The potential of Momordica charantia var. muricata, a little-known wild form, as a source of favourable alleles in breeding and improvement of bitter melons (M. charantia var. charantia), is demonstrated. The M. charantia var. charantia cultivar Priyanka and M. charantia var. muricata accession IC634896 were crossed with each other and cross ability and performance of F1 plants were studied. These botanical varieties were fully cross-compatible on either direction. Surprisingly, cross of Priyanka × IC634896 produced 80.0 fruits compared to 17.0 in Priyanka and fruit yield per plant (2287.4 g) was more than double that in Priyanka (1042.3 g). This hybrid has to be back crossed with commercial cultivar to improve its fruit size, with no compromise on fruit number. This is the first study showing the promise of M. charantia var. muricata as a potential donor in bitter melon breeding.

The persistence and effectiveness in pumpkin [Cucurbita moschata (Puch.) Poir.] weed control of several starch xanthide (SX) and commercial formulations of the ammonium (NH3) salt and methyl (CH3) ester of chloramben (3-amino-2,5-dichlorobenzoic acid) were studied in the laboratory and field. The soluble concentrate (SC) of chloramben NH3 salt and the emulsifiable concentrate (EC) of chloramben CH3 ester controlled weeds throughout the growing season on a silt loam soil. SC chloramben NH3 salt was not effective, and EC chloramben CH3 ester was inconsistent in weed control on sandy soil. Manipulation of the SX formulation produced products with slow, uniform release rates. The release rates (crosslinking reagent in parenthesis) rank as follows, from fastest to slowest: SX(Ca2+) CH3 ester = SX(H2O2) acid > SX(H2O2) CH3 ester > SX(Fe3+) acid > SX(Fe3+) CH3 ester. In trials on silt loam and sand, SX formulations did not control weeds better than EC chloramben CH3 ester.

Field studies were conducted near Tifton, GA, from 1995 to 1997 to measure Cyperus esculentus (yellow nutsedge) interference with ‘Fancipack’ Cucumis sativus (cucumber) using a response prediction experiment with a natural infestation of C. esculentus. Cucumis sativus was direct-seeded each year. Plots (1.8 by 1.8 m) were established immediately after crop emergence. Cyperus esculentus plants were counted 2 wk after crop emergence in each plot, at which time four weed-free plots were randomly established. C. esculentus densities ranged from 0 to 955 plants m−2. Total yield, plant biomass, and C. sativus stand were regressed against C. esculentus density and biomass. Regression analysis showed a 5% reduction in C. sativus yield with a C esculentus infestation of approximately 15 plants m−2. A uniform C. sativus stand maximized its competitive ability and minimized interference from C. esculentus. Cyperus esculentus was more competitive and reduced C. sativus yields when C. sativus stands were low and nonuniform.