Factors Affecting Postdispersal Weed Seed Predation in Barely Fields

Abstract

Seed predation can be exploited as a mean of natural weed control. Field experiments were conducted in 2007 in four barely fields in Mashhad, NE of Iran to determine the effects of seed covering tissues, seed distribution patterns and interactions between seed density and background seed density on postdispersal seed predation. Five weed species (Avena ludoviciana, Hordeum spontaneum, Sinapis arvensis, Rumex obtusifolius and Rapistrum rugosum), three seed densities (50, 100 and 150 seed dish-1), two background seed densities (with and without), three distribution patterns (random, even, and aggregate), and two level of seed covering tissues (with and without) were arrange in a factorial randomized complete block design. Seed covering tissues had significant negative effect on predation and the most its effect was observed for H. spontaneum. Seed predation was also affected by seed distribution patterns. The highest and lowest seed predations of all species were observed from aggregate and random treatments respectively. The interaction between density and background seed density affected seed predation. Results show that seed predation can play an important role in decreasing the weed seeds on the soil surface and thus, in soil seed bank. Therefore, seed predation could be considered as a control technique in integrated weed management.