Immunohistochemical investigation of the necrotrophic phase of the fungusColletotrichum gloeosporioidesin the biocontrol of hemp sesbania (Sesbania exaltata; Papilionaceae)

Soybean yield loss from weed interference depends upon weed density and competitiveness of crop and weed species in response to environment. Soil water availability and nitrogen fertility were evaluated for their effect on competitiveness of individual species in field experiments. Early-season temperatures in 1995, which were cool compared to 1994, slowed hemp sesbania growth without affecting soybean growth. This resulted in negligible competition with soybean by hemp sesbania at densities of 3 or 6 plants m−2. In 1994, hemp sesbania grew above the soybean canopy, decreasing soybean light interception 29 to 68%, and reducing soybean yield 30 to 48%. Fertilizer nitrogen increased soybean competitiveness, as indicated by biomass production, only in irrigated plots with hemp sesbania at 3 m−2, but did not affect soybean yield. Apparently, competition for light is a primary cause of soybean yield loss from hemp sesbania infestations. In growth chamber studies, simulating temperatures from the field, hemp sesbania growth was stimulated more by warm temperatures than was soybean. Hemp sesbania and soybean dry weights increased 4.4- and 2.7-fold, respectively, at 30/20 C day/night temperatures compared to 25/15 C.

Download Full-text

Effects of Johnsongrass (Sorghum halepense), Hemp Sesbania (Sesbania exaltata), and Delayed Harvest on Soybeans

Weed Technology ◽

10.1017/s0890037x0002772x ◽

1993 ◽

Vol 7 (2) ◽

pp. 355-360 ◽

Cited By ~ 4

Author(s):

Chester G. McWhorter ◽

James M. Anderson

Keyword(s):

Harvest Date ◽

Sorghum Halepense ◽

Foreign Material ◽

Soybean Cultivars ◽

Sesbania Exaltata ◽

Harvest Dates ◽

Early Maturing ◽

Hemp Sesbania

The effect of delayed harvest was investigated with two soybean cultivars that were grown weed free or in competition with johnsongrass or hemp sesbania over a 3-yr period. Johnsongrass reduced the yield of early-maturing ‘Hill’ soybean 32, 35, and 36% when harvested at an average of 1, 2, or 3 wk after maturity, when compared to weed-free yields of 2490, 2430, and 2270 kg ha−1, respectively. Late-maturing ‘Lee 68’ yields were reduced 27, 29, and 39% on three harvest dates compared to weed-free yields of 2570, 2310, and 2200 kg ha−1, respectively. Seed grades of both cultivars improved with delayed harvest, but this was offset when johnsongrass was present. Hemp sesbania reduced yields of Hill 23% on the first harvest date and 26% on the second and third dates. Yields of Lee 68 were reduced 16, 22, and 28% by hemp sesbania on three successive harvest dates. The value of soybean yields adjusted for excessive foreign material, moisture, and damaged kernels was decreased by delayed harvest when hemp sesbania was present in Lee 68 and when johnsongrass was present in both cultivars.

Download Full-text

Weed Competition in Rice

Weed Science ◽

10.1017/s0043174500047032 ◽

1968 ◽

Vol 16 (2) ◽

pp. 252-255 ◽

Cited By ~ 80

Author(s):

Roy J. Smith

Keyword(s):

Oryza Sativa ◽

Weed Competition ◽

Early Season ◽

Echinochloa Crusgalli ◽

Late Season ◽

Sesbania Exaltata ◽

Hemp Sesbania

Barnyardgrass [Echinochloa crusgalli (L.) Beauv.], duck-salad [Heteranthera limosa (Sw.) Willd.], hemp sesbania [Sesbania exaltata (Raf.) Cory], and northern jointvetch [Aeschynomene virginica (L.) B.S.P.] significantly reduced rice [Oryza sativa L.] yields. Damage to rice increased as populations of barnyardgrass, hemp sesbania, and northern jointvetch increased. Barnyardgrass and duck-salad lowered yields during early season, but hemp sesbania and northern jointvetch decreased yields in late season.

