Tropical Horticulture: Overview

Transcription

1 Lecture 39 Overview There are dramatically apposing attitudes towards the tropics, both anti- and pro-tropic sentiments Salubrious and balmy vs. Hot and steamy Cruise ships, waving palms vs. Poisonous snakes & crocs 1

2 Resorts & retirement havens vs. Slums & shacks Birth of civilization vs. Uncivilized Green and bountiful vs. Starvation & malnutrition 2

3 Rich in flora vs. Monotonously green Beverage Crops Cacao Coffee Tea Fruits and Nuts Avocado Citrus Banana & Plantain Date Papaya Pineapple 3

4 Cassava Starchy Vegetables Sweetpotato Taro Yam Industrial Crops Rubber tree Coconut Grasses Rice Sugarcane 4

5 Spices Cinnamon Nutmeg Clove Vanilla Ginger Pepper Ornamentals Orchids Plumeria Poinsettia Streletzia Philodendron Bougenvillia Celestial Mechanics Revolution is the movement of the earth in an elliptical orbit around the sun whose average distance is 93 million miles away. The time to travel 1 orbit = 1 year. During this time there are rotations of the earth. Theory of the Tropics 5

6 Symbol A B C D E Major climate Tropical rainy Dry Humid, mildwinter temperate Humid, severe-winter temperate Polar Chief characteristic Coolest month above 18 C (64.4 F) Evaporation exceeds precipitation Coldest month between 18 C (64.4 F) and 0 C (32 F) Coldest month below 0 C (32 F); warmest above 10 C (50 F) Warmest month below 10 C (50 F) Subclimates (incomplete) Af, tropical rainforest Am, monsoon rainforest Aw, tropical savannah BS, steppe BSh, tropical and subtropical steppe BSk, middle latitude steppe BW, desert BWh, tropical and subtropical desert Cs, Mediterranean (dry-summer subtropical) Csa, hot-summer Mediterranean Csb, cool-summer Mediterranean Ca, humid subtropical (warm summer) Caw, with dry winter Caf, with no dry season Cb, Cc, marine west coast (cool summer) Da, humid continental, warm summer Daw, with dry winter Daf, with no dry season Db, humid continental, cool summer Dc, Dd, subarctic ET, tundra EF, icecap Forests are stratified, typically 3 layers or strata 6

7 Clays Clays are the life blood of the soil due to the active exchange mechanism of bases. Clays differ in tropics and temperate climates Temperate clays: Montmorillonite (2:1 layer) Tropical clays: Kaolinite (1:1 layer) Nutrient Recycling 7

8 Net Photosynthesis as a Percent of Af Climate Time Entire Year Af 100 Aw 105 Cs (Medit) 117 Ca (Mild temperate) 91 D (Severe winter) 68 8 months (March Oct) months (May Aug) Agriculture in Tropical Systems Upland rice clearing in forest for rice, Maranhao 8

9 Cerrado Burning, Brazil Themes in Tropical Agriculture Demographic Transition 9

10 Norman E. Borlaug, 1970 recipient of the Nobel Prize for Peace, working with hybrid wheats at the CIMMYT Toluca station, Mexico Lodging susceptible and resistant rice Coffee Cherry 10

11 Cacao, Orthotropic Tree Cacao, Plagiotropic Tree Cacao fruit and dry beans 11

12 Through fermentation and drying, the cacao pod s pulp-surrounded seeds are converted into nibs ready for roasting and grinding into chocolate liquor Rice paddy near Bandung, West Java, Indonesia Sugar Mill, Ponte Nova, Brazil,

13 Tapping Rubber Trees Oil palm, Elaeis guineensis Originated in west and central Africa Tree An unbranched moneocious palm; leaves (24/year), 10 11m at 25 to 35 years. Fruit A drupe with fleshy mesocarp and hard endocarp which surround 1, usually 2, and occasionally 3 seeds. Cassava 13

14 Edible Aroids Banana Pineapple 14

15 Papaya Flower Type The flower type shows a relationship to fruit shape. I II III IV V Valencia Orange, Israel Nucellar polyembryony in Citrus 15

16 Avocado varieties, Israel Bird of Paradise Anthurium, Hawaii 16

17 Elephant pod Double Poinsettia 17