Experiment Study On Optimal Uniformity Of Gravitational Flexible Hose Micro-irrigation In The Greenhouse Tomato Under Regulated Deficit Irrigation

This test in May 2008 to October 2008 test in the Qinwangchuan in Gansu Province, Lanzhou irrigation technology to promote agricultural mechanization Station 2 pilot sites for solar greenhouse. Tomato Europe Cultivars for the Apollo F1, the tomatoes in this study was designed three different developmental stages and the whole growth period varying degrees of soil water deficit treatment, the soil moisture to deal with the minimum (or the percentage of field capacityθf) were (60%～70%)θf,(50%～60%)θf,(70%～80%)θf.The results showed that:1. The full irrigation situation can lengthen the greenhouse tomato the birth advancement,causes the birth stage to retard 2~6 day,finally causes high moisture content processing the abandoned fruit number to increase, the economical output reduces.The Greenhouse tomato number and weight of individual plant increased when the irrigation norm increase.But when the irrigation norm was higher,they would not increase but decrease. Both the deteriorated tomato number and deteriorated tomato rate increased with the irrigation norms increases. The max deteriorated rate was up to 25%.Different moisture content processing, the adult plant blossoms late, forms fruit the time to be later; The low soil moisture condition reduced tomato's normal growth growth advancement, causes time which blossoms and bears fruit early.2. The plant height, stem diameter and LAI assume linear increased tendency along with the first three growth periods of eachtreatment of Greenhouse tomato.The first three growth periods deficit water make the plant height of Greenhouse tomato significantly decrease. The more deficit water,the more reduce obvious in plant height, stem diameter and LAI of greenhouse tomato.The plant height,stem diameter and LAI growth recover very fast after re-watering of slight deficit water but slower of high deficit water treatment .The plant height, stem diameter and LAI decreased of greenhouse tomato have also related to the deficit water stage duration time and growth stage.The water deficit stage duration short made the effect small of greenhouse tomato and deficit water in critical stage for water requirement reduces the plant height, stem diameter and LAI of greenhouse tomato obviously. The leaf area assume linear increased tendency along with the plant height and growth period of each treatment of greenhouse tomato. The LAI of greenhouse tomato's increase speed begin drop were related to the deficit degree, the more the deficit degree, the more the decrease obvious and deficit water in critical stage for water requirement can also reduce the LAI of greenhouse tomato obviously. To Later fruiting period, the plant height and stem diameter nearly do not grow, the adult plant nutrition mainly transports to the fruit on.in different water treatments tomato leaf area index assume the drop tendency in this period of duration, this is the leaf blade falls off senilly creates.3. From gravitational flexible hose micro-irrigation in the tomato solar greenhouse, the greenhouse tomato shallow layer soil temperature diurnalvariation is fierce, the soil temperature diurnalvariation scope slows down along with the depth increase.The irrigation can reduce the ground temperature, is especially most obvious to the 0-20cm place influence, the different moisture content coercion has the obvious influence to the ground temperature, irrigates the quantity to be bigger, the ground temperature drops obviously.Along with the depth of soil increase, the moisture content weakens gradually to the temperature regulative function.The output is lowest, supplies water the output to be highest fully, also both have the extremely remarkable difference.In the reproduction growth stage later period, a transpiration rate starts to increase.From emerging to harvest period the dry matter increment in each day present the change patterns of small-big-small. The dry matter increment in each day of the treatments in water deficit stage was lower than other treatments. The dry matter increment in each day was decrease in large degree compared with other treatments especially the treatment of high water deficit.The dry matter decrease degree was different by deficit water in different growth stage.4. In water controlled stage the actual evapotranspiration all below CK treatment and after re-watering the evapotranspiration increased rapidly even exceed CK. The water requirement rates(WRR) decrease compared with CK in each water deficit treatment stage and the more the deficit degree, the more the decrease. The water deficit alleviation the leaf's aging speed in upper growth stage and it made the water requirement rates more than CK. In water deficit stage the water consumption modulus of these treatments were below then other treatment and the water consumption modulus of the treatment of high water deficit were below CK and other stage of this treatment. Controlled water in different growth stage can depress the growth of greenhouse tomato and in water deficit stage the growing speed and growing intensity all below other treatment. Seeding period and Later fruiting period were the upper periods of water use efficiency. Light dry in Seeding period and Later fruiting period can increase the water use efficiency (WUE) of biological yield and the biological yield not below CK by dry in Flowering and fruiting period and Fruiting period.At full irrigation condition the water consumption of greenhouse tomato was most but the yield is not highest. Light deficit water in seeding period was the best treatment of saving water and increase yield (increase yield 25.6%, saving water 11.1%) and light deficit water in Later fruiting period followed it. In the while the two treatments's WUE were also highest (the WUE was 41.28kg/m3 and 35.07kg/m3). On the contrary,light deficit water in Seeding period and Later fruiting period were the optimal deficit stage and deficit degree of greenhouse tomato.5. Addition model (Blank) and multiplication model (Jensen) obtain the sensitivity coefficient was most in Flowering and fruiting period and Fruiting period of greenhouse tomato. Lack water in Flowering and fruiting period and Fruiting period can affect the yield of greenhouse tomato mostly. In seeding period and Later fruiting period the sensitivity coefficient were least and they are account lack water in these periods insensitivity of the yield effect.