Moisture Stress Effects on Biomass Partitioning in Two Sonoran Desert Annuals

1982 ◽  
Vol 108 (2) ◽  
pp. 338 ◽  
Author(s):  
Stan R. Szarek ◽  
Stanley D. Smith ◽  
Randy D. Ryan
1979 ◽  
Vol 71 (1) ◽  
pp. 86-90 ◽  
Author(s):  
N. N. Momen ◽  
R. E. Carlson ◽  
R. H. Shaw ◽  
O. Arjmand

1985 ◽  
Vol 15 (1) ◽  
pp. 72-77 ◽  
Author(s):  
Nan C. Vance ◽  
Steven W. Running

Ten-week-old western larch (Larixoccidentalis Nutt.) seedlings were grown in a greenhouse under 70, 37, and 27% full sunlight from late July to early October. In August, seedlings under each light treatment were repetitively water stressed until predawn leaf water potential (Bψ1) reached one of three levels: no stress (> −0.4 MPa), moderate stress (−0.7 to −1.0 MPa), and severe stress (−1.5 to −1.8 MPa). Moisture stressing significantly reduced height and diameter of seedlings grown under 70% light. Light reduction reduced shoot and root biomass accumulation. A positive linear relation was found between root dry weight and light intensity. The largest seedlings (on a weight basis) received the highest light, were unstressed, and had the lowest shoot/root ratios. Terminal bud set was not affected by light reduction or moisture stressing but occurred under a 14-h photoperiod and reduced nighttime temperatures. Stressed and shaded seedlings had significantly reduced diurnal K1 and stress-cycled seedlings showed an adjustment to stressing. The K1 of unstressed seedlings was correlated with humidity deficit (ABHD), and K1 of stressed seedlings, with Bψ1, and ABHD. Maximum K1 declined with decreasing Bψ1, but not to a level indicating complete stomatal closure.


1971 ◽  
Vol 51 (1) ◽  
pp. 37-43 ◽  
Author(s):  
E. A. PAUL ◽  
R. J. K. MYERS

Labelled 15NH4NO3 was used in a growth chamber to study the effect of moisture stress on the utilization of nitrogen by wheat. This made it possible to determine the recovery of nitrogen (N) in the soil-plant system of two Chernozemic soils. Moisture stress effects were less evident in a clay soil than in a loam. Approximately 55% of the N utilized by the growing plants came from organic soil-N mineralized during the growing period. From 59 to 71% of the initial fertilizer plus soil mineral-N was utilized by the plants. Twenty to 36% remained in the soil, and 1 to 17% was lost. Losses were greatest in soils exposed to high moisture stress and were related to the residual NO3-N levels in the soil. They were attributed to denitrification. Immobilization of N was highest at low moisture stress where plant growth was the greatest, but mineralization was unaffected by the moisture stress applied. It was estimated that 5.0 to 6.2 kg N were required to produce 100 kg of wheat, the highest efficiency of N utilization being obtained at low soil moisture stress.


1988 ◽  
Vol 2 (4) ◽  
pp. 437-441 ◽  
Author(s):  
Daniel B. Reynolds ◽  
Trina G. Wheless ◽  
E. Basler ◽  
Don S. Murray

Laboratory experiments with14C-herbicides were conducted with grain sorghum as an indicator species to determine the effects of imposed moisture stress on absorption, precent recovery, and acropetal and basipetal translocation of the butyl ester of fluazifop, the methyl ester of haloxyfop, the ethyl ester of quizalofop, and sethoxydim. Haloxyfop was the only herbicide where recovery decreased between the 3-and 48-h interval. All plants absorbed more of the herbicide at the 48-h interval than at the 3- or 6-h interval under both stressed and non-stressed conditions. Increased drought stress caused more acropetal movement with fluazifop and sethoxydim and less acropetal movement with quizalofop at the 3-h interval. Basipetal transloation, although different among herbicides, responded similarly to imposed moisture stress, which decreased basipetal translocation approximately 19%.


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