How to prevent cucumber flowers from topping in the greenhouse?

First, loosen the soil in time, raise the ground temperature, promote root development and induce new roots. Second, rational fertilizer and water management, timely watering and topdressing, promoting the vegetative growth of stems and leaves and preventing flower topping. Third, after the flower is topped, remove the excess melon fetus. Fourth, spraying plant growth regulators such as Tianda 2116 and plant gold (compound gibberellin) can promote the growth of plant stems and leaves and break the top of flowers.