Evaluation of Elite Potato Clones for Drought Tolerance in Western

UgandaImelda Kashaija, Vasiter Kesiime and Prossy Namugga

Kachwekano Zonal Agricultural Research and Development Institute (NARO- KAZARDI)

First Bio-Innovate Regional Scientific ConferenceUnited Nations Conference Centre (UNCC-ECA)

Addis Ababa, Ethiopia, 25-27 February 2013

Introduction

• Potato, Solanum tuberosum L., is grown by300,000 smallholder households in Uganda

• 689,000 tons on 101,000 hectares per year

• Major production areas are the highlands ofSouthwestern, parts of Eastern andNorthwestern Uganda.

• Its cultivation has spread to non-traditionalareas in central Uganda

• Potato production is being affected byfluctuation in precipitations in both timing andamount,

• Increased temperatures reduce productivity.

• Drought prevents Potato from realizing fullgenetic potential leading to harvest losses.

• In potato, water deficit leads to reduced yieldand tuber quality

MUBUKU

KALEGYERE

MBARARA

Increase in temperature greatly affected tuber quality and yield

• Substantial potato production is expandinginto locations at lower altitudes, wheredrought is more common.

• Therefore drought stress mitigationmeasures and coping mechanisms need tobe devised to face future challenges ofclimate change

Objectives

• Identifying potato clones resilient to waterand heat stress

• Determining the effect of temperatures on theperformance of the selected clones.

Materials and MethodsGenetic materials

• A set of nine potato clones bred for droughttolerance (393077.159, 396038.107, 396034.103,396015.6, 396031.108, 391046.14, 395111.13,395029.250 and 391691.96) were introducedfrom CIP

• Varieties; Kachpot 1 (393382.44), Nakpot 5(381471.18) and Victoria (381381.20) were usedas checks.

Screening

• Two consecutive seasons on- station

• One season on - farm

• In three sites with contrasting climaticconditions; Kabale (2400masl), Mbarara(1400masl) and Kasese (1000masl approx).

Materials and Methods

• For on-farm trials, farmer participation wasright away from planting and a group of 10farmers (5 men and 5 women) was selected

• Farmer evaluation was done at flowering andharvesting stages.

• Selection of best 3 clones with traits fordrought tolerance was based on agreedcriteria by the whole group.

Materials and Methods

M & M

Farmers evaluating Elite clones at Mbarara (Mwizii) during flowering, based on vigour, resistance to pests and diseases and then plants with many flowers,

Farmer participatory evaluation

• Farmer group from Kalengyere voted forvigour, erect stems and resistance to diseaseand pest attack especially late blight.

• While those in Kasese (Isule) selected basingon vigour, green leaves and erect stems .

M &M

Data collection Number of flowered plants, number of flowers, height to the 1st

leaf, number of stems, plant height, number of branches, number ofleaves, number of leaflets, petiole lleaflet length, leafletwidth, length and leaf area. number of leaves between the previous5th and current 5th leaf (added leaves) .

Farmer participatory evaluation

• Weak significant differences were observed among the farmers’selection at Kalengyere and Isule, while there were highlysignificant differences among clones selected by farmers in Mwiziat flowering stage

Results

MS

Source of variation

Kalegyere Mwizi Isule

Rep stratum 0.2 0.7 0.7

Clone 44* 98.5** 98.5*

Residual 15.4 6.4 6.4

ResultsAt harvesting stage, farmers in

• Kalengyere based selection on high yield withmany and big tubers, free from diseases andpests, red coloured and round shaped tubers.

• Mwizi based on disease and pest attack, highyielding (many large tubers).

• Isule based on tuber size and number, freedomfrom pests and diseases.

• No significant differences observed amonggenotypes from farmers’ selection at harvestingstage both within and across sites.

Mean scores given to each clone at flowering and harvesting

Mean

Clone Kalegyere Mwizi Isule Multilocation

Flowering Harvesting

393077.159 14 9.5 1.5 7.3b 8.3

396038.107 2.5 0.0 4.0 2.3de 2.2

396034.103 6.0 3.5 10.5 1.7e 8.3

396015.6 0.0 0.5 1.0 2.7de 0.5

396031.108 7.5 2.0 4.0 3.7cde 4.5

391046.14 3.0 2.0 14.5 3.2de 6.5

395111.13 6.0 3.5 10.5 14.3a 6.7

395029.250 0.5 1.5 3.0 3.2bcde 1.7

391691.96 4.0 4.0 3.0 2.3de 3.7

393382.44 3.0 1.5 2.0 5.8bcd 2.2

381471.18 5.0 10.5 10 7.0bc 8.5

381381.20 9.0 11.0 1.0 5.3bcd 7.0

• Selection by farmers at flowering stage did notnecessarily march that done at harvesting stage, but wassomehow related.

