There is yellowness on the leaves, please help me, my friend.?

Yellowing is PH drift, your plants are not eating what you have been feeding them because cellular respiration is not happening at night in a high RH environment, no new water goes out, and no new water up stem, this means nutrients have been building up in the soil causing ph to drift most likely alkaline. PH test before you do anything find out if she is still in range.

Your daytime RH is 65%, goodness knows what its going up to at night with those big plants, at 70+rh she will close her stomata to prevent "drowning" for lack of better term, the stomata are required to be open to eject water vapor, this is the essential nighttime opposite of photosynthesis, if cellular respiration os crippled all night then nothing you do all day gets processed. You need to setup a correct negative pressure, create a 40-55 RH environment, and hold it for flowering. The cohesion-tension theory explains how negative pressure enables water movement from the roots to the leaves of a cannabis plant. As water evaporates from the leaf surfaces through stomata, tension is created, generating a suction force that pulls water upwards through the xylem vessels. This process relies on the cohesive forces between water molecules, forming a continuous column for efficient water transport. In cannabis plants, xylem vessels serve as the conduits for water transport. These specialized cells form interconnected channels that allow water to move upwards from the roots to the leaves. The negative pressure generated through the cohesion-tension mechanism helps drive the water flow within the xylem vessels. Negative pressure facilitates the movement of water from the soil, through the roots, and up to the leaves of cannabis plants. It helps maintain proper hydration and turgor pressure, ensuring the cells remain firm and upright. This is crucial for healthy growth and structural support. Negative pressure transports water and aids in the uptake and transport of dissolved nutrients within the cannabis plant. As water is pulled up through the xylem vessels, essential nutrients and minerals are transported along with it, supplying the various tissues and organs where they are needed for optimal growth and development.

Hi my growmie, I think that you have fertilized too much. In the pictures of the buds I notice that the leaves are curved upwards in jagged shapes. That is a sign of too much fertilizer. The yellow leaves indicate that you are either not fertilizing enough with Calmag or that you have a deficit due to the overdose. My suggestion would be less flowering fertilizer and more Calmag. But!!! You would have to write how much to fertilize and how often.

Hi bro, The yellowing of your plant's leaves and the curled-up bud leaves could be indicative of a few different issues, but a common culprit is a magnesium deficiency. Here's why and what you can do: Symptoms of Magnesium Deficiency: Yellowing between veins: This is a hallmark sign of magnesium deficiency. The veins themselves may remain green initially. Leaf curling: The edges of the leaves, especially older ones, may curl upwards or downwards. Stunted growth: Magnesium is essential for chlorophyll production, so a deficiency can impact overall plant health and growth. Possible Causes: Soil Issues: Soil type: Some soils naturally have low magnesium content. Overwatering: Excessive watering can leach magnesium from the soil. Soil pH: Magnesium availability is reduced in soils with high pH (alkaline). What to Do: Confirm Deficiency: Visual Inspection: Carefully observe the leaves for the characteristic yellowing between veins. Soil Test: Conduct a soil test to determine the exact nutrient levels, including magnesium. Adjust pH: If your soil is alkaline: Lower the pH to a range of 6.0-6.5, which is optimal for magnesium uptake. You can use pH down solutions available at most garden centers. Apply Magnesium Supplement: Cal-Mag: This is a common and readily available supplement containing calcium and magnesium. Follow the product instructions for application rates. Epsom Salt: Epsom salt is a good source of magnesium. Dissolve it in water and apply it to the soil or as a foliar spray. Merry Christmas buddy.