Georgia growers can benefit from double-cropping grain sorghum following watermelon to maximize land use and add economic value to their operations. However, capitalizing on the economic advantages of harvesting two crops within a single season must account for potential herbicide injury to rotational crops. An integrated weed management strategy that includes a preplant application of fomesafen and terbacil is recommended for weed control in watermelon production systems. However, currently labeled plant-back restrictions for grain sorghum require a minimum of 10 and 24 mo for fomesafen and terbacil, respectively. Therefore this research aimed to determine the tolerance of grain sorghum to fomesafen and terbacil following soil applications applied 90 to 100 d before planting (DBP). Experiments were conducted at the University of Georgia Ponder Research Farm from 2019 to 2023. The experimental design was a randomized complete block with four replicates. Five rates of fomesafen (35, 70, 140, 210, and 280 g ai ha−1), four rates of terbacil (3.5, 7.0, 10.5, and 14.0 g ai ha−1), and a nontreated control were evaluated. In 2019, fomesafen caused significant sorghum leaf necrosis, plant density reductions, height reductions, and yield reductions of at least 16%, especially when applied at rates ≥ 210 g ai ha−1. Terbacil had little to no effect on sorghum injury, density, height, or yield in any year. These results suggest that sorghum has sufficient tolerance to terbacil when applied 90 to 100 DBP. In four of five years, sorghum had an acceptable tolerance to fomesafen when applied 90 to 100 DBP. However, yield losses observed in 2019 suggest that caution should be taken when fomesafen is applied 90 to 100 DBP grain sorghum at ≥ 210 g ai ha−1.

Fine mapping and discovery of watermelon rind trait candidate genes are of great significance for modern watermelon breeding and development. In this study, we used the high-resolution genetic mapping and genome-wide genetic variation detection technology, combined with genome survey and sequencing technology, to locate and discover the candidate genes for rind traits of star watermelon varieties ‘Su XuanBai’ and ‘SHLX21’. Firstly, we identified a total of eight quantitative trait loci (QTLs) related to watermelon rind traits on chromosome 6. Secondly, a total of 208,240 single nucleotide polymorphisms and 75,345 small Indels (insertions/deletions) were detected in the two parents by high-coverage re-sequencing, respectively. Based on the genetic variation of the two parents and combined with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis using the planta database, the QTL region was reduced to 0.02 Mb. Finally, we identified the six potential regulatory factors for watermelon rind traits using real-time quantitative PCR. In conclusion, our results revealed the fine localization of candidate genes for watermelon rind traits and the successful discovery of candidate genes for regulating watermelon rind traits, which is of importance for watermelon rind traits and breeding-improved watermelon varieties.

Dicamba is a synthetic auxin herbicide that may be applied over the top of transgenic dicamba-tolerant crops. The increasing prevalence of herbicide-resistant weeds has resulted in increased reliance on dicamba-based herbicides in soybean production systems. Because of the high volatility of dicamba it is prone to off-target movement, and therefore concern exists regarding its drift onto nearby specialty crops. The present study evaluates 12 mid-Atlantic vegetable crops species for sensitivity to sublethal rates of dicamba. Soybean, snap bean, lima bean, tomato, eggplant, bell pepper, cucumber, summer squash, watermelon, pumpkin, sweet basil, lettuce, and kale were grown in a greenhouse and exposed to dicamba at 0, 0.056, 0.11, 0.28, 0.56, 1.12, 2.24 g ae ha−1, which is, respectively, 0, 1/10,000, 1/5,000, 1/2,000, 1/1,000, 1/500, and 1/250 of the maximum recommended label rate for soybean application (560 g ae ha−1). Vegetable crop injury was evaluated 4 wk after treatment using visual rating methods and leaf deformation index measurements. Overall, snap bean was the most sensitive crop, with dicamba rates as low as 0.11 g ae ha−1 resulting in significantly higher leaf deformation levels compared with the nontreated control. Other Fabaceae and Solanaceae species also demonstrated high sensitivity to sublethal rates of dicamba with rates ranging 0.28 to 0.56 g ae ha−1 causing higher leaf deformation compared with the nontreated control. While cucumber, pumpkin, and summer squash were no or moderately sensitive to dicamba, watermelon showed greater sensitivity with unique symptoms at rates as low as 0.056 g ae ha−1 based on visual evaluation. Within the range of tested dicamba rates, sweet basil, lettuce, and kale demonstrated tolerance to dicamba with no injury observed at the maximum rate of 2.24 g ae ha−1.

