Effects Of Water And Fertilizer Coupling On Growth, Yield And Quality Of Grape Under Drip Irrigation With Mulch Film In Plastic Greenhouse

Experiment was conducted in the plastic greenhouse in the grape production base of Lvfeng Group, Changchun, during Jilin in 2014 and from April to October in 2015. The “Han Xiangmi” grape,which has been growed 3 years, were selected as subjects, experimental plot was designed randomly using 2 factors, with 4 levels of total irrigation water: 180(W1), 270(W2), 360(W3) and 450 mm(W4), respectively, and 4 levels of total amount of fertilizer: N 150kg/hm~2 + P2O5 120kg/hm~2 + K2 O 165kg/hm~2(F1), N 225kg/hm~2 + P2O5 180kg/hm~2 + K2 O 248kg/hm~2(F2), N 300kg/hm~2 + P2O5 240kg/hm~2 + K2 O 330kg/hm~2(F3), N 450kg/hm~2 + P2O5 360kg/hm~2 + K2 O 495kg/hm~2(F4), respectively. A total of 16 treatments were performed in this experiment(F1W1, F1W2, F1W3, F1W4, F2W1, F2W2, F2W3, F2W4, F3W1, F3W2, F3W3, F3W4, F4W1, F4W2, F4W3, and F4W4), and each treatment was repeated biologically 3 times in a total of 48 plots. Experimental results were as follows:1. Different water and fertilizer treatments significantly affected grape growth and development. With irrigation amount of 180 mm(W1), normal plant growth was inhibited due to lack of soil moisture, and slowed migration of fertilizer in soil and uptake rate of fertilizer. Increasing the amount of irrigation and fertilizer could help to reduce water stress on plants, and promote the growth of new shoot, stem diameter and leaf area of grape. However, with fertilizer amount reaching N 450kg/hm~2 + P2O5 360kg/hm~2 + K2 O 495kg/hm~2(F4), excessive salt around plant root zone resulted in decreased soil water potential, combined with decreased soil solution concentration caused by low fertilizer amount under the condition of high irrigation amount, leading to limited nutrient uptake of the root system, and ultimately affecting the growth of aboveground plant organs. In 2014 and 2015, new shoot growth withF2W2 treatment showed a good performance at the early stage, while new shoot growth treated with F3W3 displayed the best performance at the later stage, showing no obvious difference from F2W2 treatment, which suggested that F2W2 treatment not only can promote new shoot growth, but also can control plants and prevent excessive growth at the later stage. As for both stem diameter and leaf area, F2W2 treatment showed a better performance.2. When irrigation amount was fixed, both chlorophyll content and photosynthetic rate showed a trend of first increasing and then decreasing with the increase of fertilizer amount, and reached their peaks at F2 or F3 levels. When fertilizer amount was fixed, chlorophyll content and photosynthetic rate also presented a trend of first increasing and then decreasing with the increase of irrigation amount, and reached their peaks at W2 or W3 levels. The content of proline and the malondialdehyde decreased first and then increased with the increase of irrigation amount or fertilizer amount, and F2W2 treatment provided a better performance.3. Different water and fertilizer treatments evidently influenced grape fruit quality. In 2014, when irrigation amount was fixed, fruit soluble solid content showed a trend of first increasing and then decreasing with the increase of fertilizer amount, and fruit soluble solid content under F2W2 treatment presented a highest level(19.64%). As for the titratable acid content of fruit, F2W3 treatment provided a highest level(0.93%). In addition, fruit soluble sugar content under F4W2 treatment showed a highest level, reaching 17.73%; while no significant difference was found from F2W2 treatment. In 2015, the effect of different water and fertilizer treatments on grape fruit soluble solid content was the most apparent under F3W2 treatment, reaching a highest level of 18.90%. Under F4W3 treatment, soluble sugar content showed a highest level(17.88%). Under F1W4 treatment, the titratable acid content reached its highest level of 0.91%. However, those both showed no significant differences from F2W2 treatment.4. Different water and fertilizer treatments had apparent influences on grape yield and fruit shape indexes. In 2014, fruits treated with F3W4 showed a largest longitudinal diameter(19.83mm), and fruits treated with F1W2 presented a largest transverse diameter(18.65mm), showing no significant difference from F2W2 treatment. Under F4W2, F3W3 and F2W2 treatments, fruit firmness was higher than 0.7kg/cm~2, and no obvious differences were detected among these treatments. Under F2W3 treatment, fruit yield was the highest, reaching 30.11t/hm~2; among all treatments, yield has exceeded 25t/hm~2 when F2W2 and F3W3. In 2015, fruits under F3W3 treatment showed a largest longitudinal diameter(20.30mm), and fruits under F2W3 treatment presented a largest transverse diameter(18.85mm), demonstrating no significant difference from F2W2 treatment. Fruit firmness was higher than 0.7kg/cm~2 under F3W1, F2W1, F3W2 and F2W2 treatments, and no obvious differences were detected among these treatments. As for fruit yield, F3W3 treatment provided a highest level(30.00t/hm~2), followed by F2W3, F2W2, F3W2 and F4W3 treatments(28.20, 27.80, 27.55 and 25.20 t/hm~2, respectively), and no apparent differences were found among F2W3, F2W2, F3W2 and F3W3 treatments.