Date of Award

2017

Degree Type

Thesis

Degree Name

Master of Science in Biological and Environmental Sciences (MSBES)

Department

Biological Sciences

First Advisor

Rebecca N. Brown

Abstract

This study investigated the production of amaranth (Amaranthus spp.) as a leafy green in the northeastern temperate climate. Amaranth is a productive and resilient crop with cultural, economic, and nutritional significance to many cultures around the world. Growing ethnic crops in the northeastern U.S. is an opportunity for growers to expand into new and diverse markets. Amaranth’s pervasiveness in global foodways and tolerance of many biotic and abiotic stresses make it a promising option for growers to engage with the ethnic produce market and diversify production. However, intensive production research for vegetable amaranth is lacking, especially in temperate climates, and amaranth varieties are underdeveloped.

In 2016, ten vegetable amaranth varieties were evaluated for performance in the northeastern temperate climate. The experiment was a randomized complete block design with four replications and ten plants of each variety per replication. Yields of each plot and leaf to stem ratios of a two-plant subsample per plot were recorded. CVs were calculated for each variety as a measure of yield stability. The varieties included eight commercially-available A. tricolor varieties (‘Asia Red,’ ‘Red Garnet,’ ‘Red Callaloo,’ ‘Green Pointed Leaf,’ ‘Red Stripe Leaf,’ ‘Miriah, ‘Southern Red’), one commercially-available A. viridis variety (‘Green Callaloo’), and one heirloom A. hybridus variety from Burundi (‘Mchicha’). All plants were greenhouse-started and transplanted to a low-tunnel system, constructed with galvanized metal hoops and 0.8- mil clear slitted plastic. The experiment was repeated seven times over the 2016 growing season. There was little variation between the varieties in the middle of the summer. However, two varieties that excelled in the early and late season (‘Green Pointed Leaf’and ‘Miriah’) were also top performers all-season. Targeted production and marketing strategies have the potential to improve variety desirability.

A comparison of plasticulture production systems for vegetable amaranth was also conducted during the 2016 growing season. Two varieties of A. tricolor (‘Red Stripe Leaf’ and ‘Green Pointed Leaf’) were used throughout the experiment. The four treatments were 1) gothic-style high tunnel covered in a double inflated layer of 6-mil greenhouse plastic; 2) low tunnels over raised beds with black plastic mulch, constructed with galvanized hoops covered in 0.8-mil clear slitted plastic; 3) raised beds with black plastic mulch; and 4) uncovered bare soil. A split-plot design with 10 plants in each plot and four replicates was repeated three times over the season. High tunnel plots were excluded from the second planting due to extensive Woodchuck (Marmota monax) damage. Low tunnel plots had the greatest yields in every planting. The magnitude of production system effects decreased as ambient temperatures increased throughout the season. However, rankings of the four production systems were consistent in each experiment. Yield rankings from greatest to least were: low tunnel, black plastic mulch, high tunnel (when present), and bare soil. There were occasional significant differences in leaf to stem ratios. However, the response did not follow a discernable pattern based on production system, nor was it correlated to yield. Leaf to stem ratio is likely genetic and outside the influence of production system.

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