GROWTH, YIELD AND NITROGEN UPTAKE OF AWNED AND AWNLESS WHEAT (Triticum aestivum L) AS AFFECTED BY NITROGEN AND ROW-SPACING

GROWTH, YIELD AND NITROGEN UPTAKE OF AWNED AND AWNLESS WHEAT (Triticum aestivum L) AS AFFECTED BY NITROGEN AND ROW-SPACING

Abstract:

Two field experiments were conducted at the Irrigation Research Station, Kadawa, Nigeria, during the 1989-90 and 1990-91 dry seasons, to investigate the effects of t w o wheat varieties (Siete Cerros and Florence Aurore 8193), three rowspacings (10, 20 and 30 cm) and four nitrogen levels (0, 60, 120 and 180 kg N ha”1) on crop growth, yield, yield components and nutrient uptake and also to investigate the effects of t w o varieties (Siete Cerros and Florence Aurore 8193), three nitrogen levels (60, 120 and 180 kg N ha”1) and three times of nitrogen application (seeding, seeding + tillering stage and seeding + flag leaf stage) on yield components and grain crude protein content. Variety Florence Aurore 8193 produced significantly more tillers, taller plants, greater leaf area and leaf area index and more dry matter than Siete Cerros. Even though the total dry matter accumulated by both varieties increased with crop age till maturity, leaf and stem dry matter decreased after 70 days after sowing (DAS) while spike dry matter continued to increase till crop maturity. The proportions of dry matter in leaf, stem and spike at maturity were 9, 40 and 51 per cent for Siete Cerros and 9,49 and 43 per cent for Florence Aurore. Siete Cerros significantly excelled Florence Aurore in number of grains per spike and grain yield. Florence Aurore however produced grains with higher 1000-grain weight and also had greater N uptake than did Siete Cerros; but the former significantly greater spike N uptake than that of Siete Cerros. Leaf and stem N of both varieties decreased after 70 DAS while spike N continued to increase till crop maturity. Total uptake of N, P, K, Ca and Mg at harvest was signifi-cantly higher in Florence Aurore than in Siete Cerros. Spike uptake of N, Abstract viii P, K, Ca and Mg was highest followed by that of stem and leaf. Florence Aurore produced grains with significantly higher crude protein content than Siete Cerros. The 20 and 30 cm row-spacings gave the highest grain yield which were was significantly better than the 10 cm row-spacing. Dry matter accumulation, nutrient uptake and their distribution into component plant parts were greatest at the 20 cm row-spacing. Grain yield and dry matter accumulation increased with N levels up to 180 kgN ha”1 though increases in spikelets per spike, number of grains per spike and 1000-grain weight were significant up to 1 20 kg N ha-1. The uptake of nitrogen and those of K, Ca and Mg at harvest was significant up to 180 kg N ha’1 but P uptake at harvest was significant up to 120 kg N ha-1. Grain crude protein content also increased with increase in N up to 120 kg N ha-1 in 1989-90 and up to 180 kg N ha-1 in 1990-91. Split application of N at seeding time and tillering stage gave the highest grain yield, straw yield, dry matter accumulation and longest spikes. Grain crude protein content was greatest when N was split applied between seeding time and flag leaf stage. Siete Cerros was more responsive to applied nitrogen than Florence Aurore and N fertilizer requirement was different between the two years. There were positive relationships between grain yield and spikelets per spike, number of grains per spike, spike length, effective.tillers and 1000-grain weight. The high direct effects of effective tillers, spike length, grains per spike and 1000-grain weight on grain yield were due to their indirect effects through number of spikelets per spike.

GROWTH, YIELD AND NITROGEN UPTAKE OF AWNED AND AWNLESS WHEAT (Triticum aestivum L) AS AFFECTED BY NITROGEN AND ROW-SPACING