• However, some consistence was observed with theirchoices.

• Further evaluation and selection can lead to the releaseof these clones as drought tolerant varieties since theyare already liked by famers.

Clone performance: Yield

• Analysis of variance from the three on-station trialsrevealed high significant differences at (p<.001) aswell as clone performance on-farm

On station

Results

MS

Source of variation d.f Y/HA WT TNT

Rep stratum 1 4.34 3.5 122.7

Clone 11 48.95*** 39.7*** 13084.3***

SITE 2 1138*** 921.8*** 192865.4***

Clone.SITE 22 24.*** 19.*** 6780.4***

Residual 35 2.84 2.3 827.7

Total 71

Clone performance on farm

Results

MS

Source of variation d.f Y/HA WT TNT

Rep stratum 1 4.34 3.5 122.7

Clone 11 48.95*** 39.7*** 13084.3***

SITE 2 1138*** 921.8*** 192865.4***

Clone.SITE 22 24.*** 19.*** 6780.4***

Residual 35 2.84 2.3 827.7

Total 71

Clone KLG MBZD MUB MWONGYERA MWIZI ISULE MEAN

395111.13 22.39 10.22 7.06 38.9 4.8 14.6 16.3

393382.44 20.61 9.57 5.06 50.3 6.4 1.2 13.4

396031.108 15.72 13 3.39 38.3 3.5 5.8 13.8

381471.18 21.17 7.01 1.72 45.9 7.9 10.6 15.7

395029.25 17.83 5.91 3.5 24.9 6.4 4.2 10.2

396038.107 18.56 7.46 0.11 27.6 4.7 8.4 10.1

396034.103 16.39 5.28 3.61 27.1 1.6 6.3 10.4

393077.159 21.39 0.02 0.72 26.5 6.4 9.4 12.4

381381.20 14.23 4.61 2.56 24.9 6.4 8.5 10.2

391046.14 13.72 4.25 2.11 15.6 3.1 5.7 8.4

396016.6 6.82 5.33 2.78 24.3 1.9 3.7 6.5

391692.96 4.01 4.79 0.06 19.3 2.6 0.3 6.2

Mean 16.07 6.46 2.72 31.1 4.7 6.6

Performance of clones in different site

Results• Of the twelve clones evaluated, six gave above 10t/ha implying

that they can be grown in the three agroecologies profitably.

• clones 395111.13 and 393382.44 gave fairly good results acrossthe three on-station sites meaning that further selection canlead to varieties adopted to hotter areas.

• clones that were least affected vegetatively were the ones thatgave high yields (395111.13 and 393382.44) this implies thatthey tolerent increased temperatures.

• The poor performance of 395111 .20 (Victoria) is un explained bythese results since it’s widely grown in most potato growingareas in the country.

Results

• Kalegyere offers a homely environment for potatogrowing and this explains the high yield obtainedboth on station and on farm.

• Differential performance of clones at MBAZARDIand Mubuku explains how the different clonesrespond to drought in the two environments.

• With an increase in temperatures, yield and othergrowth parameters were greatly reduced.

Growth Parameters

• Variation was observed for all the tested parameters at the six sites

• Clones showed significant differences in number of flowered plants, number offlowers, number of leaves, number of stems, leaflets length, leaflets width andleaf area.

• The interaction of clone and sites was significant only for plant height, numberof stems and number of leaves.

• Number of leaves was least reduced in clone 395111.13, 395029.250,396038.107 and 396031.108. leaves were mostly reduced in clone 381381.20,393077.159, 391046.14, and 396038.107.

Way Forward

• Final farmer participatory selection of promising clones at flowering and harvesting stages (2 seasons).

• Involve farmers and other private institutions in selecting clones with good cooking and processing quality ( chips and crisp)

Acknowledgement

• Funding Agency

• All partners

THANK YOU