Effects of Insecticide, Fungicide, and Seed Quality Treatments on the Emergence, Establishment, and Yield of Texas High Plains Cotton.

Norman Hopper, James Supak, James Leser, and Harold Kaufman


A study to evaluate the effectiveness of three rates of an insecticide (Temik at 0, 2.24, and 5.60 kg/ha), three fungicide seed treatments (Control, Captan at 1.25 g/kg, and Nuflow ND + Apron at 3.26 and 0.49 ml/kg of seed, respectively), and three seed vigor levels (low, medium, and high) was conducted on cotton during the 1989 growing season. The parameters evaluated included the emergence rate index (ERI), establishment index (El), and lint yield. Early season environmental conditions were somewhat harsh- being cool and wet prior to planting. Seasonal conditions after planting were generally hot and dry.

The treatments were evaluated using the cultivar Paymaster 145 planted on 19 May 1989 at a rate of 26 seeds/meter of row. The individual plots were four rows wide (1.016 meter) and 11 meters long. The research area was fertilized with 103 kg/ha of nitrogen and 39, 13, and 4 kg/ha of P205, sulfur, and zinc, respectively. Treflan was applied at a rate of 1.75 1/ha for weed control. The plot area received one preplant and two seasonal irrigations. The experimental design was a randomized complete block in which the treatments were factorially arranged within each of three blocks.

For the ERI (rate and totality of emergence), no insecticide main effect was observed. However, the fungicide seed treatments and seed vigor levels had a significant effect on the ERI. Both the Caplan and Nuflow ND + Apron fungicide seed treatments significantly increased the ERI over that of the Control (13 and 17%, respectively). No difference was noted, however, between the Caplan and Nuflow ND + Apron treatments. In addition, higher ERI values were observed from the medium and high levels of seed quality (18 and 27%, respectively) when compared to the low level of seed quality. The highest level of seed vigor also resulted in a significant increase (8%) in the ERI as compared to the medium level or seed vigor. A significant insecticide X seed vigor interaction was observed in which the highest rate of Temik (5.60 kci/ha) reduced the ERI of the low vigor seed only as compared to @he O' and 2.24 kg/ha rates of Temik.

The El (percentage of seeds planted producing established plants 28 days after planting-DAP) was significantly affected by both the fungicide seed treatment and seed vigor levels. Seed treated with Captan and Nuflow ND + Apron resulted in an increase (14 and 19%, respectively) in the El when compared to the Control. No difference was observed between the two fungicide seed treatments. Again, seed vigor significantly affected the El values. The medium and high seed vigor levels resulted in increases in the El (19 and 24%, respectively) as compared to the low seed vigor level with no difference noted between the medium and high seed vigor levels. In addition, a significant insecticide X seed vigor interaction was noted in which the highest rate of Temik (5.60 kg/ha) reduced the El of the low vigor seed only as compared to the 0 and 2.24 kg/ha rates.

The only factor having a significant effect on the lint yield was seed vigor. The medium seed vigor level yielded 13% @ore lint than the low vigor level (652 and 578 kg/ha, respectively). No yield differences were observed between the medium and high (631 kg/ha) seed vigor levels or between the high and low seed vigor levels. The yield trends followed the plant population levels at harvest. For some reason, the highest seed vigor level had the greatest plant mortality between 28 DAP and harvest such that the plant population at harvest was intermediate between that of the medium and low seed vigor levels.

Reprinted from 1990 Proceedings: Beltwide Cotton Production Research Conferences pp. 55 - 56
©National Cotton Council, Memphis TN

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Document last modified Sunday, Dec 6 1998