John Basera & Lennin Musundire The Master Farmer
In Zimbabwe, maize is life and the basis of the economy, as it is both a staple crop as well as a cash crop among small scale and large scale farm holds.
Food security in Zimbabwe can only be addressed through the cultivation of high grain yielding seed varieties such as maize hybrids. When we get food security right, then we are on the right track to get everything else right.
The previous Green Revolutions in Zimbabwe were fronted by surges in maize production figures and are attributed to the religious adoption of maize hybrid technology by smallholder and large scale farmers. Although mechanisation, fertilization and improved agronomic practices contributed to improving the maize grain yield in the previous green revolutions, more than 50 percent of the grain yield increases were directly attributable to the cultivation of high grain yielding hybrid technology.
There is no doubt that, even future revolutions will also be spurred by the continuous cultivation of this high grain yielding technology-hybrid.
Research in maize hybrid technology therefore has been and will always be a strategic factor and prime mover in increasing and sustaining grain yields and ensuring food security in Zimbabwe and in Africa.
The superiority of maize hybrids to other planting material is attributed to bigger, stronger and more vigorous plants, a phenomenon called hybrid vigour or heterosis, which we encourage farmers to tap into for maximum yields and returns.
Maize hybrid varieties will be coming from a background of intense selection and breeding whose focus is to select against abiotic (heat and drought, low nitrogen use efficiency, soil acidity and alkalinity), biotic (foliar and cob diseases) factors and response to different agronomic practices.
Resultant efforts has produced a number of maize hybrid varieties which have allowed farmers to adapt to the effects of climate change in their farming systems and different agro-ecological zones.
Grain yield advantage
The maize hybrid technology has proved to generate higher grain yields, increased incomes and reduced production costs. As grain yield increases, the cost of producing a ton of grain is reduced, thereby maximising margins for the farmer. Success of maize hybrids is attributed to its wide adaptability, stability across regions and across seasons, cob and foliar disease tolerance, heat and drought tolerance, stand ability and more importantly on superior grain yielding advantage.
Maize hybrids generally endows the three yielding components; excellent cobbing ability (long, fat cobs), high row number (normally up to 20 rows/cob) and high shelling out percentage (deep lying and bigger kernels).
That is where the superior grain yield advantage comes from.
Grain yield levels of 10-22 tons per Ha have been achieved by maize hybrids under good management among smallholder and commercial farmers. Numerous experiments in various agro-ecological regions of the country demonstrate superiority of maize hybrids over other planting materials by up to 68% even in low rainfall areas or seasons.
Maize hybrid technology and Climate Change
Generally maize hybrids endow drought escape and/or drought avoidance characteristics which makes them Climate Smart and hence pivotal in mitigating against climate change. In Zimbabwe we have 5 categories of maize hybrid seeds and depending with the agro-ecological region, one can choose the ultra-early, very early and early maturing hybrids in short seasoned Natural Regions such as 3 to 5 under dry land cultivation.
Examples of climate smart hybrids for this region include SC301, SC303, SC419, SC513, SC529 and SC533, to mention but just a few key ones that can withstand the rigor of drought and heat in this ecology.
The medium and late maturing categories are recommended in high rainfall potential regions such as Natural Regions 1, 2a, 2b and 3 and irrigated areas.
Notable hybrids that have transformed livelihoods and spurred farm profitability include SC627, SC633, SC649, SC719 and SC727
Long duration maize hybrids endow the stay green character, robust root and stalks with some having erect leaves, traits which make them adapt to heat and drought periods.
Latest maize hybrid varieties now endow also an extended pollen shedding period and an excellent pollen-silk synchronization aiding mid-season drought survival even at the critical flowering stages.
Maize hybrids are generally widely adapted, hardy and stable across seasons and agro-ecological regions, thereby consistently giving grain yields from one season to another and from one region to another.
The fundamental pillars to successful maize production are the choice of certified maize hybrid seeds suitable for one’s agro-ecological region coupled with the religious adoption of Good Agronomic Practices (GAPs).