l-Citrulline may improve non-invasive vascular function and cardiometabolic risk markers through increases in l-arginine bioavailability and nitric oxide synthesis. A meta-analysis of randomised controlled trials (RCT) was performed to examine longer-term and postprandial effects of l-citrulline supplementation and watermelon consumption on these markers for CVD in adults. Summary estimates of weighted mean differences in vascular function and cardiometabolic risk markers with accompanying 95 % CI were calculated using random or fixed-effect meta-analyses. Seventeen RCT were included involving an l-citrulline intervention, of which six studied postprandial and twelve longer-term effects. Five studies investigated longer-term effects of watermelon consumption and five assessed effects during the postprandial phase. Longer-term l-citrulline supplementation improved brachial artery flow-mediated vasodilation (FMD) by 0·9 %-point (95 % CI 0·7, 1·1, P < 0·001). Longer-term watermelon consumption improved pulse wave velocity by 0·9 m/s (95 % CI 0·1, 1·5, P < 0·001), while effects on FMD were not studied. No postprandial effects on vascular function markers were found. Postprandial glucose concentrations decreased by 0·6 mmol/l (95 % CI 0·4, 0·7, P < 0·001) following watermelon consumption, but no other longer-term or postprandial effects were observed on cardiometabolic risk markers. To conclude, longer-term l-citrulline supplementation and watermelon consumption may improve vascular function, suggesting a potential mechanism by which increased l-citrulline intake beneficially affects cardiovascular health outcomes in adults. No effects on postprandial vascular function markers were found, while more research is needed to investigate the effects of l-citrulline and watermelon on risk markers related to cardiometabolic health.

The loss of methyl bromide led vegetable growers to rely more heavily on herbicides to control weeds. Although herbicides can be effective, limited options in vegetable production challenge growers. Identifying new, effective tools to be applied over plastic mulch before planting, for improved weed control with minimal crop injury, would be beneficial. The objective of these experiments was to evaluate the persistence of preplant applications of glyphosate (1,125 or 2,250 g ae ha−1) plus 2,4-D (1,065 or 2,130 g ae ha−1) or dicamba (560 g ae ha−1) over plastic mulch, using analytical techniques and subsequent yellow squash and watermelon response. Glyphosate and 2,4-D were not analytically detected at damaging concentrations on plastic mulch when at least 3.5 cm of rainfall was received after application and before planting. In addition, bioassay results showing less than 10% visual injury for either squash and watermelon, with no growth or yield suppression observed, supported analytical results. In contrast, dicamba concentrations on plastic mulch, regardless of rainfall amount or time between application and planting, remained at damaging levels. Squash yields were reduced by dicamba applied 1 to 30 d before planting, whereas watermelon was more resilient. 2,4-D plus glyphosate applied preplant over plastic mulch can provide an additional herbicide option for vegetable growers. More research is needed to understand the impact of residual activity of 2,4-D when transplants land directly in holes in plastic mulch at the time of application. The relationship of dicamba with plastic mulch is complex, because the herbicide cannot be easily removed by rainfall. Thus, dicamba should not be included in a weed management system in plasticulture vegetable production.

Most of the modern-day improved watermelon varieties succumb to various biotic and abiotic stresses mainly because of their narrow genetic base. Insights into the genetic diversity and population structure are crucial for broadening the genetic base and improving the adaptive value. The present experiment was conducted to study the genetic diversity and population structure of a germplasm panel comprising 336 Citrullus sp. accessions. Another objective was to formulate a core collection of Indian Citrullus sp. accessions. Data from 23 highly polymorphic microsatellite markers were used for genetic diversity and population structure analysis while both molecular and phenotypic data from 17 traits were used to formulate the core set. The markers yielded a total of 69 alleles with an average of three alleles per locus. Initially, the accessions clustered into two populations and an admixture group. Intra-population analysis revealed three and two statistically distinct subpopulations in Pop I and Pop II, respectively. The exotic collections were predominant in Pop I-A, Pop II-A and Pop II-B while the Indian accessions were preponderant in Pop I-B and Pop I-C. Pop I-B recorded the maximum magnitude of gene diversity and the highest number of alleles. The well-adapted Indian landraces could be deployed in future watermelon improvement programmes. The formulated core collection (n = 46; 23.71% of the entire collection studied) would ease in maintenance of the diversity present among indigenous Citrullus sp. accessions; would ease trait search while exploring Indian diversity and can be pooled with other collection(s) to form a global core of watermelon.

