Open-pollinated Seedlings Research Articles

Effects of Topsoil-subsoil Fertilizer and Lime Amendments on Top and Root Growth of ‘Stuart’ Pecan Seedlings in a Simulated Norfolk Soil Profile1

Abstract Fertilizer and lime topsoil treatments increased top and root growth of open-pollinated seedlings of ‘Stuart’ pecan [Carya illinoensis (Wang.) K. Koch] under simulated Norfolk profile conditions in the greenhouse. Positive response was greatest on root growth when lime was added to the subsoil. Rate of tap root growth in the subsoil was increased 64% by increasing subsoil pH from 5.1 to 6.5. Lime additions to the subsoil reduced weights of lateral roots in the topsoil and increased yields in the subsoil. Subsoil lime at 2 and 3 meq Ca/100 g soil (pH 6.0 and 6.5) increased yields of the small feeder roots 3 and 6 fold over the untreated check (subsoil pH 5.1). Acid subsoils can be an important factor limiting growth of pecan roots under soil conditions prevalent in much of the Southeast.

Heritability and effect of selection in open-pollinated seedlings of Cryptomeria japonica D. DON

Heritability and effect of selection in open-pollinated seedlings of <i>Cryptomeria japonica</i> D. DON

Breeding Peach Rootstocks Resistant to Root-knot Nematodes1

Abstract A new root-knot nematode (Meloidogyne sp.) of peach which occurs in Florida overcomes the resistance of Okinawa and Nemaguard rootstocks (Prunus spp.). Resistance to this new nematode obtained from crosses and open-pollinated seedlings of Okinawa, Chico II, and P. davidiana has a heritability (narrow sense) of 0.31 ± .04. Two selections, Fla. 14-11 and Fla. 9-4, combine the nematode resistance of Okinawa and Nemaguard with resistance to the new nematode.