The GAPs concept is key to unlock the genetic potential of hybrids and translate it to profitability. The GAP accounts for 50% of the productivity of hybrids.
Latest maize hybrid varieties are tolerant to important diseases such as Grey Leaf Spot, Maize Streak Virus, Blights, Rusts, Stalk rots, Phaesosphaeria Leaf Spot which can cause yield losses of >20%.
The first and smartest port of disease control in maize is the use of disease tolerant maize hybrids. Seed Co scored a first in developing hybrid maize varieties which were tolerant to Grey Leaf Spot and other diseases in the 1990s.
Maize hybrids are generally uniform aiding easiness and efficiency of crop management e.g. fertilisation, chemical weed control, harvesting, and industrial processing etc.
Specific maize hybrids are designed to suit farmer preferences and tastes with regards to grain texture for domestic uses-from dent types to flint types. Grain texture has a bearing on moisture and dry down, as dents dry down faster than flints.
Fast dry down allows early harvesting, and adoption of short rotations. Generally dents have a higher bulk density and hence higher yields as compared to flint grain types.
Grain moisture and dry down:
Grain moisture content is an important physiological process influenced by weather conditions and genetic make-up.
In maize production, it is an economically important trait that can increase growers’ production costs in relation to artificial grain drying and losses due to delayed harvesting (lodging, bird and insect damage, and ear rot diseases) and reduces turnover per year (you cannot adopt double cropping with slow dry down varieties). It is therefore prudent that in current new maize hybrids focus has been on developing products that have medium to fast dry down rate when they have reached physiological maturity thus ensure farmers harvest early. Crop uniformity which maize hybrid varieties endow aids easiness to do crop operations such as herbicide application, fertilization and harvesting.
Crop stand ability
Stand ability is of paramount importance as yield is derived from 2 aspects including yield per plant and yield per unit area.
However farmers are recommended to plant at optimum plant densities to get the best possible grain yields and maize hybrids possesses the ability to stand at these population levels. The robust root and stalk systems make maize hybrids resist root and stalk lodging at recommended populations making hybrids harvestable.
High yielding hybrids with short duration in the field and climate change
In trying to mitigate against climate change, scientists are churning out varieties which matures early and at the same time make the farmer attain higher grain yields.
These special type of short season hybrids take less in the fields thereby reducing exposure to terminal drought risks and still attain higher yields. Examples include SC301, SC 303, SC 419 and SC 529. These hybrid varieties are being developed under the Top Left Approach.
Hybrids are elastic!
The latest hybrid technologies are elastic in that, under excellent weather and management conditions, they express their full yielding potential at the same time a farmer can still attain yields even under stressful conditions. The hybrid technology responds to altitude in that when grown in low altitude areas with high risk of terminal droughts, the time to reach maturity shortens reducing the risk of crop failure due to terminal drought, but at the same time not compromising the grain yield and return for the farmer.
Technology empowers productivity
To achieve production levels that meet the challenge posed by growing demand for food, there is no doubt that adoption of technologies such as the maize hybrid technology, fertiliser technology, herbicide technology and mechanisation is overarching. Effort to research and breed crop seeds with improved genetic gains is critical to attain high productivity levels in climate changing environments to the fight against hunger. Continuous research in maize hybrid is a key factor in increasing and sustaining maize productivity levels in Zimbabwe and Africa.
However, having a good variety is one thing, adoption of other technologies such as the herbicide, fertiliser are also key to improved yields.
Growth in farmer yields starts with the right seed!
Farming Quote of the Week: “Starting farming is like drinking hot tea, it gets easier after the first sip. First sip you take is always hot but gets easier, tastier and you enjoy it as you go on. Take the first step and get things done!
Do not fear paying entry level school fees but learn from your first mistakes and grow” — John Basera
About the authors
John Basera is Seed Co Agrnonmy and Extension Services Manager.
+263 772 413 184/[email protected]
Lennin Musundire is Seed Co Group Senior Maize Breeder.
+263 772 697 627/lennin.[email protected]