A life cycle of Cotton The life cycle of Cotton contains seed germination and sprouting from the first, roots and stems and leaves growth, and branches emerging and elongating, Based on the grawth of vegetative orgems,reproductive orgems formation and deuelopment,such as flower bud differentiation, budding, flowering, boll enlarging, and boll opening and cotton seeds mature. According to organs forming sequence and development process,cotton growing periods can be divided as five stages:seed sprouting, seedling, bud, flowering and boll forming and boll opening stages.
Sowing seeds and raising seedlings in nursery pots sprouting stage Transplanted seedlings
hybrid cotton seed production hybrid cotton seed production: In simple term ， hybrid cotton seed production indicates that before the flowers of female parent bloom, remove their stamens and corolla and then pollinate their stigmas with male parent’s pollens, finally the female parent bolls produce hybrid F1 seeds.
Mother line ♀ Father line ♂ Simple diagram of hybrid cotton seed production
Early management and operation procedures in hybrid cotton seed production Seedbed management and roguing Transplanting Seedling stage management Bud stage management Flowering and boll forming stage management Cotton harvest and cotton ginning Natural conditions Field selection Preparation of nutrient soil Parents seed selection and treatment Sowing Field preparation 8 10 12 11 1 4 3 2 7 6 5 9 An important part of blossoming and boll forming stage ——artificial pollination
1.Natural conditions Tilling soil layer Subsoil layer ZincBoronSulphurManganeseMolybdenum PH value Organic mater Total N Active P Active K
1.Natural conditions Water requirements: it need rainfall 450- 600mm during growing period; Light requirements: Compensation point :1000-2000lux; Saturation point :70000-80000 lux. Temperature requirements : 14 ℃ -35 ℃, the optimum 25 ℃ -30 ℃.
2 、 F ield selection Fertile soil, flat, no shadow, located leeward; contiguous vast plot, convenient irrigation and drainage, disease-free The requirements of fields ：
3. preparation of nutrient soil Prepare 6.5-7MT nutrient soil for one hectare seedbed, mix with 30kg compound fertilizer, and then water the soil 15 days ahead seed sowing. Compound fertilizer
4. Parent seeds selection and treatment Select plump, vigorous and intact seeds One day before sowing: soak the seeds with water solution of 150mg/kg DPC and 70% imidacloprid 500mg/kg for 8 hours. One kg water solution can soak 2 kg seeds. Soak seeds
5. Sowing Include ： Preparation of Nutritionpot; Filling nutrient soil in nutritionpots and watering advance; Dibble seeding; Earthing the seeds with nutrient soil; covering the seedbed with polythene membrane
5. Sowing 5.1 Nutritionpots Prepare 33000 plastic cups per hectare that each cup has a small hole at the bottom ( Making nutrition bowls for nursery )( plastic cup for nursery )
5. Sowing 5.2. Filling soil and watering filled with soil water the soil one day before sowing
5. Sowing 5.3. Dibble seeding a. Make a hole in the central of bowl (if the bowl is a plastic cup) b. Put a seed (bigger side upwards) in the hole Keep water holding capacity of the soil at about 80% Before sowing Sowing male parent seeds 3-5 days earlier than female parent
5. Sowing After sowing, cover the seeds with a layer of 1.5cm depth fine soil, press the soil slightly, then cover with plastic membrane to keep proper moisture. If the temperature is too high, sunshading nets is needed. 5.4 Earthing the seeds and covering embrane
6. Field preparation 6.1 Furrow and ridge a. Deeply plough the land and harrow the soil; b. Dig ditches every 190cm and make ridges for cotton seedling transplanting; c. make 2 trenches on each ridge for fertilizer applying. Space 190cm ditches
6. Field Preparation 6.3 Chemical weeding a.We can spray 48% Trifluralin 1500-1875g/hm2 on the surface of soil before transplanting ； use in early time Trifluralin
7. Seedbed management and roguing off-type 7.1 Seedbed management The main work is spraying chemicals to prevent diseases and pests Carbendazol,Furandan,Tachigaren
7. Seedbed management and roguing off-type 7.2 Roguing off-type b. When the seedlings are at 1.5 leaves stage, spraying kanamycin solution 8000mg/kg for roguing off-type (the plants will become yellowish and die after 5 days) a. Female parents ： identify and remove the off-type plants by the appearance of shape (such as hair and color of stem) during seedling and bud stages kanamycin Off-type plants
8. Transplanting Applying compound fertilizer 225kg/ha before transplanting. Start transplanting from 2.5 leaves stage. Timely watering after transplanting
8. Transplanting Row spacing &plant spacing of female plants (F) and male plants (M) Transplant Male plants 3-5 days earlier than female parent with the row and plant spacing 70cm: 45cm, and female plants spacing is 95cm: 45cm. Area ratio of Male and female parents is 1:7-8. Check and fill the vacant place in time after transplanting. F row to row space Plant to plant space M row to row space
9. Seedling stage management 9.1 Fertilization and watering Apply less quantity fertilizer for 1-2 times after the seedlings recovered: spot applying solution of urea apart 10-13cm from the seedlings, per acre land need urea 24 to 30 kg. Repeat once if necessary.