Download Full-text

Moisture Stress and Hydration-Dehydration Effects on Hemp Sesbania (Sesbania exaltata) Seed Germination

Weed Science ◽

10.1017/s0043174500061087 ◽

1980 ◽

Vol 28 (5) ◽

pp. 487-492 ◽

Cited By ~ 5

Author(s):

Robert D. Williams

Keyword(s):

Seed Germination ◽

Osmotic Potential ◽

Moisture Stress ◽

Germination Percentage ◽

Moisture Uptake ◽

Sesbania Exaltata ◽

Hemp Sesbania ◽

Number Of Cycles

Increased osmotic potential from 0 to −14 bars decreased the moisture uptake and germination of mechanically scarified hemp sesbania [Sesbania exaltata(Raf.) Cory] seed. Germination percentage for osmotic potential of 0, −2, −4, −6, and −8 bars was 86%, 86%, 70%, 19%, and 1%, respectively. This response to moisture stress was modified by imbibition, or hydration-dehydration, of the seed prior to the moisture stress. Imbibing the seed for as little as 2 h significantly increased its subsequent germination against moisture stress. One hydration-dehydration cycle had little or no effect on germination, but as the number of cycles increased, the germination percentage decreased. Prolonged hydration of 3 and 7 days followed by dehydration greatly reduced subsequent seed germination.

Download Full-text

Interference and Critical Time of Removal of Hemp Sesbania (Sesbania exaltata) in Cotton (Gossypium hirsutum)

Weed Technology ◽

10.1017/s0890037x0002649x ◽

1990 ◽

Vol 4 (4) ◽

pp. 833-837 ◽

Cited By ~ 15

Author(s):

Charles T. Bryson

Keyword(s):

Gossypium Hirsutum ◽

Field Experiment ◽

Weed Control ◽

Critical Period ◽

Critical Time ◽

Seedling Vigor ◽

Seed Cotton ◽

Sesbania Exaltata ◽

White Cotton ◽

Hemp Sesbania

Hemp sesbania interference in cotton was investigated in the greenhouse and in a 2-yr field experiment at Stoneville, MS. In greenhouse experiments, cotton and hemp sesbania heights and plant dry weights (PDW) were not different in ratios of cotton to hemp sesbania of 4:0, 2:2, 1:3, and 0:4 at 3 and 5 wk after emergence (WAE). Hemp sesbania PDW were less for ratios of cotton to hemp sesbania of 3:1 when compared to hemp sesbania PDW of other ratios. Early season cotton seedling vigor and growth (0 to 28 DAP) were not affected by 32 000 hemp sesbania plants ha-1(3 plants m of row-1). Hemp sesbania plants were hand removed 28, 42, 56, 70, and 84 d after planting (DAP). White cotton blooms and yields were reduced when hemp sesbania plants were not removed by 70 DAP. Seed cotton yields were 2590, 2570, 2460, 2030, 1610, and 1070 kg ha-1for hemp sesbania removed at 28, 42, 46, 70 and 84 DAP or not removed, respectively. The critical period of weed control or removal of hemp sesbania in cotton is ≤62 DAP.

Download Full-text

Behavior and Fate of Metribuzin in Soybean and Hemp Sesbania

Weed Science ◽

10.1017/s0043174500036985 ◽

1974 ◽

Vol 22 (3) ◽

pp. 238-245 ◽

Cited By ~ 33

Author(s):

T. G. Hargroder ◽

R. L. Rogers

Keyword(s):

Glycine Max ◽

Nutrient Solution ◽

Differential Susceptibility ◽

Treated Soil ◽

Metabolic Studies ◽

Solution Treated ◽

Sesbania Exaltata ◽

Absorption Studies ◽

Hemp Sesbania

The absorption, translocation, and metabolism of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H) one] by soybean (Glycine maxMerr. ‘Lee 68′) and hemp sesbania (Sesbania exaltataL.) grown in nutrient solution and in soil treated with14C-metribuzin were investigated. Absorption studies indicated there were no significant differences in the amount of14C-metribuzin absorbed from treated nutrient solution by soybean (tolerant) and hemp sesbania (susceptible). When these species were grown in14C-metribuzin treated soil, hemp sesbania absorbed appreciably more herbicide than did soybean.14C-metribuzin and (or) its14C-metabolites were translocated from the roots to the shoots of both species. Radioactivity was rapidly translocated and accumulated in all the leaves of hemp sesbania, but it tended to accumulate to the greatest extent in the roots and lower leaves of soybean. Translocation differences between the two species were apparent in plants grown either in soil or nutrient solution treated with14C-metribuzin. However, differences were greatest in plants grown in treated soil. Preliminary metabolic studies indicated that a higher rate of metribuzin degradation occurred in soybean than in hemp sesbania. The major14C-metabolite appeared to be the relatively nonphytotoxic deaminated diketo derivative [6-tert-butyl-1,2,4,-triazine-3-5(2H,4H)dione]. Thus, differences in the absorption, translocation, and metabolism of metribuzin all appeared to contribute to the differential susceptibility of soybean and hemp sesbania to metribuzin.

