Performance of new tropical pumpkin genotypes under varying cultural practices

1969 ◽  
Vol 90 (3-4) ◽  
pp. 193-206
Author(s):  
Linda Wessel-Beaver ◽  
Obed Román-Hernández ◽  
Luisa E. Flores-López
Keyword(s):  
Seed Production ◽  
Cultural Practices ◽  
Field Performance ◽  
Field Trials ◽  
Fruit Weight ◽  
Production Program ◽  
Small Fruit ◽  
Poor Seed ◽  
Planting Distance ◽  
Standard Cultivar

New tropical pumpkin (Cucurbita moschata Duchesne) genotypes were evaluated for yield, flesh (mesocarp) color, pest resistance and seed production as compared with the standard cultivar Soler in six field trials at three Puerto Rico locations during a two-year period (2003-2005). Genotypes included an open-pollinated population (PRShortvine-1) and four lines (E0305-1, E0305-2, E0305-3 and E0305-4) with a semi-bush growth habit, as well as a new long-vine open-pollinated population (PRLongvineSLR). Various within-row (0.9- and 1.9-m) and between-row (1.9- and 3.8-m) planting distances were tested. Not all genotypes nor planting distances were included in each trial. PRLongvineSLR was partially resistant to the melonworm (Diaphania hyalinata), whereas lines E0305-1 and E0305-2 were very susceptible. These same lines, as well as PRShortvine-1, were also susceptible to downy mildew, Pseudoperonospora cubensis. All genotypes produced similar yields. Within-row planting distance generally had no effect on fruit weight, fruit number and yield. All new genotypes had good flesh thickness (>4 cm) and small fruit cavities. Flesh color of PRShortvine-1 and PRLongvineSLR tended to be more orange than that of Soler. Lines E0305-3 and E0305-4 had poor seed production, whereas seed production in fruits of PRShortvine-1 and PRLongvineSLR was similar to that of Soler. Despite some shortcomings, PRShortvine-1 and PRLongvineSLR are two advanced open-pollinated populations that should be considered for formal release on the basis of their field performance, good fruit quality and ability to produce profitable amounts of seed in a seed production program. 

scholarly journals In-row Spacing Influences Triploid Watermelon Yield and Crop Value

2002 ◽  
Vol 12 (3) ◽  
pp. 437-440 ◽  
Author(s):  
Carl E. Motsenbocker ◽  
Ramon A. Arancibia
Keyword(s):  
Cultural Practices ◽  
Citrullus Lanatus ◽  
Fruit Weight ◽  
Row Spacing ◽  
Plastic Mulch ◽  
Marketable Yield ◽  
Farmers Market ◽  
Subsequent Decrease ◽  
Small Fruit ◽  
Triploid Watermelon

Triploid watermelon (Citrullus lanatus), commonly called seedless watermelon, is increasing in popularity and market share. The optimum in-row spacing of triploid watermelon has not been studied previously. Triploid watermelon `Crimson Jewel' and `Honeyheart' were grown with drip-irrigation and black plastic mulch at 1-, 2-, 4-, 6-, and 8-ft (0.3-, 0.6-, 1.2-, 1.8-, and 2.4-m) in-row spacings in 1996 and 2-, 3-, 4-, 5-, 6-, 7-, and 8-ft. (0.6-, 0.9-, 1.2-, 1.5-, 1.8-, 2.1-, and 2.4-m) spacings in 1997 to determine the effect of in-row plant spacing on fruit yield. Marketable yield of `Crimson Jewel' was not affected by in-row spacing while narrower in-row spacing resulted in greater `Honeyheart' yield both years. For both cultivars, narrower spacing resulted in the highest number of fruit per acre, but primarily more extrasmall and small fruit. Fruit number per plant, fruit weight per plant, and individual fruit weight were higher at wider spacings, and yield per acre was lower. The data suggest that triploid watermelon yield, fruit weight and number can be adjusted by in-row spacing. Narrower in-row spacing can maximize yields, depending on the specific grower's cultural practices. In wider in-row spacings, the yield of medium and large fruit is maintained with a subsequent decrease in extra small and small fruit. Gross returns per acre were only different for farmers' market prices, not wholesale, and net returns were not significantly influenced by in-row spacing.

scholarly journals Response of Long- and Short-vine Tropical Pumpkins to Varying Cultural Practices

