Adjacent Row Competition in Wheat¹

The effect of interplot competition on yield assessment in triticale trials

“…Similar results were also obtained for later experiments by AuSXIN et al (1985AuSXIN et al ( , 1986 where plots were orientated east-west (Table 3). JENSEN &FEDERER (1964) andFISCHER (1979) suggested that the effect of taller and shorter neighbours may not be complementary, the gain in yield of a tall variety when grown with shorter neighbours being greater than the loss in yield of a short variety adjacent to taller neighbours. In this case a two covariate model considered by KEMP-TON & LOCKWOOD (1984) would be appropriate.…”

“…It has long been recognised that intergenotypic competition between plants or singlerow plots in F2 or F3 populations of cereals inhibits direct yield assessment in these generations (BELL, 1963;JENSEN & FEDERER, 1964;MCGINNIS & SHEBESKI, 1968;HAMBLIN & DONALD, 1974;SNEEP, 1977;SPITTERS, 1979). In addition, interplot competition has recently been shown to lead to biased estimates of yield in trials with plots 1.5 m wide, particularly when varieties differ substantially in plant height (AusTIN & BLACKWELL, 1980).…”

Divergent evolution of wheat populations conducted under recurrent selection and dynamic management

“…This separation was related to the higher susceptibility to both diseases of PA-DMRI and to its higher percentage of bearded plants. 4 [16,19]. Yet, the increase in height was greater and more rapid in our populations than in the barley composite cross populations cultivated under comparable growing conditions [1,29].…”

Competition between cultivars of fodder kale (Brassica oleracea L.) in yield trials with single-row plots

“…However, when assessed in guarded plots, short and medium height kales can be identified that yield well in the 'pure stands' of modern farming. JENSEN & FEDERER (1964) also found that when they wanted to select semi-dwarf wheat cultivars from nurseries also containing standard height cultivars, it was necessary to change from single-row to multiple-row plots with the centre rows being harvested to avoid the misleading correlation, between plant height and plant yield, due to com- Fig. 1.…”