Avaliação de tecnologias para uso eficiente da água em tomateiro irrigado em lavoura comercial

Abstract

The present research was carried out to verify the productive characteristics and the economic efficiency of water use in an irrigated tomato crop with plastic mulch, different frequencies and water depths in the South of Minas Gerais region. Three experiments were carried at city of Ingaí-MG and the results were described in three articles. In the first, the sources of variation were soil mulch (without and with plastic mulch) and two water depths for the whole cycle (164 mm and 188 mm). The plant height and water use efficiency were not influenced by use of mulching nor the water depths. Plastic mulch provided lower average fruit mass, but with higher number of fruits per plant, which contributed to higher commercial productivity. There was interaction between the factors for total productivity, being the greater total productivity obtained with plastic mulch associated with 188 mm of water depth. The sources of variation in the second experiment were soil mulch (without and with plastic mulch) and two irrigation frequencies (continuous and pulsed drip). In this, the matric potential remained within the limits recommended by the literature for tomato. There was no significant difference in plant height. Use of mulching provided higher average fruit mass and an interaction was observed between mulching and irrigation frequency. With continuous irrigation, the treatments under plastic mulch generated higher total and commercial productivity, higher efficiency of water use, economic efficiency and more fruits per plant. In pulse drip irrigation, without plastic mulch soil presented better results for total and commercial productivity, number of fruits per plant and efficiency of water use. In the last article, the sources of variation were also the soil mulch (without and with plastic mulch) and two irrigation depths (167 mm and 206 mm). Osmotic potential values in the treatments with plastic mulch remained more intense than at treatments without plastic mulch. There was interaction between water depths and soil mulch for variables responses: fruits per plant, total and commercial productivity and efficiency of water use. The larger water depth applied resulted in greater commercial productivity. The use of plastic mulch can be an alternative to increase the efficiency of water use and the production of tomato irrigated by drip irrigation.