Production and partitioning of dry matter in leren [Calathea allouia (Aubl.) Lindl]

Abstract

Leren [Calathea allouia (Aubl.) Lindl] is an under-exploited tropical tuber crop with potential for processing and as a substitute for water chestnuts. Shade affects the photosynthetic rate, and the growth and yields are variable. There Is little research In the Improvement on the agronomy of the crop. This study set out to understand the production and partitioning of assimilates as influencing crop yield through the manipulation of light, density, and nutritional factors, as well as to determine whether the rhizome of leren is the true sink or a filter/storage receptacle for tuberization. Several field and greenhouse studies were conducted over a two-year period at the Field Station of the University of Trinidad and Tobago. The treatments were light [full sunlight and shade (50%)], density (20.8 and 27.7 thousand plants per hectare), and fertilizer [N-P₂-O₅-K₂O (13:13:20)] at varying rates (0.0 to 0.6 t/ha). The leaf area, dry matter, and tuber yield were monitored. The results indicated that LAI varied between 1.38 (full sunlight) and 3.08 (shade) and was not influenced by crop nutrition. For both the greenhouse and field trials, rhizome dry matter accumulation and partitioning into tubers was higher in the shade treatments. Fertilizer application did not influence leaf growth or dry matter production (photosynthesis capacity) in the greenhouse trials, but more assimilates partitioned from rhizomes into the tubers in the lower crop density x intercrop. The partitioning of assimilates from the shoot to rhizome, and from rhizomes into tuber was more efficient in the shade x intercrop treatments. The fertilizer application of 0.5 t/ha at the crop density of 20.8 thousand plants per hectare realized the highest dry matter (1,066 g/plant) and tuber (261.3 g/plant) yield. The study suggests that in leren, the rhizome and tubers are the primary and secondary sinks, respectively, with distinct partitioning of assimilates from shoot to rhizomes and from rhizomes to tubers.