ArticlePDF Available

Abstract and Figures

Lodging is the displacement of stem and roots of plants from their proper and vertical placement either due to the higher N application, higher wind speed, excessive soil moisture, soil density, storm damage, sowing date or over plant population. Cereals are more prone to the effects of both root and stem lodging. Both type of lodging can occur singly or coincidentally but their effects on crop production overall reduces the health and harvest. The affected plant becomes weaker and tends to earlier seed production. This lowers the crop yield and nutrient content badly. The yield is more affected when lodging occurs at the ear formation stage of the crop. From a strictly mechanical perspective, stem lodged plants are harder to harvest and there is more waste. The selection of semi-dwarf varieties of cereals can minimize the ill-effects of lodging on crop production. Apart from, maintaining proper soil moisture, efficient drainage, minimizing or delaying nitrogen application, and use of growth regulators like CCC are effective towards minimizing the decrease in yield due to lodging.
Content may be subject to copyright.
International Journal of Chemical Studies 2018; 6(1): 700-705
P-ISSN: 2349–8528
E-ISSN: 2321–4902
IJCS 2018; 6(1): 700-705
© 2018 IJCS
Received: 25-11-2017
Accepted: 27-12-2017
Seema Dahiya
Department of Agronomy, CCS
Haryana Agricultural
University, Hisar, Haryana,
Sandeep Kumar
Department of Agronomy, CCS
Haryana Agricultural
University, Hisar, Haryana,
Department of Agronomy, CCS
Haryana Agricultural
University, Hisar, Haryana,
Charul Chaudhary
Department of Agronomy, CCS
Haryana Agricultural
University, Hisar, Haryana,
Seema Dahiya
Department of Agronomy, CCS
Haryana Agricultural
University, Hisar, Haryana,
Lodging: Significance and preventive measures
for increasing crop production
Seema Dahiya, Sandeep Kumar, Harender and Charul Chaudhary
Lodging is the displacement of stem and roots of plants from their proper and vertical placement either
due to the higher N application, higher wind speed, excessive soil moisture, soil density, storm damage,
sowing date or over plant population. Cereals are more prone to the effects of both root and stem lodging.
Both type of lodging can occur singly or coincidentally but their effects on crop production overall
reduces the health and harvest. The affected plant becomes weaker and tends to earlier seed production.
This lowers the crop yield and nutrient content badly. The yield is more affected when lodging occurs at
the ear formation stage of the crop. From a strictly mechanical perspective, stem lodged plants are harder
to harvest and there is more waste. The selection of semi-dwarf varieties of cereals can minimize the ill-
effects of lodging on crop production. Apart from, maintaining proper soil moisture, efficient drainage,
minimizing or delaying nitrogen application, and use of growth regulators like CCC are effective towards
minimizing the decrease in yield due to lodging.
Keywords: Causes of lodging, Crop production, Lodging, Lodging effects, Preventive measures
Lodging is the permanent displacement of stem from its upright position. When stems of
normally upright plants fall over and do not return to their upright position, plant is said to
have lodged (Pinthus, 1973)
. Lodging is also regarded as an abundance disease which
restricts the exploitation of yield promoting factor. Although bending at base of the peduncle
has also been considered as lodging (Patterson et al., 1957)
. Lodging is often not
distributed uniformly throughout an affected field but may be scattered over certain sections or
spots. Uncertainty in climatic and weather conditions may result in lodging. Lodging, be it a
consequence of the use of tall varieties, of inadequate nitrogen management or of unfavorable
climate conditions is one of the main barriers on the way to higher mean yields and an
enhanced quality of cereal crops (Floss, 2004)
In general, lodging was provoked due to high velocity winds in February, March and April
(71, 69 and 72 km/h) coupled with rainfall especially in February and March (143 and 115
mm) at milky stage of the crop (Khakwani et al., 2010)
. The situation further aggravated
due to soil textural class (silty clay), which created temporarily water logged condition and this
favored the root lodging of the crop (Fig 4). Care should be taken while applying the final
irrigation to wheat that might be light & at early grain filling stage. Lodging is a most chronic
constraint, which is causing tremendous yield reduction in crop plants; therefore, better
understanding to control lodging-induced adversities or to enhance lodging resistance in
cereals is imperative.
Fig 1: (a) Lodging in rice at grain maturity stage, (b) Wheat lodging at harvesting stage
International Journal of Chemical Studies
Necking: Breaking of straw from top joint at maturity.
Straggling/dog legging: Falling over here and there
among upright ones.
Lodging proper: Bending of shoot from upright
Buckling: Sharp bend at weakest point.
Breaking: Culm divided in parts.
Types of lodging
There are two types of lodging as below
Stem lodging
It follows bending or breaking of lower culm internodes (Fig
2). Stem lodging occur later in the season as the stalk become
more brittle due to crop maturation. Stem lodging may occur
when the forces causing deflection exceed the elastic limit of
stem. It can be estimated by summing the external forces and
simultaneously considering plant height, stem elasticity and
stem diameter or thickness. It is restricted to plants that are
held tightly by a dry and hard upper soil layer.
Fig 2: Stem lodging
Root lodging
When the entire plant leans or falls over because of root
failure, condition is called root lodging (Fig 3). Root lodging
also refers to straight and intact culms leaning from crown,
involving a certain disturbance of root system. It occurs early
in the season. In root lodging the breakage or bending is
usually at the crown or upper part of the root system. It occurs
in moist soil and the cracks parallel to the planting rows, the
side opposite to lodging.
Fig 3: Root lodging
Causes of lodging
Lodging is induced as a result of inadequate standing
power of the crop and adverse weather conditions, such
as rain, strong winds, and/or hail, especially in the later
part of the crop’s growth (Rawson and Macpherson,
High levels of nitrogen, high seeding rates, excessive soil
moisture and use of tall varieties are the known causes of
wheat lodging (Mavi et al., 2004)
Stem lodging may occur when forces causing deflection
exceed the elastic limit of the stem.
Stem lodging may be caused by hail or by previous
damage of the culms by insect or by foot rot but its
occurrence is induced mainly by storm.
Root lodging may results from failures in the root system
or unfavorable changes in the soil as a support base.
Root lodging is predominant type of lodging occurring
during crucial growth stages and that rain and irrigation,
which moisten the soil and thus loosen the anchorage of
plants, are its main causal agent.
Mechanical aspect of lodging
Plant is lodged due to wind, rain and hail which exert forces
(p) operating perpendicularly to culms, thus including a
torque which causes bending. Once a culm has been drawn
out of its vertical position, the weight of shoot to which it
belongs operates as a force (f) which will increase the torque.