The commercial release of crops with engineered resistance to 2,4-D and dicamba will alter the spatial and temporal use of these herbicides. This, in turn, has elicited concerns about off-target injury to sensitive crops. In 2014 and 2015, studies were conducted in Tifton, GA, to describe how herbicide (2,4-D and dicamba), herbicide rate (1/75 and 1/250 field use), and application timing (20, 40, and 60 DAP) influence watermelon injury, vine development, yield, and the accumulation of herbicide residues in marketable fruit. In general, greater visual injury and reductions in vine growth, relative to the non-treated check, were observed when herbicide applications were made before watermelon plants had begun to flower. Although the main effects of herbicide and rate were less influential than the timing of applications with respect to plant development, the 1/75 rates were more injurious than the 1/250 rates; dicamba was more injurious than 2,4-D. In 2014, the 1/75 and 1/250 rates of each herbicide reduced marketable fruit numbers 13 to 20%, but only for the 20 DAP application. The 1/75 rate of each herbicide when applied at either 20 or 40 DAP reduced the number of fruit harvested per plot in 2015. Dicamba residues were detected in marketable fruit when the 1/75 rate in 2014 and 2015 and the 1/250 rate in 2015 was applied to plants at 40 or 60 DAP. Residues of 2,4-D were detected in 2015 when the 1/75 and 1/250 rates were applied at 60 DAP. Across both years, the maximum level of residue detected was 0.030 ppm. While early season injury may reduce watermelon yields, herbicide residue detection is more likely in marketable fruit when an off-target contact incident occurs closer to harvest.

Field trials were conducted in the spring of 2007 and 2008 to investigate the critical period of interference between American black nightshade and triploid watermelon. To determine the critical period, the maximum period of competition and minimum weed-free period were examined. American black nightshade (2 plants m−2) was established into watermelon plots at watermelon transplanting and removed at 0, 1, 2, 3, 4, and 5 wk after transplanting to determine the maximum period of competition. American black nightshade (2 plants m−2) was established into watermelon plots at 0, 1, 2, 3, 4, and 5 wk after transplanting and remained until watermelon harvest to determine the minimum weed-free period. To avoid yield loss from exceeding 10% of a crop grown weed-free, the maximum period of competition and minimum weed-free period were found to be 3.9 and 3.6 weeks after transplanting, respectively. Therefore, if American black nightshade is controlled at any time during the critical period of 3.6 to 3.9 wk after transplanting, yield loss should not exceed 10% of a crop grown weed-free.

Field trials were conducted to evaluate imazosulfuron applied POST at 0.1, 0.2, 0.3, and 0.4 kg/ha to watermelon at the two- to four-leaf stage or to vines 30.5 cm long. At 7 d after treatment (DAT), crop injury to watermelon increased linearly for both growth stages as rate increased. The least injury to watermelon observed 7 DAT was 19 and 15%, respectively, for the two- to four-leaf and 30.5-cm growth stages treated with 0.01 kg/ha imazosulfuron. The 0.4 kg/ha imazosulfuron treatment caused the greatest watermelon injury (approximately 30%) at both application timings. Yield of watermelon treated with 0.1 and 0.2 kg/ha imazosulfuron applied at the two- to four-leaf and 30.5-cm stages were similar to the nontreated check (all plots were maintained weed-free). For both application timings, yield decreased linearly as imazosulfuron rate increased. The application of imazosulfuron to watermelon at the 30.5-cm stage averaged across rates resulted in less injury at 15 DAT (16%) and greater yield (92,869 kg/ha) than watermelon treated at two- to four-leaf stage averaged across rates (29%, 83,560 kg/ha). Internal fruit quality was not affected by imazosulfuron.

