不同LED光质对番茄幼苗生长特性的影响

为保证设施番茄周年生产的壮苗供给,研究了人工气候环境下不同光质处理对番茄幼苗不同时期内生长特性的影响,以确定培育番茄壮苗的最佳人工光源。试验采用LED为光源,选取红蓝比分别为3(RB3/1)、5(RB5/1)、7(RB7/1)和白光(W)4个处理对番茄幼苗进行为期28 d的照射,光周期为12 h/12 h,自然光照射为对照,并利用综合评价方法分析不同LED光质对番茄幼苗不同时期内生长特性的影响。试验结果表明:光质对番茄苗期下胚轴、叶面积和根冠比的影响极显著(P0.01);生长初期光质对幼苗生长株高、茎粗、根数、根长、生物量、壮苗指数和G值的影响不显著,而后变为显著(P0.05),且不同时期内光质对各项指标的影响存在差异;依据不同生长时期各项指标的综合评价结果,确定番茄苗期较优光照组合为出芽后两周内采用红蓝比为RB7/1光质,而后采用白光LED光质进行照射;红蓝比为RB3/1的光质不适宜单独作为照射光源用于培育番茄壮苗。

Effect of Different LED Light Qualities on Growth Characteristics of Tomato Seedlings

In order to ensure the supplement of healthy seedlings in tomato anniversary production, the effect of different light qualities on the growth characteristic of tomato seedlings was investigated during different periods in the artificial climate environment, and the optimal artificial light was confirmed for the seedlings. LED was chosen as the experimental light. Because the small size, durability, long lifetime, cool emitting temperature, and the specific wavelengths for a targeted cultivation made them more suitable than traditional light sources. Therefore, three treatments of mixed red and blue LED qualities of RB3/1, RB5/1 and RB7/1 and white LED (W) were used to illuminate the tomato seedlings with the photoperiod of 12h/12h and the natural light irradiation as the compared treatment. The comprehensive evaluation method was adopted to analyze the effect of different light qualities on the growth characteristic of the tomato seedlings during different periods. The results showed that the employment of white LED and the combination of red and blue LED as the single light source in an artificial climate system could meet the requirement of tomato seedlings growth. Light quality had extremely significant effect on the hypocotyls length, leaf area and ratio of root to shoot (P<0.01). Light quality had no effect on plant height, stem diameter, number of roots, root length, biological mass, seedling index and G value during early period and then it was turned into significant level (P<0.05). The influences of light quality on these indicators differed during different phases at the same time. According to the results of comprehensive evaluation method within each phase, the optimal light formula was determined: RB7/1 maintained for two weeks after germination and then was replaced by white LED for the next stage of cultivation. While the RB3/1 treatment, which got the lowest comprehensive evaluation score and was inferior to the control group, was not suitable as the single light for tomato seedlings growth obviously. This research provided references for both of the selection of artificial light source and a model of tomato seedlings cultivation for short-time cultivation tomatoes in greenhouse.