Moreover, this force will grow as bending proceeds.
The external factors which evoke p, especially wind, act
predominantly on the head of plants Therefore, torque will
affect the whole culm and increase gradually from the top
down to basal portion, near the ground, where lever attain its
greatest value. Consequently, properties of basal region of
culm are decisive for bending. Since the nodes are too rigid to
enable bending, this will occur in the internodes, which will
permit more bending the longer they are. The total torque (T)
will be –
T = pl
+ fl
Where, l
and l
are the levers of forces p and f
The highest bending resistance moment of the culm should be
regarded as straw strength which is often confused with
lodging resistance. The property of plant to return its original
position after bending, confirms with the definition of
Straw strength may be estimated by the torque which will
cause stresses of same magnitude as the elastic limit of straw.
It is dependent on the value of elastic limit as well as on the
rate of increase of stresses with torque T.
The relation between torque and stress for a cylindrical rod is
T = S (2i/d)
Where, i is moment of inertia and d is diameter
The deformation evoked by S will be inversely proportional to
E, which is young modulus of elasticity.
International Journal of Chemical Studies
Fig 4: Effect of lodging on mean pore area of wheat and barley in different soil texture
Methods of investigation of lodging
The main methods which have been applied for investigation
of lodging are as below –
Comparison between samples from lodged and from
standing areas within same plot
Comparison of lodging plants in untreated plots with
erect plants in CCC-treated plots
Artificially prevented lodging
Artificially induced lodging
Fig 5: Effect of lodging on crop yield at harvest stage
Effects of lodging
Effects on crop growth
Plants that have lodged may shade other plants, thereby
reducing the total amount of photosynthesis that can occur per
unit area. When the stalks or stems of plants have broken,
transfer of assimilates is restricted or stopped because of
damage to vascular bundles.
In plants, that have lodged, respiration continues in the upper
parts of plants and depletes the stored carbohydrate reserve in
other parts of plant. The weakest plant, following loss of
stored carbohydrates become more susceptible to infection by
diseases or damage by insects.
Effects on grain yield
Degree of lodging i.e. degree at which culms lean from
perpendicular may also vary at different places within field
and growth stage at which it occurs. The effect of lodging on
grain yield is dependent on its severity and on the time of its
occurrence. Lodging close to maturity cannot affect grain
yield directly but may cause losses due to its interference with
harvest (Fig 5). Artificially induced lodging at heading
reduced grain yield by 27-40% whereas yield reduction due to
lodging at about soft dough stage surpassed 24% only at one
location (Pinthus, 1973)
. Khakwani et al. (2010)
demonstrate that lodging is an important factor in reducing
yield up to 38% than that obtained in normal wheat crop.
Kelbert et al. (2004) reported that lodging can cause yield
losses up to 40% if happens during the 10 days after heading.
Therefore, it is considered to be the most limiting factor in
attaining higher wheat yields (Ransom, 2005; Navabi et al.,
[20, 14]
Effects on grain yield component
Lodging at heading effects both a number of kernels per head
and individual kernel weight and lodging that occur later
effects primarily kernel weight. Increase in wheat yield from
plots in which lodging had been prevented by application of
CCC was associated in increased in number of kernels per
spike whereas kernel weight was only rarely and then slightly
effected (Pinthus, 1973)
Effect on grain quality
Lodging may cause shriveling of the grain and reduce its test
weight. It may reduce milling quality of wheat (Hirano et al.,
whereas its effect on baking quality seems to be
negligible and may sometimes even be advantageous.
Sprouting in the heads has also been found to occur frequently
in lodged than in standing crop (Kivi, 1961)
. Manitoba
observed the increments of 3 to 20% in the grain
protein content under lodging conditions, which diminishes
the grain malting quality even further. Berry et al. (2003)
concluded that the lodging in barley is seriously detrimental
for brewing purposes. In situ seed germination may occur in
lodged plants due to conducive environment especially for
cultivars with weak seed dormancy. As a result, lodging could
cause great losses in both grain yield and quality. In addition,
it also causes difficulties in harvest operations, increases
demand for grain drying, and consequently results in
increased production cost (Hoshikawa et al., 1990)
Physiological effects
The most obvious effect of lodging on the plant’s
physiological processes is its interference with carbohydrate
assimilation. This results from a large part of foliage and
other photosynthesizing parts being shaded by plants which
are leaning or lying on top of them. The heads of low lying
plants in a lodging crop may sometimes be completely empty.
Whereas those plants lying on top develop normal grain. The
protein in cereal grain originates primarily from nitrogen
which has accumulated in the foliage prior to heading.
Therefore, its absolute amount in the kernels is hardly
affected by lodging, which occurs at heading or thereafter.
Consequently the, percentage of N, or protein, in the grain of
lodged plants may rise due to decrease in carbohydrate
accumulation. Lodging which involves culm breakage will
also interfere with the translocation of carbohydrates and of
minerals. In this case the absolute content of N and other
minerals in the grain may also be reduced if lodging occurs
during heading or early grain development.
International Journal of Chemical Studies
It affects flowering, reduces photosynthetic capabilities of the
plant and eventually affect carbohydrate assimilation. Under
severe condition, lodging interferes with the transport of
nutrients and moisture from the soil and restricts mechanical
harvesting by taking about twice to harvest a lodged crop than
a standing one (Ransom, 2005) [20
Effects on culm development and tillering
The elongation of the two upper culm internodes, which is not
completed until 5-10 days after heading, can be affected by
lodging which occurs up to this period. Since these internodes
comprise about two thirds of the total culm length any
interference with their development may affect straw yield
considerably. The straw yield was indeed as much as 25 and
21% lower for lodged wheat and oat plants, respectively, than
for supported plants (Mulder, 1954) [13]. Lodging may
sometimes promote the development of late tillers,
presumably because of the reduction in the competition for
the minerals and carbohydrates by the lodging culms.
However, these tillers rarely attain normal growth.
Effect on grain harvest
Baumgartner (1969) [1] concluded that in a lodged crop,
harvest capacity can be reduced by 25% and the loss of un-
threshed heads may be doubled. The moisture content of
lodged grain will be higher than of un-lodged grain, which
also interferes with the harvest and may increase the expenses
for grain drying by 30%.
Incidence of disease in lodging crop
Some environmental factors and several plant characters
which promote lodging also improve the growing conditions
for rots and leaf diseases. Moreover, these diseases are often
favored by the microclimate prevailing with in a lodged crop.
Plant characters associated with lodging
A. Culm character
Culm length-Culm length which comprises the lever of
lodging inducing torque, is obviously associated with lodging.
