Germination Biology and Seedling Emergence of Amaranthus blitoides as Influenced by Temperature, Light, and Burial Depth

Abstract

Amaranthus blitoides is an aggressive annual weed species that has become increasingly problematic in agricultural systems due to its rapid growth, prolific seed production, and strong adaptability to diverse environmental conditions. Understanding the germination ecology and seedling emergence behavior of this weed is essential for developing effective management strategies. The present study investigated the effects of temperature, light, and seed burial depth on the germination biology and seedling emergence of Amaranthus blitoides. Laboratory and greenhouse experiments were conducted under controlled environmental conditions using different temperature regimes, photoperiod treatments, and soil burial depths. Germination percentage, germination rate, emergence percentage, and seedling vigor were evaluated to determine the ecological requirements of the species. The results demonstrated that temperature significantly influenced seed germination, with maximum germination observed under moderate to high temperature conditions, indicating the thermophilic nature of the weed. Light exposure positively affected germination, whereas reduced germination was recorded under complete darkness, suggesting partial photoblastic behavior of the seeds. Seed burial depth also had a significant effect on seedling emergence, with the highest emergence recorded from seeds located near the soil surface. Increasing burial depth progressively reduced seedling emergence due to limited energy reserves and restricted seedling growth through the soil profile. The findings indicate that environmental factors play a critical role in regulating the establishment and spread of Amaranthus blitoides in crop production systems. Understanding these ecological responses provides valuable information for designing integrated weed management practices, including tillage and cultural control strategies aimed at reducing weed emergence and persistence in agricultural fields. Effective management of this weed species can therefore contribute to improved crop productivity and sustainable agricultural production.