開英種鳳梨品系及密植度對產量之影響

Planting System in Relation to the Yields of Some Strains of the Smooth Cayenne Pineapple

（1）本試驗採複因子設計，逢機區集排列法參試因子有三個﹝1﹞鳳梨品系有二號系及三菱系二變級；﹝2﹞畦距有三尺及四尺二變級，﹝3﹞株距有一尺，一尺二寸及一尺五寸三變級，共十二種組合處理，重複四次。全部用裔芽苗作雙行交點栽植，行距概為二尺。（2）本試驗之田間管理皆按一般鳳梨栽培法進行，未施促進開花之電石處理，亦未進行除冠芽，除裔芽等工作，施肥則以株為單位，每株每年施硫酸錏484公分，過磷酸鈣15.2公分，硫酸鉀90公分。（3）一個更新期三回收穫之鳳梨生果之產量記錄，經變方分析之結果，品系，畦距，株距及品系×株距之F測驗皆極顯著。（4）二號系之產量，顯高於三菱系，每公頃一個更新期三回收穫產量，二號系超出三菱系達18.8公噸，差異極為顯著。（5）畦距為三尺者產量顯高於四尺者，差異極為顯著，株距一尺者產量最高，與一尺二寸者及一尺五寸者之產量相比較，差異皆極顯著，一尺二寸者與一尺五寸者間產量差異亦極顯著。（6）以二號系言，產量因株距之漸寬而依次遞減，三種株距相互間之產量差異皆極顯著，但在三菱系，株距一尺及一尺二寸間之差異不顯著，一尺二寸與一尺五寸間之差異顯著，一尺與一尺五寸之差異則極為顯著，可見在三菱系，株距相差二寸，產量差異並不顯著，相差至三寸或三寸以上產量差異始顯著。（7）在株距為一尺及一尺二寸時，二號系與三菱系間之產量差異，皆極為顯著，株距寬至一尺五寸，兩品系間之產量差異即不顯著，可見株距放寬至一尺五寸，不論栽植二號系或三菱系，其產量殆無顯著差異，株距縮小一二寸每公頃栽植株數即增加葚多，由本試驗之結果觀之，二號系校之三菱系更適於密植。（8）二號系栽植最密區，畦、行、株距為三尺、二尺、一尺者產量最高，每公頃一個更新期三回收穫總產量達120.96公頃，與其他十一區相比較差異皆極顯著，栽植最疏區畦、行、株距為四尺、二尺、一尺五寸者，品系不論為二號系或三菱系，產量皆最低，與上述之最高產量區相比較，總產量相差達60-65公噸之多，密植增產之效果至為明顯。（9）從三回收穫之果實成熟期觀之，各季果實以夏果占大多數，春果產量最少，在總產量上，所占比例甚微，冬果產量亦不多，僅占總產量之九分之一以下，冬果之等級，大体上言，兩品系皆以一等品所占比例較二等品為高，但夏果之等級顯然因品系而異，在二號系，各種栽植距離皆以一等品果實較二等品果實為多，在三菱系，適相反，不論栽植疏密，一等品果實皆較二等品果實為少。（10）每公頃一個更新期三回收穫之總收益，由於不同等級果實在價格上之差異，品系間之栽植距離間之差異更見顯著。（11）鳳梨植株產生吸芽和裔芽之數目因品系而異，完全受遺傳因子之控制，與栽植之疏密無關。二號系產生吸芽早，產生裔芽之數目每株平均僅三枚，三菱系產生吸芽遲、而裔芽之數目每株平均多達六枚以上。（12）多冠芽之發生率與栽植疏密無關。兩品系產生多冠芽果實之數目，亦無顯明差別。

