土壤水分对油茶果实生长的影响

Effects of Soil Moisture on Fruit Growth of Camellia oleifera

选择长沙南郊丘陵区‘湘林81’10年生油茶无性系,设置无干旱胁迫(T1)、轻度干旱胁迫(T2)、中度干旱胁迫(T3)、重度干旱胁迫(T4)和自然状况(T5)5种土壤水分处理,对油茶果实生长进行定期观测。结果表明:果径、果高和果实体积的终值都是T2最大,分别为35.7 mm,40.0 mm,26.6 cm3,T4最小,分别为29.6 mm,36.2mm,16.6 cm3;观测期果径、果高和果实体积生长模型除果径T1和果高T1为二次多项式外,其他均为三次多项式,R2均在0.944以上;果形指数终值T2最小,为1.12,T1最大,为1.29,T1有利于果径生长;油茶的果实生长可分为4个时期,即生长前期(7月14日以前)、快速生长Ⅰ期(7月14日—8月13日)、快速生长Ⅱ期(8月14日—9月7日)、生长后期(9月7日以后),7月中旬至9月上旬特别是8月中旬至9月上旬是油茶果实生长的关键时期,也是对土壤水分敏感的时期。试验表明维持轻度干旱胁迫最有利于油茶果实生长。试验结果为加强油茶水分管理、确保油茶高产稳产提供技术支撑。

A 10-year-old Camellia oleifera ＇ Xianglin 81 ＇ clone, in the south hilly area of Changsha was subjected to five different soil water regimes of： no drought stress （T1） , slight drought stress （T2） , moderate drought stress （T3） , severe drought stress （T4）, and natural state （T5）. The fruit growth of C. oleifera was regularly measured. The results showed that the fruit diameter, fruit height, and fruit volume were greatest in the group T2 and smallest in the group T4, and their terminal values were 35.7 mm,40.0 mm,26.6 cm^3 in the group T2, and 29.6 mm,36.2 mm, 16.6 cm3 in the group T4, respectively. All the fruit diameter, fruit height and fruit volume growth models, except fruit diameter and fruit high in group T1, were cubic polynomial with their R2s of over 0. 944. However the fruit diameter and fruit high in T1 were quadratic polynomial with the fruit volume growth. Meanwhile the terminal value of fruit-shape-index was smallest in T2 of 1.12, and greatest in T1 of 1.29, indicating that T1 treatment benefited for the fruit diameter growth. The fruit growth of C. oleifera can be divided into four periods： the early growth stage （before July 14 ） , fast growth f period （July 14 to August 13） , fast growth II period （August 14 to September 7） and the later growth stage （after September 7）. The key period for the fruit growth is middle July to early September, especially middle August to early September. The fruit growth in this period is sensitive to soil moisture. Experiments showed that soil moisture had a significant influence on the fruit growth, and maintaining a slight-water-shortage was the most effective way for the fruit growth. These results can provide the technical support for improving the water management and keeping high and stable yield of C. oleifera.