Responsiveness of different potato (Solanum tuberosum) varieties to phosphorus fertilizer

Daoui K., R. Mrabet, A. Benbouaza, and E.H. Achbani Institut National de la Recherche Agronomique (Maroc)

Introduction

In the Mediterranean Basin, potato is occupying an overall area of about one

million ha and producing 18 million tons of tubers,

In Morocco, potato occupies an area of about 50000 to 58000 ha annually.

The national production is about 1000000 to1400000 tones so with a national

main yield of about 23 t/ha which is below potential yield of about 40%.

Optimizing phosphorus fertilization is one way to reduce the gap between

actual and potential yield.

Potato in the world

 Harvested area (ha) Production (t) Yield (t/ha)

Afrique 1 541 498 16 706 573 10,8

Asie et Océanie 8 732 961 137 343 664 15,7

Europe 7 473 628 130 223 960 17,4

Amérique latine 963 766 15 682 943 16,3

Amérique du Nord 615 878 25 345 305 41,2

MONDE 19 327 731 325 302 445 16,8

Table 1. Potato production and yield in different part of the world(Source : FAO, 2008)

Figure 1. Potato world production (1991 – 2007) (FAOSTAT)

World 

Developed countries 

Developingcountries 

Potato in Morocco

Zone d'office Zone de DPA

Superficie (ha)Production

(T)

Superficie

(ha)Production (T)

GHARB 4410 155660 SETTAT 6725 206 500

LOUKKOS 3650 92040 KHENIFRA 4835 97 000

MOULOUYA 3375 125670 EL HAJEB 4600 144 250

DOUKKALA 2475 74200 CASABLANCA 4170 73 030

SOUSS-MASSA 2170 60060 RABAT-SALE 3135 78 050

HAOUZ 2135 52825 CHEFCHAOUEN 2025 41 000

OUARZAZATE 700 22100 MEKNES 1955 71 430

TAFILALETE 430 11740 EL JADIDA 1900 49 600

TADLA 120 3970 KHEMISSET 1765 30 615

FES 1500 45 000

BEN SLIMANE 1220 18 740

TETOUAN 1010 18 855

AL HOCEIMA 1000 17 175

Table 2. Production area of potato in Morocco(Source: MAPM/ DDFP, 2010)

Labour charge is very important from planting till harvesting

Phosphorus in question

Phosphorus is one of major mineral nutrients required by Potato crop and its

management in soil is critical. In fact, Potato requires a high amount of phosphorus

for optimum growth and yield, However, P uptake and use is also dependant on

genetic variability with the crops as well as the P fate in the environments including

the soil.

Accordingly, a better understanding of mineral application and use by crops is one

way for enhancing crop yields with a minimum impact on environment and reducing

production costs. The use of genetically enhanced plants with improved P acquisition

efficiency may represent a sustainable solution to increase crop yields.

In Morocco:

Only 50 % of farmers use fertilizers

Soil phosphus content in Saïs RegionSoil phosphus content in Saïs Region

Source:Source:

Fertilty Map of MoroccoFertilty Map of Morocco

Executed by the consortium:Executed by the consortium:

INRA – IAV - ENAINRA – IAV - ENA

Objectifs

The objective of this study is to assess, under field conditions,

responsiveness of different potato varieties to mineral

phosphorus application.

Materials & methods

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FES

TAZA

OUJDA

IFRANE

MEKNES

TANGER

AGADIR

BOUARFA

TARFAYA

LARACHE

TAN-TAN

TETOUAN

KENITRA

DAKHELA

NOUASSER

LAAYOUNE

MARRA KECHESSAOUIRA

SIDI-IFNI

EL JADIDA

KHOURIBGA

CASABLANCA

OUARZAZATE

RABAT-SALE

ERRACHIDIA

KASBA-TADLA

CHEFC HAOUENE

Pluviométrie moyenne annuelle au Maroc

Benaouda. H & Essadi. C, Laboratoire d'Agrométéorologie et Systèmes d'Information Géographique, INRA Settat.

Pluie (mm)< 100100 - 300300 - 450450 - 650650 - 850850 - 1050

Province#Y Stations

A field trial was conducted at El Annaceur ((INRA, Morocco) situated 20 km far from Fès

at latitude 33°41’, longitude 4°,50’ ; height 1345 m.

