Following a 3-Legged Approach for a Successful Cotton Crop This Season

 Experts say fast-food giant McDonald’s based its tremendous worldwide growth on a three-legged stool business model. The combination of three things – operators, suppliers and employees – provided the foundation to success.

You might same cotton growers rely on a three-legged approach to achieve a successful harvest: Monitoring square retention in the spring to guide lygus pest management strategy; monitoring nodes above white flower to determine cut-out in mid-summer and the end of lygus monitoring in mid-summer; and monitoring nodes above cracked boll (NACB) to establish the time for defoliation around early fall.

Right now, growers are on the third leg and headed on the back stretch toward harvest time. Most have completed the last irrigation of the season, according to field scout Carlos Silva.

Carlos says bolls are starting to open up on the bottom quarter or third of the plants. He anticipates growers will start defoliating their fields soon.

Like last year, harvest expects to arrive a couple weeks earlier than usual, according to growers. You might see the first harvesters roaming the fields in late September in some locales.

In this final stage of plant monitoring, the average number of nodes above cracked boll helps growers time defoliation and determine potential yield loss and the loss of fiber quality in immature bolls, according to UC Integrated Pest Management. 

Here’s what UC IPM says: Ideal timing for defoliation occurs when unopened harvestable bolls are an average of four or less nodes (including missing branches) above the highest first position cracked boll. If it becomes necessary to defoliate a field prematurely at an average of five NACB because of a honeydew-producing insect infestation, a yield loss of less than 1 percent will occur; at six NACB the loss will be less than 2 percent.

UC IPM recommends growers pick five plants randomly from four areas in each field. Select plants that have a cracked boll on the first position fruiting branch (see the chart). Then find the top cracked first position boll and use this as “fruiting branch zero.” Count the number of nodes above the fruiting branch zero until reaching the uppermost harvestable boll on the plant. This boll should be large and mature enough to be able to open before the scheduled harvest date. The number of nodes counted above fruiting branch zero is the NACB. To calculate NACB, take the total number of nodes above cracked boll and divide them by the total number of plants sample (20).

• Four NACB is used as a target for the first harvest aid in Upland/Acala
• Three NACB is used as a target for defoliant timing in Pima

UC IPM offers more information about cotton plant monitoring on its website.

On pest front, Carlos reminds growers to turn their attention to aphids and white flies now that lygus bugs are no longer a threat. While aphids and white flies are mostly in check at the moment, growers need to remain vigilant to prevent an outbreak that could lead to sticky cotton problems.

In the alfalfa fields, pests also are under control. Growers have finished irrigating and are now preparing for at least one more harvest this month. This is good news. It’s turning out to be a fairly normal season for alfalfa, an important commodity for the state’s dairy and cattle industry. Because of the drought, growers had been worried that they would come up short on water and end their season as early as June. Fortunately, they have been able to get additional water to extend their season through the summer.

In the orchards, almond field scout Jenna Horine says early varieties, primarily nonpareils, are pretty much harvested. Last week, she spotted some farm crews heading into the orchards with hand poles to knock the leftover nuts off the trees. It’s not too early to get those mummy nuts off and avoid problems with navel orangeworm next year. Kudos to these growers.

Pole used to knock off mummy nuts. (UC IPM photo)