UArizona Hires Two Extension Specialists

The University of Arizona hires two Cooperative Extension specialists, Dr. Debankur Sanyal (Soil Health) and Dr. José Luis Diaz (Weed Science). Both started serving the state based at the Maricopa Agricultural Center (MAC). Here’re short biographies of our new CE specialists:

Dr. Debankur Sanyal

Dr. Debankur Sanyal is a soil biogeochemist by profession and going to serve as an Assistant Specialist in Soil Health in the Environmental Science Department at University of Arizona, starting January 2022. He has a Ph.D. degree in Soil Science from North Dakota State University in 2018 and worked as a postdoctoral research associate at South Dakota State University since then.

As a researcher, he actively seeking answers to the fundamental questions about carbon nutrient cycling in the agroecosystems at multiple scales as impacted by plant-soil-microbe-climate interactions, using approaches that range from laboratory incubations to greenhouse trials to extensive field trials. Through his research program, he aims to create a climate-resilient, sustainable, and healthy agro-environment for human welfare. One of his passions is to develop cost-effective, applied, stakeholder-oriented methodologies to quantify the influence of various soil management and conservation techniques on soil biogeochemical properties and crop production.

Debankur has worked extensively with diverse crop production systems using soil conservation techniques such as minimum tillage, cover crops, livestock integration, diversified crop rotation, and manure application. Along with applied and basic research, his extension and outreach activities include participating in ‘Soil Health School’ and other workshops, demonstrating tools and techniques, and providing essential training to use them. Dr. Sanyal’s goal is to actively work with the stakeholders to design and carry out applied, stakeholder-oriented research, based on their needs and interests.


Email address:

Phone: (520) 621-1646

Please see his full CV here:

Dr. José Luiz Dias

Dr. José Luiz Dias joins the Plant Science Department at the University of Arizona in January 2022 as an Assistant Professor and Extension Weed Scientist. The challenges of economic, effective, and sustainable weed management are greater than ever with the fast-growing world’s population, the burdens of climate change, loss of water resources, labor shortages, greater pesticide use restrictions and herbicide resistance. Thus, in his new role with UArizona, José hopes to conduct an effective statewide extension program, as well as a meaningful research program based on grower’s needs, for weed biology, ecology, integrated weed management and innovative technology.

Before joined UArizona, José worked for one year at the University of California Cooperative and Extension (UCCE), as a Field Crops Agronomy and Weed Management Farm Advisor in the Northern San Joaquin Valley where he developed a multi-county extension and applied research program, targeted at solving growers’ problems and optimizing crop yield and sustainability for growers and allied industry. Prior to joining UCCE, José was a postdoctoral researcher at the University of Wisconsin, Madison, where he worked on identifying management practices and environmental factors to ensure successful establishment of alfalfa interseeded into corn silage, sustainable management of waterhemp in established alfalfa for dairy systems, and weed control, clover selectivity and resulting yield of grassclover mixed swards.

José earned a Doctoral Degree in Agronomy with a focus on Weed Science from the University of Florida, a Master’s Degree in Crop Protection and Bachelor’s in Agronomy from São Paulo State University in Brazil. His doctoral research centered on developing and implementing integrated management practices to reduce giant smutgrass populations in bahiagrass pastures. For his master’s degree, he researched herbicide selectivity in pre-budded sugarcane seedlings.


Email address:

Phone: (520) 621-1977

Irrigation termination of Cotton

Ayman Mostafa and Ed Martin

Last irrigation is a very crucial decision for cotton grower to make. There are some very applicable procedures to determine when to stop irrigating your cotton crop in Arizona. Three primary considerations are involved in determining the terminal irrigation:  agronomic stage of the crop, weather conditions and insect pest pressures. Putting these considerations in mind, the following steps can help you make your decision on irrigation termination:

  1. To know where you are in the fruiting cycle.  Are you at cutout? (In Arizona cutout is the point at which the crop has an average of 5 or less nodes above the white flower (NAWF) during the primary fruiting cycle.)
  2. Once you have determined where you are (at cutout – 2 weeks out) you need to start deciding whether or not to go for a top crop. The decision on whether to go for a top crop primarily lies with how well your crop has set bolls and what the overall boll load was after the first primary fruiting cycle.
    1. Research has shown that if you have 45% or more fruit retention (first two fruit sites on each fruiting branch) the probability that extending the season will result in significant yield gain is low. This probability is reduced even further as fruit retention goes up.
    2. Full season varieties have the best chance for a top crop with significant yield increase.
  3. In order to realize any real significant increase from a second crop, you need hot and dry weather. Remember you need about 600 HU in order to go from flower to hard boll, and then another 400 HU to get to open boll.
  4. Keep in mind that the last bloom you want to harvest will typically take an additional 3-5 weeks of growth. You will need to irrigate and manage pests for that extended length of time. 
  5. If you want, you can pick the last boll you want to harvest.  This typically only takes 2-3 weeks of additional management.
Heat units (86/55°F) are required for fresh blooms to reach mature bolls and open bolls.

  1. Don’t get greedy, be reasonable and practical – cotton will keep on producing flowers and before you know it, you’ll be irrigating in October.
  2. A good rule of thumb is to defoliate at about twice your normal irrigation interval. 
    1. So if you are irrigating every 10 days, you want to apply defoliant about 20 days after your last irrigation (assuming no rain has occurred). 
    2. You need to do this to assure the effectiveness of the defoliant.
    3. You want a plant in stress – but not too much so the defoliant can’t do its job

Additional references can be found at the following links:

The 2021 UArizona Cooperative Extension Field Crops “Clinics”

We had the UArizona Cooperative Extension Field Crops “Clinics” on January 27, 2021, our first event in 2021. Here’re links to presentation recordings and presentations of these clinics, as well as the Arizona Pest Management Center (Field Crops) YouTube Channel.

  • Management Approaches for Alfalfa Weevil – Dr. Ayman Mostafa, Mr. Kyle Harrington
  • Pesticide Registration Review Update – Dr. Al Fournier
  • Trends in Cotton Insect Management & What’s Next? – Dr. Peter Ellsworth, Ms. Naomi Pier, Ms. Isadora Bordini
  • Managing Pests and Crop Growth for Optimum Cotton Production in Arizona – Dr. Randy Norton
  • Cotton Disease Identification and Management – Dr. Jiahuai “Alex” Hu
  • Resistant Palmer Amaranth Control – Mr. Blase Evancho
  • Recent Weather/Climate and La Niña/Seasonal Outlook for Spring – Dr. Mike Crimmins
  • Small Grain Growth and Development – Dr. Mike Ottman
  • Improving Alfalfa Yield with Applications of Balanced P and K Fertilizers – Dr. Worku Burayu, Dr. Ayman Mostafa
  • On-Line Resources to Make Digital Zone Management Maps – Dr. Pedro Andrade Sanchez
  • Market Outlook and Policy Considerations – Dr. Russ Tronstad