Effect of water deficit and mepiquat chloride (Pix)‎ on growth and yield of two wheat cultivars

Dissertant

Amin, Zhala Muhammad

Thesis advisor

Khurshid, Muhammad Qadir

University

Salahaddin University-Hawler

Faculty

Agriculture College

University Country

Iraq

Degree

Master

Degree Date

2012

English Abstract

This study was carried out during the period, November 2010 to May 2011, in the greenhouse of Agriculture College fields in Gerda Rasha.

The study included three pot experiments using grains of Semeto and Saber beg cultivars of winter wheat (Triticum aestivum L.).

The first experiment investigated to study the effect of water stress on some vegetative and yield components characteristics of both cultivars which exposed to water regime at different growth stages by skipping three irrigation at tillering, stem elongation and heading stages, besides, control plants were irrigated with seven days intervals up to ripe state.

The second and third experiments involved the effect of plant growth regulator mepiquat chloride (Pix) at the levels of (0, 2000, and 4000) ppm under water stress levels (field capacity, 50 % field capacity).

The measurements were taken for both cultivars included shoot and root biomass changing, some chemical and biochemical characteristics of leaves in second experiment and vegetative and yield components characteristics in third experiment.

The obtained results were analyzed statistically using factorial experiments in completely randomized design (CRD) for all of the experiments, with four replicates of each treatment and the mean of treatments were compared using Fischer's Least Significant Differences (LSD) at (p < 0.05) for greenhouse measurements and (p < 0.01) for the laboratory measurements The results could be summarized as follows : 1- Skipping three irrigations at tillering and stem elongation stages caused a significant decrease in vegetative growth parameters, included plant height, tillers number, flag leaf area, blades area and shoot dry weight compared to control plants.

The greater reduction was at tillering stage.

2- Skipping three irrigations at tillering, stem elongation and heading stages caused significant reduction in yield and yield components, included spike length, spikes number plant-1, weight of spikes plant-1, grains number plant-1, -1000 grain weight and grain yield plant-1 and the greater reduction was at heading stage.

The extent of reduction in vegetative growth and yield components was higher in Semeto cultivar.

3- Plant height, flag leaf area and blades area of Semeto cultivar were significantly higher (p < 0.05) than Saber beg cultivar.

While, the tillers number, shoot dry weight of Saber beg cultivar were significantly more than Semeto cultivar.

As well as spike length, spikes number plant-1, weight of spikes plant-1, grains number plant-1, 1000-grain weight and grain yield plant -1 of Saber beg were also significantly higher than Semeto cultivar.

4- Water stress (50 % FC) caused a significant decrease in shoot dry weight and LAD of flag leaf and significant increases in root dry weight and root : shoot ratio.

Shoot dry weight, root dry weight and (LAD) were significantly higher in Saber beg cultivar than Semeto cultivar.

MC application increased root dry weight, shoot dry weight and root : shoot ratio as well as (LAD).

Both cultivars were differed in root dry weight, root : shoot ratio through interacting with MC.

Furthermore, MC alleviated the inhibitory effect of water stress on shoot dry weight.

5- The restriction of water supply (50 % FC) caused a high significant (p < 0.01) increase in leaf proline, total soluble sugars and a high significant decrease in total proteins, chlorophyll (a, b) and total carotenoids in both cultivars.

Leaves of Saber beg contained significantly more proline, total soluble sugars, ascorbic acid and total carotenoids than Semeto cultivar and opposite was true with protein and chlorophyll (a, b).

MC treatments showed high significant increases in the ascorbic acid, total soluble sugars, total protein, chlorophyll (a, b) and total carotenoids in leaves of both cultivars over untreated controls.

It was observed that application of MC under water deficit condition ameliorated the harmful effect of water stress on photosynthetic pigments and leaf protein content.

6- Water stress (50% FC) caused a high significant reduction in (N, P, K, Ca and Mg) in leaves of both cultivars.

Leaves of Saberbeg cultivar contained more (K and Ca) than Semeto; with nitrogen the case was opposite and no significant difference with (P and Mg).

Foliar application of MC increased the accumulation of (N, K and Ca) in the leaves of both cultivars under water stress.

7- Water stress (50% FC) led to significant reduction in vegetative growth, yield and yield components in both cultivars compared to control plants.

Both cultivars differed significantly in vegetative growth parameters, yield and yield components under control and water stressed condition, greater reduction in above mentioned parameters was observed with Semeto cultivar.

8- In comparison to untreated plants there were significant reduction in plant height, flag leaf area and blades area in plants treated with (2000 and 4000) ppm of MC as foliar application.

While treating the plant with MC alleviated the negative effect of water stress on tillers number and shoot dry weight, as well as on grains number plant-1 and grain yield plant-1 in both cultivars.

Main Subjects

Agriculture

Topics

• Irrigation
• Culture
• Wheat

No. of Pages

150

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-314621