A következő források alapján a fentiek szerint fordítanám a két kifejezést:

Oltott zöldség:
Két zöldségpalánta sikeres párosításából jön létre az oltott zöldség. A kertbarátok körében az oltott szó fogalma sokkal ismertebb, mikor gyümölcsfákról beszélünk. A kedvelt gyümölcsfajták csemetéi mind oltott fácskák. A nemes vesszőt egy alany növényre oltják. Találkozhatunk még az oltással a dísznövények körében is. Sok örökzöld és díszfa van, melyeket szintén oltanak. Ezek a gyümölcsfák és dísznövények már régóta ismertek, de az oltott zöldségeket hazánkban még nagyon kevesen ismerik.

http://www.borhykert.hu/kerteszetbudapest/OLTOTT-ZOLDSEGEK--...

Ennek megfelelője a forrásnyelven:

Grafting:,
Grafting or graftage[1] is a horticultural technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together. This vascular joining is called inosculation. The technique is most commonly used in asexual propagation of commercially grown plants for the horticultural and agricultural trades.
In most cases, one plant is selected for its roots and this is called the stock or rootstock. The other plant is selected for its stems, leaves, flowers, or fruits and is called the scion or cion.[1] The scion contains the desired genes to be duplicated in future production by the stock/scion plant.

http://en.wikipedia.org/wiki/Grafting

A pinched kifejezést az interneten fellelhető hivatkozások alapján fordítanám metszettnek.

Pinching

Pinching, otherwise known as tipping, is a pruning method generally used on young plants to encourage branching.
Too, these terms can be used when referring to the removal of plant buds to discourage branching. Confusing, right? Once explained, these techniques are easy to understand and valuable to use.
When a plant begins to grow from seed, it usually breaks through the soil as a single stem upon which leaves begin to form. And, it will continue to grow in this single stem formation indefinitely if not pinched. Eventually, the plant will begin to allow new buds to open, causing the plant to become bushy. However, growers can stimulate bushiness early in the plant’s growth by simply removing the tip of the plant manually. This is desirable because it can help develop full, lush plants rapidly. And, it can be done on some plants like Fuchsia to keep hanging baskets and flower beds lush for the growing season. Yes, it will mean flowering starts later, but in the end the look can be much more beautiful.
Do note: Pinching must be done properly and should not be performed on more mature plants, woody shrubs or trees. When trees are “tipped” this is called “topping” and can be seriously detrimental to your plant.

http://www2.fiskars.com/Gardening-and-Yard-Care/Projects/Too...

Újabb hivatkozás:

Pinching Seedlings
When and how should I pinch seedlings that I’m growing inside?
Answer: Pinch back your seedling to promote a bushier shape. Wait until your seedlings have three or four sets of true leaves. (Do not count the two initial “seed leaves” that appeared when the seedling first sprouted.) Then simply use your fingers or a pair of sharp, clean scissors to remove the stem and top one or two pairs of leaves, clipping back to just above a set of leaves. The plant will form two branches from this point. Don’t remove more than a quarter of the leaves at one time.

http://www.hortmag.com/weekly-tips/qa/pinching-seedlings

Define Pinching Plants
Pinching plants is a form of pruning that encourages branching on the plant. This means that when you pinch a plant, you are removing the a main stem, forcing the plant to grow two new stems from the leaf nodes below the pinch or cut.

http://www.gardeningknowhow.com/garden-how-to/info/pinching-...