Sulfentrazone is commonly used for weed control in soybeans and tobacco, and vegetable crops and cotton are often rotated with soybeans and tobacco. Studies were conducted to evaluate the potential for sulfentrazone to carryover and injure several vegetable crops and cotton. Sulfentrazone was applied PRE to soybean at 0, 210, 420, and 840 g ai/ha before planting bell pepper, cabbage, cotton, cucumber, onion, snap bean, squash, sweet potato, tomato, and watermelon. Cotton, known to be susceptible to sulfentrazone carryover, was included as an indicator species. Cotton injury ranged from 14 to 18% with a 32% loss of yield in 1 of 2 yr when the labeled use rate of sulfentrazone (210 g/ha) was applied to the preceding crop. High use rates of sulfentrazone caused at least 50% injury with yield loss ranging from 36 to 100%. Bell pepper, snap bean, onion, tomato, and watermelon were injured < 18% by sulfentrazone at 840 g/ha. Squash was injured < 3% and < 36% by sulfentrazone at 210 and 840 g/ha, respectively. Yield of these crops was not affected regardless of sulfentrazone rate. Cabbage and cucumber were injured < 13% by sulfentrazone at 210 and 420 g/ha, and yields were not affected. Sulfentrazone at 840 g/ha injured cabbage up to 46% and reduced yield in 1 of 2 yr. Sulfentrazone injured cucumber up to 63% and reduced yield of No. 2 grade fruits. Sulfentrazone at 210 and 420 g/ha injured sweet potato < 6% and did not affect yield. Sulfentrazone at 840 g/ha injured sweet potato 14% and reduced total yield 26%. Our results suggest little to no adverse effect on bell pepper, cabbage, cucumber, onion, snap bean, squash, sweet potato, tomato, or watermelon from sulfentrazone applied at registered use rates during the preceding year.

Cantaloupe and watermelon growers in the southeastern United States use a system of hybrid transplants grown on narrow low-density polyethylene (LDPE) mulch-covered seedbeds with overhead irrigation and use the mulch cover for only one crop. LDPE mulches are costly to remove from the field and dispose. Biodegradable mulches that eliminate removal and disposal costs would be of significant benefit, provided that weeds are adequately suppressed. Cotton gin trash is a biodegradable waste product, composed of fiber fragments and seed pieces. Using a proprietary process, cotton gin trash can be chopped, pressed, and heated into a loose mat and stored on a continuous roll. Preliminary studies were conducted in 2010 and 2011 to determine if rolled cotton fiber mulch made from gin trash could be applied as a seedbed cover using conventional application equipment and adequately suppress weeds. Mulching materials (rolls 91 cm wide) were applied with a mulch layer that produced a finished seedbed 40 cm wide. ‘Athena' cantaloupe and ‘Crimson Sweet' watermelon were transplanted using a waterwheel transplanter. Mulching materials included rolled cotton fiber mulch sprayed with boiled linseed oil after mulch application, rolled cotton fiber mulch sprayed with black latex paint, black LDPE, and bare ground. Herbicide treatments included ethalfluralin, halosulfuron, and glyphosate applied as directed spray and nontreated with herbicides. Rolled cotton fiber mulch was easily applied with a conventional mulch layer with no modification and minimal adjustment, producing no tears or holes. Biodegradable cotton fiber mulch treated with boiled linseed oil or black latex paint suppressed weeds equally well as LDPE and all were better than bare-ground plots. Herbicides improved control of all weeds over the nontreated control and this effect was independent of weed suppression provided by seedbed mulches. Cantaloupe and watermelon yields were not affected by seedbed mulches, but were increased by weed control provided by herbicides.

Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus] is an economically important vegetable belonging to the Cucurbitaceae family. Genotypes that exhibit agronomically important traits are selected for the development of elite cultivars. Understanding the genetic diversity and the genotype population structure based on molecular markers at the genome level can speed up the utilization of diverse genetic resources for varietal improvement. In the present study, we carried out an analysis of genetic diversity based on 3882 SNP markers across 37 core watermelon genotypes, including the most widely used watermelon varieties and wild watermelon. Based on the SNP genotyping data of the 37 watermelon genotypes screened, gene diversity and polymorphism information content values across chromosomes varied between 0.03–0.5 and 0.02–0.38, with averages of 0.14 and 0.13, respectively. The two wild watermelon genotypes were distinct from cultivated varieties and the remaining 35 cultivated genotypes were differentiated into three major clusters: 20 genotypes were grouped in cluster I; 11 genotypes were grouped in cluster II; three advanced breeding lines of yellow fruit flesh and genotype SW043 were grouped in cluster III. The results from neighbour-joining dendrogram, principal coordinate analysis and STRUCTURE analysis approaches were consistent, and the grouping of genotypes was generally in agreement with their origins. Here we reveal the genetic relationships among the core watermelon genotypes maintained at the Jiangsu Academy of Agricultural Sciences, China. The molecular and phenotypic characterization of the existing core watermelon genotypes, together with specific agronomic characteristics, can be utilized by researchers and breeders for future watermelon improvement.

