The To-Do List for Almond Growers: Weeding Orchards and Watering Roads

Weeds are the bane for any farmer. And weeding is the necessary evil – not to mention labor intensive and costly.

Tall weeds invade an almond orchard.          -  UC IPM photo

For almond growers, weeds and other orchard debris can lead to lower financial returns from processors this fall. That’s why there’s a flurry of activity in almond orchards, says field scout Jenna Horine.

With harvest around the corner, growers are clearing the orchard floor to prepare for shakers to knock the nuts off the tree and onto the ground for drying.

 

Here’s some tips to help clean the orchard floor before harvest:

Growers are mowing weeds to prepare for the harvest.

•        Keep the floor as level as possible. Some growers will till and drag the floor to level high spots and fill holes. Remember loose soil needs time to firm up.
•     A level surface lets you adjust the height of sweepers to operate more efficiently and reduces the amount of debris collected in the bins.  
•        Blank nuts fall before the good almonds do. So consider tilling again to fill depressions.
•      Try to avoid conditions that can lead to leaves falling early before harvest. Potassium-deficient orchards, water stress and aphid infestation can lead to early leaf fall.
•   Check with your pest control advisor about applying a pre-harvest herbicide in the row middles.

Watering the roads can keep mites in check.

In the meantime, Jenna says most growers have applied their hull split sprays to control pests such as navel orangeworm. On the other hand, more mites are starting to show up in orchards. Growers are trying to control the mite problem by watering dirt roads despite tight water supplies. They don’t have a choice because it’s important to keep the dust down to keep from stirring up mite activity.

“Trucks are watering the roads all the time,” Jenna says. Keeping the dust down, though, will be a challenge this week: Temperatures are expected to stay in the sizzling mid-100s all this week.

Cotton Cartography Can Set the Course Achieving Better Yields and Profits

Ancient cartographers never imaged anything like Google and Apple maps. For them, hand-drawn maps were perfectly fine. The same is true for cotton growers.

They don’t need fancy high-tech tools to put pen to paper to diagram cotton plant growth during the season – from early squaring to nodes above cracked boll. This practice can help boost yield and profits.

At the moment, plants are at their 10^th and 11^th nodes, according to field scout Carlos Silva. He is finding more lygus during his field sweeps with summer now here.

Now is an important time to monitor the development and health of the cotton plants over the course of the growing season. Analyzing the results and comparing to UC IPM crop guidelines can help guide important pest and disease management decisions.

Plant mapping doesn’t have to be complicated since you don’t want to fall into the trap of gathering too much information. 

 Plant monitoring during early squaring focuses on plant vigor and square retention.  You should measure for plant height, the number of main stem modes and the first position squats on the terminal five fruiting branches. Generally, a square retention rate of 80 percent or higher is ideal for going into bloom. UC IPM has an online tool to calculate the percentage of retention.

Square retention evaluation helps determine the need for lygus management. Growers should track the percentage of retention of the first-position squares on the top five and bottom five fruiting branches. The information helps determine the need for lygus bug management. Don’t forget to keep records.

If retention drops, growers might opt to use growth regulators to enhance development. They should check with their pest control advisor or local University of California farm advisor before making any application.

Mapping comes in handy later in the season when plants develop further when growers start monitoring nodes above white flower and nodes above cracked boll and looking toward harvest. 

They key to success is doing it regularly to check up on the crop’s progress. Happy mapping.

Time to Split Coming Early for Almonds in the Valley, State

Early hull split. Farmers and almond experts anticipated it because of California’s drought and tight water supplies.

Jenna Horine spotted this splitting almond hull.

Well, it has arrived to the northern San Joaquin Valley. Field scout Jenna Horine confirms what had been a smattering of reports of an earlier than normal almond hull split occurring in orchards around the state.

 

Jenna spotted hulls splitting in an orchard along the Interstate 5 corridor in Los Banos in Merced County. That grower started hull split sprays over the weekend.

Hull split stages - initial separation

Hull starts to open up.

Initial drying of the almond.

Completely dry. (UC IPM photos)

In the past couple of weeks, almond expert and Merced County UC Cooperative Extension advisor David Doll had been receiving a few reports about early hull split from various locations around the state. He notes water stressed orchards and those with tight water allocations are most likely to see the early splitting of the green hulls. Usually, we see hull split in early to mid-July.

As a result, many farmers are anticipating an early harvest. Jenna, for example, points out one grower is getting a head start by preparing his orchard floors for tree shaking to knock off the nuts. 

Hull split is an important time for pest management. Growers treating for navel orangeworm need to time their summer applications to the start of hull split and egg laying. Peach twig borer and hull rot fungi also are threats at this time.

