MORPHOLOGICAL CHARACTERISTICS AND FORAGE PRODUCTIVITY OF IRRIGATED CACTUS PEAR UNDER DIFFERENT CUTTING INTENSITIES

ABSTRACT: This study evaluated the effect of different cutting intensities and years of harvesting on the morphological characteristics and production of fresh (FMP) and dry matter (DMP) of cactus pear cv. Gigante (Opuntia ficus-indica Mill) under conditions of irrigation, high planting density and fertilization, with 12 months of regrowth. The experimental was completely randomized in a factorial design (3 × 2) with 12 replicates. The treatments were three cutting intensities (preserving the mother cladode (PMC), primary cladodes (PPC), or secondary cladodes (PSC)), and two years of harvesting. The soil was classified as Cambisol Haplicum and the irrigation water was classified as C4S1 (EC 5.25 dS.m-1) density of 50,000 plants ha-1. The research evaluated plant height, number of cladodes per plant (NCP), length, width, perimeter and thickness of the cladodes, cladode area (CA), cladode area index (CAI), FMP and DMP. There was no significant interaction between treatments (P > 0.05) for the variables plant height, NCP, CAI and FMP. The variables related to cladode morphology showed a significant interaction (P < 0.05). The treatment PSC resulted in a greater DMP (P < 0.05) with a mean of 27.17 Mg ha-1 yr-1, compared to PPC (18.58 Mg ha-1 yr-1) or PMC (11.78 Mg ha-1 yr-1). The treatment PSC promoted greater NCP and forage productivity at harvest and can be considered as a management practice for the sustainability of cactus pear cv. Gigante under irrigation. The more important morphological characteristics were also influenced by the lower cutting intensities.

摘要：本研究评估了灌溉、高种植密度与施肥条件下，不同刈割强度及收获年限对‘巨人’梨果仙人掌（Opuntia ficus-indica Mill）的形态特征、鲜样产量（Fresh Matter Production, FMP）与干物质产量（Dry Matter Production, DMP）的影响，试验再生周期为12个月。试验采用3×2因子完全随机设计，共设置12次重复。试验处理包含3种刈割强度：保留母茎片（Mother Cladode, PMC）、一级茎片（Primary Cladode, PPC）及二级茎片（Secondary Cladode, PSC），以及2个收获年限。供试土壤归类为简育雏形土（Cambisol Haplicum），灌溉水等级为C4S1，电导率为5.25 dS·m⁻¹，种植密度为50000株·公顷⁻¹。本研究测定的指标包括株高、单株茎片数（Number of Cladodes per Plant, NCP）、茎片长度、宽度、周长与厚度、茎片面积（Cladode Area, CA）、茎片面积指数（Cladode Area Index, CAI）、鲜样产量与干物质产量。株高、单株茎片数、茎片面积指数及鲜样产量的处理间无显著交互作用（P>0.05）。茎片形态相关指标则呈现显著交互作用（P<0.05）。其中二级茎片刈割（PSC）处理的干物质产量最高（P<0.05），均值达27.17 Mg·ha⁻¹·yr⁻¹，显著高于一级茎片刈割（PPC，18.58 Mg·ha⁻¹·yr⁻¹）与保留母茎片（PMC，11.78 Mg·ha⁻¹·yr⁻¹）处理。二级茎片刈割（PSC）处理可提升单株茎片数与收获期饲草产量，可作为灌溉条件下‘巨人’梨果仙人掌可持续栽培的管理措施。较低的刈割强度对核心形态特征亦存在显著影响。