Study of the growth rhythm in young mango (Mangifera indica L.) plants. Part 4. Experimental modification of the growth and development rhythm. Hypotheses on how it is determined.
Parisot E.
Author Affiliation: IRFA/CIRAD, BP 180, 97455 Saint Pierre, Reunion.
Fruits (Paris) 43 : 293-312
Abstract : Young mango plants were grown at 18, 25 or 32°C. The total duration of 7 growth cycles decreased with increasing temperature, being 114 days at 32°, compared with 161 days at 25°; at 18° the duration of the first three cycles was approximately 3 times longer than at 25°. The most favourable temperature for growth was 25°; the length of each morphogenetic unit and the leaf surface areas of each unit were less at 18 or 32° than at 25°. Increasing the light intensity from 4000 to 30?000 lx (at 20°) increased the leaf surface area and number of leaves of each morphogenetic unit. Plants grown under 29?000 lx at 20° were compared with those grown under 4000 lx at 25°. Increasing the light intensity compensated in part for the decrease in temperature. Removal of leaves as soon as they reached 5 cm in length resulted in the suppression of rhythmic growth. Growth rhythms found in mango are compared with those of other temperate and tropical species, and hypotheses concerning the regulation of growth rhythms are discussed.