SEEDLING GROWTH TOLERANCE OF CUCURBITS CROPS TO HERBICIDES STOMP AND ACETOCHLOR
Summary. Several species from the Cucurbitaceae family including muskmelon, watermelon, cucumber, pumpkin, and squash were used to evaluate their tolerance in a laboratory test to two herbicides (Stomp and Acetochlor) widely used in crop cultivation. The effects of concentration and site of herbicide action on the length of primary roots and hypocotyls as well as seedling fresh weight were studied. The results showed that the cultivars differed greatly in their sensitivity to the herbicide action. The difference in the growth responses was not only species-, but also cultivar-specific. In addition, there was a difference in the herbicide acting site on plants which depended on the kind of cucurbits crops. Based on the tolerance to the action of both herbicides the studied species can be classified as follows: watermelon, squash, pumpkin, muskmelon, cucumber. The tolerance differences of the studied cucurbits crops can be used in cultivation practice.
Weed Control in Cucumber and Watermelon1

Seven herbicides, alone or in combinations, were tested for weed control on watermelon, Citrullus lanatus (Thunb.) Matsum. & Nakai cv. Charleston Gray, and cucumber, Cucumis sativus L. cv. Chipper, during 1967 to 1972. Preemergence applications of nitralin (4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline) controlled most weed species without seriously injuring either crop. The combination of bensulide (O,O-diisopropyl phosphorodithioate S-ester with N-(2-mercaptoethyl) benzenesulfonamide) with either chloramben, methyl ester (methyl 3-amino-2,5-dichlorobenzoate) or naptalam (N-1-naphthylphthalamic acid) controlled a broader spectrum of weeds than any of the compounds applied singly.
Weed control and soybean response to preplant tillage and planting time.
Abstract Clay soils in the southeastern U.S.A. Typically are tilled for seedbed preparation and weed control, prior to seeding soybean (Glycine max (L.).Merr.). However, during extended wet periods when clayey soils cannot be tilled, this practice interferes with timely planting of soybean. Consequently, a 3-year study (1985–1987) investigated the role of tillage and seeding date on irrigated soybean production on Sharkey clay (Vertic Haplaquept) near Stoneville, Mississippi. Plantings were made each year, in early May and late may or early June, in seedbeds subjected to the following treatments: (1) autumn tillage and winter fallow; (2) autumn tillage and winter wheat (Triticum aestivum L.) cover; (3) late winter or early spring tillage; (4) prepared seedbed; or (5) no tillage between harvest and planting. A disk-harrow and spring-tooth harrow were used for all tillage operations. Weeds were effectively controlled during each growing season in all treatments by selected preplant, preemergence, and postemergence herbicides, plus postemergence cultivation. Seedbed tillage had no consistent effect on soybean yield, but in two of the three years, early plantings yielded significantly more seed than late plantings. The increase from early planting was 862 kg ha−1 (3598 vs. 2736 kg ha−1) in 1986, and 381 kg ha−1 (2899 vs. 2518 kg ha−1) in 1987. These results indicate that seedbed tillage of clayey soil should be avoided if it interferes with timely planting of soybean.