气象因子对广西新植蔗和宿根蔗茎伸长的影响

利用2000－2011年广西4个农业气象试验站的甘蔗旬茎伸长量和气象资料, 分析宿根蔗和新植蔗在气象因子影响下茎伸长的差异。结果表明, 新植蔗和宿根蔗茎生长具有明显差异, 新植蔗茎伸长期茎高明显大于宿根蔗, 进入茎生长期时的茎高本底值较小, 茎总伸长量较大但其伸长期较短。多数气象因子与新植蔗、宿根蔗旬茎伸长量极显著相关(P<0.05), 且对新植蔗的影响大于宿根蔗。对新植蔗、宿根蔗茎伸长起直接正作用的主要因子均为最低气温、相对湿度、最高气温, 起直接负作用的主要因子为平均气温、气压, 积温、降雨量则通过其他气象因子起明显的间接作用。旬茎伸长量对降雨量存在较明显的滞后性, 新植蔗滞后期多为2旬, 宿根蔗多为1旬, 新植蔗对日照时数的响应也存在滞后现象, 两者对温度类气象因子及相对湿度均无滞后。

Effects of Meteorological Factors on Stalk Elongation in New-planting and Ratooning Sugarcane

Sugarcane stalk elongation is the most important factor for the development evaluation and yield estimation, on which meteorological factors have significant effects. Differences between new planting sugarcane and ratooning sugarcane in development and response to meteorological factors need to be analyzed for promoting agricultural production. In this paper, taking new-planting sugarcane and ratooning sugarcane of Guangxi as the research materials, observedsugarcane agronomic data and meteorological information at four agro-meteorological experimental stations from 2000 to 2011 were used to analyze the relationship between stalk elongation and meteorological factors that were precipitation, relative humidity, maximum temperature, minimum temperature, mean temperature, air pressure, and sunshine hours at different stages. The results show that there was an obvious difference between new-planting sugarcane and ratooning sugarcane in stalk height. During the sugarcane stem elongation, compared with ratooning sugarcane, new-planting sugarcane had a higher stalk height with a lower background in most of years, besides, its total stem elongation amount was much more but elongation duration was short. There was a significant correlation between stalk elongation and most meteorological factors in both new-planting sugarcane and ratooning sugarcane. The effect of most meteorological variables was larger in new-planting sugarcane than in ratooning sugarcane. The correlation between new-planting sugarcane and meteorological factors are obviously higher than that of ratoon sugarcane. Minimum temperature, relative humidity and maximum temperature played a direct positive role on stalk elongation in both new-planting sugarcane and ratooning sugarcane, and average temperature and air pressure played a direct negative role, meanwhile, accumulated temperature and rainfall play a significant indirect effect through other meteorological factors. There was a significant lag in the response of stem elongation to rainfall for both new-planting sugarcane and ratooning sugarcane. Compared with ratooning sugarcane, lag of new-planting sugarcane was longer. The total lag time was about 20 days for new-planting sugarcane and 10 days for ratooning sugarcane. There was also a lag in response to sunshine hours for new-planting sugarcane, but no lag to temperature for both sugarcanes.