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 884A-884
Author(s):  
J. Irizarry-Morales ◽  
L. Wessel-Beaver ◽  
D. Maynard ◽  
G. Elmstrom
Keyword(s):  
Puerto Rico ◽  
Field Experiments ◽  
Cultural Practices ◽  
Total Yield ◽  
Fruit Weight ◽  
Planting Density ◽  
Cucurbita Moschata ◽  
Plastic Mulch ◽  
Planting Method ◽  
Planting Distance

Three field experiments were carried out in Lajas, Puerto Rico, to compare the effects of planting method (direct and transplant), plastic mulch (with and without), and planting density (1.8 x 1.8 m, 3.6 x 0.9 m, 1.8 x 0.9 m between and within rows) on production of short-and long-vined tropical pumpkins (Cucurbita moschata). The long-vine genotype produced greater yields and larger but fewer fruit than the short-vine genotype. However, most of the planting densities tested were probably not optimum for short-vine cultivars. Direct seeding of pumpkin was more efficient than transplanting and resulted in the same early and total yield as transplanting. Yields with plastic-covered banks were similar to yields without the use of plastic. However, use of plastic mulch increased the number of fruit and decreased the average fruit weight in the plots. The best planting distance depended on the type of genotype used. The long-vine genotype had the highest yields at 1.8 x 1.8 m, while the short-vine cultivar performed best with half that amount of space per plant (1.8 x 0.9 m). Production of short-vine cultivars might be improved by using even narrower planting distances.

scholarly journals Heritability and Genetic Variance Estimates for Fruit Weight in Watermelon

HortScience ◽  
2007 ◽  
Vol 42 (6) ◽  
pp. 1332-1336 ◽  
Author(s):  
Gabriele Gusmini ◽  
Todd C. Wehner
Keyword(s):  
Quantitative Methods ◽  
Genetic Variance ◽  
Recurrent Selection ◽  
Citrullus Lanatus ◽  
Field Trials ◽  
Fruit Weight ◽  
Phenotypic Variance ◽  
Environmental Variance ◽  
Small Fruit ◽  
Variance Estimates

Fruit weight in the cultivated watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus] ranges from 1 kg to over 100 kg. In recent years, preference of consumers has shifted toward fruit of smaller sizes than the large sizes traditionally used for parties and picnics. This has produced increased interest in the genetics of fruit weight, especially among watermelon breeders. The objectives of this study were to determine the inheritance of fruit weight. Six adapted cultivars having very large or very small fruit weight were crossed in a half diallel. Field trials were conducted at two locations in North Carolina (Clinton and Kinston). Large-fruited parents had higher phenotypic variance than small-fruited parents. Environmental variance was higher than genetic variance (mean, 7.58 and 3.82, respectively) at Kinston, NC. At Clinton, NC, genetic and environmental variances were similar (mean, 9.45 and 8.99, respectively) for 67% of the families. Narrow- and broad-sense heritability estimates were low to intermediate (mean, 0.59 and 0.41, respectively). A high number of effective factors (mean, 5.4) was found to influence fruit weight in watermelon. Watermelon breeders should use quantitative methods such as recurrent selection for population improvement to change fruit weight in the development of new cultivars.

scholarly journals Higher Temperatures Decrease Fruit Size in Strawberry Growing in the Subtropics

Horticulturae ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 34
Author(s):  
Christopher Menzel
Keyword(s):  
Fruit Size ◽  
Negative Relationship ◽  
Titratable Acidity ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Marketable Yield ◽  
Significant Relationships ◽  
Small Fruit ◽  
Solids Content

Five strawberry (Fragaria × ananassa Duch.) cultivars were grown in Queensland, Australia to determine whether higher temperatures affect production. Transplants were planted on 29 April and data collected on growth, marketable yield, fruit weight and the incidence of small fruit less than 12 g until 28 October. Additional data were collected on fruit soluble solids content (SSC) and titratable acidity (TA) from 16 September to 28 October. Minimum temperatures were 2 °C to 4 °C higher than the long-term averages from 1965 to 1990. Changes in marketable yield followed a dose-logistic pattern (p < 0.001, R2s = 0.99). There was a strong negative relationship between fruit weight (marketable) and the average daily mean temperature in the four or seven weeks before harvest from 29 July to 28 October (p < 0.001, R2s = 0.90). There were no significant relationships between SSC and TA, and temperatures in the eight days before harvest from 16 September to 28 October (p > 0.05). The plants continued to produce a marketable crop towards the end of the season, but the fruit were small and more expensive to harvest. Higher temperatures in the future are likely to affect the economics of strawberry production in subtropical locations.

