Effect of nitrogen fertilizer on growth and yield of semi-dwarf and tall varieties of winter wheat

Abstract

Eight amounts of nitrogen ranging from 0 to 210 kg N/ha were applied to two tall and one semi-dwarf variety of winter wheat in the spring of 1975 and 1976. The tall varieties were Cappelle-Desprez and Maris Huntsman; the semi-dwarf variety was Maris Fundin in 1975 and Hobbit in 1976. Interactions between varieties and nitrogen were few and small compared with the main effects. All varieties produced their maximum grain yields with 180 kg N/ha. The yield of the semi-dwarf varieties, but not the others, decreased slightly with more nitrogen.Cappelle-Desprez yielded less grain than the other varieties in both years. In 1975 the yields of Maris Fundin and Maris Huntsman were similar and in 1976 Hobbit yielded more than Maris Huntsman. The varieties had similar numbers of ears at maturity and similar patterns of tillering. The semi-dwarf varieties had most grains per spikelet, and hence grains per ear, and Cappelle-Desprez had least. The semi-dwarf varieties had the smallest grains. The semi-dwarf varieties had less straw than the other varieties and hence the largest ratios of grain to total above-ground dry weight. The decrease in dry weight of stem and leaves between anthesis and maturity was similar for all varieties. In 1975 the efficiency of the top two leaves plus top internode in producing grain was the same for all varieties, but in 1976 Hobbit was more efficient than the other two. There were some small differences between varieties in nutrient uptake that were not related to differences in growth. Maris Fundin tended to have a greater phosphorus and potassium content than the tall varieties. Hobbit contained slightly less nitrogen than the tall varieties at maturity, and had a smaller concentration of nitrogen in the grain.Applying 210 kg N/ha doubled grain yield in 1975. Applying nitrogen resulted in a large increase in number of ears and a small increase in number of grains per ear due to the development of more fertile spikelets per ear. Nitrogen decreased dry weight per grain, especially of the semi-dwarf varieties. With extra nitrogen, straw dry weight at maturity, shoot dry weight at anthesis and leaf area were all increased relatively more than grain yield, and stems lost more dry weight between anthesis and maturity than without nitrogen. The year 1976 was exceptionally dry and nitrogen had only small effects in that it affected neither straw dry weight nor number of ears but slightly increased grain yield by increasing the number of spikelets and number of grains per spikelet. It also increased leaf area proportionately to grain yield. In 1975 nitrogen increased evaporation of water from the crop before anthesis but decreased it after anthesis, even though it continued to increase the extraction of water from below 90 cm.

Effects of tillage systems in durum wheat under rainfed Mediterranean conditions

“…Under favourable growing conditions, starch and protein build up simultaneously and protein content may vary by ±2% (Pearman et al 1978;Halloran 1981). Water stress and high temperature during the grain-filling period hinder the conversion of sucrose into starch but have less effect on protein formation (Brooks et al 1982;Bhullar and Jenner 1986).…”

Cultivar differences in nitrogen translocation in wheat

“…Numerous reports have been made of an inverse relationship between grain yield and protein content in wheat (Haunold et al 1962; Thorne and Blacklock 1971 ;Pearman et al 1978). This inverse relationship most probably arises from competition between the demands of protein synthesis for carbon, most likely as carbohydrate, and those of normal catabolism for carbon frameworks in the form of organic and keto acids (Steward and Durzan 1965).…”

Effect of nitrogen and application ways of a plant biostimulant on different wheat genotypes contrasting in stature

“…SylvesterBradley and Kindred (2009) evaluating efficiency of N use and harvest index of this nutrient, explain that there are few data available about N use in cereals different genetically, however it is known that since the introduction of semi dwarf plants, these values have been modified. Pearman et al (1978) applied eight N doses in wheat plants, tall and semi dwarf, and observed that in plants with dwarfism gene, higher N doses promoted decrease in the variables evaluated, when compared with tall plants.…”