Interference interactions of two rice cultivars and their F₃cross with barnyardgrass (Echinochloa crus-galli) in a replacement series study

Abstract

Barnyardgrass (BYG) has been the most frequently reported troublesome weed in rice because it is an aggressive invader, is difficult to control, and reduces yields significantly. A replacement series study was conducted to determine how a naturally suppressive cultivar (T65∗2/TN 1; ‘PI 312777’), a nonsuppressive cultivar (‘Lemont’), and an F3 cross between the two (‘PI 312777 × Lemont’) would interfere with BYG in the southern United States. The rice cultivars did not differentially affect BYG height. The PI 312777 produced more tillers and greater shoot dry weight but was only moderately competitive (relative yield [RY]) or aggressive (relative crowding coefficient) against BYG. Competitiveness at 2:2 rice and BYG mixture proportion and replacement series illustrations on RYs for the number of tillers and shoot dry weights for the three rice cultivars indicated that PI 312777 suppressed BYG growth relatively better than the other two cultivars. Plant-for-plant, PI 312777 was more competitive than Lemont. PI 312777 × Lemont suppressed BYG relatively less than did PI 312777 and therefore would require significant genetic improvements before it is suitable for commercial use in a reduced herbicide production system.

The Effect of Biochar on Native and Invasive Prairie Plant Species

“…RYT values less than 1 suggest there is mutual antagonism between the two species (Harper 1977;Radosevich 1987). The relative crowding coefficient (RCC), which serves as an index of competition when the two species are competing at equal proportions (Gealy et al 2005), was calculated at the 3 : 3 mixture using the following equation: [2]…”

Interference of allelopathic rice with penoxsulam‐resistant barnyardgrass

“…The importance of rice-barnyardgrass allelopathic interactions, as well as the mechanisms underlying such interactions, have been a major focus of non-herbicidal alternative barnyardgrass management in recent years. [18][19][20]23 However, most studies on interference of allelopathic rice with barnyardgrass have not clearly distinguished between herbicide-resistant and -susceptible biotypes. This study identifies penoxsulam-resistant and -susceptible barnyardgrass biotypes with the same genetic background from Chinese rice fields, and highlights allelopathic rice and the potential effect of its allelochemicals against penoxsulam-resistant barnyardgrass.…”

“…Attempts to control them have met with limited success. An increasing number of studies have shown that allelopathic rice cultivars release allelochemicals to interfere with the growth and establishment of coexisting barnyardgrass . Through the release of allelochemicals, allelopathic rice cultivars can suppress barnyardgrass and provide a competitive advantage for their own growth .…”

“…An increasing number of studies have shown that allelopathic rice cultivars release allelochemicals to interfere with the growth and establishment of coexisting barnyardgrass. 18 -20 Through the release of allelochemicals, allelopathic rice cultivars can suppress barnyardgrass and provide a competitive advantage for their own growth. 21 -23 It can be assumed that allelopathic rice interferes with the growth of herbicide-resistant barnyardgrass.…”

Interference of allelopathic rice with paddy weeds at the root level

“…In the last decades much effort has focused on the use of allelopathic rice cultivars as an efficient component of integrated weed management in paddy systems (Gealy et al . ; Kong et al . ; Pheng et al .…”