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Responses of Canola Morphological andAgronomic Characteristics to Zeolite andZinc Fertilization under Drought StressNasser Shahsavariab, Hasnah Mohd Jaisb & Amir Hossein Shirani Radc

a Hajiabad Branch, Islamic Azad University, Hajiabad, Hormozgan,Iranb School of Biological Sciences, University Sains Malaysia, USM,Penang, Malaysiac Seed and Plant Improvement Research Institute, Karaj, IranAccepted author version posted online: 30 Apr 2014.Publishedonline: 27 Jun 2014.

To cite this article: Nasser Shahsavari, Hasnah Mohd Jais & Amir Hossein Shirani Rad (2014):Responses of Canola Morphological and Agronomic Characteristics to Zeolite and ZincFertilization under Drought Stress, Communications in Soil Science and Plant Analysis, DOI:10.1080/00103624.2013.875207

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Communications in Soil Science and Plant Analysis, 00:1–10, 2014Copyright © Taylor & Francis Group, LLCISSN: 0010-3624 print / 1532-2416 onlineDOI: 10.1080/00103624.2013.875207

Responses of Canola Morphological and AgronomicCharacteristics to Zeolite and Zinc Fertilization

under Drought Stress

NASSER SHAHSAVARI,1,2 HASNAH MOHD JAIS,2

AND AMIR HOSSEIN SHIRANI RAD3

1Hajiabad Branch, Islamic Azad University, Hajiabad, Hormozgan, Iran2School of Biological Sciences, University Sains Malaysia, USM, Penang,Malaysia3Seed and Plant Improvement Research Institute, Karaj, Iran

Research was performed during the 2010 and 2011 growing seasons to investigate theeffect of zeolite and zinc (Zn) foliar application on the qualitative characteristics and oilyield of canola cultivars at different moisture regimes. A factorial split-plot experimentwas performed on the basis of the randomized complete block design with three replica-tions in the Seed and Plant Improvement Institute, Karaj, Iran. The treatments were asfollows: (1) irrigation (I), complete (I1), and restricted (I2) at the pod formation stage,(2) zeolite (Z), 0 (Z1), and 15 t ha−1 (Z2), and (3) Zn, zinc sulfate concentrations of0%, 0.1%, and 0.2 % (Zn1, Zn2, and Zn3) at the pod formation stage. These treatmentswere applied on Licord, RGS003, and Opera cultivars. The results show that the simpleeffect of treatments were statistically significant for all assessed traits at P < 0; as wellas the interaction effects of Z and Zn (P < 0.01) and the interaction effects of I andcultivar (P < 0.01). The greatest rates of all studied traits were obtained by applyingZ2Zn2 (15 ton ha−1 zeolite and 0.1% Zn sulfate) in both irrigation regimes. The ratesof grain yield, biological yield, and harvest index improved by 43.82%, 73.99%, and30.04%, respectively, using a combined application of Z and Zn. Therefore, based onthe low cost of natural Z and a low Zn intake, these treatments could be used to enhancethe performance of canola, especially in regions that are exposed to water stress.

Keywords Canola, water stress, yield, zeolite, zinc

Introduction

Drought, salinity, freezing, and heat are among the environmental factors that cause harm-ful effects on plant growth. Water deficit, more than other forms of stress, limits the growthand productivity of crops (Yamaguchi Shinozaki et al. 2002). In recent years, studies onthe effects of complementary irrigation on crop yield and water-use efficiency (WUE) haveshown that adequate complementary irrigation can increase crop yield by significantlyimproving soil moisture conditions and WUE (Deng, Shan, and Shinobu 2002). Accordingto Lessani and Mojtahedi (2006), the ability of plant cells to survive intensive water losswithout experiencing nocuous damage is a core aspect of drought tolerance.

Received 20 February 2013; accepted 28 August 2013Address correspondence to Nasser Shahsavari, Hajiabad Branch, Islamic Azad University,

Hajiabad, Hormozgan, Iran. E-mail: shahsawari110@gmail.com

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2 N. Shahsavari, H. M. Jais, and A. H. S. Rad

