Spring Expert Advice for Growers

In a recent roundtable with West Pak’s field team, these ag-experts stepped up with their best words of advice for California growers for May and into June. Southern Field Manager Andrew Gabryszak, Northern Field Manager Mike Harberson, Northern Operations Field Manager Ralph Gonzalez, and Field Buyer Nick Lahr all weigh in.


According to the team, California growers are about 75 percent through the bloom in most of the growing areas, so around 25 percent of the flowers remain. “Be sure you already have your bees out. Your fruit set is going to be coming in, so it’s very important to make sure you can get good pollination for next year,” says Nick, kicking off the conversation.

Andy adds, “The pro gib sprays (Gibberellic Acid— a plant growth regulator sprayed on to enhance pollination) is another tool that we’re continuing to test. Pollination with Zutano pollen — we’ve been doing for ten plus years. It’s done in addition to other measures and is really beneficial if you have no bees on your property. But even if your property has a ton of bees, we still do the hand pollination. Auto pollination and planting Zutanos and stuff interspersed in the grove is always a plus.”


A recent heatwave did a number on the fruit remaining on the trees as it started them into the shading process. According to Nick, this shading usually is indicative of time to get the fruit off.

“We are two to three weeks ahead on maturity with the shading of the fruit,” interjects Andy. “The spring rains were great, but that also advanced maturity. Even though our weather has been mild in the last several weeks since the heatwave, its repercussions are petrifying. Between the heat and flowering, it led to a bunch of fruit drop, and a lot of growers worried about the current crop on the trees. Growers see fruit on the ground, and they want to pick, so it’s a panic harvest. The heatwave from a few weeks ago is the reason for the condition of the market today.”

According to Mike, the heat was an issue in the north to some degree. “We have a lot of ranches that are inland, and with the heat, there was some darkening of the fruit and fruit drop, causing some panic picking. We’re in a little different situation up here as when you get closer to the coast, it’s cooler, and growers have more of a luxury to hold their fruit and can wait for size. It takes the fruit longer into spring and summer to size up due to the cooler coastal influence.”

Pruning and Planting

Ideally, the timeframe for pruning is late winter into spring. However, according to Mike, there’s a lot of different ideas out there on the subject, and there is still some pruning and planting happening in some groves.


When it comes to fertilization, the West Pak field team is always looking out for what best for California growers.

“Down in the south, we are applying calcium along with a little bit of nitrogen to stick the fruitlets. To increase the set there is the new calcium thiosulfate, which we are testing a little bit. There is also the old standby, the calcium nitrate with a 17-0-0 (CAN-17) or 15-5-0-0 with calcium that we are putting on right now to help stick the fruit. Typically it is applied at this time because it carries the extra calcium to aid in fruit set and fruitlet retention,” Andy outlines.

“Will be looking at the results between the calcium thiosulfate and the calcium nitrate, whether it be the 17-0-0 or the 15-5-0-0 liquid-solid. Between the calcium nitrate and the calcium thiosulfate, we’re using them side-by-side to see if there is a difference. Do we make a switch in the future for the years down the road? Is there another tool in the toolbox that can help increase fruit production? We will keep you posted.”


One concern when it comes to pests is the lace bug. It seems to be popping up in spots and making an appearance in groves that have never looked for it or treated for it. The lace bug doesn’t necessarily do any economic threshold damage to the fruit itself, but it could get bad enough to defoliate the tree just as the looper did in the past.

“The north has not run across what we have in the south with the lace bug,” says Andy. “Seeing the lace bug on the young leaves as they are starting to harden off is worrisome, but the good thing is that it’s coming at the same time that we might be monitoring for avocado thrips, so we can possibly kill two pests with one treatment if we need to treat for the thrips. But it’s something to keep an eye on in case it does gets out of hand.”

He continues, “We are starting to see the fruitlets, which are vulnerable to the avocado thrips, so we are definitely keeping track of those numbers. With that little heat spell that we had a few weeks ago, it was detrimental to the old fruit on the trees, but it was good to get a little bit knocked down on the early populations of avocado thrips.”

With the recent cool mornings and mild temperatures, it’s in the benefit of the avocado thrips. Their numbers could increase drastically in a matter of weeks, as they’ll move from the flush to the fruitlets quickly, and we could reach an economic threshold quickly.

“Luckily, the natural predators have been building up in the groves since we haven’t had to spray, and the numbers have been low enough lately to where we have a good number of beneficials that possibly we could not spray. We don’t have any beneficials for the lace bug yet, because they seem to be recurring at a regular interval in the areas that they were last year,” adds Andy.

The consensus? Talk with your pest control advisor (PCA). Always.


The team agrees that watering and keeping trees hydrated is a top priority, especially now as we head into the warmer months.

“Sometimes, if you’re holding this year’s crop, you are setting fruit for next year. You’re losing old leaves and new leaves coming on, so there’s and a lot going on, and you just don’t want to skip on the irrigation. That is the most important thing right now. If you skip a water cycle in the heat, you’re going to lose a lot of that new fruit set,” mentions Mike.

“Also, keep an eye on the weather —I know it’s going to get warm there’s not a whole lot we can do just keep the trees hydrated. It won’t have the east winds until the fall, so that’s not really a major concern right now. It’s more just the heat inland, just want to make sure you’re not skimping on your irrigation.”

“With the fruit set, the trees need extra water, and not every grower knows that,” Nick adds. “They just keep watering with the same timer that they have been for the last three months. Check your weather station and stay ahead of it, as it takes 24 hours or more for the water to flow from the soil up through to the leaves. So, if you’re watering when it gets hot, it’s too late.”