中部山地香蕉栽植密度試驗

Experiments on Planting Density for Banana in Central Taiwan

一、本試驗自民國51年開始在南投縣龜溝舉辦，前後共計五年，於民國56年6月結束。二、本試驗設計採逢機區集設計，有四種不同株行距處理，重複三次。三、四種栽植密度處理間，經變量分析結果，其單位面積產量都有極顯著差異，每公頃種植1,650株和2,250株較第公頃種植1,157株各增加47.75%與80.03%產量。此項結果證明在中部山地增加栽植密度，可以提高單位元面積產量，足見推廣適度密植，實見有重要經濟價值，但過於密植者，第四代收穫率日低，合格品亦減低，收穫顯著延長，故適宜推廣密植度以每公頃1,400-1,650株為宜，並需配合、提早留萌與第三～四年更新一次。

The purpose of this experiment was to study the effect of plant density to the growth and yield of banana in Central Taiwan, The experiment has been carried out on slope area at Kuei-Kou, Nantou, for five years, from 1962 to 1967, by the Chiayi Agricultural Experiment Station, Taiwan Agricultural Research Institute. Four treatments of different plant density were employed in the experiment as follow: Spacing Density 1. 3.6m×2.4m 1,157 plants/ha 2. 3.0m×2.4m 1,389 plants/ha 3. 2.4m×2.4m 1,650 plants/ha 4. 1.8m×2.4m 2,250 plants/ha Some results obtained from this experiment are summarized as follow: 1. The growth measurements made at the shooting stage showed no significant difference between different plant densities, except for the plant height which increased a little with increase in plant density (Table 1). The number of leaves decreased slightly with increase in plant density that may be caused by the infection of leaf spot disease. 2. In dense planting, the rate of maturity is delayed very markedly in the ratoon crop. For example, the days from planting to flowering of the highest density (2,250 plants per hectare needed more 2,52 days in the plant crop, but 54.94 days, 106.93 days and 149.63 days in the following ratoon crops, respectively, than as compared to the lowest one (1,157 plants per hectare). Moreover, the time from flowering to harvesting is delayed significantly in the dense planting (Table 2). 3. Based on the results obtained the grade as well as the quality of fruit such as bunch weight, number of hands and fingers per hunch etc, decline slightly the higher the density. The difference of these aspects between different plant densities are not significant (Table 3). 4. The average yield in both plant crop and ratoon crops increased greatly with increasing plant density. Differences in yield between different densities were very significant statistically. However, it was found that the rate of harvesting was decreased in the highest density treatment particularly after second ratoon crop. According to the results obtained from the experiment, the mean yield of the dense planting treatments, 1,650 plants and 2,250 plants per hectare, increased 47.75% and 80.03%, respectively, as compared to the wider planting one (1,157 plants per hectare). (Table 4). Therefore, it is evident that dense planting can increase the banana yield per unit of area. 5. Since the dense planting delay the days of maturity and decrease the rate of harvesting as mentioned above, therefore, it is recommended that the suitable planting density in the plantation of Central Taiwan is about 1,300-1,650 plants per hectare. Further recommendation was taken that the amont of fertilizer applied per plant for the closely planting plantation should remain unchanged, but that applied per unit area should be proportionally increased in accordance with the number of plants to be increased. Moreover, replanting the dense planting plantation after 2-3 ratoon crops is necessary.