Download Full-text

Biocontrol efficacy of Colletotrichum truncatum for hemp sesbania (Sesbania exaltata) is enhanced with unrefined corn oil and surfactant

Weed Biology and Management ◽

10.1111/j.1445-6664.2006.00230.x ◽

2007 ◽

Vol 7 (1) ◽

pp. 70-76 ◽

Cited By ~ 19

Author(s):

C. DOUGLAS BOYETTE ◽

ROBERT E. HOAGLAND ◽

MARK A. WEAVER

Keyword(s):

Corn Oil ◽

Colletotrichum Truncatum ◽

Biocontrol Efficacy ◽

Sesbania Exaltata ◽

Hemp Sesbania

Download Full-text

Hemp Sesbania (Sesbania exaltata) Competition in Soybeans (Glycine max)

Weed Science ◽

10.1017/s0043174500043496 ◽

1979 ◽

Vol 27 (1) ◽

pp. 58-64 ◽

Cited By ~ 39

Author(s):

C. G. McWhorter ◽

J. M. Anderson

Keyword(s):

Glycine Max ◽

Critical Period ◽

Soybean Seed ◽

Foreign Material ◽

Early Season ◽

Competitive Effects ◽

Sesbania Exaltata ◽

Sharkey Clay ◽

Hemp Sesbania

The competitive effects of hemp sesbania [Sesbania exaltata(Raf.) Cory] on soybeans [Glycine max(L.) Merr. ‘Forrest’] were studied on Sharkey clay for 2 yr. In full-season competition, hemp sesbania populations of 1,600, 3,200, 3,900, and 5,500 plants/ha did not reduce adjusted soybean yields, but populations of 8,100 to 129,200 plants/ha reduced yields 10 to 80%. Competition by hemp sesbania at 68,000 plants/ha for 1 to 4 weeks after soybean emergence reduced soybean yields 8% or less, whereas competition by the same population for 6, 8, and 10 weeks after soybean emergence reduced adjusted yields 18, 27, and 43%, respectively. Hemp sesbania populations of 3,200 plants/ha or more reduced the grade of harvested soybeans and populations of 5,500 plants/ha increased the level of foreign material found in seed samples taken at harvest. Hemp sesbania populations above 10,700 plants/ha increased the levels of damaged kernels and moisture in harvested soybean seed. Early-season control was required for highest soybean yields and total returns. The most critical period for control was 4 to 10 weeks after emergence of soybeans.

Download Full-text

Temperature Effects on Growth and Leaf Production in Three Weed Species

Weed Science ◽

10.1017/s0043174500059749 ◽

1984 ◽

Vol 32 (5) ◽

pp. 655-663 ◽

Cited By ~ 19

Author(s):

Elizabeth P. Flint ◽

David T. Patterson ◽

David A. Mortensen ◽

George H. Riechers ◽

Jan L. Beyers

Keyword(s):

Leaf Area ◽

Leaf Size ◽

Dry Weight ◽

Weed Species ◽

Leaf Production ◽

Sesbania Exaltata ◽

Axillary Branch ◽

Hemp Sesbania ◽

Net Assimilation ◽

Total Dry Weight

Sicklepod (Cassia obtusifoliaL. ♯6CASOB), hemp sesbania [Sesbania exaltata(Raf.) Cory ♯ SEBEX], and showy crotalaria (Crotalaria spectabilisRoth. ♯ CVTSP) were grown in controlled-environment greenhouses with day/night temperatures of 23/17, 26/20, 29/23, and 32/26 C. Plant height, leaf area, and total dry weight at 53 days after planting increased significantly with temperatures between 23/17 and 29/23 C in sicklepod and showy crotalaria, and between 23/17 and 32/26 C in hemp sesbania. In all species, leaves were produced more rapidly as temperature increased. Axillary branch leaf production was greatest at 29/23 C in sicklepod, and at 29/23 and 26/20 C in showy crotalaria; hemp sesbania showed little axillary branch development. Total dry-matter production in all species was closely correlated with leaf area duration, but not with net assimilation rate. Differences in total main stem leaf area in all species were primarily due to differences in leaf number rather than to differences in leaf size at maturity.

Download Full-text