为了确定甜高粱适宜播期及关键气象影响因子，以新疆玛纳斯地区甜高粱主栽品种为试材，对不同播期下甜高粱糖分积累过程中光合特性的变化及其与气象因子的关系进行了比较分析。结果表明，甜高粱各个生育时期叶片叶绿素含量、光合速率的变化呈单峰曲线，开花期达到最大值，灌浆期后逐渐下降。不同播期之间甜高粱叶片叶绿素含量、净光合速率均存在显著差异(P?0.05)，不同品种间差异变化有所不同。随播期延后，‘新高粱3号’不同生育期叶绿素含量、净光合速率均以4月25日播种时最高，早熟T601以5月8日播种时较高；说明‘新高粱3号’适宜早播，T601适宜迟播。相关分析结果表明，不同播期下甜高粱叶片光合特性与温度呈显著(P?0.05)正相关，与风速呈显著负相关；温度是影响甜高粱糖分积累过程的关键气象因子，降水影响不明显。

In order to identify the suitable sowing date and the key effect meteorological factor, with the main cultivars of sweet sorghum as the tested materials in Manas Region of Xinjiang, the photosynthetic characteristics and meteorological factors were measured, to research the change of photosynthetic characteristics and its relationship with meteorological factors among different sowing dates of sweet sorghum. The results showed that, the change of chlorophyll relative content (SPAD) and photosynthetic rate (Pn) expressed in a single peak curve with the peak at flowering stage, and they decreased gradually after filling stage of sweet sorghum. There were significant differences of SPAD and Pn among different sowing dates (P?0.05). Xingaoliang No.3 and Zaoshu T601 were the main cultivars of sweet sorghum in Manas Region of Xinjiang. With the postponing of sowing date, the SPAD and Pn of Xingaoliang No.3 were all the highest under the sowing date of April 25th, and Zaoshu T601 was the sowing date of May 8th. The results also indicated that, it should be sowed proper early for Xingaoliang No.3, and sowed proper lately for Zaoshu T601. The photosynthetic characteristics were significantly positive correlated with air temperature, and negative with wind speed. The temperature was the key meteorological factor affecting sugar accumulation of sweet sorghum, and the effect of precipitation on photosynthetic characteristics was not obvious.