Here’s what UC IPM says: “The longer the nuts remain on the tree after hull split, the longer the interval that they are exposed to these invaders. Therefore, harvest your almond crop as early as possible to reduce the time it will be exposed to these pests and to avoid complications caused by early rains. If the threat of navel orangeworm is severe, the orchard can be harvested twice; once to remove the early ripening nuts and the second time to remove the later ripening ones.”

There is one catch: Not all the nuts ripen at the same time. Ripening will start on the upper and outermost sections of a tree. Experts recommend using pole pruners to cut branches from the top southwest section of a half dozen trees to see if hull split has started. Other UC IPM tips:  O

•  Continue monitoring trees until 95 to100 percent of the fruit at eye level are visibly split.
• Shake a few trees to determine if nut removal is satisfactory. If not, try again in a few days.
• Harvest blocks with poorest sanitation first. 

In the fields meanwhile, field scout Carlos Silva says alfalfa is on the verge of its third harvest of the season. Plants are approaching 24 inches in height, making them ready for harvest. Worms and lygus are on the uptick because of the recent heat wave, but they aren’t worrisome because of the upcoming cutting.

Carlos has reminded growers this is an important time to leave strips of uncut alfalfa if their crop is near a cotton field. This practice will maintain a habitat for the lygus and keep them from invading the cotton.

This strip cutting practice is important to protect cotton plans, which are developing nicely. Most plants are reaching 10 mainstem nodes with three to four fruiting branches. Right now, Carlos says lygus counts are low, but he anticipates finding more this week during his sweeps as alfalfa growers start cutting their crop.

Be a Good Neighbor to Cotton: Strip Cut Your Alfalfa Field

In recent days, you might describe field scout Carlos Silva as part Paul Revere and part State Farm insurance agent.

His jingle might sound like this: “Like a good neighbor, Carlos is there” to spread the word to alfalfa growers that the “lygus are coming, the lygus are coming” to a cotton field near you.

Lygus a threat to cotton. (UC IPM photo)

With the first squares emerging on cotton plants across the Valley, it’s time for farmers to start worrying about lygus invading their cotton fields. And these pests could be traveling from a nearby alfalfa field.

Yes, Carlos reports lygus bugs are plentiful in alfalfa fields, one of their favorite habitats. As growers prepare to start the third harvest, or cutting, in the coming week, he is going around reminding them about the importance of leaving strips of uncut alfalfa in the fields, especially where there is cotton growing nearby. The strips will leave a habitat for lygus to stay in and keep them from fleeing to a cotton field, which is not their preferred home.

“I am starting to talk about strip cutting and being a good neighbor,” Carlos says.

Strip cutting wasn’t important during the first two harvests of the season because cotton season had just started. But now the first squares are developing on the cotton plants.

Strip cutting alfalfa helps control lygus in nearby cotton fields.

Indeed, UC IPM reports lygus bugs are a threat to cotton from the earliest squaring through final boll set. The pests pierce squares, which can shrivel, turn brown and drop to the ground. Losing too many squares will trigger vegetative growth in the plants and end up reducing yields.

Here are tips from UC IPM about strip cutting alfalfa to manage lygus:

• Maintain nearby alfalfa fields in a succulent condition.
• Avoid cutting all alfalfa fields in an area within a short time period. Leave an uncut strip or check at each cutting along the border between alfalfa and cotton to slow lygus migration.
• If lygus populations get very high, uncut strips of alfalfa may be treated with an insecticide if needed, but sprays should be avoided where possible to protect beneficials.

For alfalfa growing next to a cotton field, UC IPM recommends:

• Planting a sufficient area with alfalfa, manage for succulent growth, and alternate cutting half of each strip every two weeks.
• Cutting back with a stalk cutter. In a 28-day cycle, many lygus eggs will be inside the cut stems and will die as the stems desiccate.

Carlos says this practice should be followed for alfalfa fields that are within a two mile radius of a cotton field. These bugs can easily travel that far when their habitats are disrupted during harvest.

  

 Speaking of alfalfa, we hope growers caught today’s Alfalfa Pest and Crop Management Field Day at the Scout Hut in Dos Palos. The event featured Dr. Pete Goodell of UC IPM, Fresno County ag specialist William Griffin and pest control advisor and agronomist Francisco Parra.  Those who missed their presentations about the alfalfa aphid outbreak this year, non-fumigant VOC regulations, vertebrate pest control and drip irrigation in alfalfa will be able to catch the talks on YouTube. Check out the Sustainable Cotton Project’s website for details.