The effect of temperature and growth density on the development and yield of two- and multi-rowed barley varieties

Abstract

Abstract. The effects of temperature and plant spacing on growth, on the distribution of biological mass within the plant, and on yield were studied with seven barley varieties at two temperatures, 10°C and 20°C, and two growth densities, 3 and 13 plants per pot.Vegetative development at 20°C was nearly twice as fast as at 10°C. After the plants had entered the reproductive phase, the difference in developmental rate became smaller. Plants grown at the lower temperature produced much higher total biological yields and grain yields than plants grown at the higher temperature. Percentage proportion of leaves was higher and proportion of culms lower at 20°C than at 10°C.Temperature had no significant effect on number of culms and 1000-grain weight. Number of grains per ear was higher at 10°C than at 20°C.Total biological yield per pot and grain yield per pot were larger when the plants were grown in dense populations. More culms and larger yields per individual plant were produced in sparse populations. Growth density did not affect the number of grains per ear. Length of ear and 1000-grain weight were larger in sparse than dense populations. Two-rowed barley varieties gave significantly higher total biological yields and slightly higher grain yields than multi-rowed varieties. There were no differences between the two types of barley in proportions of leaves, culms and roots. As expected, number of culms and 1000-grain weight were higher, and number of grains per ear was lower, in the two-rowed than in the multi-rowed varieties.Among the various yield components, number of culms explained most of the yield. The number of grains per ear explained a smaller proportion, and 1000-grain weight a larger proportion, of the yield of the two-rowed varieties than of that of the multirowed varieties. In both types of barley there was a significant positive correlation between number of culms and 1000-grain weight. The number of grains per ear was not correlated with the number of culms; neither was it correlated with 1000-grain weight. There were differences between the two-row and multi-row types in correlations between culm numbers, leaves and roots. The distribution of biological yield between various plant parts in different phases of development did not affect the grain yield.

Yield composition of two-rowed and multi-rowed barleys in drilled and single-plant populations in southern and northern Finnish experiments

“…In accordance with previous greenhouse experiments with the same material (Äyräväinen and Paatela 1974) there is no evidence from the field trials either that varietal differences in distribution of biological mass between different plant parts were reflected in varietal differences in grain yield. As in greenhouse, Tammi clearly was the least leafy variety in the field as well, and Porno had a higher than average proportion of leaves especially in the late stages of development.…”

“…Low temperature has been found more beneficial than high temperature to the production of both biological and grain yields of barley (Guitard 1960, Paris and Guitard 1969, Äyräväinen and Paatela 1974. Since there were only slight temperature differences between the localities Viikki and Muhos in 1971 and 1972, the reasons for the larger biological and grain yields from drilled trials at Muhos as well as for some other differences between the results of the experiments carried out at the two localities must be found elsewhere.…”

Effects of a dicamba/MCPA/mecoprop herbicide mixture on the leaves of a barley variety

“…The optimum temperature for barley is much below 20°C (Äyräväinen and Paatela 1974), which makes barley more capable of resisting the effects of herbicides at lower temperatures than at higher ones, and therefore it also needs then longer to become injured. In addition, the present observations suggest both at light and electron microscope level that the cells of vascular bundle sheath are very strongly altered by the herbicides also at low temperature.…”