Best Viewed in Mozilla Firefox, Google Chrome

23
Jun

Environmental factors Influencing Weed Competition

 1. Depending on the rice variety used, competition for light appears to intensify as the weeds grow taller than the rice crop. With decreased light transmission ratio in dry seeded rice. 

2. Grassy weeds and sedges become more competitive for solar energy than broad leaved  weeds, while in wet-seeded rice, the competitive effect of Echinochloa on tillering of rice is  the main factor in reducing the yield.  

 

23
Jun

Soil factors Influencing Weed Competition

 1. Many soil factors modify weed competition, while soil nutrient status, influences the nature and duration of competition in dry seeded rice. 

2. Usually, weeds grow better under adequate levels of nutrients, thus making them more competitive, indicating that weed control becomes more important with increase in fertilizer application.

 

23
Jun

Factors Influencing Weed Competition

 

 1. The competition between crops and weeds is mainly through the capture and utilization of resources and depends on time of germination, rate of growth of the plants and the spatial arrangement of their  foliage and roots.

2.  Limiting resources during the reproductive phase may also negatively impact yield but, more typically  reduces grain quality and yield stability. 

3. Therefore, the competitive ability of a weed may be viewed as the ov

23
Jun

Why is the type of weed important?

 

Ability to identify the weeds is important, as it helps determine the expected level of the damages and problems caused by the weeds vary in the extent to which they can reduce yield and or quality.

1. Tells extent of potential yield loss e.g., weedy rice 70% loss, Sesbania 19% loss.

2. The type of weed can also tell you about the field and its management.  For      

    example,  the presence of Ipomoea aquatica indicates prol

23
Jun

Weed flora associated with different systems of rice culture

 

The major weeds of rice fall into three categories: 

1. Broad leaved weeds - characterized by broad leaves with a network of veins.

2. Grasses: characterized by long narrow leaves, parallel veins, a hollow stem and leaves aligned in two rows on the stem.

 3. Sedges: characterized by three rows of leaves on the stem and a solid, triangular stem. 

 

Copy rights | Disclaimer | RKMP Policies