Variation And Influenced Factors Of Rice Chalkiness In Panxi Region

With multiple type rice varities as materials, on the the basis of field experiments with various sowing date, cultivating locations, altitudes, cultivating measurements.The variable characteristics and influenced factors of rice chalkiness in Panxi region were analyzed in present study. The results were as follows:1. According to variation of rice chalkiness (percentage of chakiness grain, chalkiness area, chalkiness degree) during different years in Panxi region, the variation of chalkiness degree, with variation coefficient of 106.96%, is numerically higher than other chalkiness characters. Variation coefficient of the chalkiness of Japanica rice is higher than that of other type rice varieties. The percentage of chalkiness distinguished between varieties and locations. Different cultivated measurements have great effect on rice chalkiness degree, variation coefficient of chalkiness degree of Hexi 39 is larger than that of Diantun 502. Rice chalkiness characters were different in the different years, and there are interaction between varieties and different years.2. Rice chalkiness were liable to be changed by adjustment of source-sink , different locations and cultivating measurements, temperature during grain seed setting period. Adjustment of source-sink has great effect on rice chalkiness, Rice chalkiness decreased with ear-cutting and increased with half-leaf-cutting. Meanwhile, the percentage of chalkiness grain increased with two used varieties with full-leaf-cutting and shading, but chalkiness degree and chalkiness area of Diantun502 decreased and that of Hexi39 increased with the same treatment. Rice chalkiness of inferior grain was mostly affected and superior grain was almostly change by source-sink adjustment.The percentage of chalkiness grain was significantly different among various locations. Rice chalkiness area and degree were liabled to be varied by interaction of locations and varieties. Different cultivated measurements also affect rice chalkiness. Rice chalkiness degree decreased in timing early or late sowing. Chalkiness decreased with proper cultivating density (37.5 hole/m2), proper amounts of N (14kgN/acre), proper amounts of P fertilizer (8.5kgP2O5/acre).Meteorologic factors during grain seed setting period had great effect on ricechalkiness, the results indicated that there were the linear relation between rice chalkiness character and temperature condition, temperature condition after full-heading 20d and 25d were the main inluenced factors.3. Large variation of rice chalkiness was found in different altitude, the relation between rice chalkiness and altitude presenced linear or quadratic equation; the relation between altitude and chalkiness area or degree showed quadratic equation. Moreover, chalkiness character decreased with altitude increased in mid or high-altitude (1000-1800m).4.In the light of chalkiness degree, rice varieties were selected in Xichang of Panxi region.The obtained results showed that, there are 12 japonica rices with first-class, among them japanica rice Liaojing 294-4 has lower chalkiness degree of 0.33%, 7 indica rices with second-class, 1 indica rice with first-class, 1 hybrid rice with second-class.Use present study for reference, it is suggested that product of rice in Panxi region might have taken rice chalkiness as guide line and combined yield to select and distribute varieties, optimize sowing date, cultivating density, irrigation and fertilization, in order to carry out high quality and yield in Panxi region.