| The leaf curtain structure affects the inter-leaf and inter-fruit micro-ecological conditions and leaf photosynthesis by changing the amount of light energy interception,thereby affecting the growth of new shoots and fruit quality.In this study,five-year-old Chambourcin in pergola and three-year-old Chambourcin in trellis were used as test materials to compare the effects of several different leaf curtain types on grape growth and fruit quality,in order to provide a reference for production.(I)The effects of the drooping canopy and the horizontal canopy on the microenvironment of fruit spikes,the occurrence of leaf ozone and fruit quality were compared.The main findings are as follows:(1)The effects of drooping canopy and horizontal canopy on temperature and humidity were compared,and it was found that the effects of the secondary shoots before and after trimming on the micro-environment of the two canopy types were different.When the secondary shoots were not treated in June,the horizontal canopy accounts for less than the drooping canopy due to the temperature fluctuation and high temperature(≥35 ° C)of the area of the ears covered by the secondary shoots.After the secondary shoots were trimmed in July and August,the horizontal canopy clusters were exposed to light,and the temperature fluctuations and the proportion of high temperature around the horizontal canopy clusters were larger than those of the drooping canopy;the trend of the micro-domain humidity of the spikes before the new shoots was trimmed,and the new shoots in June When not pruned,the air humidity(﹥80%)of the two canopy types was less than 20%,and the drooping canopy clusters microspheres(﹥80%)humidity is 6.46% higher than that of the horizontal canopy,and about 60%-80% humidity,the ratio was 24.16% higher than that of the horizontal canopy.In July and August,the proportion of air humidity(﹥80%)under the two canopy types was40-50%.The air humidity(﹥80%)was 2.00% and 8.80% lower than that of the horizontal canopy,respectively.The horizontal canopy of the scaffold before the secondary shoots trimming was significantly lower than the drooping canopy due to the light intensity of the secondary shoots covering the clusters.Better than drooping canopy.(2)Strong light exacerbates ozone damage.The type of canopy affects the degree of ozone damage to the leaves by affecting the light intensity.In June,lateral and primary leaves of the drooping canopy were significantly less affected by ozone than the horizontal canopy.The normal leaves were 164% and 4.55% higher than the horizontal canopy respectively.Over time,the degree of ozone damage of the leaves under the two canopy types gradually increased.By July,the proportion of third-level ozone damage in horizontal canopy was significantly higher than that of the drooping canopy,which was 90.16% higher than that of the drooping canopy.The leaf area of lateral and primary leaves of the drooping canopy and the leaf chlorophyll in the late maturity stage were higher than those of the horizontal canopy.(3)The drooping canopy promoted the early expansion of the grape fruit,and increased the weight of hoe and the number of spikelets per grain,but had no significant effect on the grain weight during maturity.The contents of soluble solids,total anthocyanins,flavanols,and total phenol in the mature stage under the horizontal canopy were 5.24%,19.39%,6.92%,and29.19% higher than that of the drooping canopy,respectively.The contents of myricetin and kaempferol were significantly higher than those of drooping canopy by 15.61% and 103.21%,respectively.The types and contents of aroma substances in the fruit were 9.10% and 35.02%higher than those of the drooping canopy,respectively.(Ⅱ)The effects of vertical canopy,umbrella canopy and early topping treatment on the micro-environment of fruit spike,ozone generation in leaves and fruit quality were compared.(1)Among the three types of canopy,the temperature of the microdomain of the vertical canopy clusters was significantly higher than that of the other two canopy types.The highest temperature in July reached 40.1 ° C,while the other two canopy types reached a maximum temperature of 40 ° C in July.Below;the vertical micro-humidity of the vertical canopy had the lowest humidity.In July,the umbrella microcurtain and early pinching treatment had a micro-humidity ratio greater than 80% of 54.53% and 64.25%,and the vertical canopy is below50%,which is 48.06%.The surrounding photosynthetically active radiation was the highest,and the highest photosynthetically active radiation in July was 1.41 and 1.29 times that of the umbrella canopy and the early pinching treatment.(2)The ozone damage of the lateral and primary leaves of different canopy types was different.Among the primary leaves,early pinching treatment and the primary leaves of the vertical canopy had a higher proportion of ozone damage.Some are second and third grade,and most of ozone damage levels are up to first grade.Umbrella canopy were the least affected by ozone due to umbrella-shaped shielding of strong light;among the auxiliary shoot leaves,vertical canopy still suffer the highest proportion of ozone damage,followed by umbrella canopy.The area of the lateral and primary leaves with early pinching treatment was the largest,and the area of the lateral and primary leaves with the umbrella canopy was the smallest.The area of the lateral leaves of the early pinching treatment was 2.06 times and 2.45 times of the upright canopy and the umbrella canopy respectively;The chlorophyll content of the main and auxiliary shoots was the highest.The number of pruning of the new shoots of the umbrella canopy was at least 2 times in summer.Vertical canopy and early pinching treatment 3 times.(3)Early pinching treatment promoted fruit enlargement,increased grape fruit vertical and acrosss diameter,grain weight,berry number per cluster and soluble solids content,while the cluster of umbrella canopy were more loose.The content of flavanols,tannins,and total phenols in the mature stage of of the umbrella canopy were higher than those of the other two hedge-frame curtains.The total phenolic content of the umbrella canopy was 3.27% higher than that of the vertical canopy.The total phenolic content of the early pinching treatment was 29.18%,caffeic acid,catechins,myricetin,and isoquercetin were 8.07%,2.69%,9.02%,and 4.36% higher than those of the vertical canopy,respectively.Umbrella-shaped veil grapes had a small amount of aroma substances but high content.The total aroma of the fruit is 39.75% and 63.84% higher than those of upright canopy and early pinching treatment,respectively. |
