Nutrient composition of leaves from defoliated grain amaranth (Amaranthus cruentus L.) plants

Utilization of both leaves and grains of Amaranthus cruentus L. could enhance the nutritional and economic benefits of the crop for improved health and livelihoods. However, little is known about the effect of defoliation on leaf composition and grain production in a dual use scenario. The nutrients and health promoting compounds of the leaves from differently defoliated A. cruentus plants were studied in a randomized complete block design (n = 4). Fifty percent of leaves were harvested from plants once at 5, 7 and 9 weeks after sowing and twice consecutively at 5, 7 and 9 weeks after sowing. The carotenoids, total polyphenols and flavonoids content increased with growth stage although significantly reduced by twice defoliation. Protein content was not affected by defoliation frequency. Iron content decreased with twice defoliation in older plants. Grain yield and plant height were not significantly affected by timing and frequency of defoliation. Earlier harvested leaves contained more iron whereas later harvested leaves had higher carotenoids and flavonoids content. Therefore, 50% of leaves of A. cruentus plants can be harvested twice consecutively without affecting plant growth and grain yield, thus promoting a dual use system.