Having been a certified organic market gardener and now a grower of organic medicinal herbs, I very much question the watering during the morning or during the heat of the day. When I was a market gardener, one of my main crops was the Australian butter pumpkin. I chose to grow this pumpkin about one acre a year on a three year rotation and during the hot sun of the day opens the pores of the leaf and the most detrimental growing procedure to this plant, amongst others, is to water, as it causes the leaf matter to burn, thus killing the plant. Also, photosynthesis occurs during the day (i.e. the intake of carbon monoxide which the plant changes into oxygen). During this process, the intake of water and the nutrient are minimal compared to the night. I request that your misinformation you offer be removed from your website. A grower of organic herbs and vegetable with 20 odd years experience. Regards Neil Price.
Certified GKH Gardening Expert
We recommend watering in the early morning hours or after the warmest part of the day.
Watering at the base of the plants is the best. Avoid overhead watering.
We do not recommend watering in the heat of the day, as you mention.
Here is an article that has more information.