- The pathogen affects the crop at any stage of crop growth.
- Three different types of symptoms are commonly noticed in Amaranthus grown in Kerala.
- Wilt: The plants show yellowing withering and drooping of leaves. The vines show blackening and drying. The roots show rotting and blackening.
- Basal swelling: The affected Amaranthus plants became stunted and weak .The base of the stem swells up to the size of a small cassava tuber. The taproot and lateral roots are affected. The basal swollen portion becomes disintegrated and shredded.
- The stem, leaf petioles become flattened. The flowers show fasciation and sterility.
The pathogen is seedborne and soilborne. High temperature and high moisture or relative humidity is congenial for disease development.
Assess the number of plants affected by observing 25 pits at random.