An early, short-strawed variety close to maturity will be taller
and more prone to lodging than a late, long-strawed variety,
which at that time has attained only the late boot or heading
Basal internode-Plants with short stem internodes especially
in the lower part of the stem are more resistance to lodging
than are plant with long stem internodes. Large stem with
thick wall resist greater external lodging forces. The taper
ratio of stem is also related to the lodging resistance. This is
the ratio of the diameter of the top of the stem to that at the
bottom of the stem. The greater the taper ratio, the lower the
point of point of fracture, when the defective forces exceed
the elastic limits.
Plant height -Within a given plant species tall plants are
more likely to lodge than short plants. Since deflection of
stem due to external forces is proportional to fourth power of
the plant height, a small change in the parameter drastically
influences lodging. The elastic limit of short plants is usually
greater than that of taller plants but this relationship is not
absolute. The plant breeder seeks to develop, not simply short
plant, but short plant that can resist lodging.
Anatomical structure-The most marked and significant
anatomical features related to lodging resistance was a great
no. of vascular bundles. The results regarding the width of
sclerenchyma layer are contradictory. This may be due to
differences in quantity of assimilating parenchyma embedded
in this layer, which was found to be negatively correlated with
lodging resistance. The relationship between anatomical
feature and lodging resistance may be partly ascribed to effect
of lignification on culm rigidity.
Chemical composition-Cellulose and lignin contents in basal
internode have been found to be associated with lodging.
B. Root and crown characters
The qualities of the root system affect the anchorage of the
plant in the soil and therefore are of major importance in
determining resistance to root lodging. Numerical ratings acc.
to visual appearances have been used for the assessment of
root development. Through such assessments as well as
determination of root volume, relationship was established
between root development and lodging resistance. Sechler
(1961) [22] found a significant correlation ranging from 0.4 to
0.9, between lodging resistance and number of coronal roots
per plant or per tiller. He also found positive relationships
between lodging resistance and coronal root diameter for the
different species when a limited number of varieties differing
greatly in lodging resistance were compared. A consistent and
rather high correlation (0.8) was established in wheat between
lodging resistance and the spread of the coronal roots,
expressed as the angle from the perpendicular at which these
roots penetrate the ground (Pinthus, 1967) [17].
C. Mechanical properties
Straw stiffness – It refers to flexural rigidity of the culm.
Straw strength – The highest bending moment that the
culm is capable of resisting.
Breaking strength – It refers to force required to break a
section of certain length of basal culm internodes.
Root pulling resistance – This resistance is the vertical
force required to pull out of soil a certain no. of plants
and is expressed as force per culm or per plant.
Factors affecting lodging
Light and temperature
Light intensity controls the balance between longitudinal and
transverse development of vascular tissue. High intensities
block the action of natural gibberellin which promotes both
division and elongation of cells. Low light intensity promotes
internode elongation and reduces culm wall thickness. Root
growth may also be depressed by low light intensity.
An indirect effect on the promotion of internode elongation
through increased temperature may be due to its effect on
release of soil nitrogen. A significant correlation was found
between culm length of barley and temperature during the
period from seedling emergence to heading (Pasela, 1967) [15].
Reduction in light integrals (photosynthetic active radiation,
PAR) and light quality (red : far-red, R : FR) also increased
lodging susceptibility in stem and root traits of wheat
(Sparkes and King, 2008; Sparkes et al., 2008) [23, 24].
Under excess nitrogen fertility, plants height tends to increase
at the expanse of stem strength. Under extreme conditions,
lodging may occur very early in the life of plant. Profilic
tillering in small grain usually is associated with strong stem-
strength and reduced lodging. However under high nitrogen
fertility, tillering may be increased excessively and results in
International Journal of Chemical Studies
weak stem. When potassium is deficient in the soil, there is
less sclerenchyma tissue produced in the stems and this
condition causes the stem tissues to be weak. When plants are
deficient in phosphorus, all parts of plant grow at lower rates
and both stems and roots tend to develop poorly. In this
weakened condition, the stems and roots may be less able to
resist the forces that cause lodging.
Soil moisture and aeration
When the water table is high, root depth is reduced and
lodging may be increased. But, if stems are rapidly
elongating, additional water application accelerates their
growth and increases water susceptibility. Water stress results
in weakened root systems as well as small stems and leaves. It
sometimes weakens stem tissues, thereby increasing the
possibility of lodging. Poor soil aeration may increase
susceptibility to lodging due to effects of respiration
inhibition on changes of metabolism which promotes cell
Plant density
When plants are planted too closely, they tend to elongate
rapidly. As a result, stems become lighter and thinner, plants
become susceptible to lodging. High plant populations modify
the microclimate around plants, which affect lodging.
Soil type
Soil type can influence lodging. For example, the black soil
zone has a high percentage of land with 6-8 percent organic
matter, which gives a larger reservoir of N for plants to draw
on, thereby increasing the risk of lodging.
On soils where large amounts of manure are applied on a
regular basis, (such as from feedlots or dairy operations),
there can be a significant buildup of N reserves and thereby
increasing the risk of lodging.
Taller varieties tend to have weaker stems and will lodge
easier than semi-dwarf varieties, which have stiffer straw.
Plant height, stem thickness and straw density can all affect
the ability of the plant to resist a lateral force. Changing plant
height can have a big influence on lodging.
Pests and diseases
Diseases, such as eyespot foot rot, straw breaker foot rot etc.
contribute to lodging. The wheat stem sawfly causes lodging
in wheat. As there is no effective chemical control, experts
suggest growing a semi solid stemmed variety. Hessian fly
can cause lodging and kinking in wheat or barley crops.
Date of planting
When winter cereals are planted too early, vegetative growth
may be excessive, thereby increasing the susceptibility of
lodging. Excessively late planting of spring grain may
increase lodging because rapid growth associated with high
temperatures may produce weak stems.
Prevention of lodging
Cultivar selection
The first step to prevent lodging is to select a variety that has
short, strong straw. Lodging resistance cultivars have been
developed by improving the length of uppermost internodes,
thickness of stem wall, quantity and intensity of mechanical
tissue, quantity of vascular bundle, content of cellulose and
lignin in stem cell wall, the amount of carbohydrate stored in
stem, quantity of silicon and potassium and mapping
quantitative trait loci for the lodging resistance (Tripathi et
al., 2003; Mao-Chun et al., 2007) [25, 11].
Careful monitoring of fertilizer application, especially
nitrogen is effective in preventing the lodging. Timing of
nitrogen application is particularly important in this context.
