| In recent years, wine has become the second alcoholic beverage to beer in the world. The wine industry also presents the fastest growth tendency in China with the rapid expansion of the cultivation area. The arid and semiarid regions in northwest China become the main areas of the wine grape cultivation due to the unique climatic conditions. Although summer light is abundant in these regions, the rainy condition is often in parallel with the summer heat, which induces coloring uniformity and low sugar content of the fruit.In addition, how to efficient use of water and fertilizer to improve fruit qualities is an urgent problem. Three experiments have been carried out to investigate the effects of fill light, irrigation, and organic manures on grape growth and fruit qualities with Cabernet Sauvignon as the test vairiety.Supplementtary light experiment: 4 treatments were deoploied: no leaf removal and reflecting film mulching(CK), leaf removal(LR), reflecting film mulching(RF), leaf removal+ reflecting film mulching(LR+RF). Water experiment: there were 4 irrigation treatments: no irrigation(RDI-0), one third of the conventional drip irrigation(RDI-1), two thirds of the conventional drip irrigation(RDI-2) and conventional drip irrigation(CDI). Fertilizer experiment: there were 3 kinds of organic fertilizer treatments. The control was local conventional fertilization(CK, Chicken manure, 9 t/hm2). Sheep manure(S) had 3 rates: 11 t/hm2, 15 t/hm2, 19 t/hm2. Oil residue(R) had 4 rates: 11 t/hm2, 22 t/hm2, 33 t/hm2, 44 t/hm2. The primary results are listed below.(1)Compared with CK(no leaf removal and reflecting film mulching), the leaf removal(LR) treatment significantly increased total soluble solids, reducing sugar, total anthocyanin and total phenol contents of the fruit by 4.6%, 5.1%, 43.2% and 46%, respectively, while it decreased titratable acidity content. Using fuzzy comprehensive evaluation method, we calculated the synthesis score of all treatmets. LR treatment had the highest score(0.6984). LR treatment was easier for field operation, lower in cost and higher in economic benefit than reflecting film mulching(RF). RF and leaf removal+ reflecting film mulching(LR+RF) treatments had higher sugar acid ratio than LR. However, higher sugar acid ratio was not beneficial to wine brewing, then it would ultimately affect the quality of the wine. In addition, the cost of LR+RF and RF was high.(2) With the deficit degree aggravated, the total soluble solids and reducing sugar content were increased, but titratable acidity content was decreased. Compared with the conventional irrigation(CDI), the 2/3CDI treatment(RDI-2) significantly increased total anthocyanin, total phenol and tannin contents of the fruit by 87.5%, 15.3% and 41.1%, respectively. RDI-2 is recommended for irrigation in this region.(3) When compared with the control(local conventional fertilization), the oil residue of 33 t/hm2 treatment significantly increased yield, clusters per vine, total soluble solids, reducing sugar, total anthocyanin, total phenol and tannin contents of the fruit by 89%, 140%, 6%, 8%, 30%, 20% and 60%, respectively. There was no significant difference of yield, clusters per vine, reducing sugar and tannin contents of the fruit between the sheep manure of 15 t/hm2 and 19 t/hm2 treatments.However, they were significantly higher than that of control. The optimum dosage for oil residue as basal fertilizer is 33 t/hm2 while the optimum dosage for sheep manure is 15 t/hm2. |
