Reliable yield performance is important in cucumber because seed companies prefer to market cultivars adapted to multiple rather than single regions of the U.S. Also, growers benefit by using a cultivar that performs well in many environments. Future performance of cultivars is also important. The objectives of the study were to (i) evaluate the yield of cucumber genotypes over successive years and in different locations, and (ii) identify cucumber genotypes with high stability for yield. A diverse set of 22 pickling genotypes was evaluated over 3 years (1986, 1987 and 1988) and in 7 locations across the United States. Yield traits were evaluated using once-over harvest and counting the number of fruit that were marketable, culled or oversize. Total yield, marketable yield (total minus culled fruit), early yield (number of oversize fruit), percent culls and fruit per plant were calculated. Data were analyzed with SASGxE and RGxE programs using SAS and R programming languages, respectively. There were strong effects of environment(E) as well as genotype(G) xE interaction for all traits. Genotypes 'Regal F1', 'Calypso F1', 'Carolina F1', 'Gy 3', 'Gy 14' and 'Fremont F1' had high marketable yield and medium to high stability for all traits. There was an advantage of hybrids over inbreds for trait performance. Hybrids fell into a single cluster with large prediction intervals. Based on the stability statistics and divisive clusters, it appears possible to breed stable cucumber genotypes with high yield. The genotype with highest performance for marketable yield, greatest stability for yield, lowest 1-R-2 ratio value (diverse and representative) were 'Marbel F1' and Gy 14.

One of the major breeding objectives for watermelon ( Citrullus lanatus [Thumb.] Matsum & Nakai) is improved fruit yield. High yielding genotypes have been identified, so we measured their stability for fruit yield and yield components over diverse environments. The objectives of this study were to (i) evaluate the yield of watermelon genotypes over years and locations, (ii) identify genotypes with high stability for yield, and (iii) measure the correlations among univariate and multivariate stability statistics. A diverse set of 40 genotypes was evaluated over 3 yr (2009, 2010, and 2011) and eight locations across the southern United States in replicated trials. Yield traits were evaluated over multiple harvests, and measured as marketable yield, fruit count, percentage cull fruit, percentage early fruit, and fruit size. There were strong effects of environment as well as genotype × environment interaction (G×E) on watermelon yield traits. Based on multiple stability measures, genotypes were classified as stable or unstable for yield. There was an advantage of hybrids over inbreds for yield components in both performance and responsiveness to favorable environments. Cultivars Big Crimson and Legacy are inbred lines with high yield and stability. A significant ( P < 0.001) and positive correlation was measured for Shukla's stability variance (σ i 2 ), Shukla's squared hat ( ŝ i 2 ), Wricke's ecovalence ( W i ), and deviation from regression ( S 2 d ) for all the traits evaluated in this study.

In a crop breeding program, multiple‐location trials can be used to define target regions and mega‐environments that, in turn, will help the breeder develop stable cultivars. In addition, locations can be chosen that are efficient for distinguishing among cultivars (genotypes) and that are good representatives of the target regions. The objectives of this study were to study mega‐environments and identify test locations that were both discriminating and representative of target regions. Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] fruit yield and yield components were evaluated in 3 yr and eight locations using replicated, multiple‐harvest trials. Data were analyzed using genotype main effect and genotype × environment interaction (GGE) biplot model as well as other methods for stability analysis. Marketable yield and percentage early fruit had a nonrepeatable crossover pattern and thus, formed a single and complex mega‐environment. Two key locations, (Kinston, NC, and Charleston, SC) were efficient representatives of two mega‐environments for fruit count. Locations at Woodland, CA, and College Station, TX, can be used interchangeably for identifying genotypes with high percentage cull fruit. There was only one mega‐environment for fruit size. Identification of mega‐environments for watermelon in the southern United States has implications for future breeding and genotype evaluation in the United States including the use of specialized genotypes for high performance in specific locations.

Lycopene is a naturally occurring red carotenoid compound that is found in watermelon. Lycopene has antioxidant properties. Lycopene content, sugar content and hollowheart resistance are subject to significant genotype×environment interaction (G×E), which makes breeding for these fruit quality traits difficult. The objectives of this study were to (i) evaluate the influence of years and locations on lycopene content, sugar content and hollowheart resistance for a set of watermelon genotypes, and (ii) identify genotypes with high stability for lycopene, sugar, and hollowheart resistance. A diverse set of 40 genotypes was tested over 3 years and 8 locations across the southern United States in replicated, multi-harvest trials. Lycopene was tested in a subset of 10 genotypes. Data were analyzed using univariate and multivariate stability statistics (BLUP-GGE biplot) using SASGxE and RGxE programs. There were strong effects of environment as well as G×E interaction on watermelon quality traits. On the basis of stability measures, genotypes were classified as stable or unstable for each quality trait. 'Crimson Sweet' is an inbred line with high quality trait performance as well as trait stability. 'Stone Mountain', 'Tom Watson', 'Crimson Sweet' and 'Minilee' were among the best genotypes for lycopene content, sugar content and hollowheart resistance. We developed a stability chart based on marketable yield and average ranking generated from different stability measures for yield attributes and quality traits. The chart will assist in choosing parents for improvement of watermelon cultivars. See http://cuke.hort.ncsu.edu/cucurbit/wmelon/wmelonmain.html.

Seeds of the cucumber line WI 1606 were treated with Cytozyme, Cytex, Erogstim, Progib, Ga47 or GA47 + ethephon using acetone and water as infusion media. Days to germination (DTG) and percentage germination (PG) at 15 and 25°C after 2 and 20 weeks storage were calculated. No significant differences in PG could be detected among control seeds at 15°C 2 and 20 weeks after treatment. The DTG of control or chemically treated seed at 2 weeks was consistently lower than at 20 weeks, regardless of infusion medium. In contrast, the DTG was increased with storage. The PG of seeds treated with GA47 + ethephon was higher than that of all other treatments after 2 and 20 weeks of storage regardless of infusion medium. Moreover, the PG and DTG of seeds treated with GA47 and Progib were higher after acetone infusion. Seeds treated with Cytex, Cytozyme or Ergostim and infused with acetone did not germinate at either 15 or 25°C. The rate and total emergence of seedlings, sex expression, maturity date and fruit yield were not affected by seed treatment or infusion media when tested in field studies.

Details are provided for construction of an extractor to be used in recovering seed from cucumber fruit ( Cucumis sativus L.). The extractor is best-suited for handling seed lots from areas of less than one hectare, but having more than 25 to 50 fruit. The machine handles about 100 fruit per minute and recovers 98% of the seed that would be extracted by hand.