Dividing the nitrogen into two or three splits and applying as
needed by crop plant helps to reduce lodging. The balance of
N, P and K in the soil must also be given proper attention.
When excess nitrogen is available to plants, it is particularly
essential to have sufficient potassium to avoid lodging. It has
been suggested to use plant growth retardants and sulphur in
order to prevent lodging problem (Ramburan and Greenfield,
2007; Hussain and Leitch, 2007) [19, 6].
Date of Sowing
The probability of the plants being at a growth stage
particularly susceptible to lodging, during a period of high
frequency of lodging – inducing factors, may sometimes be
reduced by a suitable sowing date. For each crop and cultivar
there are optimum dates of planting with lodging usually
being less when crop is planted at optimum time. When
winter cereals are planted too early the vegetative growth may
be excessive, thereby increasing susceptibility of plants to
Method and depth of sowing and row orientation
Deep sowing increases the depth at which the root crown is
located and also its length. This may strengthen the anchorage
of plants in the soil and thus increases their lodging
resistance. Sowing in drill rows in a direction parallel to that
of prevailing strong wind may reduce the incidence of stem
lodging. This should also be taken into account while the
effects are considered of plant row direction on yield due to
their influence on light interception. Bed planted genotypes
demonstrated over 50% less lodging compared with flat
planting provides an evidence that bed planting irrigated
spring wheat may be beneficial where chronic lodging occurs
(Tripathi et al., 2005) [26].
Plant spacing
The establishment of proper and uniform spacing between
plants encourages healthy plant growth and permit plants to
resist the attack of unpredictable hazards such as storms,
heavy rains and diseases. Crowded or sparsely spaced plants
tend to lodge. In conclusion, narrow inter row spacing should
increase lodging resistance without interfering to say the least
with grain yield production.
Irrigation practices
Appropriate irrigation and drainage promote root and above
ground plant growth, thus reducing the incidence of lodging.
Reduction in early vegetative growth and plant height greatly
reduce susceptibility to lodging during and following later
irrigation. This suggest advisability of withholding spring
irrigation as long as possible, preferably until early boot stage.
Crop rotation
Crop rotation is necessary for the prevention of diseases such
as common root-rot, scald, net blotch, and root rot. When a
cereal crop is grown in broad leaf crop stubble, such as canola
International Journal of Chemical Studies
or flax, the less severe is the disease pressure. Crop rotation
practices can be particularly important for irrigation farmers.
In the absence of summer fallowing, a crop rotation scheme is
useful for the maintenance of soil fertility, disease and weed
control. In addition, careful rotations can aid in lowering
protein levels in soft white spring wheat and malt barley.
Clipping and grazing
Lodging due to excessive foliage during period of elongation
of lower culm internodes may be prevented by clipping and
grazing. This should be done before culm elongation has
proceeded sufficiently for the epics to be damaged. It seems
that in order to secure high grain yields, clipping or grazing
should be performed without excessive compaction of soil,
and adequate moisture and nutrient supply must be available
during subsequent period. However, it is suspected that this
method may interfere with attainment of top yield.
1. Baumgartner G. Anpassung des Mahdrcschereinsatzes an
Klimaverhaltnisse und Ernterisiko. Helmut-Neureuter-
Verlag, M iinchen-Wolfratshausen, 1969.
2. Berry PM, Spink J, Sterling M, Pickett AA. Methods for
rapidly measuring the lodging resistance of wheat
cultivars. Journal of Agronomy and Crop Science, 2003;
3. Floss EL. Fisiologia das plantas cultivadas: o estudo que
está por trás do que se vê. UPF, Passo Fundo, 2004; 528
4. Hirano J, Eguchi H, Yoshida H. Bull. Chugoku Agr. Exp.
Sta., Ser. A. 1970; 18:15-28.
5. Hoshikawa KA, Wang SB. Studies on lodging in rice
plants. I. A general observation on lodged rice culms.
Jpn. J. Crop Sci. 1990; 59:809-814.
6. Hussain Z, Leitch MH. The effect of sulphur and growth
regulators on growth characteristics and grain yield of
spring sown wheat. J. Plant Nut. 2007; 30(1):67-77.
7. Kelbert AJ, Spaner D, Briggs KG, King JR. Screening for
lodging resistance in spring wheat breeding programmes.
Plant Breed. 2004; 123(4):349-354.
8. Khakwani AZ, Baloch MS, Nadim MA, Zubair M, Shah
I, Khan AW. Lodging: A determining factor in reducing
yield and yield structure of wheat. Sarhad J. Agric. 2010;
9. Kivi EI. Maatalous Koetoiminta. 1961; 15:101-109.
10. Manitoba J. About cereal lodging: how and why?
http:\\ 2004.
11. Mao-Chun L, Cui-Ting T, Xiao-Juan L, Jin-Xing L.
Relationship between morpho-anatomical traits together
with chemical components and lodging resistance of stem
in rice. Xibei Zhiwu Xuebao, 2007; 27(11):2346-2353.
12. Mavi GS, Nanda GS, Sohu VS. Screening bread wheat
genotypes for lodging resistance. Crop Improv. 2004;
13. Mulder EG. Plant Soil, 1954; 5:246-306.
14. Navabi A, Iqbal M, Strenzke K, Spaner D. The
relationship between lodging and plant height in a diverse
wheat population. Canad. J. Plant Sci. 2006; 86(3):723-
15. Pasela E. Hodowla Rosl., Aklim. Nasiennicrwo, 1967;
16. Patterson FL, Schafer JF, Caldwell RM, Compton LE.
Lodging by node-bending in wheat and barley.
Agronomy Journal, 1957; 49:518-519.
17. Pinthus MJ. Crop Sci. 1967; 7:107-1 10.
18. Pinthus MJ. Lodging in wheat, barley and oats: the
phenomenon, its causes and preventive measures.
Advances in Agronomy, 1973; 25:209-263.
19. Ramburan S, Greenfield PL. The effects of chlormequat
chloride and ethephon on agronomic and quality
characteristics of South African irrigated wheat. South
African J. Plant & Soil. 2007; 24(2):106-113.
20. Ransom J. NDSU Extension Agronomist - Cereal Crops,
21. Rawson HM, Macpherson HG. Irrigated wheat:
Managing your crop. FAO, Rome, 2000.
22. Sechler DT, Mo, Agr Exp Sia, Res Bull, 1961, 769.
23. Sparkes DL, Berry P, King M. Effects of shade on root
characters associated with lodging in wheat. Annals of
Appld. Biol. 2008; 152(3):389-395.
