Research And Extension Of High-yield Cultivation Technology Of Yongyou 6, An Indica-japonica Inter-subspecific Hybrid Rice

This paper studied the agronomy characteristics and high yield cultivations of Yongyou 6 (an indica-japonica intersubspecific hybrid rice, was realeased by the Ningbo Academy of Agricultural Sciences and Ningbo Seed Corporation.) in the areas which climatic ecosystem characteristics were similar to Wenling. According to the agronomy characteristics, a series of experiments were carried out. The experiments including transplanting time trial, planting density trial, rate of fertilizer application trial, nitrogen application technique trial, pest and disease control trial, seed treatment technique trial, etc. Based on the field trials a high yield cultivation technique system for Yongyou 6 was integrated, through the technology demonstration and extension, notable economic and social benefits were achieved.The main results showed as follow:1. The main characteristics of Yongyou 6 in Wenling shown below:tall plant, higher biomass, large panicle, root system develops, good plant type, mature with green stalk, strong lodging resistance, narrowly thicker leave blade with erected and rolled. The smaller leaf angle and thicker vein resulted in high light transmission rate. The large leaf area, higher chlorophyll content, high photosynthetic capacity and longer functional period of leaves resulted in stronger source. Large panicles with many spikelets, primary branches were developed and evenly distributed, High kernel filling rate and fine grain quality. The growth period was little longer. Because of the darker color at the early growth stage, the plant was easier damaged by borer and plant-hopper. Yongyou 6 was moderate resistant to blast and bacterial blight, the seed-borne bakanae disease and rice white tip were serious. It was suitable for use as single cropping late rice in Wenling.2. It was most likely to get the highest yield of Yongyou 6, when planted as single cropping late rice in Wenling with 15-30d seedling age, planted density 23.3cm×30cm or 23.3cm×26.6cm, namely 143-161 thousand hills per hectare.3. Because of Yongyou 6's longer growing period and high biomass, Nitrogen is particularly important to high yield and stable yield. The high-yield of Yongyou 6 was easily attainable if 217.5-232.5 kg pure nitrogen per hectare was used in Wenling, However, to consider typhoon and other bad weather factors,187.5-202.5 kg pure nitrogen per hectare was more appropriate for the high and stable yield. The nitrogen application rate can appropriately reduced in the high fertility field. Nitrogen should be reasonable distribution throughout the growing season, the grain yield obviously increased when nitrogen fertilizer were applied before initial heading stage.4. In order to get high yield of Yongyou 6, the technologies should focus on improving the ear rate and seed setting rate, stabling the total grain number and 1000-grain weight, ensure stronger stalk and good leaf type. Constructing source-sink-flow balance and high yield population base on the individual with strong roots, strong stalks, high seed setting rate and high grain-filling degree. The core of high-yielding cultivation technology system were "short seedling age, low sowing density and plating density, soil testing and fertilizer recommendation, intermittent irrigation, IPM and harvest after full matured". Its feasible to transplant by machine for Yongyou 6, and the appropriate planting density was 30cm×(20-24)cm (150,000-170,000 hills per hectare).So far, Yongyou 6 has spread to Fujian, Guangxi and other regions of Zhejiang and displays obviously yield increase. To make Yongyou 6 show high yield advantage in different regions, further high-yield cultivation techniques adapt to these regions for Yongyou 6 must be explored.