Editing Cucurbita (section)

==== Germination and seedling growth ====
[[File:Kabocha (GH) 21June2005 sown 14June.JPG|thumb|alt=Kabocha seedling at seven days age|[[Kabocha]] seedling seven days after being sown]]

Seeds with maximum [[germination]] potential develop (in ''C.&nbsp;moschata'') by 45 days after [[anthesis]], and seed weight reaches its maximum 70 days after anthesis.<ref name="wilsonma">{{Cite journal |last1=Wilson |first1=Mack A. |last2=Splittstoesser |first2=Walter E. |year=1980 |title=The Relationship Between Embryo Axis Weight and Reserve Protein During Development and Pumpkin Seed Germination |journal=Journal of Seed Technology |volume=5 |issue=2 |pages=35–41 |jstor=23432821}}</ref> Some varieties of ''C.&nbsp;pepo'' germinate best with eight hours of sunlight daily and a planting depth of {{convert|12|mm|in|frac=8|sp=us}}. Seeds planted deeper than {{convert|125|mm|in|frac=4|sp=us}} are not likely to germinate.<ref name="oliver">{{Cite journal |last1=Oliver |first1=Lawrence R. |last2=Harrison |first2=Steve A. |last3=McClelland |first3=Marilyn |year=1983 |title=Germination of Texas Gourd (''Cucurbita texana'') and Its Control in Soybeans (''Glycine max'') |journal=Weed Science |volume=31 |issue=5 |pages=700–706 |doi=10.1017/S0043174500070211 |jstor=4043694 |s2cid=182243467}}</ref> In ''C.&nbsp;foetidissima'', a weedy species, plants younger than 19 days old are not able to sprout from the roots after removing the shoots. In a seed batch with 90 percent germination rate, over 90 percent of the plants had sprouted after 29 days from planting.<ref name="horak">{{Cite journal |last1=Horak |first1=Michael J. |last2=Sweat |first2=Jonathan K. |year=1994 |title=Germination, Emergence, and Seedling Establishment of Buffalo Gourd (''Cucurbita foetidissima'') |journal=Weed Science |volume=42 |issue=3 |pages=358–363 |doi=10.1017/S0043174500076621 |jstor=4045510 |s2cid=132074382}}</ref>

Experiments have shown that when more pollen is applied to the stigma, as well as the fruit containing more seeds and being larger (the xenia effect mentioned above), the germination of the seeds is also faster and more likely, and the seedlings are larger.<ref name="winsor" /> Various combinations of mineral nutrients and light have a significant effect during the various stages of plant growth. These effects vary significantly between the different species of ''Cucurbita''. A type of stored phosphorus called [[Phytic acid|phytate]] forms in seed tissues as spherical crystalline intrusions in protein bodies called [[Globoid (botany)|globoids]]. Along with other nutrients, phytate is used completely during seedling growth.<ref name="beecroft">{{cite journal |last1=Beecroft |first1=Penny |last2=Lott |first2=John N. A. |year=1996 |title=Changes in the Element Composition of Globoids From ''Cucurbita maxima'' and ''Cucurbita andreana'' Cotyledons During Early Seedling Growth |journal=Canadian Journal of Botany |volume=74 |issue=6 |pages=838–847 |doi=10.1139/b96-104|bibcode=1996CaJB...74..838B }}</ref> [[Heavy metal (chemistry)|Heavy metal]] contamination, including [[cadmium]], has a significant negative impact on plant growth.<ref name="subin">{{cite journal |last1=Subin |first1=M. P. |last2=Francis |first2=Steffy |year=2013 |title=Phytotoxic Effects of Cadmium on Seed Germination, Early Seedling Growth and Antioxidant Enzyme Activities in ''Cucurbita maxima'' Duchesne |journal=International Research Journal of Biological Sciences |volume=2 |issue=9 |pages=40–47 |doi=10.1139/b96-104|bibcode=1996CaJB...74..838B }}</ref> ''Cucurbita'' plants grown in the spring tend to grow larger than those grown in the autumn.<ref name="fenner2">{{cite journal |last1=Fenner |first1=G. P. |last2=Patteron |first2=G. W. |last3=Lusby |first3=W. R. |year=1989 |title=Developmental Regulation of Sterol Biosynthesis in ''Cucurbita maxima'' L. |journal=Lipids |volume=24 |issue=4 |pages=271–277 |doi=10.1007/BF02535162 |s2cid=37220982}}</ref>