Weed Control J 2021; 20: e202100748
Sensibility of weedy rice originated of regrowth to imazapyr + imazapic
DOI: 10.7824/wcj.2021;20:00748
Abstract
Introduction
Cultivation of rice ratoon is a technique in which regrowth is cultivated after harvest, with the objective of carrying out two successive harvests in the same area. This practice is intended to improve the productivity and profitability of rice cultivation. However, this model aggravates phytosanitary problems, making weed control more complex.
Objective
To evaluate the efficiency of the formulated mixture of imazapyr + imazapic without regrowth weed control, simulating the rice society’s growing conditions.
Methods
The experiment was carried out in a greenhouse, in a completely randomized design with treatments arranged in a 4 x 3 factorial scheme. The first factor corresponded to the simulant weed rice genotypes (SCSBRS Tio Taka; SCS116 Satoru, SCS121 CL, SCS122 Miura) and the second factor as doses of imazapyr + imazapic (0.0; 73.5 + 24.5 and 147 + 49 g ha-1 of ai). Record the control efficiency at 7, 14 and 28 days after application, in addition to plant height, average number of leaves per tiller and shoot dry mass.
Results
The control of weed rice regrowth with imazapyr + imazapic was not satisfactory in any evaluation period, being less than 42%. However, a formulated mixture of imazapyr + imazapic suppresses the growth of SCSBRS Tio Taka, SCS116 Satoru and SCS122 Miura genotypes, regardless of dose.
Conclusion
The application of imazapyr + imazapic was not efficient in controlling weed rice regrowth.
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