The response of muskmelon growth and development to microclimate modification by shelterbelts

The relationships between shelterbelt (tree windbreak)-induced microclimate and muskmelon (Cucumis melo L,) growth and development were investigated a t the Univ, of Nebraska-Lincoln Agricultural Research and Development Cente r near Mead, Nebr,, during the 1992 and 1993 growing seasons, Wind speed, w ind direction, air and soil temperatures, relative humidity, and soil moist ure were monitored in both sheltered and nonsheltered areas. Plant growth p arameters (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 durati on of higher wind speeds were reduced 47% to 56% in sheltered areas. Air te mperatures in sheltered areas were slightly higher during daytime and sligh tly lower at night, and significantly so early in the growing season. Relat ive humidity was increased significantly in sheltered areas in 1992 and, wh ile higher in 1993, the difference was nonsignificant, Soil moisture conten t was not affected significantly by wind protection. Sheltered plants exhib ited earlier development and faster growth. The first female flower appeare d 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 earl ier and matured 5 and 6 days earlier in sheltered areas in 1992 and 1993, r espectively. Leaf areas and dry-matter accumulation of sheltered plants wer e greater than those of exposed plants. The shoot relative growth rate of s heltered plants increased earlier in the growing season, hut decreased slig htly later in the growing season. The earlier development and faster growth of sheltered plants were related mainly to the reduction of wind speed, hi gher total accumulated air temperatures during the daylight hours (sum of d aily average daytime air temperatures based on hourly averages), and higher soil temperature in sheltered areas, Total yields were not affected signif icantly in either year; however, early yields were significantly greater in sheltered areas in 1993. If earlier maturity and increased yield are possi ble in large sheltered fields, this practice would provide an economic bene fit to producers.