Abstract:
Abstract: In the process of facility horticulture cultivation, the model of three-dimensional cultivation has been paid more and more attention. "H" type cultivation frame is widely used in stereo-cultivation of strawberry at present. In practical applications, growers choose the different layers of cultivation for planting. The most common arrangement of planting frame is two or three layers, which way can reduce the costs with higher yields and benefits, we do not know now. Therefore, an experiment aimed to select a better combination of cultivation frame was performed in this study. In this experiment, three combinations of "H" type cultivating shelves were set up, namely, two-layer frames arranged adjacently (T1), two-layer frame and three-layer frame are alternately arranged (T2), three-layer frames are arranged adjacently(T3), to compare the light conditions, growth status and yield differences. The experiment was carried out in a solar greenhouse in Changping district of Beijing from August 2015 to April 2016. The length of the greenhouse is 100 m and the span is 8 m. Strawberry varieties is "Hong Yan", planting date was August 29, 2015. Photosynthetic photon flux density (PPFD) of strawberry canopy and growth index were measured during the trial. Growth index include strawberry plant height and leaf chlorophyll relative content (SPAD), strawberry yield per plant, the number of fruits per plant, the average weight of fruit. Measured production time was three months. Results showed that under T1 treatment, the strawberries light conditions were the best of the upper and lower cultivars. During the experiment, the trend of light curves of the three cultivars in T2 and T3 were basically the same, but PPFD of the upper, middle and lower layers in T2 were higher than that in T3 corresponding position. During the experiment, the time length that light intensity at strawberry canopy reached light saturation point (LSP) of T2 upper layer was longer than that of T3 corresponding position; the time length of T2 middle layer reached the strawberry LSP was 240 min, and that of T3 middle layer was always below the LSP. In addition, the light intensity at strawberry canopy in the lower layer of T2 reached light compensation point was 230 min, and that of T3 lower layer was always below the light compensation point (LCP) all day. During the experiment, the time length that light intensity at strawberry canopy reached the LSP within two days of T1 and T2 were calculated, results showed that the time length reached LSP in T1 upper layer increased by 40% compared with that of T2. The time length of reaching at LSP in lower of T1 and T2 was 100 min and 0 min, respectively. The time length of reaching the LCP in the upper, lower layers of T1 increased by 9.3%, 21.4% compared with that of T2, respectively. Thus, the light environment of T1 was better than that of T2. Growth index of T1 strawberry was the best, yield per plant and the number of fruits per plant in T1 was higher than that of other treatments. Correlation indexes of strawberry yield were the worst in T3. During the test period, the yield per unit area of T1 was 50.8 kg, and the cost of T1 was the lowest in three treatments, yield per unit area of T1 was increased by 2.8%, 33.7% compared with that of T2 and T3, respectively. Therefore, strawberries of all two layers arrangement of "H" type cultivation frame got better lighting conditions, reduced costs and obtained better economic benefit. All two layers arrangement of "H" type cultivation frame (T1) was suitable for application in actual production.