24. Sparkes DL, King M. Disentangling the effects of PAR
and R: FR on lodging-associated characters of wheat.
Annals of Appld. Biol. 2008; 152(1):1-9.
25. Tripathi SC, Sayre KD, Kaul JN, Narang RS. Growth and
morphology of spring wheat culms and their association
with lodging: effects of genotypes, N levels and
ethephon. Field Crops Res. 2003; 84(3):271-290.
26. Tripathi SC, Sayre KD, Kaul JN. Planting systems on
lodging behavior, yield components, and yield of
irrigated spring bread wheat. Crop Sci. 2005; 45(4):1448-
... Climate change because of global warming causes damage to crops globally [1,2]. In Japan, disastrous rainfall and floods, such as the "Heavy Rain in July, Heisei 30" [3], and large typhoons with wind speeds over 54 m/s, including Jebi and Trami, which were comparable to the worst typhoon in Japan's history (Isewan Typhoon) [4], have been occurring frequently every year [3][4][5][6][7]. ...
... These extreme weather phenomena have caused marked damage to agriculture, forestry, and fisheries (totaling 436.5 billion yen) [8]. Under these climate crises, rice must be robust and resistant to lodging [2,9]. ...
... The threat of strong typhoons, rainfall, and floods caused by global warming causes serious lodging [44], resulting in yield loss and grain quality deterioration in rice production [2]. The first author developed Koshihikari sd1, designated as Hikarishinseiki [21,23], and registered it under the Plant Variety Protection Act in Japan and the United States [23,25]. ...
Full-text available
We developed semidwarf and late-maturing isogenics of Koshihikari to stabilize high yield and avoid high temperature maturation. Whole-genome analysis (WGS) was conducted to examine the transitional changes in the entire genome, the size of DNA fragments integrated with the target gene, and genes accompanying the target gene owing to the progress of backcrossing. In both Koshihikari Hd16 (BC7F4) and Koshihikari sd1Hd16 (BC8F2), an SNP from adenine to guanine was detected in Hd16 at 32,996,608 bp on chromosome 3, which is known to be a causative mutation of Hd16 in Nipponbare. In Koshihikari sd1Hd16 (BC8F2), an SNP from thymine to guanine was detected in sd1 at 38,267,510 bp on chromosome 1. From BC7 to BC8, the size of the DNA fragment integrated with Hd16 decreased by 5871 bp. Koshihikari sd1Hd16 flowered 12.1 days later than Koshishikari or Koshihikari sd1 did and was 14.2 cm (15%) shorter than Koshihikari. The yield in Koshishikari sd1Hd16 (63.2 kg/a) was 7.0% higher than that of Koshihikari. This is a new germplasm designed to avoid heat damage at ripening during high-temperature summer periods by late maturation owing to Hd16 as well as to avoid lodging by autumn typhoons by semidwarfness owing to sd1.
... The For regulation of the source-sink system of cultivated plants, both genetic and technological ways are used, working in a complex, complementing each other. That makes it possible to reduce the amount of fertilizer required to obtain a unit of crop production, its cost and reduce the negative pressure on the environment [1,11,29,80]. ...
... It is known that phytohormones play a leading role in the regulation of growth ISBN 978-3-949059-23-0 processes, distribution of assimilates and regulation of the relationship between source and sink based on the coordination of the activity of invertase-and hexosetransporter [53,59,80]. Understanding the metabolic dynamics in terms of sourcesink relations gives an advantage for the selection of seed [63,91] or young plants that can maintain high yields of cereals and legumes [1,19,55]. ...
The monograph examines the literature and experimental data on the influence of synthetic growth regulators with different mechanisms of physiological action on growth processes, morphogenesis, formation and functioning of the source-sink system of crops in connection with their productivity. For plant physiologists, agronomists, teachers, postgraduate students and students of biological specialties.
... However, the impact of ooding on the crop depends on so many factors like soil characteristics (initial soil moisture, slope, texture, organic matter), crop characteristics (stage of the crop, crop root zone depth, crop canopy cover) and environment (temperature, wind, relative humidity). The high water table in rice weakened root, stem and leaves (Dahiya 2018). ...
Full-text available
The study investigates trend in extreme daily precipitation and temperature over coastal Odisha, India. 18 weather indices (8 related to temperature and 10 related to rainfall) were calculated using RClimDex software package for the period 1980–2010. Trend analysis was carried out using linear regression and non-parametric Mann-Kendall test to find out the statistical significance of various indices. Results indicated, a strong and significant trend in temperature indices while the weak and non-significant trend in precipitation indices. The positive trend in T max mean, T min mean, TN90p (warm nights), TX90p (warm days), diurnal temperature range (DTR), warm spell duration indicator (WSDI), consecutive dry days (CDD) indicates increasing the frequency of warming events in coastal Odisha. Similarly, positive trend in highest maximum 1-day precipitation (RX1), highest maximum 2 consecutive day precipitation (RX2), highest maximum 3 consecutive day precipitation (RX3), highest maximum 5 consecutive day precipitation (RX5), number of heavy precipitation days (≥ 64.5mm), number of very heavy precipitation days (≥ 124.5mm) and negative trend in the number of rainy days (R2.5mm), consecutive wet days (CWD) indicate changes toward the more intense and poor distribution of precipitation in coastal Odisha. The combined effect of precipitation and temperature extreme events showed negative effects on rice grain yield. With the increasing number of extreme events there was sharp decline in rice grain yield was observed in the same year in all the coastal districts. This study emphasizes the need for new technology/management practice to minimize the impacts of extreme weather events on rice yield.
... The contribution of the agriculture sector towards total GHGs production is substantially high, amounting to around 13.5% of the total GHGs CO 2equivalents (eq.) (IPCC, 2007). Use of petroleum products for performing on-farm operations, elevated soil N 2 O flux from sites where high nitrogenous fertilizers are applied asynchronously with plant N uptake and changes in land use pattern are some of the major reasons behind the GHGs production from arable crop production (Jensen et al., 2012;Plaza-Bonilla et al., 2018;Dahiya et al., 2018). The consumption of fertilizer chemicals (major fertilizer nutrients viz., nitrogen (N), phosphorus (P), and potassium (K) have increased worldwide after the inception of the green revolution to a record high of 192 million tons ( (Bajiya et al., 2017;Behera et al., 2020). ...
