Inter-Relationships Between Yield And Yield Attributes Of Potato Grown Under Supra-Optimal Ambient Temperatures

Co Amadi,Ee Ene-Obong,Jc Okonkwo,Pi Okocha

doi:10.4314/gjpas.v15i1.44878

Abstract

Forty eight potato genotypes were evaluated in Saminaka (Lat. 100 27’N and Long 40E, Mean Min. Temp 25oC, Mean Max Temp 31.5oC) during the rainy season of 1999 and 2000 to determine the inter-relationship between yield and some important agronomic traits in the potato grown under high ambient temperatures. The genotypes were laid out in a randomized complete block design with three replications. The genotypes exhibited highly significant variability (P reduced period of exposure to heat stress. Number of tubers per plant (R2 = 0.383) and average tuber weight per plant (R2 = 0.125) had the highest coefficients of determination of yield and by far the highest direct effects on yield (87.5% and 66.9%respectively) when compared to other attributes suggesting that they were the major contributors to yield under supra-optimal temperature conditions and may be relied upon in selecting for improved yield under such conditions.

Highlights

The Potato Solanum tuberosum L is generally best adapted to cool temperate zones (Hawkes, 1978)
Almost all potato cultivars bred in northern latitudes respond to such conditions with delayed emergence (Allen, et al 1992), excessive haulm growth at the expense of the tubers (Ewing, 1981), increased rate of respiration (Sale, 1974), reduced dry matter accumulation (Bushnell, 1925), delayed tuber initiation (Menzel, 1980, Nowak and Coleborne, 1989) and maturity (Amadi, 2005) and a significant loss of tuber yield and quality (Levy, 1983, 1984)
The objective of this work is to furnish information on the interrelationship between yield and yield components with a view to identifying characters of utmost importance which can be used as selection indices for tuber yield improvement in the potato germplasm exposed to heat stress prevalent in locations with supra optimal temperatures

Summary

Introduction

The Potato Solanum tuberosum L is generally best adapted to cool temperate zones (Hawkes, 1978). The optimum temperature for tuber formation and growth for most potato cultivars is about 15-20oC (Borah and Milthorpe, 1962). The adverse effect of high temperature on tuber yield and quality of potato is a major constraint for potato production in hot regions, and local breeding for heat tolerant cultivar is necessary to improve potato crops in hot environment (Levy, 1984). Analysis of the interrelationship among important agronomic characters in the available germplasm is vital to the attainment of the objective of breeding for heat tolerance. The objective of this work is to furnish information on the interrelationship between yield and yield components with a view to identifying characters of utmost importance which can be used as selection indices for tuber yield improvement in the potato germplasm exposed to heat stress prevalent in locations with supra optimal temperatures

Objectives

Methods

Results