Thirty-one accessions of Citrullus spp. belonging to Citrullus lanatus var. lanatus, C. lanatus var. citroides and Citrullus colocynthis were subjected to phylogenetic analysis using combined datasets of amplified fragment length polymorphisms (AFLPs) and simple sequence repeats (SSRs). Tree topologies inferred by neighbour-joining analysis have resolved the phylogenic relationships among the species with special reference to established taxonomic classification. In this study, we have clearly resolved species boundaries of various taxa of citroides, lanatus and colocynthis into three well-supported clusters. Clustering pattern of principal component analysis with the shared polymorphisms using the subsets of data between any two taxon combinations helped to elucidate the introgression and interrelationships among the species. We report two major groups of C. lanatus taxa, one of which has undergone wide introgressions with the taxa of C. lanatus var. citroides and C. colocynthis. In this paper, we identified 583 AFLP bands that are polymorphic within the var. lanatus of C. lanatus, which is the largest set ever reported. The species-specific diagnostic SSRs and polymorphic AFLPs that are informative within and between the taxa reported in this paper would be immensely useful for future studies of these economically important genera.

To date, there are only a few sequenced-tagged site (STS) markers associated with genes controlling fruit quality in watermelon. A normalized cDNA library for watermelon fruit (Citrullus lanatus var. lanatus) was constructed. Sequence analysis of the cDNA clones resulted in the development of 4700 non-redundant ESTs (EST unigenes) expressed in watermelon fruit (http://www.ncbi.nlm.nih.gov, http://www.icugi.org). One hundred of these EST unigenes [including 40 EST unigenes that contain simple sequence repeat (SSR) motives (EST-SSRs) and 60 customary EST unigenes (not containing SSR motives)] were used for designing primer pairs for PCR experiments. The EST primer pairs were tested in PCR experiments with genomic DNA of 25 watermelon heirloom cultivars and 13 United States Plant Introductions (US PIs) of Citrullus sp., including four C. lanatus var. lanatus, five C. lanatus var. citroides PIs and four Citrullus colocynthis PIs. The 40 EST-SSR and 60 EST primer pairs produced 108 and 142 EST-PCR markers, respectively, among the Citrullus PIs and watermelon cultivars. A large number of the EST-PCR markers were polymorphic between the Citrullus PIs and the watermelon cultivars, but significantly less polymorphic among the cultivars. Of the 108 EST-PCR markers associated with EST-SSRs, 103 exist in the Citrullus PIs and 64 in the cultivars. Of these 64 markers, 45 (70.3%) were polymorphic among the cultivars. Of the 142 EST-PCR markers associated with customary ESTs, 134 exist in the Citrullus PIs and 108 in the cultivars. Of these 108 markers, 86 (79.6%) were polymorphic among cultivars. The results in this study indicate that polymorphism exists in coding regions of genes expressed in fruits of watermelon cultivars. In total, 131 polymorphic EST-PCR markers (45 associated with EST-SSRs and 86 associated with customary ESTs) related to watermelon fruit genes were generated using the above data. These markers should be useful for DNA fingerprinting of cultivars and breeding lines, for assessing genetic relationships and for genetic mapping of watermelon.

Seed germination of watermelon (Citrullus lanatus cv. Sugar Baby) was fully suppressed by intermittent far-red (FR) irradiation (1 min every 30 min). When the intervening dark period was increased, a linearly increasing final germination percentage was obtained. However, a 4-day intermittent FR treatment induced phytochrome-controlled dormancy and the longer the dark interval the deeper was the dormancy of the non-germinated seeds. When seeds were soaked in a fully inhibitory osmotic solution, no dormancy was imposed. However, a single FR pulse at the time of transfer induced partial, secondary dormancy; the kinetics of the imposition of dormancy followed a negative exponential curve (half-life 1.5 days; 3 days for the cultivar Crimson Sweet). Seeds osmotreated for 10 days in darkness and subsequently dehydrated (with and without a final FR pulse) acquired germination characteristics similar to those in light-requiring and dark-germinating achenes, respectively, of the lettuce cultivar Grand Rapids. In the light-requiring osmomanipulated seed population, the induction of germination was brought about by the low-energy reaction of phytochrome, chilling, dry storage and decoating. The transformation through osmomanipulation of the dark-germinating watermelon seeds (the inhibition of which required prolonged exposure to light) to positively or negatively photosensitive seeds (that responded to brief light pulses), might be attributed to the slow relaxation of existing meta-Fa and meta-Rb phytochrome intermediates to Pfr upon hydration.