Full-text available
The ever-increasing population has intensified farming practices resulting in excessive use of farm inputs including fossil fuels and agrochemicals. Agriculture has proven to be one of the significant contributors, contributing 13.5% to the global greenhouse gases (GHGs) pool while still being a potent climate change mitigating option. Sustainable crop production keeping into account the pace of climate change will be a mammoth task to execute in the years to come. Apart from being a major source of dietary protein for humans and feed for animals, legumes play a major role in fixing atmospheric nitrogen (N), enhancing soil water retention and nutrient cycling. Legumes offer a wide array of functions including reducing dependence on N2 fertilizer, their strong influence soil organic carbon content and lowering agricultural born greenhouse gas emissions reduce ecological foot print of non-legume based cropping systems. They play pivotal roles in the food system, production system and cropping system levels. Therefore, it might be worthwhile to introduce legumes into crop rotations for the development of agroecosystem diversity, provide environmental and socio-economic benefits.
... Furthermore, the manufacturing of nitrogenous fertilizer incurred a huge capital investment and leads to an accompanying adverse effect of N in the environment (Mulvaney et al., 2009). Thus, the degradation of soil sustainability and raising of different environmental consequences in the intensive agriculture era, legumes play a key role in the different crop production systems Dahiya et al., 2017Dahiya et al., , 2018. ...
Full-text available
Food and nutritional security, environmental sustainability, mitigating climatic vulnerability, shifting of weed flora, weed developed resistance against the herbicide, high capital investment through manual weed management, and increasing the requirement for energy input in the agriculture sector are the major issues in crop production in the coming years. It is no doubt that the introduction of herbicide in the agriculture sector increases the income of farmers, which boost the economy of the nation, but its improper uses create several problems. The consumption of herbicide in the world during 2018 was 1.30Mt. The excess uses of herbicide in agriculture pose several consequences such as environmental pollution, increasing demand for energy in the industrial sector, increase resistance in different weed species, appearing novel weed flora in the cropping system, and incurred higher cost of cultivation in crop production. Sustainable food production is one of the important tools in maintaining ecological balance and soil health. In this circumstance, integrating legumes into cropping systems provides several ecosystem services which fulfill the objectives of ecological weed management. Sustainable intensification is fulfilling the demand for food and ensuring nutritional security in a sustainable manner while maintaining biodiversity and providing many ecosystem services. In a cropping system or single crop production weeds are poses a serious loss by reducing crop growth, yield, quality, depletes fertility status of soil, and act as an alternate host for several insects, pest, and diseases. The yields reduction in direct-seeded rice due to weeds was reported up to 90%. Globally, more than US$ 100 billion was a loss due to infestation of weed in annual crops. The weed seed of Argemone mexicana crushed mustard seed and the oil feed by human beings causes glaucoma or dropsy. The weed green Amaranthus (Amaranthus viridis) can accumulate about 3% N in its biomass and causes severe depletion of nitrogen (N) economy in soil. The three solanaceous weeds such as Solanum nigrum, Datura stramonium, and Datura ferox are act as an alternate host for tomato leaf minor. The application of herbicides during the crop production causes adverse effects on the environment, soil ecosystem, pollute ground water, damage ecological diversity, and affects human health. Besides, the use of herbicide for weed management incurred about US$ 25 billion annually across the globe. Therefore, to tackle such issues of weed the integration of legumes in the different crop production systems as cover crop, relay crop, green manure crop, brown manuring crop play a key role in providing many ecosystem services such as suppressing weed species by smothering or by allelopathy effect, break the life cycle of disease and pest, increasing carbon (C) and N pool in soil, enhancing soil organic matter content, enhance soil health by improving physical, chemical and biological properties of soil. In intercropping system, legumes have better suppression on weed flora by reducing their density and biomass. Further, legumes fulfill the requirement of N of the component crop. Legumes in the crop rotation system break the infestation of frequently occurrence weeds due to its allelopathic effects or smothering effects on the weed seed bank. Based on the diverse benefits of legumes, it is ensured that legumes either in the cropping system or alone as crop residue plays a key role in driving sustainable intensification.
... Such crops can be included in the climate-smart crop cultivation systems to intensify crop multiplicity, cut production inputs, and promote conservation agriculture. Climate and environmental change might create a harsh crop production situation which can be a great threat to sustainable agriculture and food security (Dahiya et al., 2018). Legumes can be used for phytoremediation of harsh soil environments due to their high potentiality of biomass production, and have been identified as a potential climate change coping strategy within smallholder farming systems. ...
Intensive agriculture and industrial development have damaged ecosystem balance in many parts of the world along with changes in the gaseous composition of the earth atmosphere, hydrology, and the global climate. Legumes are the gift of nature that might appear to safeguard the environment and ensure win–win benefits for society, economy, and environment. Legumes in association with bacteria can fix atmospheric di-nitrogen (N2) in root nodules. Globally, land-based biological nitrogen fixation (BNF) exceeds the amount of industrial nitrogen (N) production by 1.1 times. Such fixed N is partly utilized by the succeeding nonlegumes and thus N fertilizer can be reduced without sacrificing cereal yields. Growing legumes in rotation with cereals can increase soil carbon (C) sequestration by 9–45 Mg C ha–1, and reduce greenhouse gases emissions by 5–7 times compared to nonlegumes. Legumes need less N and can be grown under water deficit conditions. The rate of N could be reduced roughly by 200 kg N ha–1 for nonlegumes grown after grain legumes. Such savings of N from BNF could reduce carbon dioxide (CO2) emission by approximately 200 kg ha–1. Beyond BNF, mineralization of legume residues adds N and other nutrients to the soil and improves soil fertility. Legume plants can improve soil aggregates, increase soil water retention, and have a stronger adaptive capacity to adverse environments. Legumes can smartly mitigate the negative effects of climate change and acclimatize to a vulnerable environment. The inclusion of legumes in the cropping systems increases yields of both legumes and nonlegumes. Legume plants, therefore, should get priority to be included in all cropping systems, forestry, and aesthetics to get maximum social, economic, and environmental benefits. Realizing the importance of legumes, the chapter endeavored to fetch an overall scenario of climate change, multiple dimensions of climate-smart legume-based cropping systems, future research avenues, and policy implications.
... However, it has been debated that the emission of greenhouse gases is almost the same as any cereal crop, which is been countered by the fact that the more emission from a legume field is either due to decompositions of crop residues itself (Peyrard et al., 2016). Indirectly, sustainable consumption is prompted by legumes as they are cultivated for diversification of cropping patterns in several instances, in order to break the natural cycle of weeds and insect pests attributed to a specific crop (Dahiya et al., 2017(Dahiya et al., , 2018. The inclusion of legume crops in a conventional cropping pattern limits the use of pesticides for mitigating the already settled pests since many cropping seasons (Warne et al., 2019). ...
