The effect of moisture stress on nursery-grown guayule with respect to the amount and type of growth and growth response on transplanting
1945
Kelley, O.J. | Hunter, A.S. | Hobbs, C.H.
An experiment was conducted to determine the effects of soil moisture stresses, ranging from very high to very low, on the amount and type of growth in the nursery and the after-transplanting growth responses of guayule nursery stock. Guayule plants grown under high moisture stresses in the nursery in comparison with plants grown under low moisture stresses (a) produced significantly less vegetative growth; (b) when transplanted, resumed growth more quickly, grew more vigorously, and in fall transplantings had much higher percentage survival; (c) were comparatively better able to withstand unfavorable conditions after transplanting; and (d) had higher rubber and lignin contents, and in the fall had higher inulin contents. Guayule plants grown under high moisture stresses in the nursery can be transplanted with satisfactory results any time of the year provided soil moisture and temperature conditions are favorable. Four to six months of "hardening" were required under the conditions of this experiment to bring about as high survival after transplanting for plants grown under low moisture stresses as obtained with plants grown under high moisture stresses. Under the conditions of this experiment there was little difference in the depth of root penetration by plants grown under high and low moisture stresses. The guayule nursery seedlings obtained their water from the soil to the depth of root penetration. In this experiment, during the first year, this depth was 42 to 48 inches. While the soil moisture was at a low tension near the surface, water was absorbed almost entirely in this region. When the topsoil approached the wilting point the water was absorbed from the lower depths.
显示更多 [+] 显示较少 [-]