Interval of days required for determining efficient relations between climatic factors and cotton flower and boll production

2002 ◽  
Vol 82 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Zakaria M Sawan ◽  
Louis I Hanna ◽  
Willis L McCuistion
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Surface Soil ◽  
Cultural Practices ◽  
Agricultural Research ◽  
Climatic Factors ◽  
Sunshine Duration ◽  
Field Trials ◽  
Cotton Production ◽  
Surface Soil Temperature

The cotton plant (Gossypium spp.) is sensitive to numerous environmental factors. This study was aimed at predicting effects of climatic factors grouped into convenient intervals (in days) on cotton flower and boll production compared with daily observations. Two uniformity field trials using the cotton (G. barbadense L.) cv. Giza 75 were conducted in 1992 and 1993 at the Agricultural Research Center, Giza, Egypt. Randomly chosen plants were used to record daily numbers of flowers and bolls during the reproductive stage (60 days). During this period, daily air temperature, temperature magnitude, evaporation, surface soil temperature, sunshine duration, humidity, and wind speed were recorded. Data, grouped into intervals of 2, 3, 4, 5, 6, and 10 d, were correlated with cotton production variables using regression analysis. Evaporation was found to be the most important climatic variable affecting flower and boll production, followed by humidity and sunshine duration. The least important variables were surface soil temperature at 0600 and minimum air temperature. The 5-d interval was found to provide the best correlation with yield parameters. Applying appropriate cultural practices that minimize the deleterious effects of evaporation and humidity could lead to an important improvement in cotton yield in Egypt. Key words: Cotton, flower production, boll production, boll retention

SOME EFFECTS ON FRUIT SIZE OF CHROMOSOME 2 OF THE TOMATO

1965 ◽  
Vol 43 (1) ◽  
pp. 137-146
Author(s):  
L. Butler
Keyword(s):  
Linkage Map ◽  
Fruit Size ◽  
Cell Number ◽  
Major Effect ◽  
Fruit Weight ◽  
Pleiotropic Effects ◽  
Chromosome 2 ◽  
Small Fruit ◽  
Number Of Cells

Fruit weights taken from two F2's of 1500 plants indicated that the genes d p o s Lc dil and suf all affect fruit weight. The recessive alleles, except suf and Lc, were associated with small fruit size. The data were analyzed to determine whether this association was the result of linkage or pleiotropic effects. The major effect occurred in the o region, which is some 44 units from the centromere of chromosome 2. The o gene makes the genes oval or pear-shaped instead of spherical, and it is shown that when the locule wall of a spherical fruit and an oval fruit are composed of the same number of cells, the spherical fruit is always heavier. Since cell number is the inherited unit of fruit size, then o is always associated with small size. A gene controlling number of locules, which affects fruit size, is also located in this section of the chromosome. The genes d and s, which are at opposite ends of the present linkage map, both appear to be linked with fruit size genes. It is suggested that these size genes lie in the hetero-chromatin which is adjacent to both ends of the linkage map. The genes dil and suf, which were produced by radiation of the same variety, appear to have pleiotropic effects on fruit size; suf increasing, and dil decreasing fruit size.

Field performance and early test results of offspring from two Norway spruce seed orchards containing clones transferred to warmer climates

2007 ◽  
Vol 37 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Tore Skrøppa ◽  
Ketil Kohmann ◽  
Øystein Johnsen ◽  
Arne Steffenrem ◽  
Øyvind M. Edvardsen
Keyword(s):  
Norway Spruce ◽  
Field Performance ◽  
Seed Orchard ◽  
Field Trials ◽  
Climatic Conditions ◽  
Test Results ◽  
Seed Orchards ◽  
Low Altitude ◽  
Natural Stands ◽  
Seed Crops

We present results from early tests and field trials of offspring from two Norway spruce ( Picea abies (L.) Karst.) seed orchards containing clones that have been transferred from high altitudes to sea level and from northern to southern latitudes. Seedlings from seeds produced in the low-altitude seed orchard developed frost hardiness later at the end of the growth season, flushed later in field trials, and grew taller than seedlings from seeds produced in natural stands. They had the lowest mortality rate and the lowest frequency of injuries in the field trials. Similar results were observed in seedlings from seeds produced in the southern seed orchard. We found no adverse effects of the changed growth rhythm. Seedlings from two seed crops in the southern orchard, produced in years with a warm and a cold summer, had different annual growth rhythms. The results are explained mainly by the effects of the climatic conditions during the reproductive phase. Seed crops from different years in the same seed orchard may produce seedlings that perform as if they were from different provenances. It is argued that the effects of the climatic conditions during seed production must contribute to the variation among provenances of Norway spruce.

