Topping

Why does a plant have leaves? As a store for seed production As a store for seed production

Historical Perspective Late topping/ full bloom Late topping/ full bloom  Past Demand  Lighter bodied style of tobacco  Milder taste  Non-filtered  Sucker control  Hand removal  No chemical control

Physiological Aspect of Topping Leaf Spread Leaf Spread Removal of non-beneficial nutrient sink Removal of non-beneficial nutrient sink Root stimulation Root stimulation

Timing Best when 10-25% of plants have one flower open Best when 10-25% of plants have one flower open  Effects on plant  Darker cured leaf color  Prior to physiological maturity  Prior to stalk hardening  Increases root development  More leaf expansion in lower part of plant

Yield Trends Bud Topping Bud Topping  Yield loss in many varieties  Good for late maturing varieties 10-25% 10-25%  Best for most varieties  Good quality 50-75% 50-75%  Suckers initiated in some varieties 100%+ 100%+  Yield decline  Sucker initiation in all varieties  Opportunistic diseases  Senescence

Disease Incidence Hollow Stalk Hollow Stalk  Late Top  Harden Stalk  Ragged Top

Effects of Topping Time on Yield 12 trials over 10 years

Topping Height Root system Root system  Supports a finite leaf yield Leaf number Leaf number  20 leaves  Larger leaves  Yield Highest sometimesHighest sometimes  26 leaves  Smaller leaves  Yield No different most timesNo different most times

Effects of Topping Time on Yield 17 trials over 9 years

Effects of Topping Time on Leaf Yield 17 trials over 9 years

Topping Study Labor Comparisons Lawrence Co. – Malcom Smith Farm

On a Larger Scale 6 leaves per plant 6 leaves per plant 42,000 per acre 42,000 per acre  Based on7000 population 420, ,000  Based on 10 acres 1,035,000 1,035,000  Based on 24 acres

Maturity Approximately 4 weeks after topping Approximately 4 weeks after topping Influenced by residual N Influenced by residual N Signs Signs  White stem & stalk  Leaf cracks when bent  Bronzing of leaves

Harvesting Timing Timing  Yield  Increase to 4- 5 wks after topping  Decrease after 5 wks after topping  Quality  High early increase slightly to 3 wks after topping  Decline after 3 wks

Effects of Harvest Date on Yield and Quality

Harvest Date Across Five Locations HSD 0.05 = Locations = Bath, Boyle, Clay, Jackson & Pulaski

Effects of Harvest Time on Quality Jackson Co. - Harry Nicholson Farm HSD 0.05 = = Usable Tobacco, 4 to 5 = Marginal, 4 = Non-usable, 3 was described as high color, undesirable, tight faced & immature