香蕉枯萎病高抗品种‘中蕉9号’营养特性的评价

为在巴拿马枯萎病高抗品种‘中蕉9号’推广应用中合理施肥和进行有效的养分管理。以大田正常管理条件下的‘中蕉9号’为试材,采用整株肢解法研究‘中蕉9号’香蕉根、茎、叶、果穗4个器官的干物质氮磷钾养分累积及分配规律,以探讨其养分综合管理技术。结果表明,‘中蕉9号’单株鲜重、干重平均为(145.35±6.42)、(18.18±0.70) kg/株,干物质不足整个植株鲜重的1/8,干物质中灰分仅占8%。4个器官鲜重大小依次是茎（93.53 kg/株）>果穗（33.38 kg/株）>叶（14.93 kg/株）>根（3.51 kg/株）。干物质累积分配规律和鲜重一致,即茎>果穗>叶>根。茎的干重为8.44 kg/株,其中干物质主要分配在假茎中（76%）,球头仅占24%。叶的干重为2.77 kg/株,干物质在叶片中的分配比例是56%,在叶柄中的分配比例是44%。果穗的干重为6.71 kg/株,其中果实的干物质分配比高达94%,果轴的仅占6%。对整株香蕉而言,约2/3的干物质分配到根茎叶中,即2/3的光合产物用于根茎叶的生长,而只有约1/3的光合产物用于果实生长。平均而言,‘中蕉9号’每株累积吸收纯氮116.89 g、纯磷23.67 g、纯钾510.29 g,氮磷钾的吸收比例为1.00:0.20:4.37。氮磷钾吸收累积量在4个器官中的分配大小依次是：茎>果穗>叶>根;根、茎、叶、果穗中的N:P:K比例分别为1.00:0.21:6.82、1.00:0.25:7.38、1.00:0.13:1.96、1.00:0.21:3.10,可见4个器官中,茎部吸收累积氮磷钾总量以及钾的比例最大。‘中蕉9号’根茎叶特别是茎中干物质和钾的吸收累积量远大于巴西蕉是其养分管理值得重视的一个特点。根据‘中蕉9号’生物量和氮磷钾吸收累积分配规律,参考巴西蕉的研究结果,本研究提出‘中蕉9号’的养分管理的建议：孕蕾前应适当控制养分水分供应,限制茎叶徒长和养分消耗;肥料N:P₂O₅:K₂O的比例可参考巴西蕉的营养特性,在孕蕾前采用2.0:0.5~1.0:1.0,在孕蕾至抽蕾期,采用1.0:0.5:2.0,抽蕾后至收获前采用1.0:0.5:2.5~3.0的配方。为了做到更好的养分管理和实现化肥高效利用,‘中蕉9号’茎和叶中积累如此多的碳水化合物和钾以及如何促进他们运输到果实是值得研究的课题。

Evaluation of Nutrition Properties of Banana Variety ‘Zhongjiao No 9’ with High Resistance to Fusarium Wilt Disease

In order to apply fertilizer rationally and manage nutrient effectively during the promotion of banana variety of panama fusarium wilt resistant cultivar ‘Zhongjiao No. 9’, the accumulation and allocation of nitrogen, phosphorus and potassium (NPK) nutrients in the root, stem, leaf and fruit organs of ‘Zhongjiao No. 9’ under normal field management were studied by using the whole plant dismember method. The average fresh weight and dry weight of single plant of ‘Zhongjiao No. 9’ was (145.35±6.42) and (18.18±0.70) kg/plant, and ash content in dry matter was only 8%. The order of fresh weight of the four organs was as followings stem (93.53 kg/plant)>fruit (33.38 kg/plant)>leaves (14.93 kg/plant)>roots (3.51 kg/plant). The pattern of dry matter accumulation and allocation was consistent with fresh weight order. The dry weight of the stem was 8.44 kg/plant, and the dry matter was mainly distributed in pseudostem (76%) and corm (24%). The dry weight of leaves was 2.77 kg/plant, and the proportion of dry matter allocation in leaves and petioles was 56% and 44% respectively. The dry weight of the fruit was 6.71 kg/plant, the dry matter allocation of the fruit comb was up to 94%, and the fruit axis accounted for only 6%. About two-thirds of the dry matter was allocated to the root, stem and leaf, meaning two-thirds of the photosynthetic products were used for root, stem and leaf growth, while only about one-third of the photosynthetic products were used for fruit growth. On average, the cumulative absorption of pure nitrogen, pure phosphorus and pure potassium per plant was 116.89 g, 23.67 g and 510.29 g, and the ratio of N, P and K was 1.0:0.20:4.37. The N, P and K absorption accumulation in the four organs was distributed in the order of the stem>fruit>leaf>root. The ratio of N:P₂O₅:K₂O in root, stem, leaf and fruit was 1.0:0.21:6.82, 1.0:0.25:7.38, 1.0:0.13:1.96 and 1.0:0.21:3.10, respectively. Among the four organs, stems absorbed and accumulated most N, P and K. A noteworthy feature of the nutrient management of ‘Zhongjiao No. 9’ was that the accumulation of dry matter and potassium in rhizome and leaves, especially in stems, was much higher than that of Brazilian banana. The supply of nutrient and water should be controlled properly before pregnancy buds to limit the growth of stem and leaf to reduce nutrient consumption. The ratio of fertilizer N:P₂O₅:K₂O could be referred to the nutritional characteristics of Brazilian banana, and the formula of 2.0:0.5-1.0:1.0 should be adopted before pregnancy buds, 1.0:0.5:2.0 from pregnancy buds to extraction buds, and 1.0:0.5:2.5-3.0 after extraction and before harvest.