In the United States, pumpkin crops are produced primarily for wholesale, fresh-market, and ornamental use. Pumpkin production increased 6.4% in the U.S. between 2004 and 2005, totaling 1.1 billion lb in 2005 (U.S. Department Agriculture, 2006). An increase in the demand for pumpkin crops over the past decade has been the result of the growing popularity of events such as fall festivals, grade school farm tours, and u-pick crops. Most farms in New Jersey are surrounded by, or are located near, urban and suburban areas; therefore, many farmers operate roadside markets that sponsor agritourism events featuring the fall harvest of pumpkin crops. In 2007, New Jersey harvested 2500 acres of pumpkin, accounting for 5% of U.S. production (Ingerson-Mahar et al., 2007).
A critical aspect of entertainment agriculture, where agritourism is a main focus of the operation, is maintaining attractive fields that are weed-free and in a condition suitable for consumers to enter. Small farm operators near urban areas could apply autumn leaves collected from municipal shade trees to help 1) maintain an attractive field, 2) maintain suitable soil conditions for customer entry, 3) improve cleanliness of u-pick pumpkin fruit, and 4) improve overall soil health with the addition of organic matter to the soil (Heckman and Kluchinski, 2000a, 2000b). Municipal leaves spread over the soil surface may also help to conserve soil moisture, prevent soil erosion, and build soil fertility (Heckman and Kluchinski, 1996, 2000a, 2000b). Another advantage of leaf mulch is that it may serve as an effective barrier to prevent or reduce annual weeds. Leaf mulch residue that persists season-long for crops such as pumpkin may also provide a natural, physical barrier by preventing fruit from coming into direct contact with the soil, thereby resulting in cleaner fruit for consumers to handle and purchase.
Studies conducted to determine the effects of various production systems and mulches on yield, plant and soil moisture properties, soil erosion, weed control, disease, and fertility with various horticultural crops have shown benefits of mulch (Abdul-Baki and Teasdale, 1997; Acosta-Martinez et al., 1999; Christine et al., 1998; Doring et al., 2005; Hasan et al., 2005; Schonbeck 1998; Wyenandt, 2004), but few studies have been done with pumpkin. A study by Rutledge (1999) determined that vetch residue kept weed competition levels low and resulted in higher quality fruit at harvest with a cleaner, glossier, and brighter appearance compared with pumpkins that were conventionally grown.
Leaf mulching on agricultural land may also benefit local municipalities by providing a cost-effective method to use collected leaves. In New Jersey, 5 million cubic yards of leaves are collected each year by local municipalities for composting or use on farms because state regulations prohibit the disposing of leaves into landfills or with local incineration (Derr and Kluchinski, 1995). In 1994 in New Jersey, a study of municipalities and local farm operators who applied municipal leaves to their land indicated that on-farm mulching had the potential to reduce the cost of municipal leaf management while providing organic matter to the soil and monetary incentives to the farmers through tipping fees paid by municipalities to farmers averaging $3.00/yard3 (Derr and Kluchinski, 1995). However, a potential concern with the use of municipal leaves as a soil-surface mulch in vegetable production is the high carbon to nitrogen ratio (C:N) of shade tree leaves. Shade tree leaves have a C:N ratio of ≈50:1, and heavy applications of such leaves are likely to cause immobilization of soil N (Heckman and Kluchinski, 1995, 1996). The high C:N ratio of leaves would suggest that higher than normal N fertilizer application rate may be necessary when growing vegetable crops such as pumpkin with municipal leaf mulch.
The objectives of this study were to determine the effects of leaf mulch and sidedress nitrogen rate on pumpkin yield and fruit quality.
Abdul-Baki, A.A. & Teasdale, J.R. 1997 Snap bean production in conventional tillage and in no-till hairy vetch mulch HortScience 32 7 1191 1193
Acosta-Martinez, V., Reicher, Z., Bischoff, M. & Turco, R.F. 1999 The role of tree leaf mulch and nitrogen fertilizer on turfgrass soil quality Biol. Fertilility Soils 29 55 61
Christine, A.M., Bennett, M. & Regnier, E. 1998 Weed control in tomato production using spring-sown cover crops killed by undercutting HortScience 33 3 495
Doring, T.F., Brandt, M., Heb, J., Finckh, M.R. & Saucke, H. 2005 Effects of straw mulch on soil nitrate dynamics, weeds, yield and soil erosion in organically grown potatoes Field Crops Res. 94 238 249
Griffin, G., Jokela, W. & Ross, D. 1995 Recommended soil nitrate N tests 22 29 Recommended soil testing procedures for the northeastern United States Northeast Regional Publ. 493. Agr. Expt. Sta., Univ. of Delaware Newark
Hasan, M.F., Ahmed, B., Rahman, M.A., Alam, M.M. & Khan, M.M.H. 2005 Environmental effect on growth and yield of tomato J. Biol. Sci. 5 6 759 767
Heckman, J.R. & Kluchinski, D. 1995 Soybean growth and nodulation on soil amended with plant residues Biol. Fertilility Soils 20 284 288
Heckman, J.R. & Kluchinski, D. 1996 Chemical composition of municipal leaf waste and hand-collected urban leaf litter J. Environ. Qual. 25 2 355 362
Heckman, J.R. & Kluchinski, D. 2000a Agronomics of land application of municipal collected shade tree leaves. I. Soil properties J. Sustainable Agr. 17 33 40
Heckman, J.R. & Kluchinski, D. 2000b Agronomics of land application of municipal collected shade tree leaves. II Soybean and corn production J. Sustainable Agr. 17 41 52
Ingerson-Mahar, J., Rabin, J. & Wyenandt, A. 2007 Pumpkin crop profile for New Jersey 23 Jan. 2008 <http://www.pestmanagement.rutgers.edu/njinpas/CropProfiles/pumpkinCP.pdf>
Schonbeck, M.W. 1998 Weed suppression and labor costs associated with organic, plastic, and paper mulches in small-scale vegetable production J. Sustainable Agr. 13 2 13 33
U.S. Department of Agriculture 2006 2005 New Jersey annual vegetable report 23 Jan. 2008 <http://usda.mannlib.cornell.edu/usda/nass/VegeSumm/2000s/2006/VegeSumm-01-27-2006.pdf>
Wyenandt, C.A. 2004 Fusarium fruit rot (Fusarium spp.) of pumpkin (Cucurbita pepo) and its control with cover crop mulches The Ohio State Univ Columbus PhD Diss.