Effect Of RDI On Physiology Characters And Yield Quality Of Tomato

The experiment was carried on horticultural farm and establishment lab of Northwest A&F University during February of 2006 and December of 2006. The jinpeng NO.1 tomato which is wide-planted in Yanglin Agricultural Hi-tech Development Zone of shaanxi province is used as the material. Blooming and fruit setting period and fruit-development (FD) period are choosed. There were five treatments and three repetitions. Two regulated deficit levels including less deficit level(LD) and serious deficit level (SD)are designed. By this, the effect of RDI on growing, developing, earlier yield, fruit quantity and photosynthetic physiology are researched. The main results were as follows:1. The effect of RDI on tomato configuration index:A).The effect on plant length: the plant length is depressed notably by moderate regulated deficit, but the plants grow fast after resuming water supply. B). The effect on leaf length: Treated by water stress, the leaf length is depressed notably, during the 1st stage. The rise ratio of leaf is higher than CK. The compensate domino effect had put up. C). The effect on fruit number: Treated by water stress, the fruit number is declined, during the 2nd stage. It had less effect on the LD treatments than SD treatments.2. The effect of RDI on tomato physiological index:A). The effect on root activity: the effect of water stress on root activity is more serious during the 1st stage. And the root activity is weaker as the intensity of water stress is accretion. B). The effect on PRO, soluble protein and MNDA content of leaves: Results indicated that under the condition of deficit irrigation, the protein content was restrained significantly. The content of proline and MDA rose on different levels. C). The effect of RDI on tomato photosynthetic physiology index: After moisture intimidated, the Pn, Tr and Gs of tomato leave dropped at different levels. Besides, the Gs and the Tr have some relativity. But have little relation with Pn, which indicates that the decline of the Pn is not restricted by stoma factor.3. The effect of RDI on tomato quality:Treated by water stress, the tomato quality rose at different levels. And the serious treatments: T2 and T4, their soluble sugar content and Vc were 16.5%, 20.3% and 20.3%, 29.1% higher than T5. And organic acid were 25.6% and 18.6% less than T5.It indicated that the tomato fruit quality is improved more easily as deficit degree rising.4. The effect of RDI on tomato output:the output of the 1st treatment is the highest because of compensate domino effect. But the 2nd one is stressed seriously, and the compensate domino effect is limited, the output cannot catch up with CK. The T2 output declined by 20.9%, but the T1 output is 3.8% higher than CK. During 1st and 2nd periods, treatment 1 and 3 were the best designs, whose soil water content were 55-65% and 65-75%(θf).