In early October, Travis Gienger transported an enormous pumpkin (南瓜) from his home in Minnesota to the World Championship Pumpkin Weigh-Off in California. His pumpkin set the record for the biggest one ever grown in North America. How do competitive growers get their pumpkins to grow to massive sizes? 【小题1】

Gienger, who teaches horticulture (园艺学) at Anoka Technical College, begins growing his pumpkins in mid-April, starting with seeds that he grows indoors for the first few weeks, when Minnesota’s soil is too frosty. 【小题2】 They can absorb sunlight, nutrients from the soil, and water there. “At their peak, you’re watering them with at least 600 liters a day, ” he says.

Depending on the variety, pumpkin plants can grow up to a dozen fruits on a single vine (藤曼) . But to maximize size, growers remove all but one or two of these pumpkins in order to decrease each individual fruit’s competition for resources. 【小题3】

But what exactly happens inside a pumpkin as it grows? Two factors drive natural growth: cell division and cell expansion. Cell division accounts for most of the growth at the beginning of a fruit’s life. This period lasts for about 20 days in pumpkin plants. 【小题4】 Pumpkin cells will expand until around 50 or 60 days after pollination (授粉).

【小题5】 Some varieties of pumpkins have been bred specifically to maximize their size. Still, there is genetic variation even among pumpkins of the same variety. This has led to competition for the best seeds. Following each harvest, many growers auction off (拍卖掉) the seeds from their biggest pumpkins, which will then be used for the following year’s plantings.