Sensitivity of pre-sprout seedlings (MBP) of sugarcane to the herbicides clomazone and imazapic applied in pre and post-planting with and without the use of biochar

Abstract

A new sugarcane plantation system using pre-sprouting seedlings (MPB) to replace sugarcane stem fragments may limit the use of pre-emergent herbicides commonly used in the traditional system. Therefore, the objective of this work will be to evaluate the sensitivity of pre-sprouted seedlings to clomazone and imazapic herbicides applied alone and in association with post-planting and pre-planting of MPBs with and without biochar (biochar). For each mode of herbicide application (pre and post-planting), the experimental design will be completely randomized with four replicates in the factorial scheme 9 x 2, with 9 treatments and two planting systems - with and without biochar (3 t ha-1 ). The treatments were: imazapic (75 and 150 L ch ha-1), clomazone (1.2 and 2.0 L ch ha-1) and imazapic + clomazone combinations (75 ± 1.2; 150 + 1.2 and 150 + 2.0 L pc ha-1). The herbicides will be applied one day before planting of the seedlings and seven days after planting (separate pots). Phytotoxicity evaluations will be performed at 5, 15, 30 and 60 days after application of the herbicide (DAA). The other evaluation parameters used will be chlorophyll index, height, and in the last evaluation will determine the leaf area and dry matter of the aerial part of the plants, collecting them close to the soil and taking them to dry in a greenhouse with forced circulation of air at 65 ºC, until constant mass, and then the dry matter per plant is determined. The data will be submitted to analysis of variance and regression.