Division of Agronomy, Indian Agricultural Research Institute, New Delhi-110 012, India.
Present Address:1 Division of Agronomy, College of Horticulture, KAU P.O., Thrissur, Kerala-680 656, India.
The relative competitive abilities of wheat (Triticum aestivum L.) and winter wild oats [Avena sterilis ssp. ludoviciana (Dur.) Nym.] were studied by sampling at frequent intervals from a replacement series experiment at New Delhi, India. Wild oats was much slower to establish than wheat but thereafter exhibited a faster rate of growth. Wild oats was shorter than wheat in height in the early stages but at maturity it was taller than wheat by 27–34 em. Leafarea and dry matter production were also lower than wheat in the initial stages. Wild oats overtook or became equal to wheat in leafarea by 60 days after sowing (DAS) in both the years and in dry matter production by 75 DAS in the first year and by 90 DAS in the second year. For wheat and wild oats peak leaf area ratio (LAR) was at 60 DAS. The relative growth rates (RGR) of both wheat and wild oats were the maximum in the initial stages and declined as biomass increased. In general, wheat was having a relative yield of more than or equal to 0.5 in the initial stages and declined thereafter. However, wild oats at all the stages in both the years showed more than 0.5 or near equal values indicating its competitive edge over wheat. With regard to relative yield total (RYT), it was more than or equal to unity upto 60 DAS and thereafter declined.
