HOCKMAN, AARON W.*, SHERI CHAVEZ, ERICKA AGUILAR, and ROLSTON ST. HILAIRE. Department of Agronomy and Horticulture, New Mexico State University, Box 30003, MSC 3Q, Las Cruces, NM 88003. - Water deficit stress affects physiological, anatomical, and growth traits of Nepeta cataria L.
Catnip (Nepeta cataria L.) is a perennial herb that is found in
Europe, Central Asia, and North America. Catnip is not native to North
America, but it is well acclimatized in many areas of the United
States. Catnip is used as a cat toy filler and medicinal tea. We
determined the effects of three irrigation regimes on the
physiological, anatomical and growth traits of catnip. In one
experiment, plants were irrigated every two days, five days, and 10
days for 12 weeks. Irrigation regime did not affect leaf dry weight,
the ratio of root to shoot dry weight, and specific leaf weight. Root
and shoot dry weights were lowest in plants irrigated every ten days
and averaged 142 and 19 grams per plant, respectively. Average total
leaf area of plants irrigated every ten days was the lowest and
averaged 934 cm2. Leaves from plants irrigated every five
days had the thickest palisade layers. In another experiment, plants
were irrigated every other day, five days, and ten days for six weeks.
Irrigation treatment affected leaf maximal fluorescence. Plants
irrigated every 10 days had stomatal conductance rates that were
reduced to as little as 82% of plants watered every other day. We
conclude that plants watered every ten days accumulated the least dry
mass. Irrigation regime affects both physiological and anatomical
traits of catnip. Effects of those three irrigation levels on the
accumulation of essential oils in catnip are being investigated.
Key words: Catmint, Chlorophyll Fluorescence, Drought, Labiatae, Nepeta cataria