Maize production: the first 40 days
Farmer's Weekly|December 03, 2021
In this article, the first in a two-part series, Magda du Toit speaks to experts about the different growth stages of a maize plant in the vegetative phase, as well as the crucial management practices to follow during this time to achieve optimal yield. Advice on weed control is also included.
Magda du Toit

Maize farmers who properly understand the growth and development of their plants are better able to apply the correct production and management practices at the right time, and thereby achieve optimal yield.

While producers have no control over environmental stress conditions such as rain or drought, they can mitigate these risks. For example, they can choose a hybrid cultivar, improve their tillage methods, improve the condition of the soil, apply fertiliser, rotate crops, irrigate, and control pests and diseases.

There are two developmental phases in the life cycle of the maize plant: the vegetative phase (V phase) and the reproductive phase (R phase). The former provides the foundation for the latter.

EMERGENCE

Stress at certain critical growth stages of maize during and after emergence can reduce yield dramatically, says Kobus Lindeque, head of Syngenta’s seed business in Africa.“To start with, a proper seedbed and a good, uniform plant population during the emergence stage is necessary for ensuring the planned yield. It’s important to follow the recommendations of the seed companies regarding the specific hybrid in correlation with the area where the maize is cultivated.”

Lindeque adds that poor or staggered emergence can be problematic. “The longer that seedlings take to emerge, the greater the chances are that soil-borne fungus pathogens can penetrate the plant, leading to damage and yield loss.”

Soil temperature higher than 15°C is required for uniform emergence and vigour. Cool soil inhibits root development and, consequently, moisture and nutrient absorption, slowing development.

During germination, the stem and growth point are 25mm to 40mm below the soil surface. Under warm, moist conditions, seedlings emerge after six to 10 days; under cool or dry conditions, this may take two weeks or more. The optimal temperature range for germination is between 20°C and 30°C, while the optimal moisture content of the soil is about 60% of soil capacity.

After emergence, the plant continues to develop through the various leaf stages, V1 to VT, each representing the number of leaves produced by the plant during that particular stage (see box for explanation).

According to Andries Wessels, seed product development manager at Syngenta, the period from emergence until the V5 stage is critical, and any form of stress placed on the plant throughout this time will have a negative impact on yield.

“From V3 to V5, the number of [kernel] rows per ear that the plant will produce has already been determined. This key yield-determining stage is called the switching point, and for the rest of the season the yield potential can only be maintained or lowered, depending on the growth environment. Yield cannot be increased beyond the switching point stage, and by V8, the number or kernels per row has been laid down.” From V3 to V5, the growth point is still underground, where it is heavily influenced by soil temperatures. A low soil temperature can extend the time between leaf stages, and although damage caused by hail, wind and frost at this stage has little effect, it can delay the growth period by a few days. In addition, waterlogging while the growth point is still below ground, especially when associated with high temperatures, can result in significant stand loss.

Continue reading your story on the app

Continue reading your story in the magazine

MORE STORIES FROM FARMER'S WEEKLYView All

The Boathouse

Seclusion. Quiet. Natural beauty. There’s plenty of all three at The Boathouse on Boskop Dam, a delightful spot where you can relax, do a bit of fishing, canoeing, and birding, and watch gorgeous sunsets from the waterside deck. Riaan Hattingh reports.

4 mins read
Farmer's Weekly
January 21, 2022

Putting an end to the problem of food waste

In South Africa, about 30% of local agricultural production is wasted every year, which is equivalent to an estimated R60 billion, or around 2% of GDP. In a country where 30% of households are at risk of hunger, 31% experience hunger and 13 million children live in poverty, this waste is unsustainable and needs to change, says James Brand, a senior associate in ENSafrica’s Natural Resources and Environment department.

5 mins read
Farmer's Weekly
January 21, 2022

Crop spraying

The knapsack sprayer is ideal for controlling small outbreaks of pests, as it’s economical, can be applied quickly, and is very accurate, says Bill Kerr.

2 mins read
Farmer's Weekly
January 21, 2022

Worthy winners: a robot harvester and an innovative planter

Of the 16 silver medals awarded by the German Agricultural Society, organiser of the 2022 Agritechnica Innovation Awards, one went to the manufacturers of an autonomous robot for broccoli harvesting, while another recognised an implement that combines sowing and crop residue management.

2 mins read
Farmer's Weekly
January 21, 2022

How intensive sheep farmers can improve traceability and profits

Intensive sheep farming has given eastern Free State farmer Gareth Angus the opportunity to increase his lambs’ survival rate, boost profits and ensure traceability from birth to farm gate, while also decreasing predation and elemental risk. Susan Marais visited Angus’s farm during the 2021 LRF Stockman School.

6 mins read
Farmer's Weekly
January 21, 2022

How to save money in 2022

With the Christmas tinsel tidied away for another year, it’s time to face the economic realities of 2022. For many farmers, this means focusing on how to ensure a profit in the face of soaring input costs. Susan Marais asked industry experts for their suggestions on how to cut expenses without compromising farming operations.

7 mins read
Farmer's Weekly
January 21, 2022

Protecting the rhino through translocation

Due to the demand for rhino horn, populations of this iconic mammal have declined over the years. One solution to this is to introduce rhino species into other environments. Mike Knight, chairperson of the African Rhino Specialist Group at the International Union for Conservation of Nature, describes the process of translocation.

5 mins read
Farmer's Weekly
January 21, 2022

Good weather predicted for summer 2022

Favourable weather patterns have been forecast for the Southern African Development Community countries in 2022. High rainfall, for example, is predicted for South Africa‘s summer grain production region. Annelie Coleman reports.

3 mins read
Farmer's Weekly
January 21, 2022

Balancing risk to build a table grape brand

When the Beukes brothers expanded their table grape farming operation from the Hex River Valley to Brandwacht near Worcester in the Western Cape, they had no idea of the challenges this would bring. Jacques Beukes shared some of the lessons they learnt with Wouter Kriel.

8 mins read
Farmer's Weekly
January 21, 2022

Are you geared towards these developing trends?

The COVID-19 pandemic has accelerated the rate of digital integration and sped up advances crucial to the future success of many industries, including agriculture. Lindi Botha reports on the main trends that will influence farming this year.

7 mins read
Farmer's Weekly
January 21, 2022