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Get ready for springtime blossom

Image of almond blossoms with omex logo on top of it

(Sponsored) A good harvest starts with a good bloom. Use winter to get your trees ‘bloom ready’, say OMEX® agronomists Francisco Rivera Guerrero and Saul Perez. 

Focus on the bloom and nothing but the bloom. That’s how trees are programmed to behave when they wake in springtime; all systems go, setting up the tree for flowering. 

To pursue that objective effectively, trees rely on the stored carbohydrate and arginine (nitrogen) reserves that (hopefully) growers have boosted with post-harvest fertilizer applications. 

If you’ve made those fertilizer applications, well done — your trees will thank you. But don’t fully congratulate yourself unless you’ve also thought about applications of calcium and boron, critical nutrients that can significantly affect orchard success during bloom. Limited or inadequate supplies of either element can drastically influence harvest yield. 

Start with calcium. It’s an essential ingredient in the process of cell division. Flowering represents the most elevated cell-division activity at any time in the tree’s annual cycle. If there’s insufficient calcium during bloom, the tree conserves what it has available. Net result? It will shed flowers that don’t receive enough calcium. There you have it: an immediate hit to yield potential. Even after flower shedding, if calcium levels remain inadequate growers can expect slow and disappointing nut development. 

Then there’s boron. Vital for good pollination, it’s involved in pollen tube creation. Insufficient boron means no pollination, and further flower shedding. Boron’s also implicated in carbohydrate translocation between leaf tissue and the developing nut. Again, if boron isn’t available or levels are inadequate, the result is poor nut set and nut drop. 

Yet there’s something else that these two nutrients have in common, besides their essential role during bloom and subsequent nut development. Because they’re both immobile in phloem, to move these nutrients around, the plant must move them in the water-transporting xylem vessels. 

What that means, is that for calcium and boron to move through the tree successfully, water must evaporate from the leaves in order to create the transpiration stream that fuels xylem water movement. 

Spotted the problem? 

Yes, in a tree like the almond, where flowering occurs before the tree leafs out, there is no significant transpiration draw — at least, until the tree has leafed out to 50-75% of full cover. 

Hence the need to prepare for springtime blossom. It’s essential that when almonds awake from dormancy, they have access to sufficient levels of calcium and boron. It’s this kind of application we had in mind at OMEX® when we developed Cell Power®️Ca9 + B. 

It contains calcium and boron, in conjunction with OMEX®️’s Enhanced Bioavailability (EBA) formulation science technology — designed to prompt the plant into maximizing absorption and use of nutrients. Alongside the two essential flowering nutrients, we’ve included chelated forms of copper, iron, manganese and zinc, too. 

When applied to nut crops at pink bud, full bloom, and post-bloom stages, it will provide all of the crop’s calcium and boron requirements. It may also be applied throughout the growing season to help keep calcium and boron ‘topped up’ at optimum levels — essential if growers are to maximize photosynthetic efficiency during the all-important nut development and shell seal stages. 

While we’re on the subject of bloom preparedness and nutrient usage — don’t get caught out by bacterial blight. This pernicious disease, also known as bacterial canker or bacterial blast, is caused by Pseudomonas syringae and has often been a serious problem for Western nut producers. Recent years have seen a decline in prevalence, as the bacteria favors high moisture and low temperatures in spring, but it remains a threat. 

February 2021 saw the Environmental Protection Agency and California Department of Pesticide Regulation permit the use of kasugamycin to control bacterial blight, during bloom and up until petal fall. However, it should be seen as a ‘fire truck’ treatment — and growers can take earlier steps to try to reduce the potential for blight to develop. 

Cell Power®️Zynergy™ is what’s known as a ‘functional fertilizer’ — it works to complement the activity of established agrochemicals. Containing copper — an element instrumental in the plant’s defense system — and zinc, involved in physical defenses such as the epidermis and leaf cuticle, and with a role in disease suppression, Zynergy™ works as a tool both to boost agrochemicals’ mode of action as well as better withstand pathogenic attack. Crucially, it also appears to reduce the risk that pathogens can develop resistance to control products. 

Used early in the season, Zynergy™ — which isn’t registered as a pesticide — can be tank-mixed with other bloom-time foliar applications at a rate of 1-2 pints per acre and gives growers reassurance that their trees are in optimal health to fight against pathogenic attack from bacteria and fungi. 

The OMEX® team is always available to answer queries and questions from growers about nut nutrition. 

Learn more at 

The product names and brands referenced here are registered and trademarks of OMEX® Agrifluids, Inc. 

© OMEX® Agrifluids, Inc. 2021. 

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