Recent progress in cassava varietal and agronomic research in China
1992
Zheng Xueqin | Lin Xiong | Zhang Weite | Ye Kaifu | Tian Yinong
In China, agronomic research emphasizes rational fertilizer use, including the rate of application of different elements and their ratios, as well as cultural methods to reduce soil erosion. The progress made from 1987 to 1990 can be summarized as follows: release and extension of a new cultivar, SC124, which is high-yielding and cold-tolerant; breeding and selection of eight new promising clones: CM4031-2, CM4046-4, CM4040-4, CM3970-8, CM4044-1, CM483-3, ZM8013, ZM8002, which have been put into regional trials or production tests; selection of about 30 new advanced clones from breeding trials; acquisition of 70 new accessions for the cassava germplasm collection; establishment of a cassava regional trial network, which consists of 14 trials in Guangdong, Guangxi, Hainan and Fujian provinces; initiation of soil conservation trials, which indicate that contour ridge planting and/or minimum tillage can reduce soil losses due to erosion to about half; NPK fertilizer trials in Hainan showed that K application increased cassava yields by about 25 percent, while compound fertilizer increased yield by 58 percent; NPK fertilizer trials in Guangzhou and Nanning showed a significant response in the first two years to application of 50-100 kg N/ha with no responses to P and K.
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