夏季玉米生长发育及耗水特性分析.doc

夏玉米生长发育及耗水特性?夏玉米的生育进程本试验中,T1处理7月31日开始抽雄,其他处理均7月28日开始抽雄,可知T1处理推迟了夏玉米的抽雄起始日期。不同灌水定额条件下其他各生育期的起始日期均保持一致。不同灌水定额处理条件下夏玉米株高的变化株高是形成产量的基础,与抗旱性及籽粒产量密切相关(兰进好,2005年)。生育前期是夏玉米株高快速增加的阶段,灌浆期前后夏玉米的株型趋于稳定,株高生长基本停止。不同灌水定额下夏玉米的株高变化。生育期内T1处理的株高低于其他处理的,抽雄前T6处理的株高高于其他处理的,抽雄后T4和T5处理的株高最高,较T2、T3和T6处理高10cm左右,较T1处理高约30cm。可见,生育前期充足的水分供给有利于夏玉米株高的迅速增加。抽雄~灌浆阶段夏玉米的株高持续增加,但增幅有限,此阶段T6处理的株高增幅小于其他处理。不同灌水定额下夏玉米的株高增速见图2。生育期内T1处理的株高增速随生育进程的推进而持续降低,其他处理则表现出先升高后降低的变化趋势,抽雄后夏玉米各处理的株高增速均显着降低,其中T6处理的降幅最大,达77.2%。苗期T2、T5和T6处理的株高增速相近,高于其他处理的,但处理间差异较小;拔节期夏玉米的株高增速基本上表现出随灌水定额的增加而增大的变化趋势,T1处理的增速最小,为3.26cm/d,T6处理的增速最大,为7.64cm/d,T2处理的增速大于T3处理,为5.70cm/d;抽雄期T1和T6处理的株高增速均较小,低于2cm/d,其他处理均保持在2.9cm/d以上。不同灌水定额下夏玉米的茎粗不同灌水定额下夏玉米的茎粗。对比可知,夏玉米各处理的茎粗大小顺序为:T2T6T4T3T5T1。方差分析结果表明,T1处理与T2、T4和T6处理间差异显着,T2处理与T1、T3和T5处理间差异达极显着水平,且T5和T6处理间也存在显着差异。由此可知,灌水定额的不同势必对夏玉米茎秆的扩充生长产生影响,但处理间的趋势性变化规律不明显。不同灌水定额处理条件下夏玉米叶面积指数的变化叶面积指数(LeafAreaIndex,LAI)是与植物光合作用及蒸散发过程密切相关的,可用于作物监测、估产及病虫害评价等方面的关键生态参数之一。 Summer corn the birth process of the experiment, the T1 treatment started on July 31, tasseling, beginning July 28 other processing, tasseling knowable T1 treatment delayed the tasseling the starting date of summer maize. Each other under the conditions of different irrigation quota growth period starting date is consistent. Under the condition of different irrigation quota in summer maize plant height changes of plant height is formed the basis of production, are closely associated with drought resistance and grain yield (LanJin good, 2005). Birth early summer maize plant height is rapidly increasing stage, before and after the filling stage of summer maize plant type tends to be stable, the plant height growth ground to a halt. Summer maize plant height under the different irrigation quota. Reproductive period of T1 treatment plant height is lower than other treatment, T6 treatment plant height is higher than other treatments before tasseling and after tasseling T4 and T5 treatment plant height is highest, T2, T3, and T6 treatment 10 cm tall, T1 treatme