Wine Grapes: A Science-Driven Approach to Pre-Bloom Nutrition
Optimizing the crop during early spring is essential for producing a top-quality harvest later in the year.
Growing a good wine grape is no easy task. A lot of variables need to be managed to ensure the crop boasts the right brix, color, phenolics and uniform maturity at harvest to meet the needs of the winemaker. By focusing on producing grapes with the right essential qualities growers can maximize their return on investment.
Achieving a high yield of marketable wine grapes requires a science-driven approach, one that uses the Five Rs: The Right nutrient applied at the Right time in the Right form in the Right mix targeting the Right location in the plant. Agro-K’s Science-Driven Nutrition™ employs these principles to help wine grape producers grow a consistently profitable crop.
In the viticulture industry, the focus on nutrition begins early in the season. There are many important crop timings throughout the season where vine and fruit nutrition levels can be influenced, including the pre-bloom window. Growers can get a leg up on the competition by starting their nutritional programs early in the spring when the ground is still cooler.
In a vineyard, many of the nutrients never leave the field. “When you go through and prune the shoots, the cuttings end up on the ground and the grower will disc them up to incorporate them into the soil,” says Sean Jacobs, Technical Sales and Marketing Representative at Agro-K. “Now, you have a cycle going on with the microbes in the soil breaking down the prunings making the nutrients available once again”.
Supporting the benefical soil microbes with the right nutrients promotes nutrient cycling which improves vine health. Agro-K’s NutriMax, a soil microbial food source, fills this need. Containing no living organisms, NutriMax provides soil microbes with minerals like cobalt, manganese and zinc to support growth of beneficial aerobic bacteria which increases fertilizer efficiency and speeds up nutrient cycling.
In the spring, microbial activity in the soil is minimal until soil temperatures reach 42 to 44 degrees Fahrenheit. Microbial activity increases above this point making it an ideal time to apply Nutrimax and further ramp up microbial activity and nutrient availability.
The period from bud break to 8 inches of shoot growth is significant for introducing proper foliar nutrition. This is when nutrients like nitrogen, phosphorus and potassium are needed to support rapid shoot growth and early flower development. Agro-K’s Agrobest® 9-24-3 provides these required nutrients in the right ratios during this important growth stage.
“As new plant tissues develop, Agrobest 9-24-3—a 100% ortho based phosphorus—is the right foliar product to get these nutrients into the leaf where they are needed,” says Rick de Jong, International Business Development Manager for Agro-K.
In addition to the right N-P-K product, wine grapes also benefit from foliar applications of Sysstem®-LeafMax and Symspray, a nutrient enhanced Ascophyllum nodosum extract. The micronutrients in these formulations support a number of growth processes.
Sysstem-LeafMax provides the chlorophyll building micronutrients magnesium and iron along with manganese for photosynthetic efficiency and zinc to encourage leaf size. In concert with cobalt, molybdenum and copper for nitrogen metabolism and protein synthesis, Sysstem-LeafMax ramps up the capacity of the plant’s photosynthetic machinery, maximizing sugar production.
An added benefit comes from the systemic, phloem-mobile nature of Sysstem LeafMax’s zinc and manganese formulation. In phosphite form, these nutrients are capable of moving with the sugars into new leaves, shoot tips, and developing roots. Because of the unique mobility of phosphite-complexed nutrients, applications of Sysstem-LeafMax result in stronger roots and shoots more quickly that non-phosphite formulations.
As the new shoots reach and grow beyond 8 inches in length, growers should continue applying Sysstem-LeafMax to maintain existing leaf function and boost that of the developing leaves. Combining Top-Set D.L. with Sysstem-LeafMax at this time introduces boron to the mix and further increases molybdenum levels.. Together, boron and molybdenum synergize to play a significant role in bloom and fruit set..
“Now we’re also starting to think about fruit set and to think about things that improve fruit set, like boron,” de Jong says. “Pre-bloom, we want to ramp up on our boron levels. Meanwhile, the molybdenum ensures that the nitrogen that’s in the system is being metabolized properly to build amino acids and proteins in the plant. Essentially, we’re setting the stage to support bloom and making sure the leaves and vines are healthy, well-supported and functioning.”
As the crop moves toward bloom, growers must focus on different nutrients—ones that will help promote wine grape development all the way to harvest. A science-driven approach is applicable at the end of the season as well.