GROWTH ANALYSIS OF HYBRID Eucalyptus urograndis (E. grandis x E. urophylla) IN RESPONSE TO SIMULATED DRIFT OF AUXINIC HERBICIDES

ABSTRACT The aim of this study was to evaluate growth rates of E. urograndis under application of triclopyr and fluroxipyr+triclopyr herbicides. Was used a randomized block design with four replications in a factorial design (3x2x5), corresponding to herbicides (triclopyr and fluroxipyr+triclopyr), both with two doses (0.75 and 1.5% concentrations of 480 g and L-1 for triclopyr and 80+240 g and L-1 for fluroxipyr+triclopyr), plus one control (plants that did not receive herbicide application) and five evaluation dates at 15, 30, 45, 60 and 75 days after application (DAA). At 45 days after seedlings transplant, applications were performed with pressurized carbon dioxide backpack sprayer, equipped with beak tip (XR 110.02) with spray volume of 200 L ha-1 and constant pressure of 35 kgf/cm2. Were evaluated: leaf area (LA), specific leaf area (SLA), leaf area ratio (LAR), leaf weight ratio (LWR), absolute growth ratio (AGR), relative growth ratio (RGR) and net assimilatory ratio (NAR). The drift of triclopyr and fluroxipyr + triclopyr herbicide in the hybrid E. urograndis affect plant development in the beginning of the establishment. At 75 days after simulation drift of herbicides the plants showed characteristics of the symptoms of intoxication. It’s necessary to perform studies after 75 DAA to verify the complete recovery of the intoxication symptoms of E. urograndis hybrid plants resulting from the herbicide drift in the present study.

摘要：本研究旨在评估在施用三氯吡啶和氟罗西吡+三氯吡啶除草剂条件下，尿草锈病菌的生长速率。研究采用了随机区组设计，包含四个重复，采用析因设计（3x2x5），对应于除草剂（三氯吡啶和氟罗西吡+三氯吡啶），每种除草剂均设两个剂量（三氯吡啶为480克/升和1.5%浓度，氟罗西吡+三氯吡啶为80+240克/升和1.5%浓度），以及一个对照组（未施用除草剂的植株）和五个评价日期，分别在施药后15、30、45、60和75天。在幼苗移植45天后，使用压力式二氧化碳背包喷雾器进行喷雾，喷雾器配备有喷嘴（XR 110.02），喷雾量为200升/公顷，压力恒定为35千克力/平方厘米。评价指标包括叶面积（LA）、特定叶面积（SLA）、叶面积比（LAR）、叶重比（LWR）、绝对生长比（AGR）、相对生长比（RGR）和净同化率（NAR）。三氯吡啶和氟罗西吡+三氯吡啶除草剂在杂交尿草锈病菌中的漂移，会影响植株在定植初期的发育。在施药漂移模拟75天后，植株显示出中毒症状。有必要在施药后75天进行进一步研究，以验证尿草锈病菌杂交植株因除草剂漂移而产生的中毒症状是否完全恢复。