Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

After completing Units in this Lesson, you have learned to answer:

1. What is Striga?2. How striga affects chili crop?3. What cultural methods you practice to control

Striga?4. What chemical methods help in controlling Striga?5. What good husbandry practices you will adopt to

control Striga in chili crop?

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Striga is a very important weed in chili pepper cultivation.

Unlike other weeds, which compete for water and nutrients Striga, as a root parasite, literally sucks the life out of chili pepper plants. In doing so, growth is stunted and yields are greatly reduced.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

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.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

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

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Mauve flowered Striga

Red flowered Striga

Pink flowered Striga

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Small Striga seedscompared to sorghum and maize

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.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Striga plants emerge from the soil adjacent to chili pepper plants and produce many upright green stems with pink to white flowers.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Flowering can begin within 2 weeks and seeds begin to mature 2-4 weeks later. The seed capsules 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.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Striga Life-Cycle

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

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.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Control measures

Cultural control: It has been noted that chili pepper 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.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

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.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

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, chili pepper is vulnerable to stalk twisting and lodging if 2,4-D is sprayed into the leaf whorl. Spraying should only be done trained labor and cautioned to the hazards.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

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 resistant chili pepper varieties.

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Abutilon indicumIndian mallow

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Alysicarpus sp.One-leaf clover

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Argemone mexicanaMexican poppy

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Celosia argentinaWhite cock's comb

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Borreria articularisButton plant

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Cleome sp.Wild spider flower

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Digera arvensisKundra

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Corchorus olitoriusJew's mallow

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Euphorbia purvifloraEuphorbia hirta

Spurge

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Portulaca oleraceaCommon purslane

Portulaca pilosa

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Vernonia cinereaLittle iron weed

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Leucas asperaDronapushpi

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Xanthium strumariumCocklebur

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Amaranthus spp.Pigweed

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Anagallis arvensisScarlet Pimpernel

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Bidense pilosa Spanish needle

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Mollugo verticillataCarpet-weed

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Commelina spp.Benghal dayflower

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

False daisy

Eclipta albaEclipta prostrata

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Ipomea spp.Morning glory

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Tridax procumbenceTridax daisy, wild daisy

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Chloris barbataSwollen Finger grass

Chloris gayanaFeather Finger grass

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Digitaria sanguinalisCrabgrass

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Dactyloctenium aegyptiumCrowfootgrass

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Echinocloa spp.Barnyard grass

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Paspalum distichum.Water couch

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Eleusine indicaGoose grass

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Eragrostis spp.Lovegrass

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Setaria spp.Foxtail

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Cyperus rotundusPurple nut sedge

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Cyperus compressus Nut sedge

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Cyperus defformis Nut sedge

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Cyperus esculantusYellow nut sedge

Module IX: Weeds and Weed ControlLesson 1: Weeds and Weed Competition in Chili Pepper

Unit 3: Striga

Cynodon dactylonBermuda grass