As the planting distances and strains of the Smooth Cayenne variety play an essential role on the crop in pineapple, it is of great importance to ascertain the optimum spacing, between double-rows and between plants in the row, as well as a desirable strain for closer planting in order to obtain a maximum yield. This experiment was a 2×2×3 factorial randomized complete block design with four replications, using 900×300cm, plots. The three factors consisted of two levels of strains of the Smooth Cayenne variety, i.e. the No. 2 strain and the San-Ling strain; two levels of spacing between double-rows, i.e. 90cm. and 120cm.; three levels of spacing between plants in the row. i.e. 30cm., 36cm., and 45cm., as a total of twelve treatment combinations. The distance between rows were 60cm. in all plots. The experiment was conducted at the Chiayi Agricultural Experiment Station. Slips were used as planting material which were planted at the beginning of October, 1956. The field was managed as usual way. Neither de-crown nor de-slip was done after flowering of the summer crops as it was usually done by farmers in Taiwan for improving the form and size of fruit. Nor was calcium carbide treatment made for hastening the flower bud formation. Compost was used as basic manure. 0.4kg. compost per plant was applied about 30cm. under the soil surface between rows on the bed. Chemical fertilizers were applied four times a year. 13gm, of ammonium sulfate and 23gm, of a 10-6-10 mixed fertilizer were applied to each plant alternatively. Since the winter of 1946, fruits harvested were weighed and graded individually according to size. They were graded into four size classes in the conventional way with rigid iron rings having inside diameter of 130, 115 and 100 millimeters. One week before every summer crop began to be harvested, numbers of suckers and slips on the fruit-bearing plants were counted. The filed was carried into the second rations, namely a plant crop and two ratoon crops were harvested. Results obtained may be summarized as follows: (1) The analysis of variance made on the total yield data from the three harvests showed that the effects of strains, spacings between double-row, spacings between plants in the row and the interaction for strains and the spacings between plants in the row were highly significant. (2) The No. 2 strain prodnced 94.6 metric tons of fruit per hectare as a total yield of the three harvests, which was 19.8 metric toms more than the yield of the San-ling strain. (3) By decreasing the distance between paired-rows from 120cm. to 90 cm. the yield of the three harvests per hectare increase almost 12.8 metric tons or 16.2%. (4) As to the spacing between plants in the row, yields increased progressively with the reduction in spacing from 45cm to 30cm between plants, (the maximum increase being 30.6 metric tons hectare) The difference in yield between any two of the three spacing levels were all statistically very significant. (5) In case of the No. 2 strain, yield decreased with the increase of the spacing between plants in the row, difference in yields between any two levels of which showed statistically very significant. While in case of the San-Ling strain, although yield decreased too with the increase of the spacing between plants in the row, difference in yields, between 30 cm. and 30cm. was not significant, between 36cm. and 45cm. significant, and between 30cm. and 45cm. very significant. (6) When the spacings between plants in the row were 30cm. and 36cm. there were very significant differences in yields between the both strains. Spacing increases to 45cm. the difference in yield between them showed insignificant. Obviously the San-Ling strain is quite undesirable for closer planting. (7) The highest yield was obtained in the closest planting. i.e. spacings between beds, rows, and plants were 90-60-30cm. planted the No .2 strain which giving a total yield of fruit of three harvests up to 120.96 metric tons per hectare, comparing this treatment with any other eleven treatments, the differences in yield were all statistieally very significant, in the case of the widest spacings. i.e. spacings between beds, rows, and plants were 120-60-45 cm. yields were the lowest in both strains among the twelve treatments. Differences between that highest and these lowest yields were 62-65 metric tons per hectare. This fact proves that the effect of close spacing on yield is very prominent. (8) A majority of the total yield was given by the summer crop and less than one nineth of which by the winter crop, and only a very small portion of which by the spring crop. As concerning to the grades of all the fruits, both strains produced a large proportion (in weight) of first-class fruits than second-class ones in winter crop. But in the summer crop, fruit grades differed with the different strains. The No. 2 strain produced more first-class fruits than second-class ones, On the contrary the San-Ling strain produced fist-class fruits less than the second-class ones. (9) Suckering in the plant crop was uniform at all spacings of a given strain, but was different in average number per plant with different strains. The same case was the number of slips per plant in the plant crop. Obviously the formation of suckers and slips is controlled by genetic genes. The No. 2 strain produced suckers earlier and slips less in number than the San-Ling strain. (10) It was found that the formation of multiple crown fruit, which has been fairly common in pineapple plantations in Taiwan, showed no relation to the planting system. Moreover both strains produced a very similar percentage of multiple crown fruit. (average 9.40%, the No. 2 strain 8.31%, and the San-Ling strain 10.49%) Under the climatic conditions of Taiwan and the methods of crop management employed, the closer spacing does not interfere with cultural or harvesting operations. Cuite apart from the increased yield per hectare which could be expected in an average season, closer spacing would be an advantage from the point of view of weed control and soil moisture conservation; the greater shading of the soil between be rows tends to suppress weed growth early in the growing period and to reduce the loss of soil moisture by evaporation. The No. 2 strain possesses several distinctive or superior characteristics, such as it producing suckers ealier, forming slips less in number and the most important, being more productive and more favaurable to closer planting. So this strain should be propagated and distributed to the farmers in large exten in the near future in order to substitute the San-Ling strain which was commonly cultivated by farmers in Taiwan.