Canola (Brassica napus L.) is one of the most important oil crops, but its yield isreduced during the flowering and seed filling stages because of late-season drought stress.Investigations have shown that the seed filling, pollination, and flowering stages of numer-ous plants are sensitive to drought stress (Thomas et al. 2004). Masoud Sinaki et al. (2007)found that the maximum canola yield’s reduction period occurred when water stress ispresent during the developmental stages of the pod. The available water in soil is alsoan important factor in increasing crop yields (Ghooshchi, Seilsepour, and Jafari 2008).The application of superabsorbent polymers, which supply water to the crop’s roots, isone of the ways to increase the amount of available water in the soil (Pawlowski et al.2009). In normal irrigation and water-stress conditions, the desired plant yield in termsof better growth and enlargement can be achieved using superabsorbent polymers, whichoften increase water storage capacity in soil (Akhter et al. 2004; El-Hady and Wanas2006; Sarvas, Pavlenda, and Takacova 2007). In addition, the reduction in waste of waterand nutrition in soil (Adams and Lockaby 1987), reduction in soil surface water evapo-ration (Akhter et al. 2004; Sarvas, Pavlenda, and Takacova 2007; Sivapalan 2001), andincreased soil aeration (Orzeszyna, Garlikowski, and Pawlowski 2006) are significant con-tributions of such absorbents toward the generation of desired plant yield. These conditionscan be used to decrease the frequency of irrigation by increasing the gaps of irrigation,thereby saving on water cost and energy (Sivapalan 2001). Natural zeolite has been widelyapplied as a superabsorbent polymer in agricultural production and environmental protec-tion because of its high absorption capacity and cation exchanging capacity (CEC) (Haoand Zheo 2003).

Applying zeolite into the soil results in an increase in water-holding capacity.Furthermore, by allowing ions to pass through while blocking others, zeolite functions as achemical sieve (Ok, Anderson, and Ervin 2003). Zeolite reduces the leaching of nutrients,particularly nitrates, because of its high CEC. Thus, zeolites are important in agriculture(Zahedi et al. 2009). Selective uptake and regulated diffusion of nutrients by zeolite canhelp plants to grow despite deficient conditions (Masoud Sinaki et al. 2007). The uniquecharacteristics of zeolite such as high CEC, selective uptake, low cost, abundance, andstructural stability make it a suitable material for soil reinforcement to withstand droughtstress and increase fertilizer efficiency (Ok, Anderson, and Ervin 2003).

Water deficiency affects the efficiency of fertilizers. Among fertilizers, zinc (Zn) sul-fate decreases water stress by regulating the holes and ionic balance in plant systems andprevents the inaccessibility of this element for the plant by any secondary factors. Theseconditions indicate the yield and concentration of this element in various tissues such asgrain (Khurana and Chatterjee 2001). Therefore, in water-deficient situations, the use offertilizers should be balanced, and the consumption of special fertilizers such as Zn sul-fate has to be particularly considered. This research was performed to assess the effectsof applying zeolite and Zn on the qualitative characteristics of canola cultivars in differentmoisture regimes.

Materials and Methods

Research was performed during the 2010 and 2011 growing seasons to investigate theeffect of natural zeolite and Zn on the qualitative characteristics of canola varieties atdifferent moisture regimes. A factorial split-plot experiment was performed based onthe randomized complete block design with three replications in the Seed and PlantImprovement Institute, Karaj, Iran, (35◦ 59′ N, 50◦ 75′ E, and altitude of 1313 m). Thetreatments were as follows: (1) irrigation (I), complete (I1), and restricted at the pod

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Responses of Canola to Zeolite and Zinc 3

Table 1Physicochemical properties of soil collected from site study

YearDepth(cm)

EC(dsm−1) pH

Organiccarbon

(%)

Saturatedpercentage

(%)N

(%)P

(ppm)K

(ppm)Fe

(ppm)Cu

(ppm)Zn

(ppm)TNV(%) Texture

2010 0–30 1.32 7.8 0.49 30.63 0.05 4.7 174 5.5 7.3 0.84 8.55 Clay30–60 1.73 7.7 0.36 30.85 0.04 2 133 2.2 3.9 0.51 10.49 loam

2011 0–30 1.41 7.8 0.08 35.96 0.51 3.1 208 5.2 7.1 0.89 9.86 Clay30–60 1.42 7.9 0.06 37.09 0.39 2 148 2.1 3.6 0.47 10.29 loam

TNV: Total Neutralizing Value

formation stage; (2) zeolite (Z), 0 (Z1), and 15 t ha−1 (Z2); and (3) Zn, zinc sulfate con-centrations of 0%, 0.1%, and 0.2 % (Zn1, Zn2, and Zn3) at the pod formation stage. Thesetreatments were applied on Licord, RGS003, and Opera cultivars. The average annual rain-fall (for 30 years) was 244 mm (Table 1), which is concentrated in the fall and wintermonths (November to February).