Seeds of watermelon (Citrullus lanatus cv. Sugar Baby) germinated optimally in the dark, throughout the range 20–40°C. Germination was inhibited by continuous (c) irradiation with farred (FR), blue or white incandescent light; short pulses were ineffective. Intermittent FR could fully substitute for cFR; the effect of alternating red and FR pulses during 30-min dark cycles depended upon the timing of the illuminations within each cycle. It is concluded that germination in watermelon is controlled by the low-energy reaction of phytochrome. However, continuous and intermittent red light resulted in partial reductions in germinability. Opening the seed coat at the radicle end enhanced germination in the dark and reduced photosensitivity towards FR. The outer, lignified part of the testa exerted a mechanically restrictive force upon the expanding radicle; this force was estimated to be equivalent to 0.3 MPa. The kinetics, at 25°C in the dark, of the time course of germination and the escape from the inhibitory actions of cFR and osmoticum (0.5m mannitol) were all sigmoid curves, which, upon transformation to normal distributions, had different means, but statistically similar variances. The cFR-irreversible activation of germination by phytochrome and the mannitol-irreversible onset of radicle elongation preceded radicle protrusion (mean at 32 h, 25°C) by 8 and 6 h, respectively. From the results and data on imbition, it is concluded that activation of germination in watermelon takes place during the second, stationary phase of imbibition (20–30 h after sowing at 25°C).

Seeds of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai var. Congo) were subjected to mild accelerated ageing treatments of 30 and 60 d at 30°C at a moisture content of 7.2%. In comparison to a cold-stored control, normal germination and viability were slightly (but not significantly) decreased by these treatments. Subsequent construction of survival curves during storage at 40°C, at seed moisture contents ranging from 10–18%, revealed that the prior 30°C ageing treatments prolonged survival under these conditions.

A trivalent vector containing genes of Watermelon mosaic virus (WMV) coat protein (CP), and replicase genes of Zucchini yellow mosaic virus (ZYMV) and Cucumber mosaic virus (CMV), was constructed for transformation of watermelon (Citrullus lanatus) plants, mediated by Agrobacterium tumefaciens. The integrated foreign genes were identified in the regenerated progenies by polymerase chain reaction (PCR) and Southern blots. The transformation efficiency was about 1.7‰. Resistance to virus infection was determined by mechanical inoculation in the greenhouse and by field trials. The transgenic watermelon lines showed different phenotypes of susceptible, resistant, immune or recovery from virus infections in the late growth stage. A relatively high level of resistance was shown by T3 plants of the line BH1-7. This result indicates the possibility of creating, by transgenic protocols, new varieties of watermelon resistant to viral infection.

Pollination ecology was investigated in Citrullus lanatus (Thunb.) Matsum. & Nakai, which is a species vulnerable to pollinator loss. It was found that this species depends heavily on the honeybee, Apis mellifera L., as the main pollinator. Other pollen vectors identified include Xylocopa bees, halictid bees, Hypotrigona bees, flies and beetles. Phenologically, the plant was found to promote male fitness by producing numerous male flowers, which serve as pollinator attracting structures. Blooming sequence and A. mellifera visitation rates to these flowers are presented. This will enable farmers and pollination managers to better understand visitation patterns and to safeguard pollinators during pesticide application schedules.

We tested the usefulness of mulching with polypropylene landscape fabric and compost as alternatives to bare soil for growing red cabbage and watermelon. Polypropylene landscape fabric has features similar to the polyethylene film that is popular for commercial vegetable production, but its durability permits multi-year use, which would reduce excessive waste produced from the typical single-season use of polyethylene film. On the other hand, compost used as mulch enhances soil development while providing weed suppression and water retention, among other benefits. Yields of red cabbage and watermelon were measured for 3 years in plots receiving either 10 cm compost, landscape fabric, or no mulch. Labor associated with crop production and weed suppression was measured as time spent on each task. Cabbage yields over 3 years followed the treatment order of compost > no mulch > fabric, while for melon yields it was compost > fabric > no mulch. Total labor required over 3 years for both crops, according to treatments, was fabric > compost > no mulch. However, labor for the fabric-treated plots dropped sharply after the first year, because fabric was left in place after initial placement. Labor for unmulched cabbage plots increased over time due to weeding and transplanting; labor for unmulched and compost-mulched melon plots increased for the same reasons. Compost provided the highest crop yields with a moderate labor investment. Surface-applied compost substantially increased underlying soil nutrient levels. The study indicates that polypropylene landscape fabric may be a potential alternative to the more traditional polyethylene film for permanent beds in vegetable production.