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.
Dongsheng Zhang, James R. Brandle, Kenneth G. Hubbard, Laurie Hodges, and Entin Daningsih
Perry E. Nugent and Dennis T. Ray
Since 1968, three spontaneous 4× melons (Cucumis melo L.) plants were discovered in our field or greenhouse plantings. Two were found in the cultivar Planters Jumbo and one in the virescent marker C879-52. Each of these 4× plants had rounded cotyledons, shorter internodes, thicker stems and leaves, more hairs, and smaller fruits, with larger stem and blossom scars, than their 2× counterparts. Also, their flowers, pollen grains, stomates, and seeds were larger. The discovery of a 4× virescent plant in 1987 allows easier germplasm transfer between ploidy levels. Morphological characteristics of 2× and 4× melons will allow identification without need for chromosome counts.
Frank J. Dainello, Larry Stein, Guy Fipps, and Kenneth White
Competition for limited water supplies is increasing world wide. Especially hard hit are the irrigated crop production regions, such as the Lower Rio Grande Valley and the Winter Garden areas of south Texas. To develop production techniques for reducing supplemental water needs of vegetable crops, an ancient water harvesting technique called rainfall capture was adapted to contemporary, large scale irrigated muskmelon (Cucumis melo var. reticulatus L.) production systems. The rainfall capture system developed consisted of plastic mulched miniature water catchments located on raised seed beds. This system was compared with conventional dry land and irrigated melon production. Rainfall capture resulted in 108% average yield increase over the conventional dry land technique. When compared with conventional furrow irrigation, rainfall capture increased marketable muskmelon yield as much as 5355 lb/acre (6000 kg·ha-1). As anticipated,the drip irrigation/plastic mulch system exceeded rainfall capture in total and marketable fruit yield. The results of this study suggest that rainfall capture can reduce total supplemental water use in muskmelon production. The major benefit of the rainfall capture system is believed to be in its ability to eliminate or decrease irrigation water needed to fill the soil profile before planting.
James D. McCreight, Hsing-Yeh Liu, and Thomas A. Turini
Cucurbit leaf crumple virus (CuLCrV) is a geminivirus transmitted by Bemisia tabaci (Gennadius) biotype B (SPW-B) and common in melons (Cucumis melo L.) planted from July through September in the desert southwestern United States. Symptoms include chlorotic leaf spots, leaf curling and crumpling, and interveinal yellowing, and plants may be stunted. Melon breeding line MR-1, and six plant introductions (PIs; PI 124111, PI 124112, PI 179901, PI 234607, PI 313970, and PI 414723) exhibited partial resistance to CuLCrV in naturally infected field tests and controlled inoculation greenhouse tests. PI 236355 was completely resistant in two greenhouse tests. Partially resistant plants exhibited chlorotic spots, or mild expression of other typical CuLCrV symptoms; all such plants were positive for presence of virus using polymerase chain reaction analysis with a CuLCrV-specific primer pair from the BC1 region. Genetic resistance to CuLCrV in melon was recessive. Field and greenhouse data from F1, F2, and backcrosses of the F1 to ‘Top Mark’ and PI 313970 demonstrated a single, recessive gene for resistance to CuLCrV. Progenies from crosses of four partially resistant cultigens with ‘Top Mark’ were susceptible. Resistance in PI 313970 appeared to be allelic, with resistance in the other six cultigens based on F1 data. The name cucurbit leaf crumple virus and symbol culcrv are proposed for this gene.
D. W. Davis, T. J. Kalb II, and M. A. Shehata
Minnesota 101 is a monoecious, short intemode breeding line of muskmelon, Cucumis melo L. Its primary use is envisaged as that of a breeding line useful as a parent in the production of F1 hybrid cultivars, and as germplasm in the long term improvement of muskmelon.
James D. McCreight
Powdery mildew is a major problem in melon (Cucumis melo L.) production worldwide. Three genes for resistance to Sphaerotheca fuliginea (Schlecht. ex Fr.) Poll. race 1 and race 2U.S. were identified in growth chamber and greenhouse tests in the cross of PI 313970 × `Top Mark'. A recessive gene conditioned resistance of true leaves to race 1. A recessive gene appeared to condition resistance of cotyledons to race 2U.S., although a second recessive gene may be involved. A semi-dominant gene conditioned resistance of true leaves to race 2U.S. Limited data suggested linkage of the recessive gene for resistance to race 1 and the semi-dominant gene for resistance to race 2U.S. The resistance reaction of PI 313970 to infection of true leaves by race 2U.S. included water-soaked spots and resistant blisters, but segregation data for the resistant blister reaction were inconclusive. Allelic relationships of these genes with previously reported melon powdery mildew resistance genes remain to be determined.
James D. McCreight
Lettuce infectious yellows virus (LIYV), transmitted by the sweetpotato whitefly, (Bemisia tabaci Genn.), seriously affected melon (Cucumis melo L.) production in the lower desert areas of the southwest United States from 1981 through 1990. Melon plant introduction (PI) 313970 was previously found resistant to LIYV in naturally infected field tests and controlled-inoculation greenhouse tests. Data from F1 and segregating generations from crosses of PI 313970 with LIYV-susceptible lines indicated that resistance in this accession is conditioned by a dominant allele at a single locus designated Lettuce infectious yellows (Liy).
James D. McCreight
Powdery mildew is a serious disease of melon (Cucumis melo L.) worldwide. Twenty-two melon cultigens have been used to define 22 reported races of the pathogen Podosphaera xanthii (sect. Sphaerotheca) xanthii (Castag.) U. Braun & N. Shish. Comb. nov. [syn. Sphaerotheca fuliginea (Schlecht. ex Fr.) Poll.]. Discrepancies in the reactions of eight cultigens to populations of P. xanthii races 1 and 2 in California, Japan, and Spain revealed genetic differences among them that can be used to differentiate P. xanthii race 1 and 2 populations in these countries. Implicit in these results is the existence of previously unknown virulence factors in these populations of P. xanthii races 1 and 2 that permit designation of new races of P. xanthii on melon. Synthesis of these results with previous reports resulted in the identification of 28 putative races of P. xanthii on melon that include eight variants of race 1 and six variants of race 2. Six of the cultigens exhibited resistant blisters in response to heavy infection by P. xanthii in field and greenhouse tests.
Robert J. Dufault
The first objective of this paper is to review and characterize the published research in refereed journals pertaining to the nutritional practices used to grow vegetable transplants. The second objective is to note those studies that indicated a direct relationship between transplant nutritional practices and field performance. The third objective is to suggest some approaches that are needed in future vegetable transplant nutrition research. Even after review of the plethora of available information in journals, it is not possible to summarize the one best way to grow any vegetable transplant simply because of many interacting and confounding factors that moderate the effects of nutritional treatments. It is, however, important to recognize that all these confounding factors must be considered when developing guidelines for producing transplants. After thorough review of this information, it is concluded that transplant nutrition generally has a long term effect on influencing yield potential. Therefore, derivation of a nutritional regime to grow transplants needs to be carefully planned. It is hoped that the information that follows can be used to help guide this process.
Ariana Torres, Petrus Langenhoven, and Bridget K. Behe
, the 2011 cantaloupe-related foodborne illness outbreak, the deadliest outbreak in recent U.S. history ( Garner and Kathariou, 2016 ), reduced melon production by 32% during the past decade ( USDA-ESMIS, 2018 ). Since then, the melon industry has worked