北卡罗来纳州立大学的Cummings G.A.等人在一项为期10年的试验中。以红港和爱贝塔桃为试材,进行了每英亩施氮40、80和160磅的肥效试验。结果表明,每英亩施用80磅氮肥的单株其每英亩的累积产量最高。两品种的存活率随施氮量而增加,分别由通常的15%和50%提高到47和66%。在另一项为期18的试验中,使用爱贝塔桃进行了 Cummings G.A. of North Carolina State University et al. In a 10-year trial. Taking Hong Hong and Betula peach as test materials, the fertilizer efficiency test of 40, 80 and 160 pounds of nitrogen per acre was carried out. The results showed that the yield per acre per plant was the highest in single plants with 80 pounds nitrogen fertilizer applied per acre. The survival rate of two varieties increased with the amount of nitrogen application, from the usual 15% and 50% to 47 and 66% respectively. In another 18-day trial, the use of betabeta was performed