Remote Sensing for phenotyping tar spot complex in maize

by Carolyn Cowan

Multispectral and thermal images taken by cameras on unmanned aerial vehicles (UAVs) are helping researchers to monitor the resistance of maize to foliar diseases.

A new study from researchers at the International Maize and Wheat Improvement Center (CIMMYT) can reduce challenges associated with plant disease assessment in the field. By deploying cameras mounted on unmanned aerial vehicles (UAVs) that capture image information from non-visible sections of the electromagnetic spectrum, the interdisciplinary team demonstrated the effectiveness of remote sensing technologies in maize disease phenotyping.    

“Plant disease resistance assessment in the field is becoming difficult because the breeders’ trials are becoming larger, the trials have to be conducted in multiple locations, and because sometimes there is a lack of highly trained personnel who can evaluate the diseases,” said Francelino Rodrigues, CIMMYT Precision Agriculture Specialist and co-lead author of the study. “In addition, the disease notes taken in the field by a human eye can vary from person to person depending on the persons’ experience.”

Preparing the UAV for radiometric calibration for multispectral flight over a maize tar spot complex screening trial. CIMMYT’s Agua Fria Experimental Station, Mexico. (Photo: Alexander Loladze/CIMMYT)

Shifting to a demand-led maize improvement agenda

In annual meeting, STMA project partners build on the successes of research in combatting drought, heat, pests and disease. 

By  Jennifer Johnson

STMA meeting participants pose for a group photo at a field day visit to Zamseed seed company, Lusaka, Zambia. Photo: Jerome Bossuet

Partners of the Stress Tolerant Maize for Africa (STMA) project held their annual meeting May 7–9, 2019, in Lusaka, Zambia, to review the achievements of the past year and to discuss the priorities going forward. Launched in 2016, the STMA project aims to develop multiple stress-tolerant maize varieties for diverse agro-ecologies in sub-Saharan Africa, increase genetic gains for key traits preferred by the smallholders, and make these improved seeds available at scale in the target countries in partnership with local public and private seed sector partners.

Tracing maize landraces, 50 years later

by Carolyn Cowan

Scientists track down the families in Morelos, Mexico, who donated maize landraces to CIMMYT in 1966-67. Would they still be cultivating them?

Maize is more than a crop in Mexico. While it provides food, feed and raw materials, it is also a bloodline running through the generations, connecting Mexico’s people with their past.

The fascinating diversity of maize in Mexico is rooted in its cultural and biological legacy as the center of origin of maize. Landraces, which are maize varieties that have been cultivated and subjected to selection by farmers for generations, retaining a distinct identity and lacking formal crop improvement, provide the basis of this diversity.

As with any cultural legacy, the cultivation of maize landraces can be lost with the passage of time as farmers adapt to changing markets and generational shifts take place.

Doctoral candidate Denisse McLean-Rodríguez, from the Sant’Anna School of Advanced Studies in Italy, and researchers from the International Maize and Wheat Improvement Center (CIMMYT) have undertaken a new study that traces the conservation and abandonment of maize landraces over the last 50 years in Morelos, Mexico’s second smallest state.

The study is based on a collection of 93 maize landrace samples, collected by Ángel Kato as a research assistant back in 1966-67 and stored in CIMMYT’s Maize Germplasm Bank. Researchers traced the 66 families in Morelos who donated the samples and explored the reasons why they abandoned or conserved their landraces.

Doctoral candidate Denisse McLean-Rodríguez (left) interviews maize farmer Roque Juarez Ramirez at his family home in Morelos to explore his opinions on landrace conservation. (Photo: E. Orchardson/CIMMYT)

Pest management must consider the landscape context according to ATTIC project PhD thesis

by Carolyn Cowan

The control of crop pests has long been linked with chemical products like pesticides and insecticides. However, chemicals are often too expensive for smallholder farmers and require careful, appropriate use to ensure effectiveness. What if we could take advantage of natural ecological processes to suppress unwanted organisms, lessening our reliance on external inputs? This is the topic addressed in “Hide and seek: management and landscape factors affecting maize stemborers, Busseola fusca, infestation levels in Ethiopia,” the recent Ph.D. thesis by Yodit Kebede, completed at Wageningen University, Netherlands with support from the CGIAR Research Program on Maize (MAIZE) and the International Maize and Wheat Improvement Center (CIMMYT). The implications of the research hold significance for prominent pest control challenges like fall armyworm in Africa and beyond.

Yodit Kebede signs her PhD diploma at Wageningen University, to her left stand her supervisors (l-r) Pablo Tittonell, Felix Bianchi and Frederic Baudron, March 2019. Photo: Anne de Valenca