9. Seedling stage management 9.2 Disease and pest control Mainly prevent aphids, thrips and other pests in the seeding stage aphids thrips
10. Bud stage management 10.1 Bud stage Fertilization When bud appears in cotton plant, apply decomposed cake fertilizer 240-300kg, potash 60 kg and compound fertilizer 150 kg. Caution: do not use quick-acting nitrogen such as urea from the budding stage till to early flowering. After fertilization, taking soil to make ridge at the base of seedlings to prevent plant lodging and waterlogging. 10.2 Ridging and molding
10. Bud stage management 10.3 Pruning in time Remove vegetative shoots, redundant branches and buds at the bottom to create a fruitful frame. If seedlings density is low, remain 1-2 vegetative shoots to cover vacant space. Apply DPC 30g/hm2 to prevent buds shattering and over- flourishing of the seedlings after budding according to the weather and seedling conditions DPC 10.4 Chemical control
10. Bud stage management Cotton is a kind of often cross- pollinated crop, parental mutations usually occurs. During bud stage, off-type features are visible, roguing work should be done in time according to plant type, leaf shape, boll-shape or the number of stem villi, ability of insect and disease resistance etc. 10.5 Roguing
10. Bud stage management 10.6 Pests control Control of aphids, cotton bollworm, blind stinkbug, corn borer and other harmful pests in the bud stage Aphid Cotton bugs Corn borer Cotton bollworm Aphids
11. Management during the flowering and boll forming stage 11.1 Topdressing in flower-boll stage a. Ploughing near cotton plants and applying fertilizer after the first boll form (boll diameter 2cm ). Apply urea 225kg/hm2, phosphate fertilizer 600kg/hm2, potassium fertilizer 225kg/hm2, Granubor (boron) 1-2 bags b. Apply urea 150kg/hm2 after 15- 20 days of previous topdressing according seedling condition; c. Later period topdressing is spraying water solution of urea and KH2PO4, once a week.
11. Management during the flowering and boll forming stage 11.2 Proper chemical regulation ● According to the weather and seedling condition, use regulator 2-3 times from initial flowering to topping stage. 5-7 days after topping, apply 25% DPC 20-25ml/hm2 for capping (final regulation). ● Remove the tops of plants and tips of downside branches to eliminate the top superiority when fruit branches reach 20-21 per plant or in the mid- October 11.3 Remove tops
11. Management during the flowering and boll forming stage 11.4 Diseases and pests control Mainly prevent cotton bollworm: biological control and ecological chemical is the main treatment in earlier stages; organophosphorus insecticide and chrysanthemate pesticide are the main chemicals during later stages, spraying such pesticides every 5-7days, joined by manual seizing of aged larvae. bollworm Ecological pesticide Organophosphorus insecticide
11. Management during the flowering and boll forming stage An important part of flowering and boll forming stage ——artificial pollination ● What is artificial pollination? ● how to do it?
Artificial pollination Pollination time Preparation before Pollination Ways and means of emasculation and pollination Pollination notice Inspection personnel requirements
Artificial pollination 1. Preparation before Pollination Color thread sieve Pollination bottle Cloth bag forceps a.50-60 employees needed per hectare land. Reserve fingernails 10days ahead b.Preparation for pollination work c.Before the date of pollination, remove vegetative branches and new redundant branches and shoots of female plants; Check and ensure removing all the existing cotton bolls and flowers in the morning of emasculation. d.The due pollination time is tentatively scheduled around in September 1st
Artificial pollination 2. Ways and means of emasculation and pollination b. Object of emasculation ： corolla of rapid elongation of the female parent a. Time of emasculation ： every 1:00 pm to next 5:00 am Bloomed female bud is forbidden for emasculation.