Soil characteristics are: clay (27%), silt (53%) and sand (20%). pH water (8,4).

NO3- (11,6 mg/kg). Organic Matter (2,80 %), P2O5 (Olsen) (67 mg/kg) and K2Oexangeable

(520 mg/kg).

Seven potato varieties (Desirée,

Nicola, Barna, Pamela, Daifla,

Labella, Marguerita)

Combined with two phosphorus

treatments:

P0 : without any P application

and

P+ : 90 kg P2O5/ha as super

triple phosphate (45%)).

The experimental design was a

split plot with three replications,

P on main plots and varieties on

subplots.

Every subplot consisted on one line of 3m long of each variety separated on both sides by the check one (variety:

Desirée) at distance of 0.70m. Ten tubers by variety were planted on each line.

Nitrogen was added at the

rate of 50kg N/ha at planting

and another 50 kg N/ha at

tuber formation as ammonium

nitrate

The trial was implemented on

May and harvested on

August. The crop was under

drip irrigation system ,

Trial was well protected

against parasites and weeds.

At maturity for every treatments (V*P) each ten plant have been harvested and tuber yield was estimated

The data were subjected to analysis of variance procedures (SPSS). Standard errors of the means were calculated. NKS test was applied to compare measured parameters from variety.  

The responsiveness of variety “i” was calculated on the basis of:

Vi: potato variety i

TY: tuber yield of potato (t/ha) of variety i

P+: treatment with added phosphorus as fertilizer.

P0: treatment with no added phosphorus as fertilizer.

)0(

)0()((*100)(%)(Re

PTYi

PTYiPTYiVisssponsivene

Results

Effect of phosphorus and genotype on tuber yield of potatoes

Both variety (V) and phosphorus (P) have a significant effect on tuber yield of potato while interaction

(V*P) had no significant effect on this parameter (figure 1).

Tuber yield varied between 16 t/ha for treatment (Barna (P0)) and 36 t/ha for treatment Pamella (P+).

Phosphorus improves tuber yield by about 25%. .The variety Pamela gave the highest main tuber yield

(34 t/ha) and performed well in both situations of P nutrition (P0 and P+). 

Responsiveness of potatoes varieties to phosphorus fertilizer

Figure 2. Responsiveness of different potatoes varieties to phosphorus fertilizer

Responsiveness of varieties to phosphorus application varied between 9% and 71% (figure 2). The

variety Desirée showed the highest responsiveness to P application with 71% of improvement of tuber

yield, while the varieties Daifla, Labella and Pamela responses to P application was on average only

10%. The varieties Nicola, Margarita and Barna responded to phosphorus application by respectively

18, 27 and 49%.

Hypothesis

Phosphorus use efficiency

availableavailable P

PTB

PTB

GY

P

GYPUE

PTB

GY

availableP

PTB

Corresponds to grain yield per unit of P absorbed or phosphors

utilization efficiency (PUZE) And

Is P absorbed per unit of available phosphorus or phosphorus

uptake efficiency (PUPE).

Genetic adaptation of plants to low phosphorus supply

Mechanisms which improve P acquisition Mechanisms which improve P utilisation

Root morphological characteristics

Root growth and distribution

Root diameter

Root-hair development

Mycorrhizal association

Root physiological characteristics

P uptake systm

P mobilization in the rhizosphere

Partitioning of P within the plant

Remobilization of P within the plant

P status of the harvested organ

Efficient utilization of P at the cellular level

Intracellular compartmentation of P

Metabolic requirements for P

Figure Mechanisms which improve genetic adaptation of plants to phosphorus-limited tropical soils. (Rao et al. (1999))

Within this experiment, even if just for one year, we do find genetic variability

to phosphorus responsiveness among different potatoes varieties.

This indicates that choosing efficient variety may guarantee an improvement of

tuber yield with less phosphorus fertilizer demand.

This work should be reconducted. More measures should be made to

characterize genotypes and elucidate differences in performances among

those genotypes

Conclusions

Acknowledgements

Workers and technical staff at the experiment station of El Annaceur (Morroco) are gratefully acknowledged