Growing demand for nutritious, safe, and healthy food, as well as the commitment to preserve biodiversity and other resources, represents a tremendous challenge to agriculture, which is already under threat from climate change. A diverse and healthy plant-based diets may greatly reduce these diet-related diseases and other health-related issues. As a result, sustainable food production had gained increasingly attention in agricultural and food systems. In this context, grain legumes are could play a key role by delivering multiple services in human nutrition in line with sustainability principles. In addition to the contribution of grain legumes in ecosystem services, they serve as a fundamental, worldwide source of high-quality food, and feed particularly for vegetarians. Grain legumes are amazing source of proteins, essential amino acids, dietary fiber, minerals, and vitamins and therefore have a significant role in addressing global food and nutritional security. Although, still the global food supplies through grain legumes are very negligible which is only 1.1% of the total global food supply and 1.3% of total global vegetal food supplies. To maximize their involvement in daily dietary energy, these figures must be greatly improved, allowing them to contribute meaningfully to food and nutrition security, as well as sustainable and resilient crop production systems. In this chapter, we looked at how important grain legumes are for long-term livelihood, food, and nutritional security.
... Therefore, high plant height may cause thinning of plant stalks. As a result, tall varieties may sometimes have difficulty standing upright because they do not have sufficient stalk thickness, and they might fallen over in the field before harvest(Dahiya et al., 2018). The Burak variety showed promising results with high values for both features.Forage and dry grass yieldsThe average forage yield increased almost throughout the grow-ing period (first, second and third harvests). ...
Full-text available
Due to the different agricultural practices such as second cropping or more for the increase product obtained from the areas of suitable climate, some differences in harvesting stages of plants have been occurred. The study was carried out in the Menemem location of Izmir in the coastal Aegean region of Turkey under Mediterranean climate in 2018 and 2019 to determine the performance of corn cultivars in different maturity stages. Seven varieties of corn (Everest, Aga, Kilowatt, Burak, Samada-07, P30B74 and P31Y43) were harvested at 3 different growth stages (silking, end of milk and dough stages) to determine the changes in some parameters of growing, forage quantity and quality. The highest average of dry forage yield (24159 kg ha-1 average of years) was determined at the third harvest date. The maximum cob rate was also measured at the third harvest date, but the maximum leaf and stalk rates were measured at the first harvest date. The average protein rate decreased throughout the growing period while ADF and NDF increased. Almost all of the varieties were found to have large leaf areas. The Burak variety came to the fore due to its long length and relatively thick stalk features and high green and dry yields. Moreover, P31Y43 was determined to have a high quality in addition to high green and dry grass yields. Therefore, the Burak and P31Y43 can be suggested in terms of high parameters both quantity and quality under different crop conditions for increase production.
Full-text available
The Bangladesh Rice Research Institute (BRRI) has released more than 100 inbred rice varieties. Still, an old mega variety BRRI dhan28 dominates the farmers’ fields during the dry winter (Boro season: November–June) season. This variety is very susceptible to different diseases and insects, causing lower yield performance than its potential. To replace this variety, current on-farm research was planned to evaluate the newly developed four superior rice varieties: BRRI dhan58, BRRI dhan63, BRRI dhan67, and BRRI dhan74 during Boro season in 2017 and 2018. The objective was to create data and popularize new varieties among farmers all over the country. We conducted 15 on-farm trials with farmers’ active participation at Senbag, Fulgazi, and Mirsarai Upazila of Noakhali, Feni, and Chattogram districts, respectively, in Bangladesh. The results demonstrate that BRRI dhan74 produced the highest grain yield among the tested varieties, followed by BRRI dhan67, BRRI dhan63, and BRRI dhan58, while BRRI dhan28 produced the lowest. However, BRRI dhan67 obtained the highest preference scores from the farmers and extension personnel due to its medium and slender grains, shorter growth duration, resistance to lodging, less disease, and less insect invasion. Moreover, stability indices for yield revealed that BRRI dhan67 was the most stable, adaptive, and appropriate variety, followed by BRRI dhan74, across the locations. Farmers showed keen interest to grow BRRI dhan67 by themselves instead of BRRI dhan28 all over the study locations. The neighboring farmers also expressed their curiosity about cultivating BRRI dhan67 over BRRI dhan28 by collecting seeds from the participating farmers. Thus, BRRI dhan67 could be a perfect replacement for BRRI dhan28. However, conducting participatory varietal evaluation trials across the agroecological zones of the country is recommended to validate the results of this study.
Full-text available
Iran imported around 1.3 million tons of barley in 2017. Accordingly, conducting researches under low organic matter soils and limited water resources is important to enhance barley products and improve economic conditions. Field experiments were performed to evaluate the effect of different levels of irrigation water (0, 50, 75 and 100% of crop water requirement as main plot) and nitrogen fertilizer (0, 70, 140 and 210 kg ha⁻¹; as subplot) on barley (Reyhane 0–3 cv.) growth, agronomic indices and water and nitrogen use efficiency. The results revealed that the barley grain yield dropped by lowering applied water, as the grain yield in 50% irrigation water was around 44% of full irrigation, in both years. Increasing the nitrogen fertilizer to 140 kg ha⁻¹ significantly increased grain yield, while no significant difference was detected between grain yield of 140 kg ha⁻¹ and the highest nitrogen application rate. The maximum water use efficiency was obtained at 75% of full irrigation showing that application of full irrigation did not agronomically increased the grain yield. Nitrogen use efficiency increased by applying more water, while application of nitrogen more than 140 kg ha⁻¹ reduced the nitrogen use efficiency. Furthermore, nitrogen harvest index of 75% indicated that Reyhane 0–3 barley cultivar had the ability to accumulate higher portion of applied N in grain than in straw. Application of 25% deficit irrigation with 140 kg ha⁻¹ nitrogen fertilizer is suggested to obtain the maximum barley production and water use efficiency under semi-arid conditions.
