Influência da astronomia agrícola em aspectos produtivos e fisiológicos do rabanete (raphanus sativus l.)

Abstract

Radish (Raphanus sativus L.) is an culture of short cycle, whose root is the commercial interest part. In the conventional cultivation large amounts of chemical pesticides and high solubility fertilizers are used. The reason is that many external factors can put the crop at risk of loss, what makes it use to develop productive principles that make possible cultivation with reduced environmental impact and that improve the relationship between the producer, consumer and the environment. In this context there is the Biodynamic Agriculture, philosophy of culture studied by the German Rudolf Steiner in 1924, which adopts the so-called Agricultural Astronomy, line of research that considers the position of the stars in the farming system and its influence on life cycle of the plants. It is used to determine the favorable and unfavorable times for the cultivation of each different marketable plant parts such as roots, leaves, flowers and fruits by the Astronomical Calendar. Based on the above, this study was carried out in order to evaluate the production and physiological aspects of radish with sowing in four different dates, referring to Days of root, leaf, flower and fruit, each corresponding to the most appropriate period for the cultivation of their respective part of commercial interest, according to the Astronomical/Agricultural Calendar 2015, from the Brazilian Association of Biodynamic Agriculture. The experiment was conducted in an open area in the field at the Federal University of Ceará, in the period from April to June 2015. The experimental design was randomized blocks: five blocks and four treatments which consisted of different dates for sowing, during the growing phase of the moon, with upward movement. Plants produced in ‘Flower Day’ showed the best results for number of leaves per plant, fresh and dry weight of shoot and leaf area; there was no difference to ‘Flower Day’ and ‘Fruit Day’ in useful leaf area, with both treatments superior to others; ‘Leaf Day’ and ‘Flower Day’ alsoenabled higher values in chlorophyll A content for plants, and ‘Leaf Day’ stood out alone in promoting higher levels of chlorophyll B for plants; ‘Leaf Day’ and ‘Fruit Day’ were the dates that provided higher values of internal CO2concentration and both do not differ among themselves; ‘Root Day’ gave higher values of net photosynthetic rate related to 6.25 cm² leaf area and higer values of carboxylation efficiency; total net photosynthetic rate of all treatments except in 'Leaf Day' did not differ from each other, and 'Leaf Day' was the greater; for the characteristics: diameter, length, fresh and dry weight of truffles, tuberization percentage, cracked truffles percentage and total production per hectare were not found significant differences were observed among the treatments.