Mixed soil clay loam samples were collected from depths of 0 to 30 cm and 30 to60 cm to determine the physicochemical parameters (Table 2). Zeolite and chemical fer-tilizers were applied and incorporated to the soil. Each experimental plot consisted of sixcultivation lines 0.3 m apart, and a population of 100 shrubs in 1 m2 with a length of 5 m.The blocks were separated by 6 m to avoid margin effects. Every block was set at a dis-tance of 2.4 m from the main plots. The seeds were disinfected and were sown in the earlyparts of October (2010 and 2011). Irrigation was performed uniformly in the plots untilthe pod formation stage, and weed control was done by hand. Foliar application of Zn asZn sulfate was conducted in three concentrations (0%, 0.1%, and 0.2%) by using enginebackpack sprayer at the pod formation stage.

To measure the characteristics of plants, 10 plants (after eliminating the margin effects)were determined by harvesting randomly from middle of each plot. Plant height was mea-sured from the surface of the soil to the highest point of main stalk. Stem diameter wasobtained using caliper that measured the third mid-node diameter. Thirty pods were sepa-rated from the main and substems, and their lengths were measured; the averages of thesemeasurements were considered as the main and subpod lengths. In addition, seeds fromthese pods were sorted and counted; the average of each was computed as seed numbersper main and sub pods. The 1000-seed weight was determined by measuring the weight ofeight random samples, which each consisted of 100 seeds, from each plot and multiplyingit by 10 to express it to 1000 seeds. Grain yield was determined by harvesting plants atphysiological maturity from each plot at 14% humidity. Harvest index was calculated aswell. Oil content of the seeds was determined with a nuclear magnetic resonance (NMR)spectrophotometer. Therefore, oil yield was obtained by multiplying the oil content andgrain yield.

The data were analyzed using MSTATC and SPSS software version 19 (MichiganState University, East Lansing, Mich., USA; SPSS, Inc., Chicago, Ill., USA). Treatmentswere analyzed in three replications by using Duncan’s multiple-range test and werecompared at P < 0.05.

Results

The analysis of variance (ANOVA) results indicate that the effect of year and the simpleeffects of the treatments (I, Zn, Z) were statistically significant for all assessed traits at

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4 N. Shahsavari, H. M. Jais, and A. H. S. Rad

Table 2Summary of combined F significance from analysis of variance

SV DF PH SD BP PM PB PP PML PBL PL GMP GBP GP GW BY GY HI

Y 1 ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗R(Y) 4 ns ∗∗ ns ns ns ns ns ns ns ∗∗ ns ∗∗ ns ns ns nsI 1 ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗Zn 2 ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗Z 1 ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗I × Zn 2 ns ns ns ns ns ns ns ns ns ∗∗ ∗ ∗∗ ∗∗ ∗ ∗∗ ∗∗I × Z 1 ns ns ns ns ns ns ∗∗ ns ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗I × Y 1 ∗ ns ns ns ∗∗ ns ns ns ns ns ns ns ∗ ns ∗∗ ∗∗Zn × Y 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsZ × Y 1 ns ns ns ns ns ns ns ns ns ∗ ns ns ns ns ns ∗Zn × Z 2 ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗I × Zn × Z 2 ns ns ns ns ns ns ns ns ns ∗∗ ns ∗∗ ∗∗ ns ∗∗ ∗I × Zn × Y 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsI × Z × Y 1 ns ns ns ns ∗ ns ns ns ns ns ns ns ns ∗∗ ns ∗∗Zn × Z × Y 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ∗∗ nsI × Zn × Z × Y 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ∗ nsR × I × Zn × Z(Y) 44 ns ns ∗∗ ns ns ns ns ns ∗ ∗∗ ns ns ∗∗ ns ns nsC 2 ns ns ns ∗∗ ∗∗ ∗∗ ns ns ns ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ nsI × C 2 ∗ ∗∗ ∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗∗ ∗Zn × C 4 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsZ × C 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsC × Y 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsI × C × Y 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsZn × C × Y 4 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsZ × C × Y 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsI × Zn × C 4 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsZn × Z × C 4 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsI × Z × C 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsI × Zn × C × Y 4 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsI × Zn × Z × C 4 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsZn × Z × C × Y 4 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsI × Z × C × Y 2 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsI × Zn × Z × C × Y 4 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns nsR squared .96 .97 .95 .99 .98 .99 .96 .94 .98 .99 .98 .99 .99 .99 .99 .95

∗Significant at 5%.∗∗Significant at 1%.Notes. ns, nonsignificant; Y, year; I, irrigation; Z, zeolite; Zn, zinc; C, cultivar; R, replication; PH, plant

height; SD, stem diameter; BP, number of branch plant−1; PM, number of pod main stem−1; PB, numberof pod branch−1; PP, number of pod plant−1; PML, pod length main stem−1; PBL, pod length branch−1;PL, pod length; GMP, number of grain main pod−1; GBP, grain number of pod branch−1; GP, number ofgrain pod−1; GW, grain weight; BY, biological yield; GY, grain yield; and HI, harvest index.

