Premium
Nonstructure Carbohydrate and Dry Matter Relationship in Alfalfa Tap Roots 1
Author(s) -
Wolf D. D.
Publication year - 1978
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1978.0011183x001800040044x
Subject(s) - dry matter , perennial plant , forage , medicago sativa , biology , dry weight , taproot , zoology , botany , agronomy , horticulture
Total nonstructural carbohydrates (TNC) in the fleshy tap root are often used as an indicator of the physiological status of perennial forage plants such as alfalfa ( Medicago sativa L.). TNC determinations involve considerable time and expense after the root samples are obtained. An alternative gravimetric method is pro. posed that involves determining percentage dry matter (DM). Tap roots are dug from the field, and the crown and lateral roots are removed. The remaining root is trimmed to a 10‐cm length, cleaned free of soil, and soaked in water for 2 hours. Root segments are blotted dry with paper towels and weighed (saturated weight). Roots are then oven dried and weighed (dry weight). Dry matter is expressed as a percentage of saturated weight. Experiments conducted over 11 years under a wide range of varieties, plant ages, management practices, and sampling dates indicate highly significant correlations (r 2 ranged 0.70 to 0.96) between TNC and DM. TNC and DM show similar cyclic patterns caused by plant growth and degree of defoliation. An equation for predicting percent TNC values from percent DM was determined from linear regression analysis.