Respostas ecofisiológicas associadas a produção de mudas de açaizeiro procedentes de várzea e adaptadas a terra firme submetidas a diferentes regimes hídricos.

Abstract

Fruit growing is one of the agricultural activities that stands out in this scenario as the largest segment of Brazilian agribusiness, employing around five million jobs generating a gross revenue of approximately R$20 billion in 2013. In the Amazon, more precisely in the state of Pará, the açaí fruit originating from the açaí palm tree Euterpe oleraceas Mart. In 2014, the fruit production chain generated around 20 million dollars in exports alone, making it the most important fruit in the economic context in the North of the country. Due to these facts, the expansion of the planted area became necessary, however the availability of seedlings in quality and quantity did not keep up with this growth due to a lack of agronomic knowledge of the species related to various segments such as: water demand of the crop, more genetic materials recommended for different production sites, knowledge of the physiology and biochemistry of plants, etc. In view of this, the aforementioned work evaluated the vegetative, physiological and biochemical behavior of açaí plants from various floodplain and terra firma origins, including cv. and ecotype under different water supply. The experiments were carried out on the campus of the Federal Rural University of the Amazon Belém campus, in the area of the Institute of Agricultural Sciences, two provenances of Várzea Muana and Laranjeira and one cv.BRSPA and ecotype Hideo, which are already used in plantations on dry land, were used. , the plants were subjected to four irrigation levels 40%CC, 70%CC, 100%C and 130%CC, the behavior of cv. BRS-PA and ecotype Hideo under conditions of water restriction, the variables studied were related to vegetative growth, including dry matter, gas exchange and some biochemical parameters. Given the conditions under which the work was conducted, and after analyzing the data, it was possible to conclude that: The açaí tree does not tolerate irrigation below field capacity, the formation of açaí tree seedlings as a qualitative standard determined by the regulatory body MAPA. As for the genotypes grown on terra firma cv. BRS-Pa and ecotype Hideo under water restriction 40% cc and 70% cc, in the control water 100% cc showed similar morphophysiological behavior, Under water deficit cv. BRS-Pa is more efficient in mitigating the effects of water deficit on leaf turgidity through stomatal control of transpiration associated with greater growth of the root system, and has a more stable photosynthetic apparatus than plants of the Hideo ecotype, which culminates in greater synthesis of leaf carbohydrates and plant growth, consequently proving to be genetically superior.