Saltcedar (Tamarix spp.) Management with Imazapyr

1998 ◽  
Vol 12 (2) ◽  
pp. 337-344 ◽  
Author(s):  
Keith W. Duncan ◽  
Kirk C. McDaniel
Keyword(s):  
Cultural Practices ◽  
Field Trials ◽  
Western United States ◽  
Individual Plant ◽  
Stem Number ◽  
Recent Success ◽  
Water Tables ◽  
Tamarix Spp ◽  
Herbicide Activity ◽  
Herbicide Use

During the 20th century, naturalized saltcedar has become common within major tributaries throughout the western United States. Often growing in nearly monocultural stands, saltcedar is suspected of lowering water tables, thus destroying wetlands and wildlife habitats. Management efforts have primarily relied on mechanical and cultural practices, but recent success in controlling saltcedar with imazapyr has led to wider herbicide use. Based on a number of research/extension field trials in New Mexico from 1987 to present, imazapyr applied alone or in combination with glyphosate was found to control saltcedar to levels of 90% or greater, especially when applied in August or September. For fixed-wing aircraft applications, we recommend applying imazapyr at 1.1 kg ai/ha or imazapyr plus glyphosate at 0.56 plus 0.56 kg/ha. For individual plant treatments, we recommend spraying the foliage to wet with imazapyr at 1% v/v in water, or imazapyr plus glyphosate at 0.5 plus 0.5% v/v. Herbicide activity may be reduced as saltcedar height and stem number increases.

Insects Affecting Seed Production in Red Pine: IV. Recognition and Extent of Damage to Cones

1957 ◽  
Vol 89 (6) ◽  
pp. 264-271 ◽  
Author(s):  
L. A. Lyons
Keyword(s):  
Seed Production ◽  
Production Capacity ◽  
Red Pine ◽  
Natural Control ◽  
Present Contribution ◽  
Southern Ontario ◽  
Pine Cone ◽  
Poor Seed ◽  
Extent Of Damage ◽  
Cone Damage

The broad study of factors responsible for poor seed production by red pines (Pinus resinosae Ait.) in central and southern Ontario has been concerned with the seed production capacity and efficiency of sound cones (1) and the description, life history, behaviour, and natural control of cone-inhabiting insects (2, 3, 4). The present contribution, which concludes the four-part series on red pine cone insects, deals with the time and duration of cone attack by the various insect species and the variability in the intensity of cone damage from year to year and from one locality to another. As an aid to the field diagnosis of the cause of cone damage, keys based on the appearance of mature larvae and injured cones are included.

scholarly journals Reproductive Cold Stress Tolerance in Sorghum F1 Hybrids is a Heterotic Trait

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 508
Author(s):  
André Schaffasz ◽  
Steffen Windpassinger ◽  
Rod Snowdon ◽  
Benjamin Wittkop
Keyword(s):  
Cold Stress ◽  
Cold Tolerance ◽  
Combining Ability ◽  
Pollen Viability ◽  
Field Trials ◽  
Hybrid Breeding ◽  
F1 Hybrids ◽  
F1 Hybrid ◽  
Poor Seed ◽  
High Heritability

The sensitivity of sorghum to pre-flowering cold stress, resulting in reduced pollen viability and poor seed set, is a major constraint for expanding growing areas into higher altitudes and latitudes. Nevertheless, compared to juvenile cold tolerance, reproductive cold tolerance in sorghum has received much less attention so far, and very little is known about its inheritance in F1-hybrids. We have composed a representative factorial (n = 49 experimental F1-hybrids) for a comprehensive study on heterosis and combining ability for crucial tolerance traits as spikelet fertility (panicle harvest index), seed yield and pollen viability, using field trials in stress- and control environments in Germany and Mexico as well as climate chamber experiments. Our results indicate a heterotic and rather dominant inheritance of reproductive cold tolerance in sorghum, with strong effects of female general combining ability (GCA) on F1-hybrid performance in our material. These findings, together with the comparatively low contribution of specific combining ability (SCA) effects and high heritability estimates, suggest that robust and efficient enhancement of reproductive cold tolerance is feasible via hybrid breeding.

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