P < 0.01 (Table 3), as well as the interaction effects of Z and Zn (P < 0.01) and theinteraction effects of I and cultivar (P < 0.01).

The results show that morphological and agronomic characteristics of canola culti-vars responded to changes in irrigation regimes and Z and Zn rates in different ways(Tables 4 and 5). Applying Z improved the rates of grain yield, biological yield, and har-vest index to 39.40%, 23.77%, and 17.86%, respectively, as compared to nonapplicationof Z (Table 5). Applying Zn enhanced the rates of grain yield, biological yield, and harvestindex to 18.62%, 11.63%, and 8.24%, respectively, as compared to nonapplication of Zn(Table 5).

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Responses of Canola to Zeolite and Zinc 5

Table 3Monthly precipitation rate (mm) in 2010–2012 cropping seasons at the experiment site

Year Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May Total

2010−2011 1.8 26.7 5.6 49.3 75.2 3.1 42.4 11.4 2.5 2182011−2012 0 16.6 27.6 36 72.7 50.3 19.6 47.6 10.1 280.5

Table 4Mean comparisons of I, Z, and Zn on morphological characteristics

Mean

Treatment PH (cm) SD (mm) BP PM PB PPPML(cm)

PBL(cm)

PL(cm)

IrrigationI1 163.083a 13.131a 6.842a 81.906a 108.900a 190.806a 7.047a 6.072a 6.557aI2 125.131b 8.800b 4.400b 31.658b 51.189b 82.847b 3.289b 2.961b 3.119b

ZeoliteZ1 137.311b 10.050b 5.083b 48.364b 70.333b 118.697b 4.517b 3.928b 4.215bZ2 150.903a 11.881a 6.158a 65.200a 89.756a 154.956a 5.819a 5.106a 5.461a

ZincZn1 139.433b 10.296b 5.296b 51.142b 73.500b 124.642b 4.725b 4.150b 4.432bZn2 146.204a 11.271a 5.737a 59.279a 82.938a 142.217a 5.375a 4.663a 5.017aZn3 146.683a 11.329a 5.829a 59.925a 83.696a 143.621a 5.404a 4.737a 5.065a

Notes. Any two means sharing a common letter do not differ significantly from each other at 5% prob-ability. PH, plant height; SD, stem diameter; BP, number of branch plant−1; PM, number of pod mainstem−1; PB, number of pod branch−1; PP, number of pod plant−1; PML, pod length main stem−1; PBL,pod length branch−1; and PL, pod length.

Table 5Mean comparisons of I, Z, and Zn on agronomic characteristics

Mean

Treatment GMP GBP GPGW(g)

GY(Kg h−1)

BYi(Kg h−1) HI (%)

IrrigationI1 25.675a 23.603a 24.642a 4.284a 4734.417a 20460.111a 23.033aI2 9.600b 8.261b 8.931b 1.880b 1605.361b 10691.000b 14.609b

ZeoliteZ1 14.939b 13.586b 14.264b 2.502b 2648.167b 13920.889b 17.278bZ2 20.336a 18.278a 19.308a 3.661a 3691.611a 17230.222a 20.364a

ZincZn1 15.825b 14.267b 15.049b 2.722b 2826.083b 14439.833b 17.861bZn2 18.629a 16.746a 17.685a 3.237a 3352.458a 16119.833a 19.333aZn3 18.458a 16.783a 17.625a 3.286a 3331.125a 16167.000a 19.268a

Notes. Any two means sharing a common letter do not differ significantly from each other at 5%probability. GMP, number of grain main pod−1; GBP, grain number of pod branch−1; GP, number ofgrain pod−1; GW, grain weight; BY, biological yield; GY, grain yield; and HI, harvest index.

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Z1

Zn1

Zn2

Zn3

12672.833 16206.833

14013.167 18226.5

15076.667 17257.333

02000400060008000

100001200014000160001800020000

Gra

in y

ield

(kg

ha–1

)

Z2

Figure 1. Interaction effect of Z and Zn on grain yield.

The study on the interaction effects of Z and Zn on morphological and agronomic char-acteristics indicates that the greatest rates of all studied traits were obtained by applying15 ton ha−1 zeolite and 0.1% Zn sulfate (Z2Zn2). The combined application of Z and Znimproved the rates of grain yield, biological yield, and harvest index to 43.82%, 73.99%,and 30.04%, respectively (Figures 1 to 3).

