Date of Award

Spring 2016

Project Type


Program or Major

Plant Biology

Degree Name

Master of Science

First Advisor

Becky Sideman

Second Advisor

Mark Hutton

Third Advisor

Rich Smith


As high tunnel production is relatively new to the Northeast, this research has helped understand knowledge-gaps in common warm and cold-season crop systems in the region. High tunnels increase crop yield and quality and extend the growing season, and are most commonly used for tomato in the warm-season and spinach in the cold-season.

Spinach was grown in unheated high tunnels throughout the cold-season to evaluate the effects of cultivar and planting date on yield and sweetness (Brix° levels). Cultivar and planting date had a significant effect on yield, where earlier planting dates resulted in higher yields. Cultivar had a significant effect on Brix° levels and a significant negative correlation existed between in-tunnel temperature and Brix° levels.

While hydroponic tomato fertility is well understood, little research exists in high tunnel tomato soil fertility, which this experiment addressed focusing on potassium (K) because of its importance in fruit production. Tomato was grown in high tunnels throughout the warm season to establish critical soil K levels for maximum yield with organic K fertility, evaluate the effects of soil K on yellow shoulder disorder (YS), and assess if the combination of a field soil test with the saturated media extract test (SME) will improve the strength of predicting soil K levels in high tunnels under three years of continuous production. Applied K had a significant effect on marketable yield, however critical soil K levels could not be established. Applied and soil K had significant effects on YS. The field soil and SME tests were significantly correlated in their ability to measure soil K. As a result, their combination could not increase soil K prediction strength. These results can improve year-round high tunnel production of spinach and tomato in the Northeast.