Calendário agrícola da fumicultura na bacia hidrográfica do Rio Jacuizinho, RS

Abstract

The objective of this research was to elaborate an agricultural calendar for the cultivation of tobacco for the hydrographic basin of Rio Jacuizinho, because in the existing literature, there is only the calendar elaborated by the Secretariat of Agriculture, Livestock, Fisheries and Agribusiness, which is not representative for the real weather of this spatial cutout. In order to achieve the proposed objective, two field activities were carried out in order to observe the structure of small tobacco farms, in addition to identifying possible differences in the stage of development of cultivation from one location to another. Data on average tobacco productivity per crop year were requested and provided by the Brazilian Association of Tobacco Growers in Brazil (AFUBRA), for the period from 2008 to 2018. The data referring to rainfall were acquired from the database of Cooperativa Tritícola de Espumoso Ltda (COTRIEL), for the period from 2008 to 2018. The average air temperature was established through estimation calculations and, finally, a questionnaire was applied to producers in different municipalities, requesting information regarding the main phenological cycles (beginning of sowing, planting, harvest and end of harvest). The results showed that the altimetry, attributing the variability of the rainfall and the air temperature, interfere in the average tobacco productivity, being that the municipality of Lagoão, located in the highest elevation of the Jacuizinho River basin has the highest productivity for the 2008- 2018 period. The monthly rainfall has a significant influence on tobacco productivity, in addition, the rainfall that occurs over the course of a year, also reflects on the average productivity of the following crop year. The average air temperature (estimate), promotes heterogeneity in the tobacco phenological cycle, especially in relation to the mild temperatures during the planting phase. Besides information on rainfall distribution, average air temperature and interview with local producers, it appears that the agricultural calendar is different between municipalities, due to the variability of temperatures caused by the altitudinal difference between opposite points of the study area. In places with higher average temperatures during the months of cultivation, the development of the plant tends to be faster and may contain a difference of days, weeks and even months in relation to municipalities located in areas of higher altitude.