1. After completing 3 Units in this Lesson, you have learned to answer: 1.Why weed control is important in pearl millet crop? 2.When is the critical period for weed competition in pearl millet crop? 3.Name few important broadleaf weeds in pearl millet crop? 4.Name few important grass weeds in pearl millet crop? 5.Name few important sedges that compete with pearl millet crop? Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control

2. After completing 3 Units in this Lesson, you have learned to answer: 6.What is Striga? 7.How striga affects pearl millet crop? 8.What cultural methods you practice to control Striga? 9.What chemical methods help in controlling Striga? 10.What good husbandry practices you will adopt to control Striga in pearl millet crop? Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control

3. The 3 Units in this Lesson are: Unit 1: Weed Competition in Pearl Millet Unit 2: Weeds in Pearl Millet Unit 3: Striga Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control

4. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Striga is a very important weed in pearl millet cultivation. Unlike other weeds, which compete for water and nutrients Striga, as a root parasite, literally sucks the life out of pearl millet plants. In doing so, growth is stunted and yields are greatly reduced. Pearl millet plant infested by Striga

5. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Striga has been given the common name of "witchweed" because of attaching to the roots and robbing the host of water and nutrients. Striga infested pearl millet field

6. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga There are different species of Striga. The Striga found in India is most often has white flowers. But, Striga plants with yellow, pink or purple flowers are also common. White flowered Striga

7. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Mauve flowered Striga Red flowered Striga Pink flowered Striga

8. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Depending upon the extent of infestation, 30-60% of reduction in grain yield can occur. Striga infestation is most severe in low moisture and low fertility soils. Thousands of very small seeds are produced by a single plant of Striga. These seeds can remain dormant but viable for many years. Small Striga seeds compared to sorghum and maize

9. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Striga plants emerge from the soil adjacent to pearl millet plants and produce many upright green stems with pink to white flowers.

10. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Flowering can begin within 2 weeks and seeds begin to mature 2-4 weeks later. The seed capsules (Fig.) may contain 400-500 seeds and a single plant may produce 20,000 seeds. Mature seeds are dispersed by wind, rainwater, cultivation, soil on tools, or even grazing and manure fertilization.

11. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Striga Life-Cycle

12. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Control measures Physical control: Hand pulling at too early stage may break the shoot and reduce the rapid growth. Sparse infestation should be hand pulled shortly before flowering to prevent build up of seed. Such hand pulling should continue through to harvest and beyond so long as flowering is occurring.

13. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Control measures Cultural control: It has been noted that pearl millet plant shading can restrict Striga growth when generous soil fertilizer is applied. In areas of high rainfall, factors such as high plant populations, recommended fertility levels, and good weed control encourage lush crop growth and shading in spite of Striga parasitism. This is not feasible in moisture stressed rainfed areas.

14. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Control measures Cultural control: Crop rotation should be practiced with trap crops which stimulate Striga seeds to germinate without themselves being parasitized. Crops claimed to be effective include: cotton, sunflower, groundnut, castor, dolichos bean, and linseed. Unfortunately once a severe infestation has developed, it may take many years to reduce Striga population in the field to non-damaging level.

15. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Control measures Chemical control: As Striga is a broadleaf plant, pre- plant herbicides such as Atrazine, Goal, and Flex show some effect though not efficient enough to be justified. Post-emergence use of 2,4-D is effective when sprayed on the Striga leaves. Though low in cost, pearl millet is vulnerable to stalk twisting and lodging if 2,4-D is sprayed into the leaf whorl. Spraying should only be done by trained labor and cautioned to the hazards.

16. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Control measures In summary, control of Striga infestation is difficult and requires an integrated approach. Non-host crops must be rotated (for two years in heavily infested fields) with pearl millet varieties.

17. Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control Unit 3: Striga Control measures Following good practices will help reducing striga effect in pearl millet crop: plant populations and fertility adjusted for soil moisture availability to maximize shading, weeding and Striga control through hand pulling and perhaps limited 2,4-D spraying, and finally take care not to spread seeds of Striga though fodder, manure or contaminated soil on tillage tools.

18. The Unit 3 on Striga, and also this Lesson 1 on weeds and weed competition in this Module concludes. The last Lesson in this Module IX is about strategies for controlling weeds in pearl millet cultivation. Select Lesson 2 from Module IX contents Virtual Academy for the Semi Arid Tropics Lesson 1: Weeds and Weed Competition Course on Pearl Millet Production Practices Module IX: Weeds and Weed Control