Radishes often appear hollow during late growth. The main reason is that the absolute amount of boron in the soil is low and the effective boron is too low, so that the radish lacks boron and is hollow. The method of preventing boron deficiency in radish is the timely application of boron fertilizer outside the roots. Generally in the seedling stage of radish, 100-150 g of borax is used, sprayed with 50 kg of water, once in 7-10 days, and sprayed 2-3 times, about 30 days before radish is harvested, and then 0.2% of boron fertilizer solution is used. Spray 1 time. Rotary Table ,Drilling Hook Block,Drilling Swivel Kaihao Petroleum Equipment Co., Ltd. , http://www.dypetroleumequipment.com