Search Results

You are looking at 1 - 6 of 6 items for

  • Author or Editor: Entin Daningsih x
Clear All Modify Search

Experiments were conducted during summer seasons from 1991 to 1994 to find out the effect of winds on early growth of muskmelon. A randomized complete-block design with sheltered and exposed areas as treatments was used. Sensors for air temperature and relative humidity (model HMP35C or model XN217, Campbell Scientific) were placed at canopy height and 3-cup anemometers (model 12102, R.M. Young, Traverse City, Mich.) were 50 cm aboveground. All sensors were connected to CR10 automatic data loggers and recorded hourly average data. Using regression analysis, we found that the accumulative windspeed frequency below threshold (<4 ms–1) can be used to predict both accumulative hourly heat units of air temperature (GDHT) with R2's more than 0.85 and total muskmelon fresh and dry weight and leaf area index at early growth. Predicted models using accumulative hourly windspeed frequency have R2's >0.80 in sheltered areas. Adding vapor pressure deficit to the model improves the prediction of muskmelon early growth, especially in exposed areas.

Free access

Field experiments were conducted in 1991, 1992, and 1993 to evaluate the effects of antitranspirant (Folicote, Aquatrol Inc.) and polyacrylamide gel (Supersorb, Aquatrol Inc.) on early growth of muskmelon. A RCBD with split plot arrangement was used with sheltered and exposed areas as the main treatments and seven combinations of antitranspirant spray and gel dip applications as subtreatments. Two greenhouse experiments were also conducted to simulate field research. A RCBD with seven treatments described as subtreatments in the field research was used in the greenhouse studies. Based on destructive harvests in the field, treatments and subtreatments did not affect dry weight or leaf area index. Specific contrasts, how ever, showed that gel application significantly increased dry weight and leaf area index whereas the spray application tended to reduce these factors during the first three weeks after transplanting. Significant differences between dip and spray subtreatments disappeared by five weeks after transplanting. In both greenhouse experiments, gel dip application increased dry weight and leaf area index of muskmelon at all observations from 2 weeks to five weeks after transplanting. We conclude that gel application generally will provide more benefit during early muskmelon growth compared to the use of antitranspirant spray.

Free access

Field experiments were conducted over 4 years to evaluate the effects of antitranspirant (Folicote, Aquatrol Inc., Paulsboro, N.J.) and polyacrylamide gel (SuperSorb, Aquatrol Inc., Paulsboro, N.J.) on early growth of transplanted muskmelon grown either protected by tree windbreaks or exposed to seasonal winds. A randomized complete block design (RCBD) with split plot arrangement was used with wind protection (sheltered and exposed) areas as the main treatment and use of an antitranspirant spray or gel dip as subtreatments. Based on destructive harvests in the field, treatments and subtreatments did not affect dry weight or leaf area index in the first 2 years. Specific contrasts, however, showed that gel application significantly increased fresh weight, dry weight, and leaf area index over that of the untreated transplants whereas the spray application tended to reduce these factors during the first 3 weeks after transplanting. Significant differences between gel and spray subtreatments disappeared by 5 weeks after transplanting. Shelterbelts ameliorated crop microclimate thereby enhancing plant growth. Significantly, wind velocity at canopy height was reduced 40% on average and soil temperatures were about 4% warmer in the sheltered plots compared to the exposed plots during the first 5 weeks post-transplant. Muskmelon plants in the sheltered areas grew significantly faster than the plants in the exposed areas in 2 of the 3 years reported, with the 3-year average fresh weight increased by 168% due to wind protection. Overall transplanting success and early growth were enhanced the most by wind protection, followed by the polyacrylamide gel root dip, and least by the antitranspirant foliar spray. We conclude that microclimate modification by wind speed reduction can increase early muskmelon plant growth more consistently than the use of polyacrylamide gel as a root dip at transplanting or the use of an antitranspirant spray. A polyacrylamide gel root dip generally will provide more benefit during early muskmelon growth than the use of an antitranspirant spray.

Free access

Windbreaks can increase crop growth and improve crop quality. The effects of shelter on vegetable production varies with crop, location, and farming practices. While the advantages of minimizing wind stress on vegetable production is well-known, little research documents the specific response of vegetables to microclimate modification through the use of shelterbelts.

During the summer, 1991, a preliminary experiment was conducted on the effects of tree windbreaks (shelterbelts) on muskmelon plant growth, yield, and fruit quality. A split-plot design was used with shelter and exposed areas as main treatments with 3 replications. Subtreatments were 7 combinations of anti-transpirant and time of application. Leaf growth was measured 4 and 6 weeks after planting. Muskmelon fruit were harvested over a 6 week period at 2 day intervals. Muskmelon yield, fruit and cavity diameter, fruit color, and total sugar content were obtained.

The use of anti-transpirant did not significantly affect total yield, fruit or cavity diameter, total sugar content, or early leaf growth. The effect of shelter varied with the measured variable.

Free access

Studies were initiated in 1989 to characterize phonological events with corresponding growth and development phenomena of `Eagle' and `Provider' snap beans (Phaseolus vulgaris L.) Ten plantings at approximately 15 day intervals were made at Knoxville, TN from April 17 through July 27. Days to reach growth stages V0 thru R7 were recorded for each cultivar for each planting date. Air temperature, total radiant energy, wind speed and relative humidity were recorded hourly throughout the 171 day test period. Growing degree days (GDD) computed by 8 methods and growing degree hours (GDH) computed by 2 methods were regressed against plant developmental stages. GDD and GDH, along with pod size and pod fiber content, will be discussed as possible indices for predicting harvest maturity. With the methods used to calculate heat summation in this study, GDD and GDH from planting to pod maturity ranged from approximately 550 to 975 and 9,700 to 20,000, respectively.

Free access

The relationships between shelterbelt (tree windbreak)-induced microclimate and muskmelon (Cucumis melo L.) growth and development were investigated at the Univ. of Nebraska-Lincoln Agricultural Research and Development Center near Mead, Nebr., during the 1992 and 1993 growing seasons. Wind speed, wind direction, air and soil temperatures, relative humidity, and soil moisture were monitored in both sheltered and nonsheltered areas. Plant growth parameters (plant height, vine length, plant dry weight, and leaf area) were measured at various stages of development. Shelterbelts provided improved growing conditions for muskmelon transplants. Direct wind damage and duration of higher wind speeds were reduced 47% to 56% in sheltered areas. Air temperatures in sheltered areas were slightly higher during daytime and slightly lower at night, and significantly so early in the growing season. Relative humidity was increased significantly in sheltered areas in 1992 and, while higher in 1993, the difference was nonsignificant. Soil moisture content was not affected significantly by wind protection. Sheltered plants exhibited earlier development and faster growth. The first female flower appeared 2 days earlier in sheltered areas in both years. The first fruit set, as indicated by fruit swelling and retention on the vine, occurred 6 days earlier and matured 5 and 6 days earlier in sheltered areas in 1992 and 1993, respectively. Leaf areas and dry-matter accumulation of sheltered plants were greater than those of exposed plants. The shoot relative growth rate of sheltered plants increased earlier in the growing season, but decreased slightly later in the growing season. The earlier development and faster growth of sheltered plants were related mainly to the reduction of wind speed, higher total accumulated air temperatures during the daylight hours (sum of daily average daytime air temperatures based on hourly averages), and higher soil temperature in sheltered areas. Total yields were not affected significantly in either year; however, early yields were significantly greater in sheltered areas in 1993. If earlier maturity and increased yield are possible in large sheltered fields, this practice would provide an economic benefit to producers.

Free access