Reduced Tillage, Rye Residues, and Herbicides Influence Weed Suppression and Yield of Pumpkins

Abstract

Field experiments were conducted to study the effects of various tillage and mulching practices on fruit maturity and weed suppression in pumpkins. Conventional tillage (CT), disking, no tillage with rye removed (RR), no tillage with standing rye (SR), and strip tillage (ST) were evaluated with and without ethalfluralin plus halosulfuron (1.5 plus 0.036 kg ai/ha, respectively) applied preemergence. In 2001, when heavy rain after herbicide application caused significant crop injury, the herbicides delayed maturity and significantly reduced yields of mature pumpkins within each herbicide treatment, total yields did not differ with tillage. In 2002, weed populations were significantly greater than those in 2001, and in 2002, regardless of herbicides, yields of mature fruit were greater in tillage treatments with higher rye residues (SR, ST). Although weed populations were less in one year than the other, herbicides provided effective control in both seasons, and RR, ST, and SR effectively suppressed weeds compared with CT. Averaged over treatments, greater yield losses were attributable to weed competition (42%) in 2002 than to herbicide injury (32%) in 2001.

Weed Management Systems for No-Tillage Vegetable Production

“…Cover crop mulch systems modify the microenvironment, which has an impact on weed populations and vegetable crop yields (Masiunas 1998). Although the combination of NT and cover-cropping practices have certain advantages over traditional tillage (e.g., plowing and disking of soil), there has been limited research in vegetable crops, particularly when used in conjunction with chemical weed control (Rapp et al 2004). Cover crops are often integrated into NT production systems for their weed suppressive ability and numerous researchers have attempted to use cover crops as a method for weed control in vegetable crop production.…”

“…Several studies have all indicated that NT and CT produce comparable pumpkin yields when sufficient weed control is achieved in NT production systems (Galloway & Weston 1996, Rapp et al 2004. Pumpkin vegetation will provide some soil shading and weed suppression once vines form across the soil surface, but other weed control measures are generally necessary to achieve adequate weed control in NT pumpkin production.…”

“…In NT pumpkin production systems, sparse or unevenly distributed cover crop residues often result in fields having high weed densities that lead to low pumpkin yields and poor fruit quality . Several studies have indicated that although broadleaf weed control is improved, herbicide-killed winter rye will not effectively suppress many broadleaf weeds in NT pumpkin production even if used in conjunction with a standard herbicide program (Rapp et al 2004, Walters & Young 2010. Weed densities in pumpkin vary with environmental conditions, tillage strategy, and amount of cover crop residue (Rapp et al 2004).…”

“…Several studies have indicated that although broadleaf weed control is improved, herbicide-killed winter rye will not effectively suppress many broadleaf weeds in NT pumpkin production even if used in conjunction with a standard herbicide program (Rapp et al 2004, Walters & Young 2010. Weed densities in pumpkin vary with environmental conditions, tillage strategy, and amount of cover crop residue (Rapp et al 2004). Although crop residues provided by herbicide-killed winter wheat or winter rye will improve grass and broadleaf weed control, the densities of many difficult to control broadleaf weeds (e.g., many Amaranthus spp.)…”

The Effect of Tillage System and Rimsulfuron Application on Weed Flora, Arbuscular Mycorrhizal (AM) Root Colonization and Yield of Maize (Zea mays L.)

“…In addition, Chikoye et al (2007) reported that rimsulfuron did not cause any visible phytotoxicity on the maize at any dosage. Moreover, there are limited published data on the combination effects of tillage and herbicides application on weed flora and growth of crops (Rapp et al, 2007;Ritter and Menbere, 2001;Streit et al, 2002).…”