The study on the interaction effects of I and cultivar (C) on agronomic character-istics (Figures 4 to 6) reveal that the greatest rates of grain yield, biological yield, andharvest index were obtained by applying I1C3 (normal irrigation and Opera cultivar), butthe RGS003 cultivar had the greatest rates of these characteristics in stress conditions.

Discussion

There was a decrease in morphological and agronomic traits by interrupting irrigation atpod formation stage. Diepenbrock (2000) showed that pod per plant is the most sensi-tive yield component under drought-stress conditions. Drought stress affected the stagesof flowering to maturity over other stages of growth as demonstrated by Masoud Sinaki

Zn1

Zn2

Zn3

Z1 Z2

2335.083 3317.083

2641.917 4063

2967.5 3694.75

0500

10001500200025003000350040004500

Bio

logi

cal y

ield

(kg

h–1

)

Figure 2. Interaction effect of Z and Zn on biological yield.

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Responses of Canola to Zeolite and Zinc 7

Zn1

Zn2

Zn3

Z1 Z2

16.557 19.166

17.134 21.532

18.144 20.392

0

5

10

15

20

25

Har

vest

ind

ex (

%)

Figure 3. Interaction effect of Z and Zn on harvest index.

I1

I2

Licord RGS003 Opera

4789.583 4519.667 4894

1450 1732.75 1633.333

0

1000

2000

3000

4000

5000

6000

Gra

in y

ield

(kg

ha–1

)

Figure 4. Interaction effect of I and C on grain yield.

I1

I2

Licord RGS003 Opera

20639.833 19744.667 20995.833

10215.583 11086.333 10771.083

0

5000

10000

15000

20000

25000

Bio

logi

cal y

ield

(kg

–1)

Figure 5. Interaction effect of I and C on biological yield.

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I1

I2

Licord RGS003 Opera

23.101 22.774 23.224

13.822 15.236 14.768

0

5

10

15

20

25

Har

vest

Ind

ex (

%)

Figure 6. Interaction effect of I and C on harvest index.

et al. (2007). It is known that a decrease in plant height is due to decrease in cell divisionand assimilates transport. Increase in plant height occurs for two reasons, increasing thenumber of nodes and increasing the length of internodes, which are strongly influencedby water deficit (Wright et al. 1995). The results are descriptive of this fact that pod set-ting stage is a critical period for water consumption, and drought stress in these periodsdecreases pod number and grain yield. Mendham and Salisbury (1995) have reported thatsufficient irrigation at first of pod setting stage is vital for the production of desirable yield.The study observed that water-stress occurrence at first pod growth has effects on pod num-ber. Thereafter, drought stress has effects on seed number in pods. Decrease of 1000-seedweight is due to water loss and nutrients uptake by plant, and then consequent reduction ofassimilation, facilitated transfer to seed.

Positive effect of Z on morphological traits, yield, and yield components can be relatedto increment of nitrogen (N) availability and prevention of N leaching. Zeolite with highCEC acts as a sink for nutrients such as ammonium (Polat et al. 2004; Shirani Rad 2012).Water can infiltrate easily into the Z structure, and application of Z enhances water-holdingcapacity of the soil (Rehakova et al. 2004). Zeolite has the ability to reserve and main-tain water in itself and so increases the water availability to plant under stress conditions(Zahedi et al. 2009). Safaei, Shirani Rad, and Mirhadi (2008) examined the effects oftwo levels of Z (applying and not applying) and obtained a significant difference withZ treatments in all studied traits.

Foliar application of Zn sulfate indicated greater quality traits and oil yield because ofpotential factors such as increases in oxine biosynthesis and chlorophyll concentration,decrease in sodium concentration in plant tissues, and increase in N and phosphorousuptake in the presence of Zn (Malekoti and Tehrani 1999; Moinuddin and Imas 2008).Khurana and Chatterjee (2001) believed that the availability of Zn in soil solution declinedwith decreasing soil moisture content because of root growth limitation. Therefore, inwater-deficient conditions, the use of fertilizers should be balanced, and the consumptionof special fertilizers such as Zn sulfate has to be particularly considered.

The effect of the year was significant. It seems that it occurred due to more rainfall inthe months of April and May of the second year (Table 1).

This study shows that although applying Z and Zn had positive effects on the mor-phological and agronomic characteristics of canola, the greatest performance and the best

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Responses of Canola to Zeolite and Zinc 9

results were obtained using a combination of Z and Zn. Therefore, based on the low cost ofnatural Z and a low Zn intake, these treatments could be used to enhance the performanceof canola, especially in the regions that are exposed to water stress.

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