Table of Contents
Foster, M., G. Kleine, and J. Moore. 1993. Impact of
seeding rate and planting date on guayule stand establishment by direct seeding in West Texas. p. 354-355. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York.
Impact of Seeding Rate and Planting Date on Guayule Stand Establishment by Direct Seeding in West Texas
Michael Foster, Greg Kleine, and Jaroy Moore
- RESULTS AND DISCUSSION
- Fig. 1
Transplanting of greenhouse-grown seedlings has been the only reliable method of guayule stand establishment. Bucks et al. (1986) estimated that development of direct seeding methods could reduce the cost of establishment to below $400/ha versus $900 to $1,200/ha for transplanting. Recently, Foster et al. (1991) calculated that the cost of establishment could be reduced to $250/ha or less.
Foster and Moore (1991) demonstrated that guayule stand establishment was
possible with conditioned seed and precision planting. Seeding rate and the
optimum date of planting still must be defined throughout the potential guayule
production region. The objectives of this study were to examine the effects of
seeding rate and planting date on guayule stand establishment by direct seeding
in west Texas.
The study was conducted during 1991 at the Texas Agricultural Experiment
Station Guayule Research Site near Fort Stockton. A split plot design arranged
in a randomized complete block with four replications was used with date of
planting (31 May, 28 June, 15 Aug., and 1 Oct.) and seeding rate (30, 40, 50,
60, 80, 100 seeds/m) as main and subplots, respectively. Main plots were 6 m
wide (six 1 m wide rows) and 9 m long. Subplots consisted of single rows 9 m
long seeded with a Gaspardo SV 255 pneumatic planter. Mexican bulk guayule
seed was conditioned by the process outlined by Chandra and Bucks (1986). Seed
germination was 80%. Seedling density (Fig. 1) was not adjusted for percentage
germination. The plots were sprinkler irrigated and kept moist during
germination and emergence.
Initial germination and emergence was greatest in August (Fig. 1). Seedling
density was consistently greater in the 80 and 100 seeds/m treatments as
compared to the lower seeding rates. Based on plant spacing recommendations
for transplants, 2 to 3 established seedlings/m would be required for an
acceptable stand (27,500/ha or 11,500/acre). Even the lower seeding rates (30
to 60 seeds/m) satisfied these requirements. Seeding rate may need to be
adjusted for seed quality (% germination), weather factors (heavy rain and
hail), insect damage to young seedlings, and reduced germination by
preemergence herbicides. Therefore, rates of 40 or 50 seeds/m may be more
realistic, and would require 0.22 to 0.30 kg of seed/ha (0.20 to 0.22 lb./A).
Initial seed quality can affect the germination rate of conditioned seed.
Just after plant emergence, the May seeding was damaged by heavy rain and hail,
which can occur throughout the growing season. Seedlings in the cotyledon
stage were damaged by fall armyworms (Spodoptera frugiperda) in the July
Direct seeding guayule during 1991 in west Texas was successful in May, June,
and August. Seedling density was greatest in the 100 and 80 seeds/m
treatments. Based on plant population recommendations for guayule transplants,
even lower seeding rates (30 to 60 seeds/m) were acceptable for stand
establishment. Seeding rates of 40 to 50 seeds/m may be more realistic and
should be adjusted for seed quality, weather factors, insect damage to young
seedlings, and possible reduced germination by preemergence herbicides.
- Bucks, D.A., R.L. Roth, D.E. Powers, and G.R. Chandra. 1986. Direct seeding
for economical guayule field establishment, p. 77-87. In: D.D. Fangmeier and
S.M. Alcorn, (eds.). Proc. Fourth Int. Guayule Res. Dev. Conf., Tucson, AZ,
16-19 Oct. 1985. Guayule Rubber Soc., Inc., College Station, TX.
- Chandra, G.R. and D.A. Bucks. 1986. Improved quality of chemically treated
guayule (Parthenium argentatum Gray) seeds, p. 59-68. In: D.D.
Fangmeier and S.M. Alcorn, (eds.). Proc. Fourth Int. Guayule Res. Dev. Conf.,
Tucson, AZ, 16-19 Oct. 1985. Guayule Rubber Soc., Inc., College Station, TX.
- Foster, K.E., N.G. Wright, and S.F. Fansler. 1991. Guayule natural rubber
commercialization: a scale-up feasibility study. Univ. Ariz., Office of Arid
Lands Studies, Tucson, AZ.
- Foster, M.A. and J. Moore. 1992. Direct seeding techniques for guayule stand
establishment in West Texas. J. Prod. Agr. (in press).
||Fig. 1. Average number of guayule seedlings/m row in plots planted at
100, 80, 60, 50, 40, and 30 seeds/m.
Last update September 12, 1997