If weather is too cool or too hot, pollination does not occur well. In the early part of our growing season tomato flowers often do not set fruit because it is too cool for pollination (below 70 degrees). Pollination is also poor when temperatures become too high (above 90 degrees). Partial shade would reduce temperature.
Although we have had many days this summer higher than these temperatures, it is usually for only a few hours. We normally have several hours each day that is suitable for tomato pollination and fruit set.
This year, I planted plants of three tomato varieties in my back yard where they receive about six hours of direct sun per day. I also planted these same varieties in a community garden plot, which gets full sun all day long. The plants in full sun are bigger and have produced almost twice as much fruit per plant as the plants in partial shade.
This article mentioned several other factors to improve tomato yield. One of these was deep watering to reach the full depth of the roots. This is a good recommendation. Tomato roots often grow to a depth of 10 to 12 inches. It takes a lot of water to reach that depth.
The article also recommended harvesting fruit before it is fully ripe. This may be a good practice if fruit is touching the ground where it may rot. However, in our dry humidity that is seldom a problem. Fruit flavor and sweetness is better if it is allowed to remain on the plant until ripe or almost ripe.
The recommendation for mulching is a good idea for all vegetable plants. I often apply grass clippings as mulch for my vegetables. It reduces water evaporation and reduces weed seed germination. Bark dust is also a very effective mulch. When mulch is incorporated into the soil after the garden is fully harvested, it improves the soil for next year’s garden.
As to direction of planting, I don’t think it makes any difference whether you plant north to south or east to west.
