Cotton

Leading Countries 1. China 2. USA 3. India 4. Pakistan 5. Uzbekistan

Botany A perennial Coldest temps. 650F Height = 2-5 feet Deep tap root (up to 3’ deep) Bolls (Fruit – lint) Squares (Flowers) Only open for one day

Cotton plants produce far more fruiting structures than they can mature. They will shed as much as 60-70% Of the early season squares, 40 – 50% are shed. Of the late season squares, up to 90% are shed.

Fruiting Structures 75 % of the total yield comes from bolls at the first node on a fruiting branch. About 15% of the total yield comes from bolls at the second position on a fruiting branch. About 10% of the total yield comes from bolls beyond the second position on a fruiting branch.

Heat Units Planting to emergence 50 First true leaves 100 First square 450-500 First open flower 850-900 First boll susceptible to pink boll worm 1,050-1,100 First open boll 1,900-2,000 How to calculate heat units: Daily low + daily high ÷ 2 – 600F = heat units

Varieties Acala – Gossypium hisutum Pima – Gossypium barbadense Cross - Hazera

Acala Fibers range from ¾” to 1 ¼” White Flowers 4-5 lock bolls 7-9 ovules 55 – 70 bolls per pound of seed 2-5’ tall

Pima Fibers range from 1 ½” to 2” Yellow Flowers 3 lock bolls 5-7 ovules 100 – 135 bolls per pound of seed 2-5’ tall

Cultural Practices Tillage Planting Crop Rotation Rip Disc Seed bed (row spacing – 38” – 40”) Planting Depth, ¾ - 2 “ 2-3 plants per foot Crop Rotation Follows Alfalfa or other legume

Planting 1 pound of seed = 3,500 to 5,200 seeds Rates = 24 to 40 pounds per acre 20,000 to 50,000 plants per acre gives the best yields. 30” beds for high density planting 38” – 40” normal planting Plants are 3” to 8” apart.

Fertilization N, 80-120 lbs./ac P, 18-20 lbs./ac K, 18-20 lbs./ac Note; to much N can cause rank growth. Also amounts will depend on the soil type. In addition, 60% of the mineral nutrients are taken up between squares and boll formation.

Irrigation The goal is to keep 50% field capacity or higher through out the growing season. You will apply, depending on the soil texture, 2-3.5 acre feet per season. (normal 27” – 30”) A plant during peak season can take up to .25 - .45 of an inch of water a day.

Growth and Development Cotton matures 150 days after planting. It emerges 7-10 days after planting. Blooms early July. First bolls open mid to late August. Fibers length is fully developed in 18 – 21 days Note: to prevent rank growth one might apply a growth regulator such as; Pix, Mepex, Topit, Mepichlor, ect..

Cut out is determined by “NAWF” Nodes above White Flower “NAWF” Gin Turn Out Cut out is determined by “NAWF” Nodes above White Flower “NAWF” 5 for Acala 3.5 for pima Nodes above Cracked Boll “NACB” 4 nodes

Weed management Early season weeds reduce yields due to the competition for nutrients and light. Late season weeds cause problems in harvesting and quality. Common herbicides; Prowl, Poast, Lorax, Fusilade 2000, & Round-up in Round-up ready varities. Mechanical cultivation is a common practice.

Diseases Fursaruim Wilt Vericilium Wilt Bacterial blight Cotton-boll rots Root-knot nematode Root rot

Fursaruim Wilt

Vericilium Wilt

Bacterial blight

Cotton-boll rots

Root-knot nematode

Root rot

Insects Pink Bollworm Boll Weevil Aphid White Fly Lygus Mites

Pink Bollworm

Pink Bollworm

Cotton Bollworm

Boll Weevil

Western Yellowstriped Armyworm

Aphid

White Fly

Lygus

Mite

Harvesting Defoliation Why do we defoliate? Picking Modules How does the cotton picker work?

Ginning The cotton fibers are removed from the seed. There are two different methods used and they depend on the variety.

Grades of cotton Grades are determined on; Color Ginning preparation Maturity Leaf and other foreign matter There are 9 basic grades of cotton which are broken into 32 different grades

Quality Grades These are determined by; Fiber length (staple) measured by a fibrograph Length uniformity, measured by a high value instrument Fiber strength, measured by a high value instrument Fiber fineness and maturity, measured by a micronaire instrument. What is city cotton?

Cotton Grades & Grade Characteristics 1 Middling fair 2 Strict good middling 3 Good middling 4 Strict middling 5 Middling 6 Strict low middling 7 Low middling 8 Strict good ordinary 9 Good ordinary

Quality specification of cotton Staple Classification Fiber strenth Length uniformity Quality factor **look at Table 26-5**

Tools used to measure and grade cotton HVI = high value instrument, use to measure length uniformity and strength. Nickerson-Hunter colorimeter = this instument measures color and assigns a values Rd (light or dark) and +b (yellowness) Micronaire = the diameter of the lint fiber

Terms Square Boll Lock Lint Tagging Rank growth City cotton Cotton seed Seed cotton Linters Bale Nip Nap Hue Gin turn out Lint / lint + seed