CIMMYT breeders selecting new CIMMYT line candidates in stage 4, scoring hybrid entries according to their drought tolerance in Kiboko research station – 5 September 2019
To accelerate annual genetic gains under various stress conditions, maize breeders are looking at cost-effective ways to assess a larger number of maize plants and to collect more accurate data related to key plant characteristics like kernel number and size per ear, leaf angles or ear heights.
Recent innovations in digital imagery and sensors, packaged in what plant scientists call high-throughput phenotyping platforms, save money and time by replacing lengthy paper-based visual observations of crop trials with real-time big data collection and management.
Authors of a recent review study on high-throughput phenotyping tools observe that obtaining accurate and inexpensive estimates of genetic value of individuals is central to breeding. Under the Stress Tolerant Maize for Africa project, researchers like Mainassara Zaman-Allah use drone and create new digital tools, like the ear analyzer, for cheaper and faster plant selection. Drone cuts data collection costs by 25 to 75 percent compared to conventional methods. The ear analyzer allows to collect maize ear and kernel trait data 90 percent faster. This mobile app has been used by CIMMYT and the GOAL NGO to assess the extent of fall armyworm impact on maize crops yield in eastern Zimbabwe.
Read more about how STMA makes maize breeding faster and cheaper here
Agriculture, Ecosystems and Environment 268, 79-89. DOI: https://doi.org/10.1016/j.agee.2018.09.006
Abstract: The 2015/2016El Niño was the most severe on record in southern Africa and was associated with drought and heat stress. To help farmers to cope with such extreme production constraints the International Maize and Wheat Improvement Centre (CIMMYT), has been developing multiple stress tolerant maize varieties through a rapid-cycle breeding strategy. These CIMMYT stress tolerant maize hybrids were evaluated using two types of trials. The first one comprised a regional on-farm trial with forty maize varieties (20 early-intermediate and 20 intermediate-late varieties), planted across 30 locations in four countries in southern Africa. The second set comprised a multi-locational evaluation trial with six hybrids that were tested under conventional ridge tillage (CP) and conservation agriculture (CA) using a randomized block design with each farm as replicate in nine extension planning areas (EPA), across two years. CIMMYT stress tolerant varieties outperformed non stress tolerant varieties. CZH142020 (5.6 t ha −1) and CZH131008 (4.8 t ha −1) had significantly higher yield advantage over commercial control varieties (<4.5 t ha −1) in both early and late maturity groups. They also had larger grains and smaller ear uniformity index (EUI) (calculated as among plots ear size variance); compared non-stress tolerant varieties. In the CA/CP evaluation trial, varieties under CA yielded ≥0.7 t ha-1 more grain compared to those under CP. Therefore, combinations of climate-smart agriculture technologies are required to mitigate negative effects of extreme events like El Niño and increase resilience of low-input farming systems.
Stress tolerant maize varieties have been named as one of the 10 best innovations for adaptation in agriculture to help smallholders improve food security and livelihoods while adapting to the impacts of climate change. Read More.