal area of the stem compared with POST-directed distal or POST. Internode shortening was greatest in treatments where halosulfuron was applied to the distal region of the stem. However, Tri-X-313 in the POST-directed 25% distal treatment produced similar total and marketable fruit weight as the nontreated control at Clinton. Fruit number did not differ among treatments for either cultivar. At Kinston, Precious Petite nontreated control and POST-directed 25% distal end treatment had greater marketable fruit weight than the POST-directed 50% proximal and POST treatments. The current halosulfuron registration allows POST application between rows or PRE. Limiting halosulfuron contact to no more than 25% of the watermelon plant will likely improve crop tolerance.

scholarly journals Deficit irrigation and fertilization strategies to improve soil quality and alfalfa yield in arid and semi-arid areas of northern China

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4410 ◽  
Author(s):  
Qianmin Jia ◽  
Muhammad Kamran ◽  
Shahzad Ali ◽  
Lefeng Sun ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Soil Quality ◽  
Deficit Irrigation ◽  
Biomass Yield ◽  
Northern China ◽  
Arid Areas ◽  
Abandoned Farmland ◽  
Irrigation Levels ◽  
Semi Arid

Background In the arid and semi-arid areas of northern China, overexploitation of fertilizers and extensive irrigation with brackish groundwater have led to soil degradation and large areas of farmland have been abandoned. In order to improve the soil quality of abandoned farmland and make reasonable use of brackish groundwater, we conducted field trials in 2013 and 2014. Methods In our study, we used three fertilization modes (CF, chemical fertilizer; OM, organic manure and chemical fertilizer; NF, no fertilizer) and three deficit irrigation levels (I0: 0 mm; I75: 75 mm; I150: 150 mm). Results The results showed that the activities of soil urease, alkaline phosphatase, invertase, catalase, and dehydrogenase in the OM treatment were significantly improved compared with those in the CF and NF treatments under the three deficit irrigation levels. Compared with NF, the OM treatment significantly increased soil organic carbon (SOC), water-soluble carbon (WSC), total nitrogen, microbial biomass carbon and nitrogen (MBC and MBN), and soil respiration rate, and significantly decreased soil C:N and MBC:MBN ratios and the metabolic quotient, thus improving the soil quality of abandoned farmland. Furthermore, the OM treatment increased alfalfa plant height, leaf area index, leaf chlorophyll content, and biomass yield. Under the CF and OM fertilization modes, the activities of urease and catalase in I150 were significantly higher than those in I0, whereas irrigating without fertilizer did not significantly increase the activity of these two enzymes. Regardless of fertilization, alkaline phosphatase activity increased with an increase in irrigation amount, whereas invertase activity decreased. Discussion The results showed that deficit irrigation with brackish groundwater under the OM treatment can improve soil quality. Over the two years of the study, maximum SOC, total nitrogen, WSC, MBC, and MBN were observed under the OM-I150 treatment, and the alfalfa biomass yield of this treatment was also significantly higher than that of the OM-I0 treatment. Therefore, the OM-I150 treatment could be used as a suitable measure not only to improve the quality of abandoned farmland soil but also to increase the alfalfa biomass yield in arid and semi-arid areas of northern China.

scholarly journals YIELD AND QUALITY OF TRIPLOID WATERMELON HYBRIDS.

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 859f-859
Author(s):  
Donald N. Maynard ◽  
Gary W. Elmstrom
Keyword(s):  
Total Yield ◽  
Fruit Weight ◽  
The Other ◽  
Soluble Solids ◽  
Yield And Quality ◽  
Other Hand ◽  
Seedless Watermelon ◽  
Triploid Watermelon

Evaluations of 30 triploid (seedless) watermelon hybrids were conducted in the Spring 1989 season at Bradenton and Leesburg, Florida. There was considerable variation in relative cultivar yields at the two locations. However, consistency in some cultivars did occur. 'HMX 7924' produced the highest total yield and 'CFREC 88-2' had high total yields at both locations. On the other hand, 'ACX 882322', 'Fengshan No. 1', 'FMX 28', 'Fummy', 'Honeyheart', 'Nova', and 'NVH 4295' produced low total yields at both locations. Average fruit weight was high for 'Ssuper Sweet Brand 5244', 'CFREC 88-4', and 'HMX 7924' whereas 'ACX 882322', 'FMX 28', 'Fengshan No. 1', 'Nova', and 'PSR 49087' produced low average fruit weight. Soluble solids exceeded 11% in all entries at Bradenton whereas two entries were lower than 10% at Leesburg. Several experimental lines out performed the named cultivars suggesting that future introductions will be superior to those already available.

scholarly journals Carotenoids and Quality of Watermelon as Affected by Deficit Irrigation and Growing Season

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 803D-803 ◽  
Author(s):  
Haejeen Bang* ◽  
Daniel I. Leskovar ◽  
Kilsun Yoo
Keyword(s):  
Deficit Irrigation ◽  
Growing Season ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Carotenoid Content ◽  
Early Planting ◽  
Total Carotenoid Content ◽  
Triploid Watermelon ◽  
Solids Content ◽  
The Individual

This experiment was conducted to determine the effects of deficit irrigation and growing season on fruit quality, carotenoid content and yield of red-, orange-, and yellow-fleshed diploid and triploid watermelon. Irrigation rates were 1.0 evapotranspiration (ET) and 0.5 ET. Diploid cultivars were Summer Flavor 710 (red), Tendersweet (orange), and Summer Gold (yellow). Triploid cultivars were Summer Sweet 5244 (red), Sunshine (orange), and Amarillo (yellow). Four-week old containerized transplants were planted in the field at TAES-Uvalde on 27 Mar. and 21 May 2003. Deficit irrigation imposed after plants were fully established reduced the individual fruit weight and size in the early planting. Soluble solids content (SSC) and firmness was not affected by irrigation rate in both plantings. SSC varied across cultivars and increased with maturity, particularly for the triploid cultivar Amarillo. In general, triploids were firmer than diploid cultivars. Total carotenoid content was not affected by irrigation during early planting. Diploid and triploid red-fleshed watermelon cultivars had significantly higher carotenoid content than orange- and yellow-fleshed cultivars. The major carotenoid was lycopene (more than 65%), followed by prolycopene (20%) and B-carotene (7%).

Sign in / Sign up

Export Citation Format

Share Document