An investigation into the relations between some growth parameters and yield of barley

Abstract

S U M M A R YTwenty-five field experiments on barley were done at four sites from 1970 to 1975, with an additional site in 1975, comparing five rates of nitrogen application. The crops were sampled at c. 14-day intervals from about the four-leaf stage to maturity to follow changes with time in the dry weights of the constituent plant parts and to measure fertile tiller number, grain number per ear and grain weight. Some data have been selected from this body of information and regression analysis has been used to assess the possible importance of pre-and post-anthesis growth in determining the yield of barley. Ear emergence was taken as an approximate indicator of anthesis. Yield was closely related ( r = +0*96) and almost equal to the amount of dry matter accumulated before ear emergence for twenty-one of the experiments, with a regression coefficient of 0'95. I n two of the remaining experiments the regression coefficient was greater, 1-14; and smaller in the other two, 0.81. Plant population is also shown to affect the regression coefficient. Despite these anomalies grain yield was more closely related to plant dry weight at ear emergence than to the increase in weight after ear emergence ( r = +0-79). The increase in plant dry weight after ear emergence was frequently less than the yield of grain, suggesting that the plant can compensate for inadequate photosynthesis during grain filling. The result of this compensation is a reduction in straw dry weight. This implies that previously assimilated dry matter is transported to the grain, or that respiratory losses from the straw are not replaced by current photosynthesis. These observations suggest that yield may be limited by sink capacity rather than by photosynthesis after ear emergence. The main component of sink capacity, grain number per m2 was closely related to yield ( r = +o95) and is known to be determined at or before anthesis. Grain size was shown to be related to grain number per ear ( Y = + 0*99), suggesting that grain size is also, at least partially, determined at ear emergence. Therefore, all the yield components are determined, wholly or partly before ear emergence. I N T R O D U C T I O NA programme was initiated in 1969 to intensify studies on the responses of arable crops to management, soil type and environmental factors. I n particular, information was required concerning the factors which cause variation in response to fertilizer, and hence affect the validity of fertilizer recommendations. The first requirement of 405-422.

The relation between grain yield and some related traits of spring barley (Hordeum vulgare L.) and their usefulness in a breeding program

“…In all the experiments, significant correlations were present between grain yield and number of grains/m 2 and harvest index, thus confirming the results obtained by Gallagher et al (1975) and Dyson (1977). Grain weight was shown to be a very stable trait, but its contribution to grain yield was small.…”

“…Contrary to Dyson (1977), dry matter yield at anthesis did not predict grain yield. The suggestion of Russell & Ellis (1988), that the amount WSC in the dry matter at anthesis might be a good predictor for the number of grains/m 2 proved not to be true in this study.…”

“…Dyson (1977) comparing two barley varieties in 25 field experiments found a very high correlation between dry matter yield at anthesis and grain yield (r = 0.96). The number of grains, which is set at the time of anthesis, was related to the crop weight at anthesis.…”

“…The relationship between grain yield and yield components in barley has been investigated by many authors; They have demonstrated that the yield of barley was more strongly correlated with the number of grains/m 2 than with individual grain weight (Gallagher et al, 1975;Dyson, 1977). Dyson (1977) comparing two barley varieties in 25 field experiments found a very high correlation between dry matter yield at anthesis and grain yield (r = 0.96).…”

Genetic improvement of spring barley cultivars grown in eastern Canada from 1910 to 1988

“…The objectives of this experiment were 1) to estimate the genetic gain in yield for cultivars of sixrowed spring barley released in Quebec since the (Dyson, 1977) . At that time, a 1-m long section of a single row was randomly selected, handharvested and used to determine total aboveground biomass and N. At maturity, another 1-m long section of a single row was randomly selected, handharvested and used for yield component analysis and determination of dry matter and N accumulation.…”