Growth Of Wheat Cultivars Research Articles

Cereal and Pulse Crops with Improved Resistance to Pratylenchus thornei Are Needed to Maximize Wheat Production and Expand Crop Sequence Options

In the subtropical grain region of eastern Australia, two experiments were conducted, one initially with 2490 P. thornei/kg soil, the other with 8150 P. thornei/kg soil at 0–0.9 m soil depth. We determined the effect of P. thornei, residual from a weed-free fallow and pre-cropping with several cultivars each of barley (Hordeum vulgare), faba bean (Vicia faba), chickpea (Cicer arietinum), and wheat (Triticum aestivum) (Phase 1), on the growth of wheat cultivars with intolerance or tolerance to P. thornei (Phase 2). Pratylenchus thornei substantially increased after growing all cultivars of the Phase 1 faba bean, barley, and most cultivars of chickpea and wheat, and decreased after two moderately resistant wheat cultivars and the fallow treatment. The biomass of the Phase 2 tolerant cultivar ranged from 5070 to 6780 kg/ha and the intolerant cultivar 1020 to 4740 kg/ha. There was a negative linear relationship between P. thornei population densities and biomass of the Phase 2 intolerant cultivar but not of the tolerant cultivar. Growers are at risk of financial loss because they are restricted in their choice of crops to reduce damaging population densities of P. thornei. The development of resistant and tolerant crop genotypes can maximize production in P. thornei-affected farming systems.

Response of Two Wheat Varieties to Irrigation Blocking and Ethephon Foliar Application

A filed experiment was carried-out during the winter season of 2010-2011 and 2011-2012 at the experimental farmof Baghdad University. The main objectives were to asses the role of irrigation blocking and ethephon spraying on growthof wheat cultivars. Two bread wheat cultivars were included. These were IPA-99 and Abu-ghraib-3. Ethephon foliarapplication and irrigation blocking was applied at elongation and booting developmental stages. A split-plot design withfour replicates was used. Main plots were assigned to irrigation blocking-ethephon spraying treatment, whereas, cultivarsassigned to sub-plots. Data presented as an average of the two seasons since the interaction of season treatments was notsignificant. over irrigation blocking-ethephon spr aying treatment the wheat cultivar IPA-99 was significantly superior toAbu-Ghraib-3 in plant height, flag leaf area, dry weight of flag leaf, specific weight of flag leaf, chlorophyll content,tillers number and dry weight of above ground plant parts after 95 and 155 days of sowing. Meanwhile, the differencebetween the two cultivars had not reached the level of significance in crop growth rate and relative growth rate. Irrigationblocking and ethephon spraying at elongation stage, although significantly increased plant height, flag leaf area, dryweight of flag leaf, specific weight of flag leaf, chlorophyll content, tillers number/plant and dry weight of plant after 95and 155 days, the difference in crop growth rate and relative growth rate between elongation and booting stages wasinsignificant. It might be concluded that ethephon foliar application might compensate the suppressing effect of irrigationblocking through modifying plant physiology and regulate the transmission of auxins that lead to reduction in water needand an increase in wheat plant growth.

Variation of grain growth of wheat cultivars

An experiment was carried out to study the grain growth pattern of wheat (Triticum aestivum L.) cultivars and to find out association and linear regression of spike weight and grain weight with time. Spike characters indicated that cultivar differences were significant in all the cases with a few exceptions. Linear regression and correlation coefficients revealed that the association between both spike weight and grain weight with time were highly positively significant among the cultivars but their regression coefficients were non- significant. Key Words: Grain growth, correlation, regression, wheat. DOI: 10.3329/bjar.v34i3.3960 Bangladesh J. Agril. Res. 34(3) : 351-359, September 2009