| Summary: | 碩士 === 國立臺灣大學 === 園藝暨景觀學系 === 106 === Tea plants (Camellia sinenesis L.) are leafy plants. During producing process, nitrogen giving is concerned. Over-fertilization nitrogen in ground would threat economy other than low rate of nitrogen usage. Using foliar fertilization as partial nitrogen resource might be a solution to overcome the disadvantages. Main purposes of this research are to look into how foliar application effect on tea plant (Camellia sinensis L.) growth and tea quality related content in new-born flush. Foliar application or ground application at timing combination and urea dosage are two treatment factor.
In first experiment, ‘TTES 12’ tea plants were treated in 2017. ‘After cutting’, ‘fish leaf extend’, ‘two true leaf extend’ are three fertilization timings. Timing combinations are treatments that choose none, one, two and three fertilization timings for nitrogen foliar application and the others for ground nitrogen application. Taking urea as nitrogen source, dosage differentiates are operated by 0.5% 8ml urea solution applying once or 0.5% 8 ml urea solution applying twice, five days as time interval. At 60th days after cutting, whole new-born flushes were investigated and analyzed. Investigated item include length, number of extend leaf of new-born flush and number of emerge flush. Analysis items include total amino acid, total polyphenol and total nitrogen.
In 2017 spring trail, more average new-born flush length was showed in double dosage treatments. When concerning about foliar application times effect, choosing two timing and three timing for foliar fertilization are statistically no difference in average new-born flush length. But they still statistically higher than none foliar fertilization and foliar fertilization once. Multiple linear regression are used to analyze effect of ground fertilization and foliar fertilization at timings. Result shows that fertilizing at ‘fish leaf extend’ doesn’t help growing of new-born flush.
In 2017 summer trail, ‘fish leaf extend’ timing was excluded, another detail that way of treatments and investigate items are as spring trail. Collected new-born flushes are separated into one bud with two leaves and below part for content analysis. Repeated trail was practiced in 2018 spring again for comparing seasonal discrepancy.
General speaking, growth potential of tea plant in spring is weak. At the trial end, new-born flushes are all at ‘banjhi’ stage. Total nitrogen content is lower than summer sample, but total polyphenol concentration is as much as that in one bud with two leaves part in summer trail. Except for total amino acid concentration, samples for double dosage treatment have nearly twice as much as summer ones. According to multiple linear regression, amount of ground nitrogen fertilization at ‘after cutting’ and ‘two true leaves extend’ can be used to predict amount of total nitrogen in spring new-born flush.
In summer trail, growth potential of tea plants are high. At the trial end, new-born flushes are all at ‘growing’ stage. Almost 50% content concentrated in part of one bud with two leaves, but it didn’t happen to excess accumulation. According to multiple linear regression, foliar or ground fertilize at ‘two true leaves extend’ both can be used to predict amount of total nitrogen in summer new-born flush, but amount of nitrogen from foliar fertilization at this timing have higher correlation to it.
Another experiment explore that how leaves absorb and metabolism urea after urea foliar application. Tea plants with several new-born flush are treated urea solution for whole plant. Treatments are 1% urea solution applying once and 0.5% urea solution applying twice, 128 hours as time interval. Sampling at before urea spray, 1, 2, 4, 8, 16, 32, 64, 128 hours after urea spray, urea concentration in tea leaves of new-born flush are analyzed. Urea foliar application can make urea concentration increase in mature leaves. 1% urea solution treatment have higher instant cumulate than 0.5% urea solution treatment in one hour. Then they will reach stable leaf-urea-accumulating limit and decrease in similar variation trend. And both back to before-treated level after 128 hours. Continuing sampling for 0.5% urea solution treatment, second-time 0.5% urea spray make similar variation trend as the first time spraying. When 32 hours after second-time 0.5% urea spray, it has been in a downward trend. As a result, 0.5% urea solution and five days at least as time interval is more suitable for tea plant to urea foliar fertilize.
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