Studies On High-efficient And High Quality Cultivation Techniques Of Ornamental Lettuce

With the development of social economy, people have an increasing demand of ornamental vegetables. Ornamental lettuces are the cultivars with various colors,unique leaf shapes and are in high nutrition value. Most of all, ornamental lettuce has a wide research and development prospect because of its extremely high ornamental value. Therefore, It has profound significance in the development and research of ornamental lettuce with edible and ornamental value. The aim is to establish a high quality cultivation technique system of ornamental lettuce from varieties screening, substrate culture, irrigation mode and fertilization mode four aspects to provide a scientific theory basis for the population and application of ornamental lettuce.The main results showed as follows:1.7 ornamental lettuce varieties were used as materials to study the morphological indexes, nutritional quality, ornamental quality and yields. The results showed that there was a significant difference of quality among cultivars. Principal component analysis(pca) was used for the comprehensive evaluation of ornamental lettuce. 12 main indexes of the ornamental quality of lettuce were: leaf width, leaf length, nitrate nitrogen content, soluble protein content, moisture content, soluble sugar content, Anthocyanin content, leaf color, plant type, etc.‘Regina Delle Ghiacciole’was the finest variety by using the 5 principal components comprehensive quality scoring and ranking.2. Different ratio wormcast complex substrate had significant Influence on nutritional quality of ornamental lettuce. Results showed that the wormcast complex substrate could effectively promote the yields and quality of ornamental lettuce. At the same time, adding a certain proportion wormcast in substrate can reduce the nitrate content of lettuce, but the high proportion may lead to an increase on nitrate nitrogen content. J2(wormcast: vermiculite: pearlite = 6:2:2) was the best treatment for the cultivation of ornamental lettuce among all the tested treatments.3. The influence of different irrigation frequency and immersion time were studied under the tidal irrigation system. The results showed that under the 3 d irrigation frequency, the growth condition, yields, soluble protein and soluble sugar content increased compared with the 2 d irrigation frequency, while the nitrate nitrogen content increased at the same time. The vitamin C content and water content is higher, nitrate nitrogen content is decreased under the 2 d irrigation frequency. As the growth of the immersion time, soluble sugar content, soluble protein content and vitamin C content increased while nitrate nitrogen content decreased.4. The influence of biogas slurry application was studied with 3 different concentrations of biogas slurry application and two contrast s. The results showed that, biogas slurry application accelerated the growth and development of ornamental lettuce. The yields,vitamin C content, soluble sugar content, soluble protein content and anthocyanins content increased. The nitrate content was effectively decreased.