Full-text available
containing the Lr19 gene which has been shown to contribute to crops and usually occurs near or after anthesis, mainly increased grain yield potential. Lodging behavior and yield potential the result of wind during or soon after irrigation or rain- were studied for 16 spring wheat genotypes under disease free, irri- gated conditions at the CIMMYT (Centro Internacional de Mejora- storm events. To avoid lodging, many farmers in south miento de Maiz y Trigo) experiment station near Ciudad Obregon, Asia forego the last irrigation, which may be crucial for Sonora, Mexico, during the 1997-1998 and 1998-1999 crop cycles. grain filling and can ultimately limit grain yield (Hobbs Among the genotypes tested were SUPER SERI, which carries the et al., 1998). This practice is common in India for the Lr19 gene, and Seri 82, which is a near isogenic cultivar lacking the following reasons: (i) occurrence of frequent high winds gene. Comparisons were made between the widely used, flat planting during grain-filling; (ii) the wide use of flat planting and system with flood irrigation versus an innovative bed planting system flood irrigation which can lead to extended, saturated with furrow irrigation that has been widely adopted by many farmers soil moisture conditions following irrigation that are in northwest Mexico. An additional treatment using support nets to conducive to crop lodging; and (iii) the lack of accept- eliminate lodging for the flat planting system was included to estimate able cultivars that are lodging tolerant at higher N rates yield losses attributable to lodging. There were yield differences among planting systems and genotypes and their interactions were (180 kg ha 1
A general observation was conducted on lodged rice culms in cultivars Sasanishiki and Koshihikari grown in paddy fields in 1986, 1987, and 1989. The shape of the cross section of internodes was observed to be not circular, but elliptical with a major and a minor axis. Flattening of internode calculated based on the difference between the major and minor axis was higher in lodged culms than in unlodged ones in the lower internodes. Values of the major and minor axis, which reflect the width of internodes, were lower in lodged culms, also, lengths of the lower internodes were longer than unlodged ones. The broken internode was found to be mainly the IV internode in Sasanishiki and IV, V internodes in Koshihikari. The breaking position in the broken internode was restricted to the portion ranging from 10 to 30% of the full internode length distant from the lower node level. This 20% portion was regarded as a breaking area of the broken internode. The breaking direction was observed to be the minor axis of the cross section of the broken internode in most cases. These results suggested that lodging occurs in limited internodes and at a specialized position and direction.
Plant growth regulators (PGR's) that reduce lodging have not been evaluated on commercial wheat cultivars under local irrigated conditions. The objective of this study was to assess the effects of PGR's on agronomic and quality parameters of three wheat cultivars under irrigation in the field. A control (water) and two PGR's, chlormequat chloride and ethephon, were applied either individually or in combination with each other at the tillering, stem elongation or the flag leaf stages of growth to the cultivars Kariega (lodging susceptible), Olifants (lodging tolerant) and SST 876 (lodging tolerant) at Vaalharts and Bethlehem. The 4 × 32 factorial treatment combinations were tested in a RCBD with four replications in the 2003, 2004, and 2005 seasons. Ethephon and the PGR combination were most effective at reducing plant height and lodging when applied to Kariega at the flag leaf stage. Grain yields were either improved or reduced depending on the presence or absence of lodging, the PGR applied, and the time of application (TOA). Significant PGR X TOA interactions were observed for hectoliter mass, protein content, and falling number. The results suggest that PGR's should be recommended on specific cultivars in environments conducive to lodging.
Lodging resistance ratings for winter wheat cultivars are frequently based upon observations of lodging. This is an unreliable method because of the frequent occurrence of years without significant lodging events. It also does not distinguish between stem and root lodging resistance. This paper describes the development and testing of instrumentation and procedures for two field-based methods to rapidly assess stem and root lodging resistance. Both methods used a specifically designed instrument for measuring the resistance of shoots against rotational displacement. Stem lodging resistance was assessed when the soil was dry and strong, whereas resistance to root lodging was assessed after the soil had been weakened by irrigation. Tests were carried out on 14 winter wheat cultivars grown at two sites in the UK during 2002. Both methods were able to detect statistically significant differences between the cultivars for their resistance to stem and root lodging. A comparison of these results with observations of lodging in the field showed that the methods accounted for about 60 and 50 % of the stem and root lodging respectively.
Previous work has shown that as the density of wheat plants increase, the spread of the root plate, root length and root number per plant decrease, leading to reduced anchorage strength and increased lodging susceptibility. The aim of this study was to determine which aspect of mutual plant shading [reduction of photosynthetically active radiation (PAR) or the ratio of red to far red light (R : FR)] is associated with this reduction in anchorage strength. Field experiments were conducted at Sutton Bonington, Leicestershire, UK, in two seasons using a range of plant densities in conjunction with shading materials to manipulate PAR and R : FR independently. The spread of the root plate, which has been linked most strongly with anchorage strength, was almost exclusively influenced by PAR intercepted per plant at the beginning of stem extension. Root number and root length were influenced by both PAR and R : FR. When structural roots (defined as thicker than 0.5 mm) and nonstructural roots were considered separately, it was discovered that increasing plant density and PAR shading reduced the length of both structural and nonstructural roots. However, reducing R : FR only reduced the length of structural roots without affecting the length of nonstructural roots.
It has been previously demonstrated that large wheat canopies are more prone to lodging than smaller canopies and it has been suggested that this is because of the plant’s response to changes in the light environment. However, it is unclear whether plants are responding to reduced light quantity (photosynthetically active radiation, PAR) or reduced light quality (red:far-red, R:FR). Two glasshouse experiments were designed, using shading materials and supplementary light, to manipulate PAR and R:FR independently, so that the response of lodging-associated characters of wheat could be ascribed to the different aspects of shade. The increase in lodging susceptibility associated with mutual plant shading was found to be because of both PAR and R:FR. Calculated stem failure wind speed and its component traits responded to shading entirely through their response to reductions in PAR. Ear number, which led to differences in plant leverage, was also explained by differences in PAR. In contrast, calculated anchorage failure wind speed and rooting traits demonstrated additional responses to R:FR, over and above those to PAR. Thus, the aspect of mutual plant shading responsible for increased lodging susceptibility of wheat varied between stem and root traits. PAR was solely responsible for changes in stem traits associated with lodging but R:FR played a role in determining rooting traits that affect the anchorage capacity of wheat plants.
Selection for lodging resistance in Canadian hard red spring wheat under natural conditions is difficult due to the sporadic and often random nature of lodging events. We conducted field trials in Edmonton AB Canada (2000–2002) to determine if either a high seeding rate, or artificially inducing lodging (by dragging a weighted apparatus across plots at the early milk stage), would be an effective screen for determining genetic lodging resistance in wheat breeding programmes. For the 25 genotypes tested, applying artificial lodging at the experimental mean early milk stage was a suitable method to screen and identify lodging tolerant and susceptible genotypes. Tolerance to artificially induced lodging was mainly found within semi-dwarf genotypes, and susceptibility was mainly found within Canadian bread wheat genotypes. Severe lodging resulted in yield losses as high as 40%. Lodging tolerant genotypes identified in this study are now being crossed into elite western Canadian bread wheat in an effort to increase genetic lodging resistance within Canadian breeding lines.