西瓜起源于非洲热带草原,瓜瓤脆嫩多汁,营养丰富,是夏季重要的消暑果品,在我国除西藏外均有栽培,黑龙江、山东、河南、河北及新疆、内蒙古等省自治区栽培面积较大。近年来,由于推广双膜覆盖和塑料大棚保护栽培,多进行育苗移栽。一、优质壮苗标准①苗龄适宜:自根苗为30～35天;嫁接苗为40～45天。形态指标 Watermelon originated in the African savannah, melon crisp tender and juicy, nutrient-rich, is an important summer heat summer fruit, except in Tibet have cultivated in our country, Heilongjiang, Shandong, Henan, Hebei and Xinjiang, Inner Mongolia and other provinces more than the cultivated area Big. In recent years, due to the promotion of double-film coverage and plastic greenhouses protection and cultivation, transplanting more nursery. First, the standard seedlings of high quality ① age suitable: self-rooted seedlings for 30 to 35 days; grafted seedlings for 40 to 45 days. Morphological indicators