W
atermelon breeding today is not 
only about choosing the right 
traits, but about delivering them 
reliably in a crop where many of the most 
important characteristics are polygenic, 
highly sensitive to environment, and 
increasingly exposed to external pressures 
beyond the breeder’s control.
Across the interviews, a clear picture 
emerges of a discipline under strain but also 
in transition. Breeders still walk fields, cut 
fruit, taste, score texture and judge plant 
architecture with trained eyes,  because 
no algorithm can yet replace experience. 
But climate volatility, rising disease pres­
sure and shrinking crop protection options 
have pushed watermelon breeding toward 
larger trial networks, deeper exploration 
of genetic diversity and heavier reliance on 
molecular and digital tools. The challenge 
is not whether to modernise, but how to 
do so without losing the practical intuition 
that has always defined successful breeding.
CLIMATE CHANGE: BREEDING 
FOR THE WEATHER YOU DON’T 
RECOGNISE ANYMORE
Few breeders speak about climate change as 
an abstract future scenario. It’s already 
here, and it is already rewriting what 
“normal conditions” mean.
Diego Maestre, global 
crop manager melon & water­
melon at BASF | Nunhems, 
describes climate adver­
sity as one of the pillars 
shaping his programme’s 
WHY IT MATTERS
If Part 1 explained what breeders 
are aiming for, this Part 2 explores 
why it’s so difficult to deliver. 
Watermelon may be a global 
success story, but its breeding reality 
is increasingly defined by pressure: 
climate volatility, rising disease 
incidence, evolving virus threats, and 
fewer crop protection tools available 
to growers.
At the same time, many key traits 
in watermelon such as sweetness 
stability, yield consistency, earliness 
and quality under stress, are 
polygenic and heavily influenced 
by the environment. Add the crop’s 
relatively narrow genetic diversity, 
and the job becomes a long-term 
balancing act: improving resilience 
and resistance without sacrificing 
flavour, colour, texture and shelf life.
This matters because the seed 
sector is now being asked to do 
more with less: fewer chemical 
options, tougher seasons, higher 
retailer demands, and consumers 
who won’t accept a “nearly good” 
watermelon. The next generation 
of varieties will depend on smarter 
trialling, better use of germplasm, 
and a growing toolkit of genomics, 
markers, digital phenotyping and 
(potentially) gene editing, all in 
service of one outcome: reliable 
performance in the field and reliable 
quality on the plate.
THE HARD SCIENCE BEHIND 
A PERFECT SLICE
WHY RESILIENCE, RESISTANCE AND ADVANCED TOOLS NOW DEFINE WATERMELON IMPROVEMENT.
BY: MARCEL BRUINS
vision. Growers face rising temperatures, 
unpredictable heat waves, soil-borne dis­
eases, exhausted soils and increasing salin­
ity. These pressures, he stresses, are daily 
realities. In response, breeding moves 
toward toughness: stronger root systems, 
improved plant coverage to protect fruit 
under extreme heat, and rustic varieties that 
can thrive under challenging conditions. 
This work requires persistence, long-term 
thinking and a global perspective, because 
the genetic pool must be broad enough to 
supply solutions for different regions.
But Maestre adds a key warning: resil­
ience is not enough. If the final fruit doesn’t 
delight consumers, the science doesn’t 
matter. Taste quality remains an uncom­
promising standard.
Jovan Djordjevic, watermelon breeder 
at Murray River Seed Co., and director of 
the UC Davis Plant Breeding Academy, 
describes climate pressure in direct, prac­
tical terms: heat waves, water stress, storms 
and erratic production windows are now 
realities across growing regions worldwide. 
His breeding vision leans toward varieties 
Watermelon variety ‘Polinesia'. 
Photo: Bayer
36  I  SEED WORLD EUROPE  I  SEEDWORLD.COM/EUROPE | MAY 2026

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