Abstract：‘Yanhu No.4’is a new summer squash F1 hybrid developed by technique of induced breeding on space flight. It is an early maturing variety. The plant grows vigorously with short nods. Its leaf is bottle green with white spots, likes palm with five cracks. The first female flower starts from node 5-6. The long cylindrical commercial fruit is 20-22 cm in length, 5.5 cm in diameter. Its average fruit weight is 350 g. The tender fruit is glossy with bottle green skin, and tastes crispy. The fruit cavity is small. It is suitable for early spring cultivation in plastic tunnel and greenhouse. It yields about 90 t•hm-2 in greenhouse.