Artificial pollination c. Emasculation ： insert forceps or thumbnail into a crown base, remove the corolla and anther around the ovary. No anther left, no injury to the bract, ovary and stigma. All removed anthers taken out of the field 2. Ways and means of emasculation and pollination
Artificial pollination a. Pollen collection requirements ： collect anthers together with the corolla from male plants’ flowers 4.Pollen collection male Sieve the pollen out and collect them into vials for pollination
Artificial pollination 4.Pollen collection b. Issues for pollen preservation If the next day may rain, fetch the male plant ready-flowering buds in advance, and store them in refrigerator at 10-15 ℃. Weather forecastFetch male bud Cold store
Artificial pollination 4. pollination Every sunny day, start pollination after dew dried, about 9:00 am
During rainy season, one end closed tube should be used to protect the post-emasculated stigma and to prevent subsequent pollination failing from rain soaking 。 The next day, remove the bloomed buds and take out of the field before emasculation. 5. Pollination notice Artificial pollination
（ NOTE: The pollens would lose activity if the pollens of male parent blooming flowers were soaked by rain, or pollinated pollens on stigma met rainwater within 2 hours. Therefore, we should pay attention to the weather: If the next day may rain, fetch the male plant ready- flowering buds in advance (the night or next early morning), and store them in refrigerator at 10-15 ℃. Artificial pollination 5. Pollination notice Pollinate after the drew on the stigma dried
Artificial pollination ● Remove all non-emasculated flowers and self-pollinated bolls on the female plants in time, including those resulted by consecutive rainy days ● Cut off new branches after the pollination period 5. Pollination notice
Suffered by high temperature and dry weather, the pollen number of male flowers will be lessened, spraying water or irrigating in time could reduce temperature and increase the pollens. Artificial pollination 5. Pollination notice
Artificial pollination 6. The duty of the inspection staff 5:00-7:00 AM check emasculating condition of the previous day, examine by monitoring points. 7:00-9:00AM check and clear white and red flowers and the quality of previous pollination, Remove red and white flowers in time before pollination to prevent self-crossed bolls. Clearance standard: no white and red flowers exist in seed production fields before hand-pollination
First, check whether the pollination is sufficient and uniform. (Observe the pollen on the stigma) Artificial pollination Second, check whether buds kept un-pollinated. Check the quality of pollination 6. The duty of the inspection staff
19 、检验人员工作要求 Afternoon (15:30-18:30): Check the quality of emasculating and situation of removing self-crossed boll. Artificial pollination 人工授粉棉桃 自交成桃 6. The duty of the inspection staff Female Emasculation Hand-pollinated boll Self-pollinated boll Bract Hand-pollinated Boll Self-pollinated Boll
First, whether the emasculation of the buds is perfect. Anther can not be left. The removed corolla and stamens should be taken out of the field and destroyed. Second, whether the emasculation of the fields is thoroughly. Emasculate all the buds which will bloom on the next day. Check the quality of emasculation ： Artificial pollination 6. The duty of the inspection staff
● Inspection staff must urge the workers to remove the self-pollinated bolls all the time, and check before and after the work. 3-5 days after the pollination and removing, inspection staff check and accept it. Rate of self- pollinated bolls (include flowers and buds) in the seed field must be less than 0.1%. Artificial pollination ≤ 0.1% 6. The duty of the inspection staff
23 、授粉结束 The pollination would be probably end on November 1st. Remove male plants after completing the whole pollination work; cut away the tops of female branches and spray water solution of DPC 80-120g per hectare. Clear the later flowers and buds continuously for 10days.
12. Cotton harvest and cotton ginning a. Harvest cotton every 7 days after cotton boll opened. b. Sundry the cotton, remove out rotten and rigid pieces. Amass ginning after cotton dry. 12.1Cotton harvest 晒 花晒 花 Harves t Picking
Ginning machine of more than 40 sheets of saw tooth ? are used for cotton ginning. Ensure the seed broken rate is less than 2%, percentage of healthy seeds is above 85% and germination is above 72% 12.2 Examination of cotton ginning 12. Cotton harvest and cotton ginning