Stand establishment and early vigor are critical to the successful production of cotton (Gossypium hirsutum L.). Rapid early growth could provide significant advantages to young plants relative to diseases, insects, and weeds. The objectives of this research were to identify traits that contribute to differences in early growth, characterize genotypic variation in early vigor among modern cultivars and advanced breeding lines, and determine the effect of the seed production environment on early vigor. Early growth of 10 genotypes from private companies and 18 unreleased breeding lines was compared through measurements of leaf area and biomass under field conditions in 2 yr. A positive correlation of seed weight and rapid early growth was observed up to 32 d after planting (DAP). Cotyledon area was positively associated with shoot dry weight over the course of the first 52 DAP. Significant genotypic differences were observed for cotyledon and total leaf areas, and for cotyledon, first true leaf, total leaf, stem, and total shoot dry weights in both years within approximately the first 4 wk after planting. No correlation between lint yield and rapid early growth was found. For the first 17 (2009) and 32 (2008) DAP—but not after that—plants grown from seeds produced in distinct environments differed in early vigor. Overall, seeds from breeding lines produced more vigorous seedlings than did seeds of commercial genotypes. Although heritability of the examined traits has not been established, the broad range in values and significant genotypic variation suggest that breeding for enhanced early vigor should be possible without compromising yield.

Potassium chloride (KCl) preplant or foliar applied with fungicides to soybean [Glycine max (L.) Merr.] may allow farmers to increase yields when soil K availability is reduced and/or when Septoria brown spot (SBS) (Septoria glycines), frogeye leaf spot (FLS) (Cercospora sojina), or sudden death syndrome (SDS) (Fusarium solani (Mart.) Sacc. f. sp. glycines) are present. Interactions between fertilizer and fungicide management programs have not been examined in the central United States. Our objective was to evaluate the eff ect of preplant-and foliar-applied KCl alone or combined with pyraclostrobin, azoxystrobin, or azoxystrobin plus lambda-cyhalothrin on soybean response and severity of SBS, FLS, and SDS. Experiments were conducted in northeastern (Novelty) and southeastern (Qulin) Missouri in 2006 and 2007 on soils with low to medium K. Leaf K concentrations increased 1.4 to 6.1 g kg −1 following preplant KCl compared to nontreated or foliar KCl. Leaf Cl concentrations increased signifi cantly with preplant KCl at Qulin and foliar KCl at R4 at Qulin and Novelty. At Novelty, preplant KCl reduced the severity of SBS and FLS up to 6%, and increased yield 340 kg ha −1 , while foliar KCl increased yield 110 kg ha −1 . An R4 application of strobilurin fungicides increased yields 230 to 360 kg ha −1 at Novelty. At Qulin, soybean yield increased 390 kg ha −1 with preplant KCl, while there were variable eff ects of fungicides on the severity of SBS, FLS, or SDS, and no yield increase due to fungicides or foliar KCl. Foliar applications of KCl were no substitute for preplant KCl.

A field experiment was conducted from 1986 to 1988 on a highly erodible soil in north Mississippi to study the effects of seven cotton (Gossypium hirsutum L.) cropping systems on soil erosion, stand establishment, fruiting, earliness, and yield. Stand counts for no‐till cotton following hairy vetch (Vicia villosa Roth) averaged 30% less than for conventional tillage cotton. No significant difference in yield between cropping systems occurred in 1986. Yields in 1987 decreased as tillage intensity increased, but this trend was reversed in 1988. Rainfall distribution within each growing season contributed to the variability in yield and fruiting response to tillage and cover crops. In 1986, no‐till cotton following wheat (Triticum aestivum L.) had 16 fruiting sites per plant as compared with 32 sites with conventional‐till cotton. Lower rates of abscision in cotton planted no‐till into wheat offset the reduced fruiting site production. Averaged over years, the number of fruiting sites on the four lower reproductive branchs (Nodes 5/2‐8) were 11% less with no‐till cotton following wheat than conventional‐till cotton. Cotton fruiting for no‐till with vetch or native winter cover was similar to reduced and conventional‐till cotton.

Incidence of Phomopsis seed decay is frequently high and quality low in seed from early-maturing maturity group III and IV soybean cultivars planted in early to mid-April in the southern United States. Cultivars resistant to this disease have not been available until the recent release of germ plasm lines SS 93-6012 and SS 93-6181. Our objective was to determine the effects of planting dates with these lines and one Phomopsis seed decay-susceptible soybean cultivar, Asgrow 3834, on seed infection by Phomopsis spp. and on yield and the correlation between percentage of Asgrow 3834 infected with Phomopsis spp. and seed quality. Generally, yields averaged over years were significantly greater for mid-April than mid-June plantings, and yields of cultivars were similar within a planting date. Soybean lines SS 93-6012 and SS 93-6181 were highly resistant to Phomopsis seed decay compared with the susceptible cultivar, Asgrow 3834. There was a significant, negative correlation between germination of seed from mid-April plantings of Asgrow 3834 and percentage of these seed infected with Phomopsis spp. Moreover, there were significant correlations between fatty acid composition of Asgrow 3834 seed and the percentage of these seed infected with Phomopsis spp. This altered composition of fatty acids may be responsible for reduced quality of oil derived from seed infected with this fungus. Phomopsis seed decay-resistant soybean lines SS 93-6012 and SS 93-6181 should be useful in breeding programs focused on developing high-yielding cultivars resistant to this disease.